Part 2

Question 1

gene amplification: double minutes

Answer 1

lots of little pieces amplified

Question 2

gene amplification: homogeneously staining regions

Answer 2

one big piece amplified

Question 3

t(8;14) (q24;q32)

Answer 3

up regulation MYC (growth factor)

in 85% of Burkitt lymphoma

Question 4

t(9,22) (q34;q11)

Answer 4

philadelphia chromosome

in over 95% of chronic myeloid leukemia

Question 5

epigenetic silencing

Answer 5

DNA methylation (at C5)
inhibits transcription due to closed formation

Question 6

hypermethylation

Answer 6

loss of tumor suppressor activity

Question 7

hypomethylation

Answer 7

oncogene activation

Question 8

Tumor suppressor genes

Answer 8

usually missense mutations and truncating mutations

Question 9

oncogenes

Answer 9

usually missense mutations and have mutational hotspots

Question 10

Wnt-signalling

Answer 10

1. in resting cells APC degrades B-catenin bc no growth factors bind to WNT
2. w/ WNT stimulation APC is released from B-catenin
3. B-catenin goes into nucleus and stimulates growth
4. in a tumor w/ mutated APC: WNT signalling not needed bc B-catenin already released from APC

ppl w/ germline APC mutation develop adenomatous coli cancer (40 years, incidence 100%)

E-cadherin also involved

Question 11

Lynch syndrome

Answer 11

germline variant in mismatch repair gene

usually only gives a few polyps

Question 12

MUTYH

Answer 12

= DNA repair gene
repairs damage due to oxidative stress
GC–>TA

Question 13

polymerase n

Answer 13

repairs DNA damage by UV

Question 14

most common causes of ‘spontaneous’ mutations

Answer 14

depurination
deamination (of 5mCytosine = methylated cytosine)