Shemanko lecture 13

Question 1

What are the two principles of cancer biology?

Answer 1

Cancer cells are normal cells that have acquired genetic mutations that enable them to survive and proliferate independently of normal signals
Metastasis is the spread of cancer from where it started

Question 2

What are the three main groups of tumours?

Answer 2

Sarcomas- relatively rare, less than 2%- are solid tumors of connective tissues
leukaemia and lymphomas- are approx 8% of cancers- they arise from blood forming cells and cells of the immune system
carcinomas- are 90% of cancers- originate from epithelial cells

Question 3

What are the four causes of cancer?

Answer 3

Carcinogenic chemicals
Ionizing radiation
Viruses— alter the genome
Ultraviolet light

Question 4

How can viruses cause cancer?

Answer 4

they carry genes from hosts who’s protein products interfere w the cells growth regulating activities

Question 5

Is cancer an inherited disease in most cases?

Answer 5

no

Question 6

What is cancer traces back to?

Answer 6

alternations within specific genes that arise mostly from somatic mutations (not from parents)

Question 7

Inherited mutations in what gene increases risk of breast and ovarian cancer?

Answer 7

BRCA1 and BRCA2 genes

Question 8

Chromosome mis-segregation happens when in the cell cycle?

Answer 8

mitosis

Question 9

What are the 6 hallmarks of cancer?

Answer 9

sustaining proliferative signaling
evading growth suppressors
activation invasion and metastatis
enabling replicative immortality
inducing angiogenesis (formation of new blood vessels)
resisting cell death

Question 10

What is contact inhibition? Do tumour cells have this?

Answer 10

Is the inhibition of cell division in normal cells when they contact a neighbouring cell, form a monolayer as they can’t move over one another. Tumour cells don’t have this.

Question 11

How do cancer cells become growth factor independent?

Answer 11

They proliferate in the absence of growth factors

Question 12

How are cancer cells anchorage independent?

Answer 12

The cancer cells grow in soft agar, normal cells can’t do this because they don’t need adhesion to an ECM- don’t need integrins to bind to it

Question 13

Cancer cells lose what things that connect them ti the basement membrane?

Answer 13

e-cadherins and integrins

Question 14

Mutations in tumour suppressor genes and orotonomcigenes results in what?

Answer 14

the progression of cancer

Question 15

How does cancer digest the basement membrane?

Answer 15

use of matrix metalloproteinases

Question 16

How do you measure metastasis?

Answer 16

Put cells in upper chamber with porous membrane that measure migration
out ecm, cells have to digest and results in an invasion assay as cancer cells digest ecm

Question 17

How do the cancer cells inavde other tissues?

Answer 17

using matrix metallo proteinases

Question 18

How do matrix metallo proteinases assist in the spread of cancer?

Answer 18

they are required to breakdown ecm to break down other ecm to invade and to break down other ecms for extravasion

Question 19

What is zymography and how is it used?

Answer 19

Zymography is used to detect specific matrix-metalloproteinases

Question 20

What cell originate tumours?

Answer 20

can be from cancer stem cells that can become progenitor cells and self renew, or from a tumour initiating cell

Question 21

What are the seven steps of apoptosis?

Answer 21

1. overall shrinkage in volume of the cell and nucleus
2. loss of adhesion to neighbouring cells
3. bleb formation at the cell surface
4. chromatin fragmentation
5. nuclear fragmentation
6. cellular fragmentation
7. phagocytosis of the cell and apoptotic bodies (membrane bound cell fragments)

Question 22

Why is apoptosis important for development?

Answer 22

apoptosis removes the cells that form webbing between our fingers in early development.