Tumor suppressor gene

What it is

A tumor suppressor gene is a gene that normally restrains cell growth and division, helping prevent cancer. When a tumor suppressor gene is lost or inactivated, this brake on growth is removed, contributing to tumor development. Several tumor suppressor genes are involved in gliomas.

Understanding Tumor suppressor gene

Tumor suppressor genes act as the body's brakes on uncontrolled growth — detecting problems, repairing damage, or stopping division when needed. Cancer can develop when these brakes fail. In gliomas, important tumor suppressors include TP53 (the "guardian of the genome," often mutated in IDH-mutant astrocytomas) and CDKN2A/B (whose loss can raise a tumor's grade). Because cells carry two copies of most genes, both copies often must be lost or inactivated for a tumor suppressor to fail completely — which is why "homozygous deletion" (loss of both copies) is significant. Tumor suppressor genes work opposite to oncogenes (which drive growth). Understanding tumor suppressor genes clarifies how the loss of growth-restraining genes contributes to gliomas.

Why it matters

Understanding tumor suppressor genes helps patients and families see how the loss of growth-restraining genes — like TP53 or CDKN2A/B — contributes to gliomas, complementing the role of overactive oncogenes.