Question

Please describe one well-studied example of a tumor suppressor gene, and highlight its normal function and how it might play a role in cancer.

Answer 1

Tumor suppressor genes are the genes that regulate cell cycle during the normal cell development.
The mutation of this gene causes the cell to undergo uncontrollable division leading to the formation of tumors.
Examples include p53, BCL2, pRB, etc.

p53 is a tumor suppressor gene that encodes for a protein known as p53 which protects the genome of the cell.
This protein is mainly involved in apoptosis, DNA repair, transcription and maintaining cell cycle. This protein mainly prevents tumor formation and functions as a tumor suppressor. In normal cells, p53 is in the inactive state, when there is a
damage then p53 gets dissociated with mdm2 complex and gets activated and induces cell cycle arrest and either
repair the cell or induces apoptosis.
If p53 is mutated, then whenever a cell undergoes damage, the p53 does not perform its function.
As a result, the cells might divide abnormally without undergoing repair or apoptosis .

The accumulated effect leads to the development of the tumor.