Lecture 21 - Cancer

Question 1

important epithelial cancer types

Answer 1

breast
colon
prostate

Question 2

important examples of non epithelial cells

Answer 2

melanoma
all the blood ones
osteosarcoma

Question 3

what is a carcinoma

Answer 3

tumours from epithelial cells

Question 4

what are adenomas and adenocarcinomas

Answer 4

tumours arising from secretory epithelial cells
adenomas are benign
the other is malignant

Question 5

why is cancer more prev in older people

Answer 5

is a multi step process
so it develops over decades

Question 6

4what is the process that cancer follows

Answer 6

normal epithelium
mutation causes hyperplastic epithelium
early to intermediate to late adenoma
then turns into carcinoma
finally, invasion and metastasis

Question 7

what is metastasis

Answer 7

spread of cancer to other places

Question 8

4 of the hallmarks of cancer

Answer 8

• sustained proliferative signalling
• evading growth suppressors
• resisting cell death
• genome onstbaility and mutation

Question 9

what genes need to be mutated to cause cancer

Answer 9

oncogenes
tumour suppressor genes

Question 10

how do mutations disrupt tissue homeostasis

Answer 10

alters gene expression
dysfunctional protein networks
abnormal cell function
loss of tissue homeostasis

Question 11

what is rous sarcoma virus

Answer 11

a retrovirus
causes cancer
- infected cells will hyperproliferate

Question 12

how is RSV different from other retrovirus

Answer 12

RSV has an extra gene
v-src

Question 13

what genes do retroviruses have that make it so they can inflitrate cells

Answer 13

gag
pol
env

Question 14

what is v-src cellular coutnerpart

Answer 14

c-src
cancer causing gene

Question 15

what is src

Answer 15

non receptor tyrosine kinase
activating it will stimulate cells to enter the cell cycle

Question 16

what is ras

Answer 16

a viral oncogene and a cellular cancer causing gene if mutated

Question 17

what is the ras mutation that causes signalling pathways to be constantly on

Answer 17

Ras G12V
only one allele needs to be mutated
causes inactivated of RASability to inactivate itself

Question 18

what are types of oncogenic mutations

Answer 18

• mutation in coding sequence
• gene cmplification
• chromosome rearrangement
  (either causing overexpression or fusion protein with a new function

Question 19

what are the 2 types of retinoblastoma

Answer 19

• sporadic
  no family history, only one eye, low risk of other tumours
• familial
  vice vers

Question 20

what gene needs to be mutateed to cause retinoblastoma

Answer 20

Rb
and both copies

Question 21

what happens when Rb mutated

Answer 21

can’t inhibit E2F as usual
and so E2F is active
and drives entry into S phase in absence of mitogens

Question 22

what mutated gene causes neurofibromatosis

Answer 22

NF1 gene
NF1 is a tumour surpressor
and if lost, Ras is always active

Question 23

what does wnt do

Answer 23

wnt is a mitogen
that when bound, it inhibits degraation of B catenin
so b catenin can go into nucleus and stim production of cyc D

Question 24

what complex phosphorylates B catenin and subsequently tags it for degradation

Answer 24

GSK-3B, APC, B catenin comlpex

Question 25

what 2 things can be mutated in wnt pathway that cause cancer

Answer 25

APC - a tumour supressor
B-catenin - an oncogene

Question 26

what type of cancer is caused when wnt mutated

Answer 26

colon cancer

Question 27

what is TGF-B signalling

Answer 27

acts as inhibitory ligand
so if its removed, then process not inhibited