Oncogenes
Genes that, when mutated or overexpressed, have the potential to cause cancer by promoting cell growth and survival while inhibiting cell death mechanisms.
Oncogenes
Oncogenes are genes that have the potential to cause cancer when they function abnormally. Originally normal genes called proto-oncogenes, they can transform into cancer-promoting agents through various molecular alterations.
Origins and Discovery
The study of oncogenes began in the 1970s with research into retroviruses and their ability to cause tumors. Scientists discovered that certain viral genes could transform normal cells into cancerous ones. This led to the revolutionary understanding that our own cellular genes, when altered, could drive cancer development.
Mechanisms of Activation
Oncogenes can become activated through several mechanisms:
- Point Mutations that change protein function
- Gene amplification leading to overexpression
- Chromosomal rearrangements creating fusion proteins
- Epigenetic modifications affecting gene expression
Major Categories
Growth Factor-Related
- Growth Factors and their receptors (e.g., HER2/neu)
- Signal transduction proteins (e.g., RAS family)
Cell Cycle Regulators
- Cyclins and cell cycle regulatory proteins
- Transcription factors affecting cell division
Survival Signaling
- Proteins inhibiting apoptosis
- Cellular stress response mediators
Clinical Significance
Understanding oncogenes has revolutionized cancer treatment approaches:
- Targeted therapies designed to inhibit specific oncoproteins
- Diagnostic markers for cancer classification
- Prognostic indicators for disease progression
Regulation and Control
Cells possess multiple safeguards against oncogene activation:
- tumor suppressor genes that counteract oncogenic signals
- DNA repair mechanisms
- cellular senescence pathways
Future Directions
Current research focuses on:
- Identifying new oncogenic pathways
- Developing more effective targeted therapies
- Understanding resistance mechanisms
- Exploring combinations of treatments
The study of oncogenes continues to be central to our understanding of cancer biology and the development of more effective treatments for various types of cancer.
Related Disease Processes
Oncogenes play crucial roles in many cancers, including:
Their activity often intersects with other cellular processes such as metabolism and inflammation, creating complex networks of disease progression.