Cancer Flashcards

Question

Define: leiomyosarcoma

Answer 1

Smooth muscle sarcoma (malignant tumour from mesenchymal cells)

Answer 2

Nerve sheath sarcoma (malignant tumour from mesenchymal cells)

Answer 3

Malignant tumour of bone marrow derived cells which circulate in the blood ``` Acute= blastic Chronic= more mature ```

Answer 4

Malignant tumour of lymphocytes (usually) in lymph nodes Found in every organ

Answer 5

Tumour derived from germ cells, which have the potential to develop into tumours of all 3 germ cell layers Ectoderm Mesoderm Endoderm

Answer 6

Commonly affect testes and ovaries (gonadal teratomas) ``` Ovaries= often benign Testes= almost always malignant ```

Answer 7

Localised overgrowth of cells and tissues native to the organ Cells are mature but architecturally abnormal Common in children, and should stop growing when they do E.g. bile duct hamartomas, bronchial hamartomas

Answer 8

An adenoma

Answer 9

Evidence of normal function still present production of: Keratin, mucin, bile, hormones Various grading systems- for Ca breast, prostate, colon No differentation= anaplastic carcinoma

Answer 10

TUMOUR NODE METASTASIS Grade= degree of differentiation Stage= how far tumour has spread Tumours of higher grade (i.e. poorly differentiated) tend to be of higher stage (i.e. spread further) STAGE IS MORE IMPORTANT THAN GRADE in determining prognosis

Answer 11

Different cells divide at different rates Embryonic vs adult cells Complexity of system Necessity for renewal (e,g. intestinal epithelial cells much quicker than hepatocytes) State of differentiation (some never divide e.g. neurons and cardiac myoctyes) Tumour cells

Answer 12

Premature, aberrant mitosis results in cell death

Answer 13

Abnormal chromosome number and content Mutations in oncogenes and tumour suppressor genes-> most solid tumours are aneuploid

Answer 14

Loose and gain whole chromosomes during cell division

Answer 15

Perturbation of protein levels of cell cycle regulators is found in different tumours- abnormal mitosis

Answer 16

One of the most successful anti-cancer strategies in clinical use

Answer 17

Orderly sequence of events in which a cell duplicates its contents and divides in two Duplication Division Co-ordination

Answer 18

M-phase= mitosis (division) - Nuclear division - Cell division (cytokinesis) Interphase (duplication= G0, G1, S, G2) - DNA - Organelles - Protein synthesis

Answer 19

Cells are more easily killed (irradiation, heat shock, chemicals) DNA damage can not be repaired Gene transcription silenced Maybe metabolism?

Answer 20

M phase= mitosis ``` Interphase: G0= cell cycle machinery dismantled G1 phase (Gap)- decision point S phase= synthesis of DNA/ protein G2 phase (Gap)- decision point ```

Answer 21

Replication for division DNA replication Protein synthesis= initiation of translation and elongation increased: capacity is also increased Replication of organelles (centrosomes, mitochondria, Golgi etc) in case of mitochondria, needs to coordinate with replication of mitochondrial DNA

Answer 22

Consists of 2 centrioles (barrels of nine triplet microtubules) - mother and daughter centriole Functions= microtubule organizing centre (MTOS) and mitotic spindle

Answer 23

G1= pair of centrosomes Then split up and duplicate themselves-> elongated microtubules Then they continuously divide Microtubules growing from centrosomes at nucleating sites (from y-tubulin ring complexes)

Answer 24

``` Prophase Prometaphase Metaphase (Metaphase to anaphase transition) Anaphase Telophase ``` Cytokinesis

Answer 25

Condensation of chromatin (replicated chromosomes condense) Duplicated centrosomes migrate to opposite sides of the nucleus and organize the assembly of spindle microtubules Mitotic spindle forms outside nucleus between the 2 centrosomes

Answer 26

Each consists of 2 sister chromatids, each with a kinetochore (around the centromere)

Answer 27

Radial microtubule arrays (ASTERS) form around each centrosome (microtubule organising centres- MTOC) Radial arrays meet Polar microtubules form NB. Microtubules are in a dynamic state

Answer 28

Chromosomes aligned at equator of the spindle NB. Prometaphase early and late

Answer 29

Breakdown of nuclear membrane Spindle formation largely complete Attachment of chromosomes to spindle via kinetochores (centromere region of chromosome)

Answer 30

Microtubule from opposite pole is captured by sister kinetochore Chromosomes attached to each pole congress to the middle Chromosome slides rapidly towards centre along microtubules

Answer 31

Centromere protein E (kinetochore tension sensing)

Answer 32

Paired chromatids separate to form 2 daughter chromosomes Cohesin holds sister chromatids together Anaphase A and B

Answer 33

Breakdown cohesin Microtubules get shorter Daughter chromosomes pulled toward opposite spindle poles

Answer 34

1- Daughter chromosomes migrate towards poles | 2- Spindle poles (centrosomes) migrate apart

Answer 35

Daughter chromosomes arrive at spindle Nuclear envelope reassembles at each pole Assembly of contractile ring

Answer 36

New membrane inserted Acto-myosin ring contracts Midbody begins to form Chromatic decondenses Nuclear substructures reform Interphase microtubule array reassembles

Answer 37

During transition out of metaphase Senses completion of chromosome alignment and spindle assembly (monitors kinetochore activity) *Unattached kinetochores generate checkpoint signals* Requires CENP-E and BUB protein kinases (Need BUBs to dissociated to-> anaphase)

Answer 38

BUBs dissociate from kinetochore when chromosomes are properly attached to the spindle When all dissociated, anaphase proceeds

Answer 39

When the sister kinetochores are correctly connected to microtubules from opposite poles -> bioriented chromosome

Answer 40

Only one of the sister chromatids is connected to a spindle pole, the chromosome is mono-orientated

Answer 41

Both sister kinetochores are attached to a single spindle pole and the chromosome is mono-orientated

Answer 42

Usually one (or rarely both) sister kinetochores are connected to both poles instead of one Chromosomes are bioriented in merotelic attachments

Answer 43

Mis-attachment of microtubules to kinetochores Aberrant centrosome/DNA duplicaiton

Answer 44

Cohesion defects/synthelic attachment-> both sister chromatatids at the same pole Merotelic attachment-> chromosome loss at cytokinesis

Answer 45

Aberrant cell cycle (DNA and centrosome duplication affected)-> multipolar spindle-> aberrant cytokines

Answer 46

Inhibition of attachment-error-correction mechanism Checkpoint kinase inhibitior

Answer 47

Breast and ovarian cancers Alter microtubule dynamics Produces unattachment kinetochores Causes long-term mitotic arrest

Answer 48

CELL CYCLE ARREST At check points (G1 and spindle check point) Can be temporary (i.e. following DNA repair) PROGRAMMED CELL DEATH (APOPTOSIS) DNA damage too great and cannot be repaired Chromosomal abnormalities Toxic agents Cell cycle progression aborted and cell destroyed

Answer 49

G2 checkpoint checks for DNA damage (TUMOURS INHIBIT THIS) Metaphase checkpoint checks for sister chromatid alignment (TUMOURS INHIBIT THIS) G1 checkpoint for growth factors (TUMOURS CAUSE THIS)

Answer 50

De-regulation of cell cycle Exit cell cycle (G0)-> dismantle cell cycle apparatus (TUMOURS INHIBIT THIS)

Answer 51

In the absence of stimulus, cells go into Go (quiescent phase) Most cells in the body which are differentiated to perform specific functions Cells are not dormant, but are non-dividing Exit from G0 highly regulated- requires growth factors and intracellular signalling cascades

Answer 52

Response to extracellular factors Signal amplification Signal integration Modulation by other pathways Regulation of divergent responses

Answer 53

Ligand binds and activates the receptor - Epidermal growth factor (EGF): platelet-derived growth factor (PGDF) - Respective receptors found as monomeric, inactive state - Receptor Protein Tyrosine Kinase (RPTK) ---- In presence of ligand - Receptors form dimers - Are activated by phosphorylation (of AA residues in kinase domain)

Answer 54

Transfer of phosphate from ATP to hydroxyl groups The added phosphate group (negatively charged) can alter protein function by: - Causing a change in shape (conformation) leading to change in activity (+ve or –ve) - Creating a docking site for another protein

Answer 55

Signalling by peptide growth factors - > receptors form dimers, are activated by phosphorylation - > receptor activation - > triggers different phosphorylation events (kinase cascades and binding of adapter proteins)

Answer 56

Protein regulated by a kinase may be another kinase etc. Leads to signal amplification, diversification and opportunity for regulation NB. phosphorylation by kinases and reversed by phosphatases NB2. Protein kinase cascades driven by GFs

Answer 57

Most adult cells aren't constantly dividing In absence of growth signals they go into the G0 (or quiescent) phase E.g. liver hepatocytes

Answer 58

Point in G1 (end towards S) | Where cell monitors its own size and external signals

Answer 59

c-Myc= transcription factor that stimulates the expression of cell cycle genes Key role in cell cycle entry

Answer 60

Regulation of enzymes activity by protein phosphorylation (kinases) Adapter proteins Regulation by GTP-binding proteins

Answer 61

Mitogenic GF - > receptor protein tyrosine kinase - > small G (GTP-binding) protein (Ras) - > kinase cascade - > immediately early genes (c-Jun, c-Fos, c-Myc- TFs)- control the expression of other genes

Answer 62

Growth signals from other cells e/g/ hepatocyte growth factor released after liver damage

Answer 63

Cancer treatment Prevents further activation Blocks all signals through the cell's interior

Answer 64

Tyrosine phosphorylation provides docking sites for adaptor proteins Protein-protein interactions: protein binding- bringing proteins together

Answer 65

Proteins are modular and contain domains Some domains are important in molecular recognition- have no enzymatic function of their own, simply bring other proteins together

Answer 66

``` SH3= bind to proline-rich regions (constitutive) SH2= bind to phosphorylated tyrosines (inducible, specific sequence context) ``` SH3-SH2-SH3

Answer 67

Exchange factors e.g. Sos (exchange of GTP for GDP) - Signal in-> GTP binding activates-> Ras ON -> signaling by GTP-binding protein (not kinases) GAP (GTPase activating proteins) and GTP hydrolysis inactivates -> Ras OFF

Answer 68

Exchange factor | Constitutively (i.e. always bound to Grb2 via SH3 domains)

Answer 69

Mutations-> increase amount of active GTP-loaded Ras e. g. V12 Ras- constitutively active (glycine-> valine)= prevents GAP binding (i.e. prevents inactivation) e. g. L61 Ras- constitutively active (glutamine-> leucine)= prevents GTP hydrolysis

Answer 70

ERK (specifically)= EC signal-regulated kinase cascade MAPK (generically)= mitogen-activated protein kinase cascades

Answer 71

Raf MEK ERK (NB. generic= MAPKKK, MAPKK, MAPK)

Answer 72

Protein kinases stimulate changes in cell proteins and gene expression to promote division

Answer 73

Oncogenes Activated by protein kinases

Answer 74

Ras bound to GTP activates the ERK cascade

Answer 75

Need correct timing and sequence

Answer 76

Cell cycle based is on cyclically activated protein kinases Cdks are present in proliferating cells throughout cell cycle Activity is regulated by: - Interaction with cyclins - Phosphorylation

Answer 77

Transiently expressed at specific points in the cell cycle Regulated at level of expression Synthesised, then degraded

Answer 78

Different cyclin-Cdk complexes trigger different events in the cell cycle Different cyclins and different cdks required at different stages of cell cycle Cyclins activate Cdks but also alter substrate specificity Substrate accessibility changes through the cell cycle

Answer 79

Cdk1 and mitotic cyclin B

Answer 80

Cdks require activating phosphorylation And removal of inactivating phosphorylation

Answer 81

At the end of interphase Dephosphorylation activates Cdk1 Positive feedback Reinforces activation of MPF and drives mitosis

Answer 82

Signal from fully attached kinetochores causes cyclin B to be degraded: Cdk1 inactivated Key substrates dephosphorylated Mitosis progresses

Answer 83

Mitosis 'on hold'- key substrates phosphorylated

Answer 84

Growth factor stimulates the pathway that promotes G0 to G1 transition Immediate early gene transcriptionfactors (e.g. c-jun, c-fos, c-myc) -> Stimulate transcription of other genes (e.g. cyclin D) (OVERALL- GFs bind to R-> Activated cell cycle control system)

Answer 85

Cyclin D activates Cdk4 and Cdk6 to stimulate synthesis of cyclin E

Answer 86

Timing process Cdks become sequentially active and stimulate synthesis of genes required for next phase, e.g. cycD/Cdk4/6 stimulates expression of cycE – gives direction and timing to cycle Cyclins susceptible to degradation, hence cyclical activation

