Lecture 12 - Cancer Flashcards Preview

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Flashcards in Lecture 12 - Cancer Deck (18):
1

Cellular characteristics associated with human cancers

Increased number of growth factor receptors
RAS protein activated by mutations
Abl kinase activated by abnormal chromosomes in CML
Src kinase activated by mutations
Mutated or deleted pRB
Mutated or deleted p53

2

Retinoblastoma

Rare tumor that arise from neural precursor cells in the immature retina.

3

True or false: A large number of mutations are necessary for a retinoblastoma develop.

False

4

How many forms of retinoblastoma are there and what are they?

There are two forms, one is hereditary and the other is not

5

True or false: The Rb gene is frequently missing in several other types of cancer

True

6

What is bound to RAS when it's in the "on" position? What is bound to in in the "off" position

GTP = on
GDP = off

7

What converts RAS from the on to the off and vice versa?

GTPas activating proteins (GAPs)

8

What does the NF1 gene encode and what is its significance as it relate to cancer?

It encodes neurofibromin which includes a GAP domain and is associated with café-au-lait spots and benign neurofibromas; defective signal transduction possibly through RAS

9

What are fos and jun?

transcription factors

10

True or false: Tumor cells often have overexpression of fos and jun.

True

11

What is up-regulated in Burkitt's lymphoma and what causes it?

Myc is up-regulated because of a translocation that moves the myc gene against a promotor for IgH chains that are constitutively expressed

12

True or false: Chromosome translocations are associated with leukemias and lymphomas.

True

13

What do viral proteins made by cancer-causing viruses sequester? What does this lead to?

p53 and pRB
unregulated cell proliferation

14

What does HPV target?

p53 and pRB

15

Which HPV genes target which proteins?

E6 binds and induces proteolysis in p53
E7 binds and inactivates pRB

16

What are the 6 hallmarks of cancer?

1. Evading apoptosis (p53 problem)
2. Self-sufficiency in growth signals (RAS mutation, always turned on, bound to GTP)
3. Insensitivity to anti-growth signals (pRB mutation)
4. Sustained angiogenesis (blood vessel genesis)
5. Limitless replicative potential (all tumors will have turned on telomerase, mitotic clock is gone; up-regulation of telomerase
6. Tissue invasion and metastasis

17

True or false: Familial adenomatous polyposis coli is caused by the accumulation of mutations in colon cells over time.

True

18

True or false: Genetic stability is associated with cancer.

False