MCM Final - Cancer and Aging

Question 0

neoplasm

Answer 0

tumor (abnormal mass or growth)

Question 1

neoplasia

Answer 1

new growth

Question 2

tumor progression

Answer 2

natural selection and genomic instability occur

Question 3

cancer cells

Answer 3

more heterochromatin

-silenced gene that would normally block division

Question 4

viruses and cancer

Answer 4

15% of human cancer thought to arise from viruses

usually DNA virus

Question 5

proto-oncogene

Answer 5

gain of function can drive a cell toward cancer
-only requires one allele mutation (dominant-like)

“overactivity mutation”

Question 6

tumor supressor gene

Answer 6

act in a recessive manner (loss of function)

need mutations in both alleles (recessive like)

“underactivity mutation”

Question 7

DNA maintenence genes

Answer 7

mutations result in genomic instability

Question 8

two hit hypothesis

Answer 8

involved in the tumor supressor gene

may be a mix of epigenetic and genetic changes

Question 9

what DNA damage from cigarettes?

Answer 9

intercalating agent that results in the bulky lesion
-conjugated ring structure

nucleotide excision repair- repairs bulky lesions

Question 10

benzo [a] pyrine

Answer 10

molecule in tobacco smoke that is a mutagen

- created by cytochrome p450
	- converted into benzo[a]pyrene 7,8-diol

causes intercalation of DNA
-bulky lesion

Question 11

DNA damage from sun exposure?

Answer 11

pyrimidine dimers
-bulky lesions

repaired by nucleotide excision repairs

Question 12

damage from UVA and UVB

Answer 12

UVA oxidative stress

UVB - dimer formation between pyrimidines

Question 13

SNPs

Answer 13

involved in nucleotide excision repairs

-different expression can lead to different rates of this mechanisms in individuals

Question 14

Ras

Answer 14

protooncogene

point mutation affects the hydrolysis of GTP from Ras

constitutively active Ras protein results in mitogenic activation

Question 15

Myc

Answer 15

transcription factor

constitutively expressed

mutations result in cell division with DNA damage

Question 16

which cancer protein acts in a dominant manner?

Answer 16

oncogenes

Question 17

Bcl2

Answer 17

involved in the intrinsic pathway of apoptosis

cytochrome c from mito

Bcl2 family acts on cytochrome c release

Question 18

proapoptotic proteins - oncogen or TS?

Answer 18

tumor supressor

Question 19

anti-apoptotic proteins - oncogene or TS?

Answer 19

oncogene

Question 20

Rb

Answer 20

retinoblastoma
-most common in childhood

supresses activation of S-phase genes

allows cell cycle to continue

Question 21

Li-Fraumeni syndrome

Answer 21

heritable mutation in p53

only one somatic mutation can lead to p53 inactivity
-already have one mutation

Question 22

DNA damage checkpoints

Answer 22

G1 to S, Slow S, and S to M

ATM protein activated when DNA damage present
-initiates the p53 > p21 cascade

Question 23

APC

Answer 23

mutation in this gene leads to familial adenomatous polyposis

autosomal dominant with 100% penetrance

involved in the Wnt pathway (frizzled receptor)

tumor supressor

Question 24

classical adenoma-carcinoma sequence

Answer 24

adenoma - benign

carcinoma - malignant

Question 25

what are the proto-oncogenes and tumor supressors?

Answer 25

proto-oncogenes - Ras Bcl2 Myc

Tumor Supressors - Rb p53 APC

Question 26

Von Hippel Lindau Syndrome

Answer 26

VHL is a tumor suppressor

Question 27

angiogenic switch

Answer 27

induced by hypoxia

Hif1 marked for degradation by VHL (normoxia)

loss of function of VHL - always on Hif1 - lots of angiogenesis

Question 28

warburg effect

Answer 28

hypoxic environment in solid tumor

anaerobic glycolysis to get ATP

Question 29

vessels in tumors?

Answer 29

heterogenous diameter

tortuous - not regular in shape

leaky

Question 30

neuronal cells have high metabolic activity

Answer 30

increase in oxidative damage