Oncogenes are genes that have the potential to cause cancer when mutated or overexpressed. These genes play a crucial role in regulating cell growth, division, and differentiation. When oncogenes are activated, they can promote uncontrolled cell proliferation, leading to the development of cancer. Mutations in oncogenes can occur through various mechanisms, such as point mutations, gene amplification, or chromosomal translocations. Targeting oncogenes has become a key strategy in cancer therapy, as inhibiting their activity can help to slow down or stop the growth of cancer cells.
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Google Gemini AI
14 hours ago
Oncogenes
Definition: Oncogenes are genes that have the potential to transform normal cells into cancer cells. They are mutated or overexpressed versions of normal genes (proto-oncogenes) that play essential roles in cell growth, differentiation, and apoptosis.
Characteristics:
- Dominant: Oncogene mutations are typically dominant, meaning that only one mutated copy of the gene is sufficient to promote cancer development. - Gain-of-function: Oncogene mutations often result in a gain-of-function, where the gene product becomes overactive or acquires new functions. - Hyperactivation: Oncogenes promote cell proliferation, survival, and metastasis by hyperactivating certain cellular pathways, such as growth factor signaling, cell cycle regulation, and DNA repair. - Addiction: Cancer cells become addicted to oncogene signaling and rely on it for their survival and growth.
Proto-Oncogenes:
Proto-oncogenes are normal genes that perform essential functions in cellular processes. They include genes involved in:
Oncogenes can become activated through various mechanisms, including:
- Point mutations: Single-nucleotide changes that alter the protein structure or function. - Deletions or insertions: Loss or gain of genetic material that changes the gene product. - Chromosomal rearrangements: Translocations, deletions, or amplifications that lead to overexpression or deregulation of oncogenes. - Gene amplification: Multiple copies of an oncogene are present in the genome, leading to increased gene expression.
Role in Cancer:
Oncogenes play a critical role in the development and progression of cancer. They:
- Promote uncontrolled cell proliferation - Inhibit cell death (apoptosis) - Enhance cell motility and invasion - Facilitate angiogenesis (blood vessel formation) - Suppress the immune system
Examples:
Common oncogenes include:
- KRAS: Involved in lung cancer, colorectal cancer, and pancreatic cancer - MYC: Associated with leukemia, lymphoma, and breast cancer - EGFR: Overexpressed in lung cancer and head and neck cancer - HER2: Amplified in breast cancer - BRAF: Mutated in melanoma