Answer 87

Phosphorylate proteins (on serine or threonine) to drive cell cycle progression Cdk1 with mitotic cyclin (e.g. B) e.g. nuclear lamins (causes breakdown of nuclear envelope) Cd2 with G1 cyclin (e.g. E) e.g. retinoblastoma protein (pRb)

Answer 88

pRb acts as a “brake” on the cell cycle (stops G0-> prolierating cell) Cdks phosphorylate (at multiple sites) and progressively inactivate pRb Rb is a “tumour suppressor”

Answer 89

``` PROTO-ONCOGENES c-Myc N-Myc B-Myb IGF-1 ``` ``` CELL CYCLE E2F-1,2,3 pRb p107 cyclin A cyclin E CDK4 CDK2 ``` ``` DNA SYNTHESIS Thymidine kinase Thymidine synthetase Dihydrofolate reductase (DHFR) DNA Polymerase ```

Answer 90

Cdk inhibitor binding-> inactivion of cyclin-cdk binding

Answer 91

G1 PHASE CKIS= inhibit Cdk4/6 by displacing cycD ``` INK4 family: p15INK4b p16INK4a p18INK4c p19INK4d ``` -- S PHASE CKIS= inhibit Cdks by binding to the Cdk/cyc complex CIP/KIP family: p21CIP1/WAF1 p27KIP1 p57KIP2 Must be degraded to allow cell cycle progression

Answer 92

Mutationally activated or overexpressed in many breast cancers Treated= Herceptin antibody for the treatment of HER2-positive metastatic breast cancer

Answer 93

Mutationally activated in many cancers Treated= inhibitors of membrane attachment

Answer 94

Over expressed in 50% of cancers

Answer 95

Mutationally activated in melanomas Treated= kinase inhibitors in trials

Answer 96

Overexpressed in many tumours

Answer 97

Inactivated in many cancers

Answer 98

Underexpression correlates with poor prognosis in many malignancies

Answer 99

Cdk1 must be phosphorylated at 2 sites to be active

Answer 100

``` Surgery Radiotherapy Chemotherapy Immunotherapy Hormonal therapy ```

Answer 101

Chromosome translocation Gene amplification (copy number variation) Point mutations within promoter or enhancer regions of genes Deletions or insertions Epigenetic alterations to gene expression Can be inherited

Answer 102

Cytotoxic chemotherapy Target therapies

Answer 103

``` Alkylating agents Antimetabolites Anthracyclines Vinca alkaloids and taxanes Topoisomerase inhibitors ```

Answer 104

Small molecule inhibitors | Monoclonal antibodies

Answer 105

'Select' rapidly dividing cells by targeting their structures (mostly the DNA)

Answer 106

Given IV or by mouth Works systemically Given: - Post-op= adjuvant - Pre-op= neoadjuvant As a monotherapy or in combo Curative or palliative intent

Answer 107

Non "targeted"- affects all rapidly dividing cells in the body

Answer 108

Add alkyl (CNH2N+1) groups to guanine residues in DNA Cross-link (intra, inter, DNA-protein) DNA strands and prevents DNA from uncoiling at replication Trigger apoptosis (via checkpoint pathway) Encourage miss-pairing - oncogenic

Answer 109

Add platinum to guanine residues in DNA Same mechanism of cell death as akylating agents Examples: carboplatin, cisplatin, oxaliplatin

Answer 110

Chlorambucil, cyclophosphamide, dacarbazine, temozolomide

Answer 111

Carboplatin, cisplatin, oxaliplatin

Answer 112

``` Hair loss (not carboplatin) Nephrotoxicity Neurotoxicity Ototoxicity (platinums) Nausea Vomiting Diarrhoea Immunosuppression Tiredness ```

Answer 113

Masquerade as purine or pyrimidine residues leading to inhibition of DNA synthesis, DNA double strand breaks and apoptosis Block DNA replication and transcription Can be purine (A/G), pyrimidine (T/U/C) or folate antagonists

Answer 114

Methotrexate (folate), 6-mercaptopurine, decarbazine and fludarabine (purine), 5-fluorouracil, capecitabine, gemcitabine (pyrimidine)

Answer 115

Inhibit dihydrofolate reductase required to make folic acid, an important building block for all nucleic acids- especially thymine

Answer 116

Hair loss (alopecia)- not 5FU or capecitabine Bone marrow suppression causing anaemia, neutropenia and thrombocytopenia Increased risk of neutropenic sepsis (and death) or bleeding Nausea and vomiting (dehydration) Mucositis and diarrhoea Palmar-plantar erythrodysesthesia (PPE) Fatigue

Answer 117

Inhibit transcription and replication by intercalating (i.e. inserting between) nucleotides within the DNA/RNA strand Also block DNA repair - mutagenic They create DNA and cell membrane damaging free oxygen radicals

Answer 118

Doxorubicin | Epirubicin

Answer 119

``` Cardiac toxicity (arrythmias, heart failure)- probably due to damage induced by free radicals Alopecia Neutropenia Nausea and Vomiting Fatigue Skin changes Red urine (doxorubicin “the red devil”) ```

Answer 120

Originally derived from natural sources Work by inhibiting assembly (vinca alkaloids) or disassembly (taxanes) of mitotic microtubules causing dividing cells to undergo mitotic arrest

Answer 121

Nerve damage: peripheral neuropathy, autonomic neuropathy Hair loss Nausea Vomiting Bone marrow suppression (neutropenia, anaemia etc) Arthralgia Allergy

Answer 122

Topoisomerases are required to prevent DNA torsional strain during DNA replication and transcription They induce temporary single strand (topo1) or double strand (topo2) breaks in the phosphodiester backbone of DNA They protect the free ends of DNA from aberrant recombination events Effects through their action on DNA

Answer 123

Topotecan and irinotecan (topo I) Etoposide (topo II) Alter binding of the complex to DNA and allow permanent DNA breaks

Answer 124

(Irinotecan): Acute cholinergic type syndrome – diarrhoea, abdominal cramps and diaphoresis (sweating). Therefore given with atropine Hair loss Nausea, vomiting Fatigue Bone marrow suppression

Answer 125

Anti-metabolite (cytotoxic chemo) ``` SEs: PPE Nausea and vomiting Bone marrow suppression causing anaemia, neutropaenia and thrombocytopaenia Mucositis Diarrhoea ``` ``` Treatment: Pyridoxine (vitamin B6) Antiemetics Transfusions/platelets/GCSF/dose reduction Mouth washes Loperamide ```

Answer 126

Anthracycline (cytotoxic chemo) ``` SEs: Cardiac toxicity Alopecia Neutropaenia Nausea and vomiting Fatigue Skin changes ``` ``` Treatment: Irreversible but can cap dosing Scalp cooling Antiemetics Transfusions/platelets/GCSF/dose reduction ```

Answer 127

Alkylating agent (cytotoxic chemo) ``` SEs: Alopecia Nausea Vomiting Diarrhoea Immunosuppression ``` Treatment: Scalp cooling Antiemetics Loperamide

Answer 128

DNA adducts replaced by Base Excision repair (using PARP) DNA repair mechanisms upregulated and DNA damage is repaired-> DNA double strand breaks Drug effluxed from the cell by ATP-binding cassette (ABC) transporters THE RESISTANT CELL SURVIVES

Answer 129

You can “cut the wiring” in monogenic cancers but for others, parallel pathways or feedback cascades are activated

Answer 130

Prevent feedback loops but increase toxicities New therapeutic strategies required

Answer 131

``` 6 FIRST KNOWN Self-sufficient Insensitive to anti-growth signals Anti-apoptotic Pro-invasive and metastatic Pro-angiogenic Non-senescent ``` ``` EMERGING HALLMARKS Dysregulated metabolism Evades the immune system Unstable DNA Inflammation ``` siappndeui= u pained pis

Answer 132

Normal cells need growth signals to move from a quiescent (resting) to active proliferating state These signals are transmitted into the cell via growth factors binding transmembrane receptors and activating downstream signalling pathways

Answer 133

GF Rs move closer to each other C terminal region connections Bind to SH2 Kinase cascade and signal amplification

Answer 134

Crosses membrane Ligand-binding site Kinase domain C-terminal region with lots of tyrosines (for autophosphorylation)

Answer 135

>50% associated with human malignancies

Answer 136

HER2= amplified and overexpressed in 25% breast cancer EGFR= overexpressed in breast (and colorectal) cancer PDGFR= glioma in brain cancer VEGF= prostate cancer, kidney cancer, breast cancer Overall there is increased kinase cascade and signal amplification

Answer 137

``` EGFR= lung cancer FGFR= head and neck cancers, myeloma ``` Increase kinase cascade and signal amplification

Answer 138

- momab (derived from mouse antibodies) - ximab (chimeric) e.g cetuximab - zumab (humanised) e.g. bevacizumab trastuzumab - mumab (fully human) e.g. panitumumab

Answer 139

Murine regions interspersed within the light and heavy chains of the Fab portion

Answer 140

Murine component of the variable region of the Fab section is maintained integrally

Answer 141

They neutralise the ligand-> prevent receptor dimerisation Cause internalisation of receptor mAbs also activate Fcγ-receptor-dependent phagocytosis or cytolysis induces complement-dependent cytotoxicity (CDC) or antibody-dependent cellular cytotoxicity (ADCC)

Answer 142

Monoclonal antibody Binds and neutralises VEGF Improves survival in colorectal cancer

Answer 143

Monoclonal antibody Targets EGFR

Answer 144

Bind to the kinase domain of the tyrosine kinase within the cytoplasm and block autophosphorylation and downstream signalling (I.e. target internal TK)

Answer 145

The first targeted therapy (cancer) A small molecule inhibitor and targets the ATP binding region within the kinase domain Doesn't work because all cancers aren't monogenic

Answer 146

Act on RTKs but also IC kinases= therefore can affect cell signalling pathways Inhibiting receptors include erlotinib (EGFR), gefitinib (EGFR), lapatinib (EGFR/HER2), sorafinib (VEGFR)

Answer 147

They block cancer hallmarks (e.g. VEGF inhibitors alter blood flow to a tumour) without the toxicity observed with cytotoxics

Answer 148

``` ADVANTAGES High target specificity Cause ADCC, complement mediated cytotoxicity and apoptosis induction Can be radiolabelled Cause target receptor internalisation Long half-life (lower dosing frequency) Good for haematological malignancies Liked by regualatory authorities (FDA) ``` DISADVANTAGES Resistance Large and complex structure (low tumour or BBB penetration), Less useful against bulky tumours Only useful against targets with extracellular domains Not useful for constitutively activated receptors Cause immunogenicity, allergy Parenteral (IV) administration Risky! (though humanisation reduces risk) Expensive

Answer 149

ADVANTAGES Can target TKs without an extracellular domain or which are constitutively activated (ligand independent) Pleiotropic targets (useful in heterogenic tumours/ cross talk) Oral administration Good tissue penetration Cheap DISADVANTAGES Resistance Shorter half-life, more frequent administration Pleiotropic targets (more unexpected toxicity)

Answer 150

Mutations in ATP-binding domain (e.g BCR-Abl fusion gene and ALK gene, targeted by Glivec and crizotinib respectively) Intrinsic resistance (herceptin effective in 85% HER2+ breast cancers, suggesting other driving pathways) Intragenic mutations Upregulation of downstream or parallel pathways

Answer 151

Used in cancer for 'undruggable' targets Single stranded, chemically modified DNA-like molecule 17-22 nucleotides in length Complementary nucleic acid hybridisation to target gene hindering translation of specific mRNA Recruits RNase H to cleave target mRNA

Answer 152

Small molecule inhibitors Monoclonal antibodies

Answer 153

Single stranded complementary RNA Has lagged behind anti-sense technology –especially in cancer therapy Compounds have to be packaged to prevent degradation- nanotherapeutics CALAA-01 targeted to M2 subunit of ribonucleotide reductase (Phase I clinical trials in cancer- results awaited)

Answer 154

Tracking heterogeneity and bottlenecks Tumor sampling bias Drivers of heterogeneity Actionable mutations

Answer 155

Present on the surface of cancer cells Required to maintain T cell activation After binding the ligand PDL1, the body’s T cells can no longer recognise tumour cells as foreign If either is blocked, immune system is stimulated

Answer 156

An anti-PD1 antibody Had an effect on improving melanoma

Answer 157

Sequence them Useful for treatment and prognostic info

Answer 158

Nanotherapies- delivering cytotoxics more effectively Virtual screening technologies to identify “undruggable” targets Immunotherapies using antigen presenting cells to present “artificial antigens” Targeting cancer metabolism

