Exam I Flashcards

Question

Locally Invasive Tumors

Answer 1

Abnormal appearance, abnormal division, abnormal assembly, invasion of adjacent tissues

Answer 2

Abnormal appearance, abnormal division, abnormal assembly, invasion of adjacent tissues, spread to other organs

Answer 3

Cells are protruding into the lumen of the milk duct

Answer 4

All cells of a tumor come from a single mutated cell

Answer 5

Normal cells rely primarily on oxidative phosphorylation to generate energy; Cancer cells primarily rely on aerobic glycolysis to generate energy

Answer 6

The observation that most cancer cells obtain their energy from glycolysis, even in the presence of abundant oxygen; "Aerobic glycolysis"

Answer 7

An agent involved in the promotion of cancer (Example: coal tar, a chemical agent); Composed of initiators (mutagens, 60%) and promoters (signal promotes cell division, 40%)

Answer 8

An agent that changes the genetic information (Examples: X-ray; WWII chemical agents)

Answer 9

First successful induction of cancer by treatment of rabbit ears with coal tars by Katsusaburo Yamagiwain

Answer 10

Chemical Agents, Physical Agents, and Viral Agents

Answer 11

Test for mutations; Treat bacteria with substance; Try to grow bacteria in condition under which it should NOT be able to live; Those that survive mutated

Answer 12

Mutagenicity and Carcinogenicity are directly correlated

Answer 13

All mutagens (mutating DNA) are carcinogens (promoting cancer), but not all carcinogens (promoting cancer) are mutagens (mutating DNA).

Answer 14

1) Heredity 2) Environment (most common cancers are caused by environmental factors)

Answer 15

The rates with which the disease is diagnosed; Cancer incidence rates are dramatically different among different populations

Answer 16

Human cells are 10-30 micrometers; Bacteria 2 micrometers; VIRUSES 10-300 nanometers; Viruses need bacteria, plant, or animal cell to grow and reproduce; Consist of a genome (DNA or RNA) wrapped in a protein coat (capsid); Can be virulent or temperate

Answer 17

Virulent means the cell is lysing and spreading the virus; Temperate means the cell continues living; ALL CANCER VIRUSES ARE TEMPERATE

Answer 18

Took chicken with sarcoma in breast muscle; removed sarcoma and broke it up into small chunks of tissue; Ground up the sarcoma with sand; Collected the filtrate that passed through a fine-pore filter; Injected the filtrate into young chickens; Observed sarcoma in injected chickens

Answer 19

Transformed chicken embryo fibroblasts using robs Sarcoma Virus (RSV); Normal cells had contact inhibition, elongated shape, and were non-refractile (dark); RSV-Transformed Cells had no contact inhibition; rounded shape, and were refractile (white)

Answer 20

Cell clusters

Answer 21

One-cell thick layer of cells

Answer 22

A natural process of arresting cell growth when two or more cells come into contact with each other

Answer 23

Conversion of a normal cell into a tumor cell

Answer 24

Agarose prevents cell attachment...incubate...all cells except transformed cells will die

Answer 25

A generically critical test that gives a definitive answer

Answer 26

The ability of cultured cells to give rise to either benign or malignant progressively growing tumors in immunologically non-responsive animals

Answer 27

The DNA version of the viral genome

Answer 28

A single-stranded positive-sense (pairs with mRNA) RNA virus with a DNA intermediate in the host cells

Answer 29

[gag (core proteins), pol (reverse transcriptase), env (virus surface proteins)] --> Required for Replication, [src (presumably causes transformation)] --> Required for Transformation

Answer 30

RSV is a side-product of avian leukosis virus (ALV) production; On occasion, the c-src gene will be transcribed with the ALV provirus, making v-src, making RSV (EXTREMELY RARE)

Answer 31

A gene capable of transforming a normal cell into a tumor cell (causes cancer); v-src

Answer 32

The precursor of an active oncogene (could cause cancer); c-src

Answer 33

1) Implied that the genomes of normal cells carry genes that have the potential to induce cancer 2) Implied that other tumor viruses may convert other porto-oncogenes into oncogenes using a similar mechanism 3) Implied that porto-oncogenes can be activated by other mechanisms than viruses, such as mutation 4) Implied there might be many more proto-oncogenes

Answer 34

When B-cell lymphomas caused by ALV where analyzed, it was found that ALV always inserted into DNA segment containing c-myc (proto-oncogene); As an oncogene, c-myc would cause uncontrolled cell growth

