Pathology Intro To Cancer

Question 1

Proto-oncogenes

Answer 1

Gene involved in normal cell growth

Question 2

Oncogene

Answer 2

Mutated proto-oncogene that could lead to cancer

Question 3

Tumor suppressor genes

Answer 3

Can synthesize growth factors to increase proliforation

Question 4

Cell growth pathway 1

Answer 4

Signal, GF binds to pathway, activates cytoplasmic signaling of transducing proteins to nucleus

Question 5

Cell growth pathway 2

Answer 5

Activated transcription factors (DNA) transcripts growth promoters and regulators

Question 6

Signal transducing proteins - RAS

Answer 6

RAS - activated by tyrosine kinase activity
Encodes for protein to bind to GDP/GTP
Inactive ras binds GDP

Question 7

Signal transducing proteins PI3

Answer 7

PI3 kinase - AKT signaling
Activated for GF binding & TKA
Common mutation for canine mammary tumors

Question 8

Transcription factor Myc

Answer 8

Activates many gene expression in cell growth, can upregulate expression of telomerase, can reprogram somatic cells
Common in lymphoma & prostate carcinoma

Question 9

RB protein

Answer 9

Inhibits cell proliferation

Question 10

RB protein mechanism

Answer 10

Binds & inhibits transcription factors, prevents cells from G1->S phase
Mutated rb is common in canine hemangiosarcoma & osteosarcoma

Question 11

Tumor suppressor genes & common cancers

Answer 11

APC - colorectal cancer
PTEN - histiocytic sarcoma
(E-Cadherin, CDKN2A)

Question 12

P53 - function & common cancer

Answer 12

Tumor suppressor - check point
canine melanoma

Question 13

What protein signals for intrinsic apoptosis?

Answer 13

Bcl-2 -> cytochrome C

Question 14

What protein signals for extrinsic apoptosis?

Answer 14

FLIP, FasL, Fas, FADD

Question 15

Steps for successful metastasis (4)

Answer 15

Invade extracellular matrix
Disseminate through vessels
Locate distant site of tissue
Successfully grow/proliferate

Question 16

Function of vascular dissemination & homing

Answer 16

Tumor cells aggregating with tumor cells, platelets & coagulation factors to reduce systemic stress on tumor cells

Question 17

Types of tumor antigens (5)

Answer 17

Viral coded proteins
Mutated proteins
Differentiation antigens
Excessive amts of normal proteins
Cancer/testis antigens

Question 18

Source of tumor antigens (5)

Answer 18

Viral coded - products of genes of oncogenic viruses
Mutated - altered forms of normal proteins
Differentiation antigens - proteins associated w specific stages of cell differentiation
Excessive proteins - over production of normal cell protein
Cancer antigens - unknown function

Question 19

Cytotoxic t lymphocytes

Answer 19

Presence is marker for better prognosis, can respond to new antigens (abnormal)

Question 20

Natural killer cells

Answer 20

Recognize lack of MHC I or stress induced proteins expressed on cell surface

Question 21

M1 (macrophage)

Answer 21

Pro-inflammatory/anti tumor

Question 22

Immunoediting

Answer 22

How cancer reduces immune response, reduces MHC expression & antigen neg variants

Question 23

Immunosuppression: targeting Th1 & macro

Answer 23

TGFb & IL-10 suppress immune, target tumor cells, suppress Th1, convert T cells

Question 24

Immune suppression- reduction

Answer 24

Evade immune system, remove growth suppressors, ROS (genetic damage)

Question 25

Immunosuppression: activation

Answer 25

Enhance cell death resistance, induce angiogenesis, activate invasion/metastasis, promote proliferation

Question 26

Proteins activated by TKA

Answer 26

RAS PI3 C-kit

Question 27

A mutation in P53 is a common cause of what cancer?

Answer 27

Canine melanoma

Question 28

A mutation in what protein is the common cause of canine hemangiosarcoma and osteosarcoma?

Answer 28

Rb protein - brake failure in cell division

Question 29

A mutation is Rb protein is the common cause of what cancer?

Answer 29

Canine hemangiosarcoma and osteosarcoma

Question 30

A mutation in what transcription factors is the common cause for canine lymphoma & porstate carcinoma?

Answer 30

MYC - upregulate telomerase expression, reprogram somatic cells to pluripotenial stem cells

Question 31

A mutation in Myc transcription factor is the common cause of what cancer?

Answer 31

Canine lymphoma and prostate carcinoma

Question 32

A mutation in what signal transducing protein is the common cause of canine mammary tumors?

Answer 32

PI3 kinase

Question 33

A mutation in PI3 kinase is the common cause of what cancer?

Answer 33

Canine mammary tumors

Question 34

Mutations in RAS can cause what types of cancer?

Answer 34

Pancreatic carcinoma Prostatic carcinoma

Question 35

Bcl-2 normal function

Answer 35

Normally inhibits release of cytochrome C Cytochrome c initiates the intrinsic pathway Inhibiting cytochrome c = more cells survive

Question 36

FLIP function

Answer 36

Anti apoptotic Blocks extrinsic pathway by binding to procaspase-8 Unregulated expression of flip = more cells survive

Question 37

Fas function

Answer 37

Fas makes cells susceptible to FasL - tagged for apoptosis Decreased Fas = pro survival