Answer 159

The term used to describe the way cells interact with their external environment and their reactions to this Particularly proliferative and motile responses of cells

Answer 160

Chemical (and biochem)= hormones, GFs, ion concs, ECM, molecules on other cells, nutrients and dissolved gas (O2/CO2) concs Physical= mechanical stresses, temp, the topography or 'layout' of the ECM and other cells

Answer 161

Growth factors Cell-cell adhesion Cell-ECM adhesion

Answer 162

Cell starts spherically Cell settling on culture surface Spreading (acquires polarity- front) Acquiring motility

Answer 163

Requires energy to modulate cell adhesion and the cytoskeleton during spreading Not passive, gravity-dependent event Can be tidy or more random

Answer 164

When it has no contact with the ECM substratum E.g. directly above another cell

Answer 165

Agar is non adhesive Cells require binding to ECM to be fully competent for responding to soluble growth factors

Answer 166

If the cell can't spread it will die by apoptosis Cell spreads-> survives and grows

Answer 167

In suspension, cells do not significantly synthesise protein or DNA Cells require to be attached to ECM (and a degree of spreading is required) to begin protein synthesis and proliferation (DNA synthesis) Attachment to ECM may be required for cell survival I.e. anchorage dependence

Answer 168

Cells have receptors on their cell surface which bind specifically to ECM molecules These molecules are often linked at their cytoplasmic domains to the cytoskeleton This arrangement means that there is mechanical continuity between ECM and the cell interior

Answer 169

Most important ECM receptors Heterodimer complexes of alpha and beta subunits Associate extracellularly by their HEAD regions Each of their TAIL regions spans the plasma membrane

Answer 170

Alpha/beta heterodimers (both sub-units span the plasma membrane one) 10a and 8B known

Answer 171

Recognise short, specific peptide sequences (e.g. α5β1 fibronectin receptor binds arg-gly-asp (RGD) More than 20 combinations of α/β known Each combination specifically binds a particular peptide sequence Such peptide sequences found in more than one ECM molecule, e.g. RGD found in fibronectin, vitronectin, fibrinogen plus others

Answer 172

Linked, via actin-binding proteins, to the actin cytoskeleton (most integrins) Integrin complexes cluster to form focal adhesions (most) or hemidesmosomes= involved in signal transduction Integrins also bind to specific adhesion molecules on some cells

Answer 173

The α6β4 intergin complex found in epithelial hemidesmosomes Linked to the cytokeratin (intermediate filament) network

Answer 174

More than 20 combos of a/B heterodimers (in integrins) known which bind specifically to short peptide sequence on ECM proteins

Answer 175

"Outside-in" integrin signalling = ECM receptors act to transduce signals (receive info from its adhesion to ECM)-> can alter the phenotype of the cell E.g. ECM binding to an integrin complex can stimulate the complex to produce a signal inside the cell "Inside-out" integrin signalling = A signal generated inside the cell can act on an integrin complex to alter the affinity of an integrin (i.e. alter its affinity for ECM binding) E.g. in inflam or blood-clotting, switching on adhesion of circulating leukocytes

Answer 176

Amount of force that is generated at a focal adhesion depends: - The force generated by the cytoskeleton (F cell) - The stiffness of the ECM

Answer 177

Ligand-binding opens the legs of the complex (conformational change)-> allows cytoplasmic signalling molecules to bind

Answer 178

Recruit cytoplasmic proteins which promote both signalling and actin assembly

Answer 179

In interstitial matrix (type 1 collagen), mammary epithelium does not differentiate to secretory cells In basal lamina (basement membrane) matrix, mammary cells organise into “organoids” and produce milk proteins

Answer 180

False Flow of medium stimulates cell proliferation

Answer 181

Cells have cell-cell contact-> cease proliferating and slow down many other metabolic activities There is also competition for external growth factors Density-dependence of cell division

Answer 182

(NB. required for cyclin D expression) Adapter on RTK - > Ras - > Raf (MAPKKK) - > MEK (MAPKK) - > ERK (MAPK) - > Gene expression (proliferation) in nucleus NB. There is cross-talk between ECM and GF signalling

Answer 183

Density dependence

Answer 184

Anchorage dependence GF Rs and integrin signalling complexes can each activate identical signalling pathways (e.g. MAPK) Individually weak and/or transient but together= strong and sustained Separate signalling pathways act synergistically

Answer 185

Short term= transient interactions b/w cells which don't form stable cell-cell junctions Long term= stable interactions resulting in formation of cell-cell junctions

Answer 186

When most non-epithelial cells “collide”, they do not form stable cell-cell contacts They actually “repel” one another by paralysing motility at the contact site, promoting the formation of a motile front at another site on the cell, and moving off in the opposite direction OVERALL EFFECT= Reponsible for preventing multi-layering of cells in culture and in vivo

Answer 187

Some cell types strongly adhere and form specific cell-cell junctions ``` Epithelial cells (form layers) Endothelial cells (form layers) Neurones (form synapses) ```

Answer 188

Contact between epithelial cells leads to the mutual induction of spreading So the total spread area of the contacted cells is greater than that of the sum of the two separated cells This could result in a stable monolayer

Answer 189

When there are no cell-cell junctions, activated MAPK, decreased p27KIP1-> high proliferation When there are cell-cell junctions form, inactive MAPK, increased p27KIP1-> low proliferation NB. Can have adhesion blocking antibodies-> stimulates proliferation

Answer 190

Seems that cadherin binds to B-catenin which binds to a-catenin which binds to actinfilament

Answer 191

Inherited colon cancer (number of familial forms) APC gene-product is a protein involved in the degradation of the junction-associated molecule (B catenin)

Answer 192

APC-> Degradation (cytoplasm) Cytoplasm-> APC Sequestered (bound to cadherin at plasma membrane) -> LEF-1-> gene transcription (nucleus) SEE DIAGRAM

Answer 193

When bound to cadherin at the membrane, B-catenin not available for LEF-1 binding and nuclear effects Normally, cytoplasmic B-catenin rapidly degraded If B-catenin cytoplasmic levels rise (as a result of inhibition of degradation or loss of cadherin-mediated adhesion)-> B-catenin/LEF-1 complex enters nucleus -> influences gene expression, leading to proliferation

Answer 194

Clustering of cadherins after cell-cell contact is known to alter the activation of small GTPases (Rac is activated, Rho is inhibited-> can influence proliferation) Some growth factor receptors are associated with cell-cell junctions -> reduced their capacity to promote proliferation

Answer 195

Cells can lose their behavioural constraints As a result, they will: - Proliferate uncontrollably (lose density dependence of proliferation) - Are less adherent and will multilayer (lose contact inhibition of locomotion and anchorage dependence) - Epithelia breakdown cell-cell contacts - Not Hayflick limited, express telomerase i.e. cancer

Answer 196

Lost Forms a multilayer of uninhibited cancer cells (instead of contact-inhibited monolayer of normal cells)

Answer 197

If the gene coding for a component of a signalling pathway is mutated so that the protein is constitutively active, that pathway will be permanently ‘on' Receptors, signalling intermediates and signalling targets (e.g. transcription factors) are proto-oncogenes This is the mechanism of short-circuiting -> uncontrolled proliferation as a result of loss of GF dependence etc.

Answer 198

Mutant gene which promotes uncontrolled cell proliferation

Answer 199

Normal cellular gene corresponding to the oncogene

Answer 200

``` EGF receptor Ras (signalling intermediate) c-Raf (signalling intermediate) c-Jun (transcription Factor) ```

Answer 201

V12Ras (Gly12Val mutation) L61Ras (Gln61Leu mutation) v-Raf (deletion of regulatory domain) v-Jun (deletion of regulatory domain)

Answer 202

30% of all cancers

Answer 203

GF (density dependence lost) ECM (anchorage dependence lost) Signals short circuites Mutant gene products (constitutively active so upstream signals aren't required for the pathway to be 'on') -> nucleus-> proliferation

Answer 204

In order to spread to other sites (metastasis), cells must break away from the primary tumour, travel to a blood or lymph vessel, enter the vessel, lodge at a distant site, leave the vessel, and ultimately establish a secondary tumour

Answer 205

Cell-cell adhesion must be down-regulated (e.g. cadherin levels reduced) The cells must be motile Degradation of ECM must take place; matrix metaloproteinase (MMP) levels increased in order to migrate through basal lamina and interstitial ECM The degree of carcinoma cell-cell adhesion is an indicator of how differentiated the primary tumour is (indicates its invasiveness and the prognosis)

Answer 206

Microfilaments Regulation of actin dynamics Cytoskeletal proteins Signalling proteins

Answer 207

Homeostasis Genetic alterations Hyper-proliferation De-differentiation (disassembly, cell-cell contacts) Invasion (increased motility, cleavage of ECM proteins)

Answer 208

Epithelial cells in primary tumours are tightly bound together Metastatic tumour cells become mobile mesenchyme-type cells and enter the bloodstream Metastatic cells then travel through the bloodstream to a new location in the body Metastatic cells enter the circulation and invade a new organ Cancer cells lose their mesenchymal characteristics and form a new tumour

Answer 209

Ameoboid Mesenchmal (single cells or chains) Cluster/cohorts Multicellular strands/sheets

Answer 210

Lymphoma Leukaemia SCLC

Answer 211

Fibrosarcoma Glioblastoma Anaplastic tumours

Answer 212

Epithelial cancer | Melanoma

Answer 213

Epithelial cancer | Vascular tumours

Answer 214

``` 2D sheet Branching morphogenesis (mammary gland) Vascular sprouting Multi-cellular 3D invasion strands Border cells Detached cluster ```

Answer 215

Migration of primary glial cells= move as a coherent front until they touch eachother (contact inhibition of migration) Migration of a glial tumour cell line= move much fast, hyperactive motility in all directions with no regard for surrounding

Answer 216

Up-regulated

Answer 217

Organogenesis and morphogenesis Wounding GFs/chemoattractants Dedifferentiation (tumours)

Answer 218

Where to go= directionality (polarity) When to stop= contact-inhibition motility (Moves with specialized structures e.g. focal adhesion, lamellae, filopodium)

Answer 219

Important cellular functions as the mobility and contraction of cells during cell division

Answer 220

Focal adhesion is a type of adhesive contact between the cell and extracellular matrix through the interaction of the transmembrane proteins integrins with their extracellular ligands, and intracellular multiprotein assemblies connected to the actin cytoskeleton

Answer 221

Finger-like protusions rich in actin filaments

Answer 222

Sheet-like protrusions rich in actin filaments

Answer 223

Within a cell to coordinate what is happening in different parts Regulate adhesion/release of cell-extracellular matrix receptors From outside to respond to external influence

Answer 224

Directional motility or outgrowth of cells

Answer 225

The movement of an organism in response to a chemical stimulus

Answer 226

Extension Adhesion Translocation De-adhesion

Answer 227

``` G= small soluble units F= large filamentous polymer ```

Answer 228

Signal (e.g. nutrient source) - > disassembly of filaments and rapid diffusion of subunits - > reassembly of filaments at a new site (F and G= different roles depending how they grow and shrink)

Answer 229

Stress fibres= antiparallel contractile structures near nucleus of cells (with focal adhesions) Lamellipodium= branches and cross-linked filaments around outside of cell Filopodium= bundle of parallel filaments

Answer 230

``` Bundling Motor proteins Side-binding Cappnig Cross linking Severing -> G actin ```

Answer 231

Nucleating Sequestering -> F actin

Answer 232

Limiting step in actin dynamics Formation of trimers to initiate polymerization Adding of actin, Arp2 and Arp3 at plus end Attaches to actin monomers-> nucleated actin filament

Answer 233

Reverse of nucleation Profilin (monomer binding) competes with thymosin for binding to actin monomers and promotes assembly Thymosin inhibits free actin monomers forming actin filaments

Answer 234

Biological processes in which an organism accumulates a compound or tissue

Answer 235

Proteins added to end of actin chains + end= CapZ, Gelsolin, Fragmin/severin - end= tropomodulin, Arp complex

Answer 236

In unsevered population, actin filaments grow and shrink relatively slowly In severed population, actin filaments grow and shrink more rapidly Severing proteins= gelsolin, ADF/cofilin, fragmin/severin

Answer 237

Inhibits polymerization (so stops free actin monomers forming actin filaments)

Answer 238

All processes work together ``` Prolifilin-actin barbed end elongation Growth pre-existing end Annealing Barbed-end capping Filament severing ``` Needs ATP and ADP and proteins

