tumor suppressor gene
A gene that normally prevents uncontrolled cell growth and whose loss or inactivation contributes to cancer development.
Full Definition
Tumor suppressor genes are normal genes that regulate cell division and prevent tumor formation when functioning properly. These genes encode proteins that control cell cycle checkpoints, DNA repair mechanisms, and apoptosis pathways. When tumor suppressor genes are inactivated through mutations, deletions, or epigenetic silencing, cells lose critical growth control mechanisms, leading to malignant transformation. Classic examples include TP53 (the 'guardian of the genome'), RB1 (retinoblastoma gene), and BRCA1/BRCA2 (associated with hereditary breast and ovarian cancers).
Usage
Usage note: Always specify the gene name when discussing specific tumor suppressors (e.g., TP53 tumor suppressor gene).
In Context
- "Germline mutations in the BRCA1 tumor suppressor gene significantly increase breast and ovarian cancer risk." — Genetic counseling report
- "Loss of heterozygosity at the TP53 tumor suppressor gene locus was observed in 60% of the analyzed specimens." — Molecular genetics study