Biochemistry of Cancer

Question 1

hallmark features of cancer

Answer 1

• disordered proliferation

- growth of cells

Question 2

genetic disease caused by mutations

Answer 2

Cancer

Question 3

Retinoblastoma explain the one-hit/two-hit

Answer 3

• normal two Rb+ alleles
• one missing allele–> predisposed to develop retinoblastoma
• loss of both–> inducesr tumor formation

Question 4

pRB inactivates

Answer 4

E2F

Question 5

what happens when pRB is phosphorylated by a cyclin-dependent kinase

Answer 5

inactivates it, allowing E2F to transcribe genes for S phase of cell growth

Question 6

loss of pRB results in loss of

Answer 6

regulation of E2F and cell growth is accelerated

Question 7

tumor suppressor for various cancer

Answer 7

p53

Question 8

p53

Answer 8

halts the cell cycle and promotes apoptosis

Question 9

tumor suppressor for retinoblastoma

Answer 9

Rb

Question 10

tumor suppressor for neuroblastoma

Answer 10

NF1

Question 11

tumor suppressor for colon/stomach

Answer 11

APC

Question 12

tumor suppressor for breast cancer

Answer 12

BRCA1

Question 13

upon DNA damage what does p53 do?

Answer 13

induces the production of p21 protein

Question 14

p21

Answer 14

binds to the Cdk/cyclin complexes and halts the cell cycle

Question 15

only one of cell’s two gene copies needed to altered (dominant effect)

Answer 15

oncogenes

Question 16

type of enzyme inhibition where the immediate product of an enzyme reaction binds to the enzyme and inhibits its activity

Answer 16

product inhibition

Question 17

a signal from outside the cell that effects gene expression; tumor call generate many of their own growth signals

Answer 17

signal transduction

Question 18

sis oncogene encodes part of the PDGF, induce signal transduction

Answer 18

altered growth factor

Question 19

mutant epidermal growth factor receptor, constantly stimulate growth, even in absence of EGF; includes ErbB/HER2

Answer 19

altered growth factor receptors

Question 20

explain Ras signaling

Answer 20

• “on” is with GTP
• “off” is with GDP
• GTPase activating protein (GAP) switches it off
• GTP-bound signal transduction to nucleus
• mutant Ras is locked on

Question 21

neurofribroma on skin

Answer 21

NF1

Question 22

neurofibromin protein has a _____ domain and possibly acts through _____

Answer 22

neurofibromin protein has a GAP domain and possibly acts through Ras

Question 23

C-fos and C-jun

Answer 23

transcription factor proteins that stimulate cell growth

Question 24

transcription factor that recruits histone acetyltransferases

Answer 24

Myc

Question 25

present in many cancers and upregulates many genes of cell proliferation

Answer 25

mutant Myc

Question 26

a translocation involving Myc results in its continous expression

Answer 26

Burkitt’s lymphoma

Question 27

DNA virus that can inactivate p53 or Rb

Answer 27

HPV:

• HPV E6–> p53
• HPV E7–> Rb

Question 28

overall cancer is characterized by several features

Answer 28

• evade apoptosis
• self-sufficiency in growth signals
• insensitive to anti-growth signals
• limitless replicative potential

Question 29

one of many parallel pathways needed to convert normal tissue to malignant carcinoma

Answer 29

Familial adenomatous polyposis coli

Question 30

loss of _____ contributes to colon cancer

Answer 30

APC