Answer 239

Way of forming effective interactions between cytoskeletal filaments ``` Proteins involved: alpha-actinin fimbrin filamin spectrin villin vinculin ```

Answer 240

Severing Barbed-end capping Bundling Buckling ATP, ADP and proteins involved

Answer 241

Branching-> more connections Branching protein= Arp complex

Answer 242

Gel-> rigid | Sol-> can flow

Answer 243

Alzheimer (neurodegenerative)

Answer 244

Disassembly/ nucleation/ branching/ severing/ capping/ bundling-> EXTENSION (actin activities) Polymerization-> EXTENSION Gel/sol transition-> ADHESION Attachment ECM-> ADHESION Contraction-> TRANSLOCATION Detachment-> DE-ADHESION

Answer 245

Polymerization, disassembly, branching, capping Net filament assembly at leading edge Net filament disassembly behind leading edge

Answer 246

Actin polymerization Bundling Cross linking

Answer 247

Ion flux changes (i.e. intracellular calcium) Phosphoinositide signalling (phospholipid binding) Kinases/phosphatases (phosphorylation cytoskeletal proteins) Signalling cascades via small GTPases

Answer 248

Rho subfamily proteins are activated by RTK, adhesion Rs and signal transduction pathways Expression levels up-regulated in different human tumours

Answer 249

Rho (subfamily of small GTPases belongs to the Ras super-family) - Family members: Rac, Rho, Cdc42 best known Participate in a variety of cytoskeletal processes Including control of actin cytoskeleton

Answer 250

Cdc42-> filopodia Rac-> lamellipodia Rho-> stress fibres

Answer 251

Actin binding proteins regulated by Rac/Cdc42 SEE DIAGRAM Rac.GTPCdc42.GTP Leads to actin polymerization/organization

Answer 252

Rac-> EXTENSION (involved in actin polymerization, branching) Rac and Rho-> ADHESION (focal adhesion, assembly) Rho-> TRANSLOCATION (stress fibres, tension, contraction) Rho-> DE-ADHESION Cdc42= filopodia, polarized motility, actin polymerization

Answer 253

Harmful cells (e.g. cells with viral infection, DNA damage) Developmentally defective cells (e.g. B lymphocytes expressing antibodies against self antigens) Excess/unnecessary cells (e.g. embryonic development) Obsolete cells (e.g. mammary epithelium at the end of lactation) Exploitation (chemotherapeutic killing of cells)

Answer 254

Unregulated cell death associated with trauma, cellular disruption and an inflammatory response

Answer 255

Programmed cell death Regulated cell death, controlled disassembly of cellular contents without disruption (no inflammatory response)

Answer 256

Plasma membrane becomes permeable Cells and organelles swell, chromatin condenses and rupture of cellular membranes Release of proteases leading to autodigestion and dissolution of the cell Cell lysis with invasion of phagocytic cells and localised inflammation

Answer 257

Latent phase | Execution phase

Answer 258

Death pathways are activated, but cells appear morphologically the same

Answer 259

Loss of microvilli and intercellular junctions (chromatin begins to condense) Cell shrinkage (epithelium closes around) Loss of plasma membrane asymmetry (phosphatidylserine lipid appears in outer leaflet) Chromatin and nuclear condensation DNA fragmentation Formation of membrane blebs (violent blebs) Fragmentation of these blebs into membrane-enclosed apoptotic bodies Apoptotic bodies phagocytosed by neighbouring cells and moving macrophages (PLASMA MEMBRANE REMAINS INTACT- NO INFLAMMATION)

Answer 260

DNA fragmentation leads to more “ends” | can be labelled by adding an extra fluorescently-tagged base-> yellow nuclei on cells that are dying in TUNEL assay

Answer 261

Dying becomes rough Loss of microvilli, cell shrinkage and cell blebbing

Answer 262

Necrosis Apoptosis Apoptosis-like PCD Necrosis-like PCD

Answer 263

Some, but not all, features of apoptosis Display of phagocytic recognition molecules before plasma membrane lysis

Answer 264

Variable features of apoptosis before cell lysis | 'Aborted apoptosis'

Answer 265

Features of both apoptosis and necrosis

Answer 266

The executioners- Caspases Initiating the death programme - Death receptors - Mitochondria The Bcl-2 family (controllers of this) Stopping the death programme

Answer 267

Cysteine-dependent aspartate-directed proteases Executioners of apoptosis Activated by proteolysis Cascade of activation

Answer 268

Initiator (2, 9) Initiator with DED (death effector domain) (10, 8) Effector (3, 6, 7)

Answer 269

Card domains bind to card domains Provide protein interactions at particular site they are needed

Answer 270

Cleavage of the inactive procaspase precursor is followed by folding of 2 large and 2 small chains to form an active L2S2 heterotetramer Tetramer is the activated species that you should worry about

Answer 271

Trigger apoptosis by cleaving and activating

Answer 272

Carry out the apoptotic programme Cleave and inactivate proteins or complexes (e.g. nuclear lamins leading to nuclear breakdown) Activate enzymes (incl. protein kinases; nucleases, e.g. Caspase-Activated DNase, CAD) by direct cleavage, or cleavage of inhibitory molecules

Answer 273

Amplification Divergent responses Regulation Initiator caspases-> effector caspases SEE DIAGRAM

Answer 274

Death by design= Receptor-mediated (extrinsic) pathways - External to cell - Cell senses signal and dies Death by default= Mitochondrial (intrinsic) death pathway - Signal from inside the cell usually involving mitochondria

Answer 275

Secreted or transmembrane ligands (trimeric) ``` Have cysteine rich domains= EC Transmembrane domain Death domain (DD)= IC ```

Answer 276

FADD= activates programme of cell death (DED and DD) FLIP= inhibits (DED and DED)

Answer 277

Death effector domain

Answer 278

Death domain

Answer 279

1. Receptor (Fas) trimerisation by ligand (Fas-L on lymphocyte) 2. Recruitment of adapter protein (FADD) through its DD to DD of Fas 3. Recruitment and oligomerisation of procaspase 8 through its DED to FADD DED –> Death-Inducing Signalling Complex (DISC)

Answer 280

Trimerised R tails/FADD and initiator procaspase 2 - > cleavage of initiator procaspase 2 - > active initiator caspase 8 tetramer released from receptor Some initiator procaspases have intrinsic low catalytic activity (oligomerisation allows transcleavage) Others are activated by conformational change on oligomerisation Need at least 2 procaspases to form an active tetramer

Answer 281

Binds to caspase 9 and will block its ability to cleave itself Inhibited by FLIP FLIP - caspase homology in DED domain, but no proteolytic activity therefore competes with procaspase

Answer 282

Trimerised receptor tials/FADD and initiator procaspase 8-> no cleavage Competes for binding to receptor tails/FADD via DED domains Incorporates into R-procaspase complexes and interferes with transcleavage

Answer 283

Activates caspase 3 and caspase 7 Caspase 3 activates caspase 6, 2 and 1 Caspase 6 activates caspase 10 (which activates caspase 8 and the loop)

Answer 284

Cellular stresses e.g. lack of or overstimulation by GFs, DNA damage (p53) ``` Loss of mitochondrial membrane potential (ΔΨ) ``` Release of cytochrome c and other apoptosis- inducing factors ``` Formation of the apoptosome complex (Apaf1, caspase 9) ```

Answer 285

'Wheel of death' Apaf-1 heptamer (Apaf-1 scaffold) ``` CONTAINS: Apaf-1 (can potentially bind to procaspase 9) Cytochrome c (bound to WD4repeats) ATP Procaspase 9 (binds to CARD domain) ```

Answer 286

Oligomerisation brings multiple procaspase 9s close together ->cleavage, activation and release as active caspase 9 tetramer Active caspase 9 tetramer initiates a caspase cascade leading to apoptosis

Answer 287

Bid links receptor | Mitochondrial death pathways

Answer 288

Caspase 8 cleaves Bid which enhances release of mitochondrial proteins, thus engaging the intrinsic pathway

Answer 289

The apoptosome requires ATP Energy levels in the cell may determine whether death is by necrosis or apoptosis (+ATP= apoptosis, -ATP= necrosis)

Answer 290

Bcl-2 family proteins Group I, II and III Group I= BH4, BH3. BH1. BH2, TM (Bcl-2) Group II= BH3, BH1, BH2, TM (Bax) Group III (BH3 only)= BH3 (maybe TM) (Bid, Bak, Bad)

Answer 291

Bcl-2 Bcl-xL (Mitochondrial)

Answer 292

Bid Bad Bax Bak (Move between cytosol and mitochondria)

Answer 293

GF e.g. ECF, insulin binds to GFR e.g. EGFR, insulin R - > PI3K (inhibited by PTEN) - > PDK-1 - > PKB/Akt - > cell survival, proliferation, protein synthesis

Answer 294

Phosphatidylinositol 3’-kinase (PI3’-K) A lipid kinase (not a protein kinase) involved in growth control and cell survival Activates PKB/Akt which is anti-apoptotic

Answer 295

Phosphorylates and inactivates Bad and caspase 9 Inactivates FOXO transcription factors (FOXOs promote expression of apoptosis-promoting genes) Other, e.g. stimulates ribosome production and protein synthesis

Answer 296

GF absent Bad dephosphorylated and released Displaces Bcl-2/xL from -> Bax/Bak Pore-> apoptosis

Answer 297

GF present PI3K and PKB/Akt Heterodimers are inactive Phospho-Bad inactive Cell survival

Answer 298

PTEN | Dephosphorylates

Answer 299

Inhibitor of Apoptosis Proteins (IAPs) regulate Programed Cell Death Bind to procaspases and prevent activation Bind to active caspases and inhibit their activity

Answer 300

Bcl-2, Bcl-xL: intrinsic pathway FLIP, IAPs: extrinsic pathway Growth factor pathways via PI3’-K and PKB/Akt

Answer 301

Bcl-2 PKB/Akt PTEN

Answer 302

Harmful (oncogenic) cells (e.g. cells with viral infection, DNA damage) Chemotherapeutic killing of tumour cells, e.g. Dexamethasone stimulates DNA cleavage

Answer 303

Cycle checkpoints (growth arrest ensures genetic fidelity) Specific proteins accumulate/are destroyed during the cycle - Cyclins, cycle dependent kinases, cycle dependent kinase inhibitors Permanent activation of a cyclin can drive a cell through a checkpoint

Answer 304

Essential proteins involved in maintenance of cell growth, division and differentiation

Answer 305

Mutation Oncogene protein product no longer responds to control influences

Answer 306

Aberrantly expressed Over-expressed Aberrantly active

Answer 307

Mutation in the coding sequence (point mutation of deletion) Gene amplification (multiple gene copies overproduced) Strong enhancer increases normal protein levels (e.g. Brukitt's lymphoma) Chromosomal translocation (chimeric genes) OR Fusion to actively transcribed gene overproduces protein or fusion protein is hyperactive (e.g. Philadelphia chromosome) Insertional mutagenesis (e.g. viral infection)

Answer 308

Normal activity disrupted Affects TK signalling, nuclear/cytosolic signalling and GPCR signalling Affects phosphorylation, proliferation, transcription and translation

Answer 309

Upon binding GTP, RAS becomes active Dephosphorylation of the GTP to GDP switches RAS off Mutant RAS fails to dephosphorylate GTP and remains active

Answer 310

Function= tyrosine kinase Mechanism of activation= overexpression/C-terminal deletion Location= cytoplasmic Associated human cancers= breast, colon, lung

Answer 311

Function= transcription factor Mechanism of activation= translocation Location= nuclear Associated human cancers= Burkitt's lymphoma

Answer 312

Function= transcription Mechanism of activation= overexpression/deletion Location= nuclear Associated human cancers= lung

Answer 313

Function= G protein Mechanism of activation= point mutation Location= cytoplasmic Associated human cancers= bladder

Answer 314

Function= G protein Mechanism of activation= point mutation Location= cytoplasmic Associated human cancers= colon, lung

Answer 315

e. Protooncogenes are not expressed in normal cells. | What

Answer 316

Typically proteins whose function is to regulate cellular proliferation, maintain cell integrity. E.g. RB Each cell has two copies of each tumour suppressor gene Mutation or deletion of one gene copy is usually insufficient to promote cancer. Mutation or lost of both copies means loss of control

Answer 317

Family history of related cancers Unusually early age of onset Bilateral tumours in paired organs Synchronous or successive tumours Tumours in different organ systems in same individual Mutation inherited through the germline

Answer 318

Malignant cancer of developing retinal cells Sporadic disease usually involves one eye Hereditary cases can be unilateral or bilateral and multifocal

