Tumor Suppressor Genes Function
Tumor suppressor genes are genes that normally prevent uncontrolled cell growth and division, thereby protecting the body from cancer.
Functions of tumor suppressor genes
Regulate the cell cycle
Stop cells from dividing when they should not.
Example: p53 halts the cell cycle when DNA is damaged.
Promote DNA repair
Detect and help repair damaged DNA before the cell divides.
Induce apoptosis (programmed cell death)
Trigger the death of cells with severe DNA damage to prevent cancer development.
Maintain genomic stability
Prevent accumulation of mutations in the genome.
Key point
Cancer can develop when both copies of a tumor suppressor gene are inactivated or lost (the "two-hit hypothesis"), removing the normal brakes on
cell proliferation.
Examples
TP53 (p53) – "guardian of the genome"
RB1 – regulates the cell cycle
BRCA1 and BRCA2 – involved in DNA repair
In short: Tumor suppressor genes act as the "brakes" of the cell cycle, preventing abnormal cell growth and cancer formation.
