Library · Genetics
Oncogenes and tumor suppressor genes
Make it clearer
Oncogenes and tumor suppressor genes are genes that influence when a cell divides. An oncogene is a mutated gene, meaning one whose instructions have been changed, that can cause cancer. Before it mutated, it had another name, proto-oncogene, and it was a gene that helped regulate normal cell division.
When a mutation turns a proto-oncogene into an oncogene, the cell can start dividing uncontrollably. Some oncogenes are like a car's accelerator stuck to the floor. The tumor suppressor gene is the brake: it keeps division in check. If a mutation inactivates it, the protein it makes is missing or does not work properly, and division can also run out of control.
Classic suppressors are recessive at the cellular level. Each one has two copies, and being recessive means a single healthy copy is enough to keep braking. It is like a car with two brakes: in tumors, both are usually found disabled.
In brief
An oncogene is a mutated proto-oncogene that can cause cancer; the proto-oncogene helps regulate normal cell division, and the tumor suppressor gene keeps division in check.
When a mutation turns a proto-oncogene into an oncogene, the cell can divide uncontrollably; if a mutation inactivates a suppressor, its protein is missing or does not work properly, and division can also run out of control.
Some oncogenes are like a stuck accelerator; the suppressor, like a brake.
Classic suppressors are recessive at the cellular level: tumors usually have both copies inactivated.
Sources (3)
- National Human Genome Research Institute, National Institutes of HealthOncogene, Talking Glossary of Genomic and Genetic Terms, NHGRI
- National Human Genome Research Institute, National Institutes of HealthTumor Suppressor Gene, Talking Glossary of Genomic and Genetic Terms, NHGRI
- National Center for Biotechnology Information, StatPearls PublishingTumor-Suppressor Genes, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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