Answer 319

Sporadic or hereditary Hereditary: Due to mutation of the RB1 tumour suppressor gene on chromosome 13q14 RB1 encodes a nuclear protein that is involved in the regulation of the cell cycle

Answer 320

Regulate cell proliferation Maintain cellular integrity Regulate cell growth Regulate the cell cycle Nuclear transcription factors DNA repair proteins Cell adhesion molecules Cell death regulators Suppress the neoplastic phenotype

Answer 321

Function= cell cycle regulator Location= nuclear Associated human cancer= many (colon, breast, bladder, lung etc)

Answer 322

Function= cell cycle regulator Location= nuclear Associated human cancer= breast, ovarian, prostate

Answer 323

Function= tyrosine and lipid phosphatase Location= cytoplasmic Associated human cancer= prostate, glioblastoma

Answer 324

Function= cell signalling Location= cytoplasmic Associated human cancer= colon

Answer 325

Function= cell cycle regulator Location= nuclear Associated human cancer= colon and others

Answer 326

Function= mismatch repair Location= nuclear Associated human cancer= colon, gastric

Answer 327

p53 is a 'guardian of the genome'= key player in decision making during the cell cycle Although p53 is a tumour supressor gene, mutants of p53 act in a dominant manner and mutation of a single copy is sufficient to get dysregulation of activity

Answer 328

FAMILIAL ADENOMATOUS POLYPOSIS COLI Due to a deletion in 5q21 resulting in loss of APC gene (tumour suppressor gene) Involved in cell adhesion and signalling Sufferers develop multiple benign adenomatous polyps of the colon There is a 90% risk of developing colorectal carcinoma

Answer 329

WNT signalling pathway

Answer 330

APC protein helps control the activity of B-catenin and thereby preventing uncontrolled growth Mutation of APC is a frequent event in colon cancer

Answer 331

b. Metabolism of drugs

Answer 332

Oncogene Tumour suppressor gene Proto-oncogene Defective tumour suppressor gene -> Cell growth and proliferation-> cancer

Answer 333

Normal epithelium (APC->) Hyperproliferative epithelium (K-ras and DNA hypomethylation->) Adenoma (p53->) Carcinoma Metastasis

Answer 334

``` Gene active in tumour Specific translocations/point mutations Mutations rarely hereditary Dominant at cell level Broad tissue specificity Leukaemia and lymphoma ```

Answer 335

``` Gene inactive in tumour Deletions or mutations Mutations can be inherited Recessive at cell level Considerable tumour specificity Solid tumours ```

Answer 336

Critical gene targets These targets, proto-oncogenes and tumour suppressor genes, regulate cell cycle decisions (mitosis, arrest, differentiation, apoptosis)

Answer 337

Wound healing Menstrual cycle Embryonic development

Answer 338

Baldness MI- ischaemia Limb fractures Thrombosis

Answer 339

Angiodysplasia (HHT & VWD) Cerebral malformations (AVM/CCM)

Answer 340

Retinal disease Cancers Atherosclerosis Obesity

Answer 341

VASCULOGENESIS Bone marrow progenitor cell (recruitment or mobilization, capillary plexus, mature network) ANIOGENESIS Sprouting (SMC recruitment) ``` ARTERIOGENESIS Collateral growth (shear stress, cytokines-> matrix remodelling/SMC growth) ```

Answer 342

Selection of sprouting ECs - Modulation of EC-EC contacts and PC contacts - Promoted by ECM degradation and GFs - Inhibited by lateral inhibition, growth inhibitors and pro-quiescent signals (local and systemic) Sprout outgrowth and guidance) - EC proliferation - Maintenance of junctions - Deposition of new ECM - Promoted by GFs, ECM and invasive behaviour - Inhibited by growth inhibition Sprout fusion and lumen formation - Stalk-cell proliferation - Vacuole formation and fusion - Promoted by tip cells encountering adhesion - Inhibited by tip cells encountering repulsion Perfusion and maturation - Stabilisation of EC-EC adhesion - Stabilization of PC contacts - Decreased EC proliferation - Inhibited by increased pro-quiescent signals

Answer 343

Initiation Selection of sprouting ECs Tip-cell navigation Sprout outgrowth and guidance (stalk elongation) Sprout fusion and lumen formation Perfusion and oxygenation) Maturation and stabilization Quiescence

Answer 344

Hypoxia-> activates GFs-> stimulates sprouting

Answer 345

Thrombospondin-1 | Statins= angiostatin, endostatin, canstatin turnstatin

Answer 346

``` VEGFs FGFs PDGFB EGF LPA ```

Answer 347

ABSENCE OF OXYGEN HIF-a doesn't bind to pVHL (there isn't any hydroxyproline) HIF-a binds to HIF-B Activates hypoxia-inducible genes (VEGF, PDGF-B, TGF-a and EPO)

Answer 348

PRESENCE OF OXYGEN HIF-alpha has ubiquitin attachement, hydroproline head and is bound to pVHL Loses pVHL and hydroxyproline HIF-a with ubiquitin binds to proteasome HIF-a destroyed

Answer 349

VEGF PDGF-B TGF-a EPO

Answer 350

Vascular endothelial growth factor ``` VEGF-A VEGF-B VEGF-C VEGF-D PIGF (placental growth factor) ```

Answer 351

Major mediator of VEGF-dependent angiogenesis | Activates signalling pathways that regulate endothelial cell migration, survival and proliferation

Answer 352

Tyrosine kinase receptors VEGFR-1 VEGFR-2 VEGFR-3 ``` Co-receptors Neuropilin 1 (Nrp1) Neuropilin 2 (Nrp2) ```

Answer 353

Notch signalling between adjacent endothelial cells at the angiogenic front Determined by VEGFR02, NRP1, integrins, HIF-1a, PGC01a, MT1-MMP, JAGGED1, DLL4 Specialised endothelial tip cells lead the outgrowth of blood-vessel sprouts towards gradients of VEGF

Answer 354

Specialised endothelial tip cells lead the outgrowth of blood-vessel sprouts towards gradients of VEGF

Answer 355

Notch Rs and ligands are membrane-bound proteins that associate through their EC domains The IC domain of Notch (NICD) translocates to the nucleus and binds to the TF RBP-J Important for tip cells to bind to stalk cells

Answer 356

TIP CELL SELECTION In stable blood vessels, DII4 and Notch signalling maintain quiescence VEGF activation increases expression of DII4 INDUCTION OF SPROUTING DII4 drives Notch signalling which inhibits expression of VEGFR2 in the adjacent cell DII4-expressing tip cells acquire a motile, invasive and sprouting phenotype Adjacent cells (stalk cells) form the base of the emerging sprout, proliferate to support sprout elongation

Answer 357

Lumen formation (VE-caherin, CD34, sialomucins, VEGF) Pericyte recruitment (PDGF-B, ANG-1, NOTCH, ephrin-B2, FGF) Tip cell guidance and adhesion (semaphorins, ephrins, integrins) Liberation of angiogenic factors from ECM (VEGF, FGFs) Stalk elongation (VEGFR-1, NOTCH, WNT, NRARP, PIGF, FGFs, EGFL7) Myeloid cell recruitment (ANG-2, SDF-1a, PIGF)

Answer 358

Physiological and pathological angiogenesis Macrophages have been shown to carve out tunnels in the ECM-> provides avenues for subsequent capillary infiltration Tissue-resident macrophages associated with angiogenic tip cells during anastomosis

Answer 359

Quiescent phalanx resolution: Transendothelial lipid transport (VEGF-B) Vascular maintenance (VEGF, ANG-1, FGFs, NOTCH) Phalanx cells (PHD2, HIF2a, VE-cadherin, TIE-2) Barrier formation (VE-cadherin, ANG-1) Basement membrane deposition (TIMPs, PAI-1) Pericyte maturation (PDGF-B, PDGFR-B, ephrin-B2, ANG-1, NOTCH, TGF-B1)

Answer 360

In adherens junctions Constitutively expressed Homophilic interaction mediates adhesion b/w endothelial cells and IC signalling Controls contact inhibitIon of cell growth and promotes survival of EC

Answer 361

Caludins, occludin, JAMs, ESAM, nectin

Answer 362

Vessel stabilisation and quiescence Controls contact inhibitIon of cell growth and promotes survival of EC

Answer 363

Mural cells (progenitor cells of pericytes) Work with pericytes to stabilise vessels

Answer 364

Stalk cells attached to pericytes which are recruited Pericytes-> TIMP3 and ANG1 act on stalk cells (Angiopoietin/Tie-2 system) DLL4 ligand binds to notch R

Answer 365

Ang-1 and Ang-2 are antagonistic ligands of the Tie2 receptor Ang-1 binding to Tie2: Promotes- vessel stability Inhibits- inflammatory gene expression Ang-2 antagonises Ang-1 signalling Promotes- vascular instability and VEGF-dependent angiogenesis

Answer 366

Ang-1 binding to Tie2 Promotes- vessel stability Inhibits- inflammatory gene expression

Answer 367

Ang-2 antagonises Ang-1 signalling | Promotes- vascular instability and VEGF-dependent angiogenesis

Answer 368

Congestive heart failure Sepsis Chronic kidney disease

Answer 369

Tumours <1mm receive oxygen and nutrients by diffusion Larger tumours need vessel network (so tumour secretes angiogenic factors that stimulate migration, proliferation and neovessel formation by endothelial cells in adjacent established vessels) Once a tumour is newly vascularized, doesn't rely on diffusion solely so can grow progressively

Answer 370

Discrete step in tumour development that can occur at different stages in the tumour-progression pathway Depends on the nature of the tumour and its microenvironment

Answer 371

Irregularly shaped, dilated, tortuous Not organised into definitive venules, arterioles and capillaries Leaky and haemorrhagic, partly due to overproduction Perivascular cells often become loosely associated (Some tumours may recruit endothelial progenitor cells from the BM)

Answer 372

Anti-VEGF antibodies Soluble VEGF Rs (e.g. VEGF-Trap) Anti-VEGFR antibodies (e.g. IMC-1121b) Small molecule VEGFR inhibitors (e.g. vatalanib, sunitinib, ZD6474, AZO2171)

Answer 373

Reduces tumor growth VEGFR1 binds to VEGF and 'mops it up' preventing it from stimulating angiogenesis Flt-1 expression reduces tumor growth in vivo, without affecting tumor cell growth in vitro SO IT MUST BE ON VASCULATURE

Answer 374

Anti-VEGF humanised MAb ``` GI perforation Hypertension Proteinuria Venous thrombosis Haemorrhage Wound healing complications ``` NB. No overall survival advantage over chemo alone No QoL or survival advantage

Answer 375

In some cases= benefits are transitory Followed by a restoration of tumour growth and progression In other cases there's no objective benefit

Answer 376

Reduces hypoxia Increase efficacy of conventional therapies

Answer 377

May damage healthy vasculature leading to loss of vessels, creating vasculature resistant to further treatment and inadequate for delivery of oxygen/drugs

Answer 378

VEGF INHIBITION AGGRAVATES HYPOXIA -> increased tumour production of other angiogenic factors or increases tumour invasiveness TUMOUR VESSELS MAY BE LESS SENSITIVE TO VEGF INHIBITION Due to vessel lining by tumour cells or endothelial cells derived from tumours TUMOUR CELLS THAT RECRUIT PERICYTES May be less responsive to VEGF therapy

Answer 379

Tumour cell vasculogenic mimicry (VM) Plasticity of aggressive cancer cells forming de novo vascular networks (i.e. tumour cells organise themselves to form vessel-like channels which hook up to channels within the tumour mass) Associated with malignant phenotype and poor clinical outcome

Answer 380

In combo with other anti-cancer therapies Need to consider resistance (combinatorial strategies to inhibit angiogenesis and target drug resistance mechanisms) Novel non-VEGF targets

Answer 381

AMD Abnormal growth of choroidal blood vessels: Leaky vessels cause oedema Visual impairment

Answer 382

Lucentis (ranibizumab) High efficacy of treating and improving vision Very expensive but more effective than Avastatin (bevacizumab)

Answer 383

Tumours are complex 3D structures with microenvironemnts Lack good in vitro models Studies generally performed on cell lines growing as 2D monolayers which don't mimic interplay b/w tumour cells and their EC environment Tumours receive nutrients and therapeutics through vasculature (can't study in vitro)

Answer 384

Microphysiological system that incorporates human cells in a 3D ECM Supported by perfused human microvessels Useful in drug screening (considers vasculature)

Answer 385

``` CHEMICALS (carcinogens) Dietary Lifestyle Environmental Occupational Medical Endogenous ``` RADIATION Ionizing Solar Cosmic Damaged DNA can -> cancer

