Oncogenes and Tumor Suppressor Genes
Start with the big picture
Proto-oncogenes normally support cell growth, but gain-of-function changes in a single allele can turn them into oncogenes that promote autonomous proliferation. Such changes may involve mutations, amplification, or chromosomal rearrangements, affecting proteins such as receptor tyrosine kinases, RAS, BRAF, MYC, and cell-cycle regulators. By contrast, tumor suppressor genes normally limit growth, support DNA repair, or promote cell death; loss of function in both alleles can remove these controls. Examples include TP53, RB1, APC, BRCA1/2, and PTEN. The lesson uses gene–pathway relationships and clinical associations to distinguish these mechanisms and show how alterations in growth signaling and cellular safeguards contribute to cancer.
What you'll learn
- Distinguish oncogenes from tumor suppressor genes by their normal roles and mutation effects.
- Explain how mutations, amplification, and chromosomal rearrangements can activate oncogenes.
- Identify major oncogenic protein classes, including kinases, GTPases, transcription factors, and cell-cycle regulators.
- Relate selected tumor suppressor genes to their functions and associated conditions.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
