Cancer

Question 1

Metastatis

Answer 1

Tumors create secondary tumors

Question 2

Genetic evidence for cancer

Answer 2

• Ames test for carcinogenicity
• chromosomal abnormalities
• inheritance (if germ line mutations

Question 3

Knudson’s multi step model of cancer

Answer 3

• requires several mutations, typically somatic mutation following an inherited mutation
• higher possibility of getting cancer if you start with cells that are already mutated (from inheritance)
• proposed that retinoblastoma results from two separate genetic defects, both of which are necessary for cancer to develop

Question 4

sequential mutation

Answer 4

EXAMPLE: colorectal cancer
- multiple gene mutations contribute to progression of cancer

Question 5

What environmental factors contribute to cancers?

Answer 5

• location
• lifestyle
• air quality/density
• pollutants
• diet

also, occupation, radiation, infections, obesity, smoking and drinking

Question 6

What are oncogenes?

Answer 6

stimulatory genes that cause cancer (dominant mutation)
- prototype oncogenes: regular gene responsible for basic cellular functions that is mutated, becoming oncogenes, in germline tissues AND somatic
- can be somatic or germ line, if in germ line, it will be passed on, if in somatic, it will not be

if mutated, they can lead to cancers

Question 7

What are tumor suppresor genes?

Answer 7

mutated recessive-acting inhibitory genes
- loss of heterozygosity (physical loss of a heterozygote–>deletion, leads to cancer because there is no wild type to make up for it)

if mutated, they can lead to cancers

Question 8

What mutations in genes lead to cancers?

Answer 8

• DNA repair genes
• genes regulating telomerase
• genes promoting vascularization and tumor spread
• genes controlling cell division
• microRNAs (degrading gene products) and cancer genes
• oncogenes and tumor-suppresor genes

Question 9

what is telomerase?

Answer 9

lengthens the telomeres, helping with the end replication issue, if mutated, the cell would undergo apoptosis

if a cell doesn’t go through apoptosis, the cell would continue to X

Question 10

What mutations in genes control the cycle of cell division?

Answer 10

• Control of the Cell Cycle: CDKs, cyclins
• G1 to S transition: RB, retinoblastoma
• G2 to M transtition: mitosis promoting factors (MPF)
• Spindle assemnly checkpoint
• singal transduciton pathways: mutations here, there won’t be the correct response to signals, turn on incorrect or too many transcription factors, ras protein

WE NEED HEALTHY CHECKPOINTS

Question 11

What is associated with cancer?

Answer 11

EPIGENETICS
- hypermethylation/hypo
- reversible, not mutation in the sequence

how the environment impacts your genes

Question 12

What structural changes are associated with cancer?

Answer 12

chromosomal instability:
- deletions, inversions, translocations
- EX: reciprocal translocation between 9 and 22 causes chronic myelogenous leukemia
- chromosomal abnormalities

Question 13

karyotypes

Question 14

Can viruses cause cancers?

Answer 14

retroviruses:
through retrotransription, proto-oncogenes can be:
- rearranged, mutated, or strong promoters near them are inserted, changing regulation by attracting transcription factors to that location

EXAMPLE: hepatitis B, HPV, etc