Answer 386

DNA adducts and alkylation Base dimers and chemical cross-links Base hydroxylations and abasic sites formed Double and single strand breaks

Answer 387

Addition of functional groups e.g. oxidations, reductions, hydrolysis Mainly cytochrome p450-mediated

Answer 388

Conjugation of phase 1 functional groups E.g. sulphation, glucuronidation, acetylation, methylation, amino acid and glutathione conjugation Generates polar (water soluble) metabolites

Answer 389

Common environmental pollutants Formed from combustion of fossil fuels Formed from combustion of tobacco

Answer 390

Benzo[a]pyrene - > (p450) - > TOXIC benzo[a]pyrene-7,8-oxide - > (EH) - > less toxic benzo]a]pyrene-7,8-dihydrodiol - > (p450) - > Benzo[a]pyrene-7,8 dihydrodiol-9,10- oxide Spontaneously breaks off Charge around C Incredibly reactive (with DNA and RNA) Electron rich molecule in body -> DNA adducts

Answer 391

Formed by Aspergillus flavus mould Common on poorly stored grains and peanuts Aflatoxin B1 is a potent human liver carcinogen, especially in Africa and Far-East - America have money to test for it and avoid it - Poorer countries can’t so eat it

Answer 392

C=C substrate for p450 on aflatoxin B1 - > generate epoxide (p450) Aflatoxin B1. 2,3-epoxide - Adducts directly to guanine - Can lead to mutation in genetic sequence

Answer 393

Aromatic 2-naphthylamine has amine group -> (CYP1A2) -> N-hydroxy-2-naphthylamine -> (glycuronyl transferase) -> Adds glucuronide -> (urine pH means nitrenium ion added) -> DNA-reactive electrophile causes bladder tumours

Answer 394

Metabolised by cytochrome p450 but bladder cancer (not liver) because of the way it is metabolically activated CYP1A2 forms hydroxyl amine which is very toxic -> acidic pH of urine leads to breakage of glucoronide-> release of nitrenium positive ion which reacts with DNA

Answer 395

Past components of dye-stuffs Include 2-naphthylamine and benzidine German dye industry epidemiology

Answer 396

Pyrimidine (thymine) dimers Skin cancer

Answer 397

Generates free radicals in cells Includes oxygen free radicals - Super oxide radical: O2* - Hydroxyl radical: HO* Possess unpaired electrons - Electrophilic and therefore seek out electron-rich DNA

Answer 398

Double and single strand breaks Apurinic and apyrimidinic sites Base modifications: - Ring-opened guanine and adenine - Thymine and cytosine glycols - 8-hydroxyadenine and 8-hydroxyguanine (mutagenic)

Answer 399

c. Cytochrome P450

Answer 400

PRODUCTION OF P53 (stims MDM2, inhibited by MDM2) - Ribonucleotide depletion - Nitric oxide - Hypoxia - Oxidative stress - Mitotic apparatus dysfunction - Oncogene activation - DNA replication stress - Double-strand breaks - Telomere erosion ``` MILD/PHYSIOLOGICAL STRESS Regulates p53 target genes -> metabolic homeostasis -> antioxidant defence -> DNA repair -> growth arrest -> senescene -> apoptosis ``` SEVERE STRESS Protein-protein interactions -> apoptosis

Answer 401

Direct reversal of DNA damage Base excision repair (mainly for apurinic/apyrimidinic damage) Nucleotide excision repair (mainly for bulky DNA adducts) During- or post-replication repair

Answer 402

Photolyase splits cyclobutane pyrimidine-dimers Methyltransferases and alkyltransferases remove alkyl groups from bases

Answer 403

DNA glycosylases and apurinic/apyrimidinic endonucleases and other enzyme partners A repair polymerase (e.g. Polβ) fills the gap and DNA ligase completes the repair - Mutagen exposure - DNA-glycosylase - AP-endonuclease - DNA polymerase (replaces nucleotide base based on complementary base pairing) - DNA ligase

Answer 404

Xeroderma pigmentosum proteins (XP proteins) assemble at the damage A stretch of nucleotides either side of the damage are excised Repair polymerases (e.g. Polδ/β) fill the gap and DNA ligase completes the repair - Mutagen exposure - Endonuclease - Helicase - DNA polymerase (replaces 100s of bases based on complementary base pairing) - DNA ligase

Answer 405

Mismatch repair | Recombinational repair

Answer 406

Endogenous damage: - Depurination - Depyrimidination - Single-strand breaks - Alkylation - Free radical base oxidations The greater the persistence of damage then the greater the chance of a mutagenic event Repair rate per cell vs damage per hour per cell

Answer 407

Carcinogen damage leading to altered DNA -> A, B or C A. Efficient repair-> normal cell B. Apoptosis -> cell death C. Incorrect repair/altered primary sequence -> DNA replication and cell division: fixed mutations -> transcription/translation giving aberrant proteins OR -> Carcinogenesis if critical targets are mutated: oncogenes, tumour suppressor genes

Answer 408

Structural alerts/SAR e.g. amino group, aromatic group that could form an epoxide - > In vitro BACTERIAL gene mutation assay e. g. Ames test with S. typhimurium - > In vitro MAMMALIAN CELL assay e. g. chromosome aberration, TK mutation in mouse lymphoma cell, Micronucleus assay - > In vivo MAMMALIAN assay e. g. Bone marrow micronucleus test transgenic rodent mutation assay -> Investigative in vivo MAMMALIAN assays

Answer 409

Chemical to be tested Has rat liver enzyme preparation (S9) added - Bacteria that don't synthesis histidine (e.g. salmonella strain) Conversion of chemical to reactive metabolite On histidine-free media: if mutations occur in bacterial genome then bacteria acquire ability to synthesise histidine = colonies

Answer 410

Treat mammalian cells with chemical in presence of liver S9 Look for chromosomal damage e.g. chromosome interchanges, acentric ring etc.

Answer 411

Cells treated with chemical and allowed to divide Cytokinesis blocked using cytochalasin-B Binucleate cells assessed for presence of micronuclei Can stain the kinetochore proteins to determine if chemical treatment caused clastgenicity (chromosomal breakage) or aneuploidy (chromosomal loss)

Answer 412

Base excision repair

Answer 413

Can lead to mutation and possibly neoplasia

Answer 414

False 4th most common in cancer overall 2nd leading cause of cancer death

Answer 415

Extracts water from faeces (electrolyte balance) Faecal reservoir (evolutionary advantage) Bacterial digestion e.g. for vitamins B and K

Answer 416

Crypts of Lieberkuhn Differentiation UP Proliferation UP and DOWN Contains columnar, goblet, endocrine and mesenchymal cells

Answer 417

Projection from a mucosal surface into a hollow viscus, and may be hyperplastic, neoplastic, inflammatory, hamartomatous, etc.

Answer 418

Benign neoplasm of mucosal epithelial cells

Answer 419

Prevents cell loss-> mutation Normally have protective mechanisms to eliminate genetically defective cells

Answer 420

Makes them vulnerable

Answer 421

``` Hyperplastic / metaplastic Adenomas Juvenile Peutz Jeghers Lipomas Others (essentially any circumscribed intramucosal lesions) ```

Answer 422

``` Very common <0.5cm 90% of LI polyps Often multiple Benign (no malignant potential) Commonly from K-ras mutation (15%_ ```

Answer 423

Type of cell: can be tubular or villous (or tubulovillous if mixed) Protrusion: can be pedunculated (tree) or sessile (rug) Sessile ones tend to be more villous, but both can be either

Answer 424

Columnar cells with nuclear enlargement, elongation, multilayering and loss of polarity Increased proliferative activity Reduced differentiation Complexity/disorganisation of architecture

Answer 425

Mucinous cells with nuclear enlargement, elongation, multilayering and loss of polarity Exophytic, frond-like extensions Rarely may have hypersecretory function and result in excess mucus discharge and hypokalaemia

Answer 426

Bad growth (literal meaning) Abnormal growth of cells with some features of cancer C.f. atypia Subjective analysis Indefinite, low grade and high grade (indefinite not used now)

Answer 427

Ulcerative colitis causes increased proliferation in an attempt to repair damage, and the inflammation also damages the basement membrane, making invasion easier

Answer 428

Most colorectal cancer comes for polyps

Answer 429

NORMAL Germline or somatic mutations of cancer suppressor genes (!st hit) MUCOSA AT RISK Methylation abnormalities Inactivation of normal alleles (2nd hit) ADENOMAS Protoncogene mutation Homozygous loss of additional cancer suppressor genes (Grow into lumen, submucosa extends) CARCINOMA Additional mutation Gross chromosomal alterations (Invasion through muscularis propria)

Answer 430

5q21 gene mutation FAP (familial adenomatous polyposis)= inactivation of APC tumour suppressor genes

Answer 431

25% at 50y have colonic adenomas 5% become cancers if left

Answer 432

10-15 years | Stay at curable stage 2 years approx

Answer 433

Large (>1cm)

Answer 434

Adenomas NB. Residual adenomas may remain (in 10-30% of CRCs)

Answer 435

``` APC Kras Smads p53 Telomerase activation ```

Answer 436

HNPCC (hereditary non-polyposis colorectal cancer): due to microsattelite instability. Microsatellites are repeat sequences prone to misalignment, often mismatch repair genes

Answer 437

FAP | HNPCC

Answer 438

``` Rare= Japan, Mexico and Africa Common= US, Eastern Europe, Australia ``` (Generally 50-80y olds)

Answer 439

``` High fat Low fibre High red meat Refined carbohydrates Chemicals in food ```

Answer 440

Food through GI system Contains carcinogens (also some anticancer agents) Head modifies chemicals further HCAs= heterocyclic amines (cooked e.g. in meat -> mutagenesis)

Answer 441

Vit C= ROS scavenger Vit E= ROS scavenger Isothiocyanates )cruciferous veg) Polyphenoles (green tea, fruit juice)-> activate MAPK-> regulates Phase 2 detox enzymes and other genes that reduce DNA oxidation Also garlic associated apoptosis (Ajoene, allicin) Green tea (EGCG-induced telomerase activity)

Answer 442

Folates Co-enzyme for nucleotide synthesis and DNA methylation MTHFR Deficiency-> DNA synth disruption-> DNA instability-> genomic hypomethylation and focal hypermethylation-> gene activation and silencing

Answer 443

``` The big ones: Change in bowel habit (more/less constipated, going more frequently, anything) Bleeding PR (peri rectum) Iron deficient anaemia (otherwise unexplained) ``` ``` Also potentially: Mucus PR Bloating Cramps (‘colic’) Constitutional changes (weight loss, fatigue, etc.) ```

Answer 444

Most colorectal cancers occur in the sigmoid colon or rectum, the rest distributed fairly evenly 22% caecum/ascending colon 11% transverse 6% descending colon 55% rectosigmoid

Answer 445

70% of colorectal cancers are moderately differentiated (10% well and 20% poorly)

Answer 446

TNM classification is used in colorectal cancer management today Duke’s classification was the first staging system which proved that staging a cancer improved its management

Answer 447

Duke’s A - Growth limited to wall (muscularis propria) - Nodes negative Duke’s B - Growth beyond muscularis propria - Nodes negative Duke’s C1 - Nodes positive - Apical lymph node negative Duke’s C2 - Apical lymph node positive (There is a D)

Answer 448

Diagnosis in asymptomatic patients- unknown (probably improved) Rectal bleeding-> improved prognosis Bowel obstruction-> diminished prognosis Tumour location-> colon better than rectum, left better than right Age <30-> diminished prognosis Preop serum CEA-> diminished prognosis with high CEA level Distant metastases-> markedly diminished prognosis

Answer 449

Depth of bowel wall penetration-> increased penetration, diminish prognosis No. of regional lymph nodes-> 1-4 better than >4 Degree of differentiation-> well is better than poorly Mucinous (colloid) or signet ring cell-> diminished prognosis Venous invasion-> diminished prognosis Lymphatic invasion-> diminished prognosis Perineural invasion-> diminished prognosis Local inflamm and immuno reaction-> improved prognosis

