Oncogenes

Question 1

oncogene

Answer 1

cancer-inducing gene; can transform cells

Question 2

oncoprotein

Answer 2

protein product of an oncogene

Question 3

tumor suppressor gene

Answer 3

a gene whose partial or complete inactivation increases likelihood of cancer development

Question 4

two sources of oncogenes

Answer 4

viral infection and cellular

Question 5

retroviral oncogenes

Answer 5

stolen from host; RSV

Question 6

human tumor virus oncogenes

Answer 6

evolved as part of virus

Question 7

rous sarcome virus

Answer 7

src gene

Question 8

spontaneous point mutation of proto-oncogene

Answer 8

glycine to valine causes Ras to become an oncogene by inhibiting GAP activity –> will always be on

Question 9

mutation of regulatory sequence (telomerase)

Answer 9

promoter mutation of hTERT causing increased expression –> more telomerase means cells do not die

Question 10

gene amplification of proto-oncogenes

Answer 10

erbB2/HER2 duplications linked to cancer

Question 11

homogeneously staining region

Answer 11

tandem arrays of myc gene

Question 12

myc-myc or myc-max

Answer 12

activates transcription of genes encoding growth-promoting factors (cyclin D and E2F)

Question 13

myc-miz/mxd

Answer 13

represses transcription of genes encoding cell cycle inhibitors (p15, p21, p27)

Question 14

Burkitt’s lymphoma

Answer 14

myc on chromosome 8 translocates to IgH on chromosome 14 –> myc expression is now being driven as if it were an antibody

Question 15

HMGA2

Answer 15

component of chromatin that facilitates DNA architectural changes at promoter regions –> negatively regulated by Let-7

Question 16

HMGA-2 mutation

Answer 16

Let-7 cannot bind to repress, causing it to now act as an oncoprotein

Question 17

philadelphia chromosome

Answer 17

translocation between chromosome 9 and 22 causes chronic myeloid leukemia

Question 18

philadelphia chromosome effect

Answer 18

Bcr-Abl fusion results in a constitutively active kinase

Question 19

viral causes of cancer in humans

Answer 19

HPV and HepB/C

Question 20

E7 of HPV

Answer 20

inactivates pRb

Question 21

E6 of HPV

Answer 21

inactivates p53

Question 22

E5 of HPV

Answer 22

increases EGFR

Question 23

tax oncoprotein

Answer 23

HTLV; activates NF-kappaB which induces pro-survival genes