Answer 35

Activation of cellular proto-oncogene by inserting provirus near the proto-oncogene; Almost ALL retroviruses have the potential to induce cancer

Answer 36

A retrovirus that carries its own endogenous viral oncogene, tax; tax is an intrinsic HTLV-I viral gene whose product stimulates expression of cellular GF

Answer 37

1) Carry no oncogenes (ALV) (weeks to months due to random insertion) 2) Carry acquired oncogenes (RSV) (days to weeks due to presence of oncogene) 3) Carry endogenous viral oncogenes (HTLV-I) (days to weeks due to presence of oncogene)

Answer 38

Do NOT generally insert into host chromosome

Answer 39

Papillomavirus and Hepatitis

Answer 40

Responsible for about 20% of all cancers

Answer 41

Provides evidence that a cellular gene can be mutated by a chemical or physical agent to cause cancer

Answer 42

A technique of introducing foreign genetic material into eukaryotic cells

Answer 43

1) Point Mutation 2) Gene Amplification 3) Chromosomal Translocation 4) Translocations liberating an mRNA from miRNA inhibition 5) Deregulated firing of GF-R 6) Formation of oncogene through reciprocal chromosomal translocations

Answer 44

Molecular switch; On (active) or off

Answer 45

Transcription factors increase the amount of DNA, driving cell proliferation

Answer 46

Causes cancer when expressed in large amounts

Answer 47

Tyrosine-kinase receptor: divide or not

Answer 48

Tyrosine-kinase receptor: divide or not

Answer 49

Nearly all mutations occur at AA residue 12, some at 13, few at 61; ras oncogenes are involved in >20% of human tumors

Answer 50

The production of multiple copies of a particular gene or genes

Answer 51

The region of chromosome DNA that undergoes amplification; Homogeneously Staining Region (HSR)...end-to-end linear arrays of amplified segments; Double Minutes...the region carrying the amplified segments breaks away from the chromosome, forming extrachromosomal particles Amplicon might be visible in metaphase. Gene amplification doesn't always equal over-expression (not always more protein)

Answer 52

N-myc is amplified to 10-150 copies, responsible for 40% of advanced pediatric neuroblastomas; Chromosomes are BIGGER in cancer cells

Answer 53

The percentage of patients surviving is plotted as a function of time after initial diagnosis or treatment

Answer 54

B-Cell Lymphoma; Malaria and Epstein-Barr Virus (EBV) are cofactors to Burkitt's Lymphoma; Normal chromosome 8 has myc and 14 has IgH; Burkitt's Lymphoma has t(8;14) causing 8 to have IgH and 14 to have myc; Also can have t(8;22) or t(8;2) -c-myc is placed under the control of the IgH promoter sequence, causing A LOT of protein to be produced

Answer 55

HMGA2 is expressed when cells are dividing; Normally, miRNA controls translation of HMGA2 by degradation based on physiological conditions...if the 3' UTR region is replaced by gene X, lost binding site for miRNA, no control

Answer 56

Naturally occurring proteins capable of stimulating cellular growth, proliferation, and cellular differentiation

Answer 57

Epidermal growth factors

Answer 58

Epidermal growth factor receptors

Answer 59

The tyrosine kinase receptor can have the extracellular domain removed (truncated genetically) so that a signal to grow is CONSTANTLY emitted

Answer 60

Chromosome break and recombination forms a FUSION ONCOPROTEIN, a hyperactive, completely new protein

Answer 61

Gene amplification, viral promoters, strong cellular gene promotor

Answer 62

Threonine (Threonine Kinase), Serine (Serine Kinase), [Tyrosine (Tyrosine Kinase)] --> CRITICAL role in cell proliferation - 99.9% of kinases are T or S - 0.1% of kinases are Y

Answer 63

src (the first oncogene discovered) makes a cell express many proteins (confirmed by Western Blot) which are phosphorylated by tyrosine kinase, indicating that src is a tyrosine kinase

Answer 64

3 Functional Domains: Ectodomain (621 AA), Transmembrane Domain (23 AA), and Cytoplasmic Domain (542 AA) -The cytoplasmic domain shows homology (similar in sequence and structure) with src, so EGF-R is a tyrosine kinase receptor

Answer 65

Consist of 3 domains, all of which are diverse except the highly conserved tyrosine kinase domain; A favorable target for treating/curing ailments/cancer

Answer 66

1) Based highly upon the Fluid Mosaic Model 2) If GF is added, the receptor becomes a stable dimer (without GF, the receptor is a monomer) 3) Dimer is essential for transphosphorylation