Answer 450

``` I= surgery II= surgery, 5FU III= surgery, 5FU/leucovorin IV= surgery, metastatectomy, chemo, palliative rT ```

Answer 451

Patients who have.... Had a previous adenoma A close relative affected by colorectal cancer <45yo 2 close relatives affected by colorectal cancer at all Evidence of a dominant familial cancer trait Ulcerative colitis or Crohn’s disease

Answer 452

The practice of investigating apparently healthy individuals with the object of detecting unrecognised disease or a high risk of developing disease, and of intervening in ways that will prevent the occurrence of disease or improve the prognosis when it develops

Answer 453

Condition should be important in respect in respect to seriousness and/or frequency Natural history of disease must be known (to ID where screening can take place and enable effects of any intervention to be assessed) Consider test characteristics - Simple and acceptable to patient - Sensitive and selective Screening population should have equal access to screening procedure Cost effective

Answer 454

FOB (fecal occult blood) Positives referred for: - 60-75y colonoscopy - 55-60y sigmoidoscopy

Answer 455

D. Colorectal malignancy must be excluded in the first instance

Answer 456

A. Many carcinomas are derived from adenomas

Answer 457

Cancer of the bone marrow and other blood-forming organs (5% all cancers) Most common cancer in M&F 15-24

Answer 458

Series of mutations in pluripotential haematopoietic stem cells, single lymphoid cell (stem cell, pre B lymphocyte or pre T lymphocyte) or myeloid stem cell Cells show abnormalities in proliferation, differentiation or cell survival-> expansion of cell clone

Answer 459

MATTER STATES Most cancers exist as solid tumours- leukaemic cells replace normal bone marrow cells and circulating freely in the blood stream BEHAVIOUR Haemopoietic and lymphoid cells behave differently from other body cels Recirculate METASTASIS Leukaemia doesn't have concepts of invasion and metastasis Instead 'benign'= chronic (goes on) 'Malignant'= acute (very aggressive if untreated)

Answer 460

``` 'Benign'= chronic (goes on) 'Malignant'= acute (very aggressive if untreated) ``` Lymphoid or myeloid - Lymphoid can be B or T lineage - Myeloid can be any combo of granulocytic, monocytic, erthroid or megakaryocytic

Answer 461

Acute lymphoblastic leukaemia (ALL) Acute myeloid leukaemia (AML) Chronic lymphocytic leukaemia (CLL) Chronic myeloid leukaemia (CML)

Answer 462

Mutation in a known proto-oncogene Creation of a novel gene, e.g. a chimeric or fusion gene Dysregulation of a gene when translocation brings it under the influence of the promoter or enhancer of another gene Loss of function of a tumour-suppressor gene can result from deletion or mutation If there is tendency to increased chromosomal breaks-> increased risk

Answer 463

Down’s syndrome Chromosomal fragility syndromes Defects in DNA repair Inherited defects of tumour-suppressor genes

Answer 464

Irradiation Anti-cancer drugs Cigarette smoking Chemicals e.g. benzene

Answer 465

Immune deficiency | Bone marrow failure syndrome

Answer 466

Generally due to mutations affecting TFs (so transcription of multiple genes is affected) Often oncogene product prevents normal protein function Dominant negative effect Cells continue to proliferate but they no longer mature - > build up of the most immature cells (myeloblasts/blast cells) in BM (spread into blood) - > failure of production of normal functioning end cells e.g. neutrophils, monocytes, erythrocytes, platelets

Answer 467

Generally due to mutations affecting a gene encoding a protein in the signalling pathway between a cell surface R and nucleus Protein may be membrane receptor or a cytoplasmic protein Cell kinetics and function not as seriously affected as in AML Cell becomes independent of external signals (altered stromal interactions, reduced apoptosis-> cells survive longer)

Answer 468

``` AML= failure of production of end cells (increased lymphoblasts) CML= increased production of end cells (abnormal mature cells) ```

Answer 469

Increase in very immature cells | Failure to develop into mature T and B cells

Answer 470

Leukaemic cells are mature T cells or B cells (although abnormal)

Answer 471

Accumulation of abnormal cells Metabolic effects Crowding out of normal cells

Answer 472

Hyperuricaemia and renal failure Weight loss Low grade fever Sweating

Answer 473

ACCUMULATION OF ABNORMAL CELLS - > Leucocytosis - > Bone pain (if leukaemia is acute) - > Hepatomegaly - > Splenomegaly - > Lymphadenopathy (if lymphoid) - > Thymic enlargement (if T lymphoid) - > Skin infiltration

Answer 474

Anaemia Neutropenia Thrombocytopenia

Answer 475

Palor Haemorrhages (Signs of anaemia and thrombocytopenia)

Answer 476

Monocytic differentiation Haemorrhage into gums (thrombocytopenia) Thickened gums due to infiltration via leukaemia cells

Answer 477

Delayed exposure to a common pathogen OR CONVERSELY Early exposure to pathogens protect Theorised because of studies of family size, new towns, socio-economic class, early social interactions, variations between countries More affluence-> more like to get leukaemia

Answer 478

Irradiation in utero In utero exposure to certain chemicals (e.g. Baygon, Dipyrone) Epstein-Batt virus infection Rarely due to mutagenic drug

Answer 479

Accumulation of abnormal cells Crowding out of normal cells

Answer 480

``` Bone pain Hepatomegaly Splenomegaly Lymphadenopathy Thymic enlargement (mass) Testicular enlargement (bilateral) ```

Answer 481

Fatigue, lethargy, pallor, breathlessness (caused by anaemia) Fever and other features of infection (caused by neutropenia) Bruising, petechiae, bleeding (caused by thrombocytopenia)

Answer 482

Leucocytosis with lymphoblasts in the blood Anaemia (normocytic, normochromic) Neutropenia Thrombocytopenia Replacement of normal bone marrow cells by lymphoblasts

Answer 483

Blood count and film - ALL-> increased numbers, more immature cells Check of liver and renal function and uric acid Bone marrow aspirate Cytogenetic/molecular analysis - Immunophenotyping - Fluorescent antibodies are applied to cells recognise antigens on cell surface Chest X-ray

Answer 484

How to manage patient (info about prognosis) Advances knowledge of leukaemia

Answer 485

Hyperdiploidy= good prognosis t(4;11)= poor prognosis

Answer 486

Formation of a fusion gene (due to translocation) Dysregulation of a prot-oncogene by juxtaposition of it to the promoter of another gene e.g. T-cell receptor gene Point mutation in a proto-oncogene

Answer 487

FISH= fluorescence in situ hybridization Detected by 2 fluorescent probes (different for different regions) (e.g. red and green) When a fusion gene is formed the two colours fuse to give a combined signal (e.g. yellow)

Answer 488

Supportive= red cells, platelets, antibiotics Systemic chemotherapy Intrathecal chemotherapy

Answer 489

Rapid change implies lifestyle/environment factors act late in carcinogenesis Slow change implies exposures early in life are the most relevant Persistence of rates between generations suggests genetic susceptibility is important in determining risk

Answer 490

Incidence is increasing for common cancer sites in both high-income (now with plateauing and even decreases) and low-income countries (e.g. breast, colorectum, prostate)- effects of earlier diagnosis, screening, changes in risk factors? Mortality is decreasing in most high-income countries but not in low income countries Total burden increasing becuase of demographic changes (ageing populations and increasing size) and Westernization of lifestyles

Answer 491

Retinoblastoma

Answer 492

Skin cancer

Answer 493

Kidney cancer

Answer 494

Sarcomas, brain, breast, leukaemia

Answer 495

Colon, rectum cancer

Answer 496

Bone cancer

Answer 497

Leukemia, liver, skin

Answer 498

``` Smoking Diet Alcohol Infection Occupation Reproductive hormone ```

Answer 499

45% of cancers in men and 40% in women These could have been prevented had risk factors been reduced to the optimal levels or eliminated (like tobacco)

Answer 500

30% | 90% of lung cancer deaths in men and 80% in women

Answer 501

Oral cavity, pharynx, larynx, oesophagus, liver Mechanisms poorly understood Synergism with tobacco Balance with preventive effect for CHD

Answer 502

World Cancer Research Fund Be as lean as possible without becoming underweight Be physically active for at least 30 mins every day Avoid sugary drinks and limit consumption of energy-dense foods Eat more of a variety of vegetables, fruits, wholegrains and pulses Limit consumption of red meats and avoid processed meats Limit alcoholic drinks (2 for men and 1 for women a day) Limit consumption of salty foods and foods processed with sodium Don't use supplements to protect against cancer just eat well

Answer 503

Exogenous and endogenous hormones | E.g. pill

Answer 504

Energy dense diet, rich in fat, refined carbs and animal protein Low physical activity Smoking and drinking

Answer 505

Greater adult body height Early menarche Obesity Diabetes Cardiovascular disease Hypertension Cancer

Answer 506

16% worldwide

Answer 507

HPV-> cervix, head and neck EBV-> Hodkin's lymphoma, Burkitts HCV/HBV-> liver H. pylori-> stomach

Answer 508

Cancer incidence is related to: Age Common environmental causes Geographical variation and secular trends

Answer 509

Yes but rare | Provide valuable info in understanding the process of carcinogenesis

Answer 510

Breast (1 in 8 will develop in UK and USA, 1 in 5 cancer deaths) Liver more common overall

Answer 511

Developed countries

Answer 512

Incidence rising | Mortality falling

Answer 513

Early diagnosis Chemo and radiotherapies Hormonal therapies

Answer 514

Only organ that develops post-natally Dramatic changes in size, shape and function through infantile growth, puberty, pregnancy, lactation, weaning and postmenopausal regression

Answer 515

Carcinomas (tumour of epithelial cells)

Answer 516

Lobular cancer (lobule) Ductal cancer (duct) Duct ecstasia (duct) Paget's disease (lactiferous sinus) Phyllodes (fat and connective tissue stroma= very rare, sarcomal)

Answer 517

Puberty | Dependent on high levels of estrogen and progesterone produced by ovary

Answer 518

Cyclical increases in ductal branching -> Resulting in extensive branching in the fat pad

Answer 519

Estrogen not necessary for the prenatal development of the mammary gland Estrogen required for prepubertal and pubertal gland development

Answer 520

Characterised by large increases in side branching and development of secretory acini from the terminal ductal alveoli

Answer 521

Involved extensive apoptosis

Answer 522

2 layers of epithelial cells Inner- luminal (make contact with lumen) Outer- myoepithelial (make contact with basement membrane)

Answer 523

Inner= luminal epithelial cells (steroid hormones act on these) Outer= myoepithelial cells (able to contract in response to hormonal cues e.g. oxytocin) During lactation this is important

Answer 524

Invasive ductal carcinoma (80%) | Invasive lobular carcinoma (5-15%)

Answer 525

In the terminal duct lobular unit Progress from an initial hyperproliferative stage to a pre-cancerous in situ carcinoma stage Then progresses to invasive breast cancer Gives rise to range of carcinomas e.g. medullary carcinoma, carcinoma and lobular carcinoma

Answer 526

Any cell that expresses ER will be senstivie to oestrogen (oestrogen drives growth of cell) Different labs have different cutoff points for the calling the cancer either ER-positive or ER-negative Any positive result at all suggests hormonal therapy could be used

Answer 527

Age of onset of menarche Age to first full-term pregnancy (having children earlier-> lower incidence) Some contraceptive pills Some hormone-replacement therapies Late age to menopause Diet, physical activity, height, medication (aspirin) Obesity

Answer 528

Gets across cell membranes easily | Can only have an action if cell has estrogen R (nuclear receptor)

Answer 529

Binding estrogen activates estrogen receptor Gene expression induced by binding to specific DNA sequences called estrogen response elements Estrogen-induced gene products increase cell proliferation-> breast cancer

Answer 530

Progesterone receptor (estrogen makes cells with ERs also receptive to progesterone) Cyclin D1 c-myc TGF-alpha

Answer 531

1/3 Sensitive to effects of estrogen

Answer 532

Responds to high dose therapy with synthetic estrogens i.e.g causes breast tumour regression

Answer 533

70% | Presence is indicative of better prognosis

Answer 534

Estrogen regulates the expression of genes involved in cellular proliferation leading to breast cancer

Answer 535

SURGERY Mastectomy= removal of breast Lumpectomy= surgery to remove tumour and a small amount of normal tissue around it (breast conserving- almost always includes radiation therapy)

Answer 536

Surgery Radiation therapy Chemotherapy Endocrine therapy

Answer 537

Any kind of treatment given after primary therapy to increase long-term disease-free survival Useful to kill any cancer cells that may have spread Increase chance of long-term survival

Answer 538

Ovarian suppression Blocking estrogen production by enzymatic inhibition Inhibiting estrogen responses

Answer 539

End of follicular phase just before ovulation

Answer 540

PREMENOPAUSAL Hypothalamus releases LHRH-> pituitary gland releases gonadotrophins (FSH + LH) -> ovary (aromatization) releases esterogens and progesterone-> acts on body PRE/POST MENOPAUSAL Hypothalamus releases ACTH-> adrenal glands release corticosteroids, progesterone and androgens Androgens undergo peripheral conversion to estrogens -> acts on body

Answer 541

Surgical oophorectomy | Ovarian irradiation

Answer 542

Morbidity and irreversibility Now can have reversible/ reliable medical ovarian ablation

Answer 543

Using LHRH agonists Act on pituitary gland = LHRH agonists bind to LHRH Rs in the pituitary-> R down-regulation and suppression of LH release and inhibition of ovarian function (including estrogen production) Prevent production of FSH and LH

Answer 544

Goserelin Buserelin Leuprolide Triptorelin

Answer 545

LHRH agonists (pit gland LHRH Rs) Aromatase inhibitors (aromatization in ovary and peripheral conversion) Antiestrogens (inhibit estrogen activity)

Answer 546

Upon binding ligand, the receptor dissociates from hsp90 dimerises and binds to response elements in regulated genes, enabling transcriptional activation These inhibit the effects triggered by activation of the response element (prevent TATA-> gene expression)

Answer 547

Anti-estrogen (selective estrogen receptor modulator= SERM) Competitive inhibitor of estradiol binding to the ER Administered as tamoxifen citrate and undergoes extensive metabolism in GI tract and liver (particularly by hydroxylation)

Answer 548

For metastatic disease in postmenopausal patients (approx 1/3 respond) As effective in pre-menopausal as in post-menopausal women

Answer 549

Negate stimulatory effects of estrogen by blocking ER-> holds cell at G1 phase of cell cycle

Answer 550

BONE Long-term administration of an anti-estrogen has the potential to precipitate premature osteoporosis (Because estrogen important to maintain bone in premenopausal women) CV SYSTEM Following menopause, women at same risk for CHD as men Long-term administration of an antiestrogen could produce a population at risk for premature coronary heart disease (Because estrogen lowers LDL levels and raises HDL levels)

Answer 551

SEs= 29% have hot flushes LIVER= Possible subsequent thromboembolic episodes UTERUS= Endometrial thickening (-> cancer), hyperplasia, fibroids, polyps, vaginal discharge HYPOTHALAMUS= Increased vasomotor symptoms EYE= Increased cataracts DVT

Answer 552

BREAST= reduces breast cancer LIVER & HEART= lowers cholesterol, reduces atherosclerosis and heart attacks BONE= maintains density to help prevent bone loss

Answer 553

BRAIN= improves cognitive function BREAST= programs glands to produce milk LIVER & HEART= lowers cholesterol, reduces atherosclerosis and heart attacks UTERUS= programs uterus to nourish a fetus BONE= maintains density to help prevent bone loss

Answer 554

BREAST= promotes breast cancer LIVER= increases thromboembolism UTERUS= promotes endometrial cancer

Answer 555

Toremifene ICI 182, 780 Raloxifene (faslodex SERM)

Answer 556

High risk patients - Previous benign breast pathology (5 years) - Previous family history

Answer 557

38% reduction in overall breast cancer incidence No effect on ER negative breast cancer incidence No association between prevention and patient age

Answer 558

Major source of estrogen in post-menopausal women derives from conversion of adrenal hormone (androstenedione, A and sometimes testosterone to estroen, E2)

Answer 559

Extra-adrenal or peripheral sites e.g. fat, liver and muscle Catalysed by aromatase enzyme complex (3 separate steroid hydroxylations) -> production of estrone sulphate (which is circulated in the plasma)

Answer 560

A complex containing a cytochrome P450 heme containing protein as well as the flavoprotein NADPH cytochrome P450 reductase

Answer 561

Type 1= irreversible, mechanism-based/ suicide inhibitors (initially compete with natural substrate then irreversibly inactive enzyme) e.g. exemestane drug Type 2= competitive inhibitors (reversible binding) e.g. anastrozole drug

Answer 562

Progesterone= dominant naturally occurring progestin Influence proliferation and differentiated functions in human breast

Answer 563

Clinically proven antineoplastic properties Used for metastatic breast cancer as 2nd or 3rd line therapy following selective estrogen

Answer 564

Megestrol acetate

Answer 565

Happens in significant proportion of patients Most cases continue to demonstrate estrogen responses and contain estrogen receptor

Answer 566

Initial response but eventual relapse Relapse due to resistance during prolonged endocrine therapy NOT due to tumours becoming ER-independent Recent data shows that resistant tumours have mutated ER

Answer 567

Continue endocrine therapies | But with additional therapeutic agents/strategies for endocrine resistant, metastatic disease

Answer 568

>60% of ERα-positive tumours respond to endocrine therapy Anti-estrogens e.g. tamoxifen Inhibitors of estrogen synthesis e.g. exomestane

Answer 569

