Biology of Cancer (REVISE AND ADD A LOT - SECOND HALF)

Question 1

Key Feature of Cancer

Answer 1

The ability to spread

Question 2

What is a cancer cell

Answer 2

Divides continuously & inappropriately
No longer maintains its original function

at least some of the cancer cells must be able to spread to other sites

Question 3

Features of Cancer

Answer 3

Proliferation independently of signals (must also avoid signals that tell them to stop)

Immortality - avoiding senescence/telomere shortening

Avoiding apoptosis

Angiogenesis - must be fed

Metastasis and ability to proliferate in a new environment

Question 4

How does cancer arise

Answer 4

Sporadic (95%) or Genetic Predisposition

REVISE?

Question 5

What differentiates cancer from other genetic diseases

Answer 5

Mutations in a single cell can cause a life threatening disease

Question 6

How many sporadic mutation diseases are there

Answer 6

One - Cancer

Question 7

How long does sporadic cancer take to develop and why

Answer 7

Decades, because a series of mutations must accumulate in a cell for it to become a successful cancer

Question 8

How does familial cancer grow

Answer 8

A mutation is already present, and has a selective advantage, dividing more and accumulating more mutations that lead to more selective advantages until a malignant tumour manages to develop

Question 9

Driver and Passenger Mutations

Answer 9

Driver mutations - Mutatiosn that affect the function of genes which regulate proliferation, apoptosis, immortality etc. (cancer causing)

Passenger mutations - All other mutations that are not relevant to the promotion of cancer

Question 10

Classes of genes that are targets for driver mutations

Answer 10

Oncogenes and Tumour Suppressor Genes

Question 11

Oncogenes

Answer 11

Genes that promote cell proliferation

Gain of function mutations in cancer

Question 12

Tumour Suppressor genes

Answer 12

Inhibit events leading to cancer

Loss of function mutations in cancer

Question 13

Proto-oncogenes vs Oncogenes

Answer 13

Proto-oncogenes are the normal genes and oncogenes are those that are mutated

Question 14

Checkpoints that are well characterised in the cell cycle

Answer 14

Restriction point in G1 phase (tells cells to either proliferate or not)

DNA Damage checkpoints in late G1 & G2

Metaphase checkpoint

Question 15

Which regulatory checkpoint of the cell cycle is targeted by oncogenes

Answer 15

Restriction point in G1

Question 16

Quiescence G0

Answer 16

A cell enters G0 and stops dividing, but this process is reversible

Question 17

Immortality of a cancer

Answer 17

Two processes play a role in the intrinsic limit in the number of times a cell lineage may divide

Senescence - Cells in G0, don’t proliferate and this is irreversible
Apoptosis

Both processes severely restrict tumour growth and must be overcome to develop cancer

Question 18

Sesescence

Answer 18

REVISE MINORLY

Question 19

P53 Protein

Answer 19

A protein that detects telomeres getting too short and leads to senescence when they get to a certain shortness

All cancers must at some point overcome this protein and have a mutation in it

Question 20

Cell in crisis

Answer 20

Damage accumulates in the telomeres that become too short

Question 21

REVISE REST OF LECTURE, NOT LONG, ONLY LIKE 15 MINS