Hallmarks Of Cancer

Question 1

DNA methylation

Answer 1

Promotor methylation = Silencing = repressed expression
Cystine adjacent to Guanine

Question 2

Epigenetics

Answer 2

Things that change gene expression without changing gene sequence ( factors beyond genetic code)

Question 3

x2 types of genetic damage

Answer 3

Inherited and Aquired

Question 4

Aquired genetic damage examples

Answer 4

chemical, microbes,Radiation, spontaneous mutation

Question 5

Inherited genetic damage

Answer 5

Autosomal dominant + autosomal recessive

Question 6

Histone Acetylation

Answer 6

promotes gene transcription
At lysine residue of histone

Question 7

Carcinogen

Answer 7

Substance or agent that causes cancer
Biological, chemical, physical

Question 8

Biological carcinogen

Answer 8

viruses+ microbes
E-g HPV,EBV, Hep B,Helicobacter Pylori

Question 9

physical carcinogen

Answer 9

Radiation = chromosomal breakage, translocation, mutation
E.g uv, X-ray, nuclear

Question 10

characteristics of cancer cells (Hallmarks of cancer)

Answer 10

Self-sufficient in growth signals, Evade apoptosis,insensitive too anti growth signals, Tissue invasion/ metastasis, sustained angiogenesis

Question 11

Genes which mutation= Tumour x 3

Answer 11

Proto oncogene
Tumour repressor gene
heres involved in DNA repair

Question 12

carcinogenesis

Answer 12

Multi step process = aquire a series of genetic changes

Question 13

self sufficient in growth signals

Answer 13

Synthesise & secrete own growth factors = independent of external signals

Question 14

3 ways to achieve self sufficient growth signals

Answer 14

1. Alteration of extracellular signalling
2. Alter transcellular transducer (receptor) of specific signal
3. Ater intracellular circuit ( signalling proteins)

Question 15

Insensitivity to growth - inhibitory signals (Rb )

Answer 15

Rb unphosphorylated = E2FS active all time = drives cell cycle

Question 16

Transforming Growth factor - b (TGFB )

Answer 16

Growth inhibitor
TGFb receptor mutations / unactivation = cells no longer respond to growth inhibitory signals.

Question 17

How tumours override R-point in mitosis x3

Answer 17

Inactivates TGFb = Less cyclin E
Over-express cyclin E by gene amplification
Inactivates pRb by gene deletion

Question 18

Evasion of Apoptosis

Answer 18

loss of p53= no longer halts cell cycle during stress conditions

Question 19

Limitless replicative potential

Answer 19

Produces more telomerase = ability to Proliferate more
chromosome translocation.

Question 20

Metastasis Steps

Answer 20

Detachment,invasion, intravasation , extravacation, migration

Question 21

metastasis: detachment

Answer 21

reduction in cell adhesion molecules (CAMS) + E.cadherin = decreased adhesion

Question 22

metastasis invasion

Answer 22

Release Proteases in Ecm degrades protein in membrane

Question 23

metastasis intravasation

Answer 23

Tumour cells access arculaction (lymphatic System )

Question 24

metastasis extravasation

Answer 24

vascular cell adhesion molecule 1 (VCAM_1) facilitates binding to vascular wall

Question 25

Sustained angiogenesis

Answer 25

Hypoxia = hypoxia induced Factor (HIF.1) increased vascular endothelial growth factor (VEGF) = formation of new blood vessels

Question 26

spatial+ Temporal Hetrogeneity (tumours)

Answer 26

Spatial = different genetic variation due to region of tumour
Temporal = changes as tumour progresses