What Genes are Mutated in Cancers?
Genes that directly control cellular proliferation (rate of cell birth or cell death)
àOncogenes
àTumor suppressor genes
Genes that do not directly control cell growth, but instead control the rate of mutation
àCaretaker genes or DNA damage-response genes
Oncogenes
Normal genes (regulate cell growth)
1st mutation
(leads to accelerated 
cell division)
1 mutation sufficient for role in cancer development
Tumor Suppressor Genes
Normal genes (prevent cancer)
1st mutation
(susceptible carrier)
2nd mutation or loss (leads to cancer)
DNA Mismatch Repair
Normal DNA
repair
Base pair mismatch
T C T A C |
A G C T G |
Mutation introduced by unrepaired DNA
T C G A C
A G C T G
T C T A C |
A G C T G |
T C T A C
A G A T G
The Cell Cycle
|
|
Oncogenes |
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|
M |
G1 |
|
|
(cell growth) |
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|
(mitosis) |
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|
G2 |
|
|
DNA repair |
S (synthesis) |
||
G0 (resting) |
|||
genes |
REPAIRS |
||
|
AHEAD |
|
|
Tumor suppressor genes