Cancer biology

Question 1

clonal evolution

Answer 1

accumulation of mutations within cells, allowing the evolution of cancer through multiple generations.

Question 2

sustaining proliferative signallin

Answer 2

Cancer cells reduce their dependence on growth signals by

• production of their own extracellular growth factor signals
• overexpression of growth factor receptors
• alterations to intracellular components of signalling pathways.

Question 3

evading growth suppressors

Answer 3

cancer cels become insensitive to antigrowth signals.

disruption to the tumour suppresor genes.

Question 4

how does retinoblastoma evade growth signals

Answer 4

retinobastoma protein pathway prevents inappropriate transition from G1 to S at the G1 checkoint. in retinoblastoma the pRB is damaged, allowing the cell to divide uncontrollably.

Question 5

Li-fraumeni syndrome

Answer 5

p53 mutations- high frequency of rare cancers.

Question 6

angiogenesis mediator

Answer 6

VGEF
FGF
PDGF

Question 7

First cells involved in metastasis

Answer 7

Pioneer cells

Question 8

epithelial-mesenchymal transition

Answer 8

allows transport of cancer cells around the body- allowing metastasis

Question 9

Epithelial cell properties:

Answer 9

Cell polarity 
cell adhesion 
stationary 
high level of e cadherin 
low level of N cadherin

Question 10

Mesenchymal cell properties

Answer 10

no cell polarity 
no cell adhesion 
ability to migrate and invade 
low level of e cadherin 
high level of N cadherin

Question 11

replicative immortality

Answer 11

hijacking telomeres so they don’t shorten

Question 12

telomeres properties

Answer 12

tandem hexanucleotide repeats, get shorter with each division. enables hayflick limit

Question 13

hayflick limit

Answer 13

40-60 divisions

Question 14

resisting cell death

Answer 14

resist apoptosis

Question 15

deregulating cellular energetics

Answer 15

shift from mitochondrial oxidative phosphorylation to cytoplasmic glycolysis due to increased energy demand and decreased oxygen supply.

Question 16

Warburg effect

Answer 16

The Warburg effect is the phenomenon in which cancer cells produce additional energy through increased oxygen-dependent glycolysis followed by lactic acid fermentation with secretion of lactate.

Question 17

Mechanisms for increased metabolism

Answer 17

increased anerobic respiration

upregulation of GLUT1 transporter

Question 18

How does a PET scan work

Answer 18

using radiolabelled glucose (FDG) as tracer dye