``` Ovarian ablation (and then if relapse with metastatic disease= tamoxifen, aromatase inhibitors, progestins, ?faslodex) ``` Tamoxifen (and then if relapse with metastatic disease= ovarian ablation, aromatase inhibitors, progestins, ?faslodex)

Answer 570

Tamoxigen | and then if relapse with metastatic disease= aromatase inhibitors, progestins, ?faslodex

Answer 571

Mammography to screen all women between 50-64 (being extended to age 70) Once every 3 years More than 70% women attend 6/100 asked to go back for more tests

Answer 572

ERa -ve - Basal-like(metaplastic/ medullary/ mucinous/ others) - ErbB2 +ve (herceptin) - Normal-like ERa +ve - Luminal B/C (hormone therapy) - Luminal A (hormone therapy)

Answer 573

Lump detected (self exam/GP) Referred to hospital Examined by surgical team (mammogram, FNA) Surgery performed (lumpectomy/ mastectomy) Tumour examined pathologically (ER/ PR) See physician for first time ER+ (tamoxifen 5 years) ER- (chemo 6 months) Disease free interval If patient returns with secondary tumour (no cure)

Answer 574

``` Basal cell carcinoma Squamous cell carcinoma Malignant melanoma Kaposi’s sarcoma Mycosis fungoides ```

Answer 575

Epidermis (1st line of defence) Dermis Hypodermis NB. Have blood vessels, hair follicles and sebaceous glands

Answer 576

``` OLD at top, YOUNG at bottom Dead keratinocytes (at surface- flake off) Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum (includes dendritic cells and living keratinocytes) Stratum basale (includes melanocytes) Dermis (includes sensory nerve ending) ```

Answer 577

Basal cell carcinoma | Squamous cell carcinoma (aka non- melanoma skin cancer, NMSC)

Answer 578

Malignant melanoma

Answer 579

Kaposi's sarcoma, angiosarcoma

Answer 580

Mycosis fungoides (not actually a fungus just incorrectly named)

Answer 581

Uncontrolled cell proliferation

Answer 582

Gorlin’s syndrome= defect in patch gene-> basal cell Xeroderma pigmentosum= genetic condition (DNA repair damaged- BCCs, MCCs, and melanoma)

Answer 583

HHV8 in Kaposi’s sarcoma HPV in SCC

Answer 584

BCC, SCC and malignant melanoma

Answer 585

Drugs, HIV, old age, leukaemia

Answer 586

Irregular margin and colour | Often on trunk

Answer 587

Most common kind of skin cancer Glistening surface Dilated vessels on surface Often on head

Answer 588

``` UVC= 100-280 UVB= 280-310 UVA= 310-400 ```

Answer 589

``` C= only through ozone layer B= to sea level (main cause of skin cancer) A= to Dead Sea level ```

Answer 590

Essential for photosynthesis (plants) Infrared spectra provide warmth Effect on human mood Stimulates the production of vitamin D in the skin

Answer 591

A= 100x more UVA penetrates to Earth's surface

Answer 592

Skin ageing | Contribution to skin carcinogenesis (B most important)

Answer 593

UVB directly induces abnormalities in DNA e.g. mutations UVB induces photoproducts (mutations): 1) Affects pyrimidines - i.e. Cytosine and Thymine bases cyclobutane pyrimidine dimers - 6-4 pyrimidine pyrimidone photoproducts 2) Usually repaired quickly by nucleotide excision repair

Answer 594

DNA forming cyclobutane butane pyrimidine dimers Less efficiently than UVB Free radicals which damage DNA and cell membrane

Answer 595

Cell division DNA repair Cell cycle arrest

Answer 596

Removed by Nucleotide Excision Repair Defective-> Xeroderma pigmentosum

Answer 597

Genetic condition with defective Nucleotide Excision Repair Any skin type Hundreds/thousands of skin cancers Die at early age If diagnosed early may have a relatively normal life

Answer 598

Mutations that stimulate uncontrolled cell proliferation Mutations that alter responses to growth stimulating / repressing factors Mutations that inhibit apoptosis

Answer 599

Very rapid accumulations of mutations in DNA Skin reacts by causing apoptosis (to remove UV damaged cells which might become cancer cells) - Keratinocyte cell apoptosis Sun burn cells= apoptotic cells in UV overexposed skin

Answer 600

Normally UV-> DNA damage-> repair of DNA-> normal cell Cancer UV-> p53 mutation inactivated wildtype -> skin cancer Apoptosis UV-> DNA damage-> damage too severe so can't repair-> apoptosis

Answer 601

UVA and UVB effect the expression of genes involved in skin immunity (depletes Langerhans cells in the epidermis) Reduced skin immunocompetence and immunosurveillance (Basis for UV phototherapy for e.g. psoriasis) Further increases the cancer causing potential of sun exposure

Answer 602

Immune response-> cell death (malignant transformation) Skin cancer develops

Answer 603

I - Always burns never tans II - Usually burns, sometimes tans III - Sometimes burns, usually tans IV - Never burns, always tans V - Moderate constitutive pigmentation - Asian VI - Marked constitutive pigmentation - Afrocaribbean

Answer 604

Pigment responsible for skin colour Produced by melanocytes within the basal layer of the epidermis Colour depends on melanin type/amount not density of melanocytes (which is fairly constant) 2 types (eumelanin and phaeomelanin) Dictates skin sensitivity to UV damage

Answer 605

Melanocytes normally only on BM | Melanin is equally distributed along basal layer

Answer 606

Eumelanin= brown or black Phaeomelanin= yellowish or reddish brown Melanin is formed from tryosine via a series of enzymes

Answer 607

Codes for melanin >20 gene polymorphisms Variation in eumelanin: phaeomelanin produced (explains different hair colour and skin types)

Answer 608

Produced by melanocytes: Tyrosine-> Dopa-> Dopaquinone -> Eumelanin and pheomelanin -> melanin Transfered into keratinocytes

Answer 609

Malignant tumour of melanocytes (become abnormal, atypical cells and architecture) Cause by UV exposure and genetic factors Risk of metastasis

Answer 610

Melanoma in situ Flat large tumours, irregular shape, light/dark brown colours, usually >2cm, often on face Proliferation of malignant melanocytes within the epidermis No risk of metastasis (hasn't invaded deeply through BM)

Answer 611

Malignant melanocytes proliferate laterally Invade basement membrane Risk of metastasis

Answer 612

ABCD rule ``` Asymmetry Border irregular Colour variation (dark brown-black) Diameter >0.7mm and increasing Erythema (redness) ```

Answer 613

Vertical proliferation of malignant melanocytes (no previous horizontal growth) Risk of metastasis

Answer 614

Downward proliferation of malignant melanocytes Following previous horizontal growth Nodule develops within irregular plaque Prognosis worse than superficial spreading melanoma

Answer 615

``` Acral= hands and feet Lengtiginous= flat ``` Occur in darker skin people

Answer 616

Tumour that doesn't make melanin

Answer 617

``` Superficial spreading Nodular Lentigo maligna melanoma Acral lentiginous Amelanotic ```

Answer 618

Breslow thickness Measurement from granular layer to bottom of tumour Ticker= worse

Answer 619

Family history of dysplastic nevi or melanoma UV irradiation Sunburns during childhood Intermittent burning exposure in unacclimatized fair skin Atypical/dysplastic nervus syndome Skin type I or II Personal history of melanoma

Answer 620

Sudden growth no risk of metastasis

Answer 621

Malignant tumour of keratinocytes Caused by: UV exposure, HPV, immunosuppression, smoking, scarring process Risk of metastasis

Answer 622

Well differentiated squamous cell carcinoma

Answer 623

Malignant tumour arising from basal layer of epidermis Cause by sun exposure and genetics Slow growing Invades tissue but doesn't metastasis Common on phase

Answer 624

Arborizing vessels | Telangiectasia

Answer 625

Takes years or decades to progress

Answer 626

HIV and HHV8 associated

Answer 627

Rare autosomal recessive condition | Predisposition to HPV induced warts and SCCs

Cancer Flashcards

(663 cards)