Answer 67

Essentially making the receptor LIGAND INDEPENDENT 1) Truncation by deleting the ectodomain 2) Point Mutation requiring no GF 3) Overexpression due to ligand-independent firing 4) Genome Instability causing gene fusion, forcing the dimerization of receptors and continuous firing

Answer 68

Normal Cells Do NOT Produce Their Own Ligands; Epithelial cells have EGF-R and Mesenchymal cells have PDGF-R (platelet-derived growth factor receptor); Epithelial cells produce PDGF and Mesenchymal cells produce TGF (transforming growth factor); v-sis is very similar to PDGF, not affecting Epithelial cells but transforming Mesenchymal cells (AUTOCRINE signaling)

Answer 69

The great majority of signaling molecules in the cell are PROTEINS

Answer 70

Ordered sequence of biochemical reactions inside the cell with HIGH specificity and HIGH speed

Answer 71

Ommatidia: light-sensing unit of fruit fly eye - Each ommatidium is formed by seven cells - Sevenless gene (one cell missing in ommatidium) encodes a homolog of the FGF-R (fibroblast growth factor receptor)

Answer 72

Functions downstream of the Sevenless and activates Ras; Sos in fly = GEF (guanine nucleotide exchange factors in yeast); GEF activates Ras proteins...Ras is a molecular switch, switching GDP to GTP (active form)

Answer 73

Receptor Tyrosine Kinases (RTKs) affect the physical location of downstream components without necessarily changing their intrinsic activity by 1) Attracting molecules to their location after activation and 2) src can be recruited to cytoplasmic domain of tyrosine receptors

Answer 74

Contains 3 Domains: SH1 (catalytic domain; kinase domain; phosphorylates using ATP), SH2 (binding to pY-containing peptide), SH3 (binding to proline-rich sequence domain)

Answer 75

Typical SH2 domain is composed of 100 AA; One binding site binds to pY with great affinity while the other binds nearby AA on C-terminus side - SH2 functions as modular plug - Human genome encodes at least 120 types of SH2 groups - Certain AA sequences after pY determine the specificity for substrates - Substrates binding intracellularly are responsible for the response after ligand binding

Answer 76

- Ras is a protein that is ALWAYS attached to the inner surface of the plasma membrane - Ras is a G-protein - Ras is inactive when bound with GDP - Ras is active when bound with GTP - RTK --> Grb2 --> Sos --> Ras - RTK --> Shc --> Grb2 --> Sos --> Ras

Answer 77

The effector loop interacts with 3 important downstream effectors of Ras; Mutations can prevent GTP --> GDP, causing unchecked activation of Ras - Bound to GDP; effector loop cannot bind to downstream molecules (Raf, PI3K, Ral-GEF) - Bound to GTP; conformational change of effector loop increases affinity for Raf, PI3K, Ral-GEF

Answer 78

1) MAPK Pathway 2) PI3K Pathway 3) Ral-GEF Pathway

Answer 79

Mitogen-Activated Protein Kinase (MAPK) Pathway; GTP-Ras attracts Raf, binding of both leads to conformational change of Raf; Raf phosphorylates MEK; MEK phosphorylates both Y and S/T kinases; Erk 1 or 2 phosphorylates and activates TFs (ex: cyclin D1) and other proteins -Deregulation can increase kinase activity, causing increased cell proliferation

Answer 80

Ras activates PI3K (phosphatidylinositol 3-kinase); PI3K synthesizes PIP3 (phosphatidylinositol (3,4,5) triphosphate); PIP3 is a special type of phospholipid; PIP3 attracts Akt/PKB (very powerful kinase) and Rho-GEFS

Answer 81

Causes: - Bad inhibits apoptosis - mTOR stimulates protein synthesis (cell growth) - GSK-3beta stimulates cell proliferation

Answer 82

- PI is part of the inside of the plasma membrane - PI is composed of two fatty acids with long H-C tails, glycerol, and inositol - PI, PI (4,5)-diphosphate (PIP2), and PI (3,4,5)-triphosphate (PIP3) are tethered to plasma membrane

Answer 83

- PIP3 formation is controlled by PI3K and PTEN - PIP3 serves as docking site for Akt/PKB - Once bound to PIP3, Akt/PKB becomes phosphorylated and activated - PTEN is a phosphatase, converting PIP3 to PIP2 (important for tumor suppression)

Exam I Flashcards

(107 cards)