An oncogene is a mutated gene that can potentially cause cancer. Before mutation, it's known as a proto-oncogene and plays a crucial role in normal cell division.
Understanding Oncogenes
Oncogenes are essentially genes that have gone wrong. To fully grasp what they are, let's break it down:
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Proto-oncogenes: These are normal genes that help regulate cell growth and differentiation. Think of them as the "go" signals for cell division.
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Mutation: When a proto-oncogene mutates, it can become an oncogene. This mutation often results in the gene being overly active or producing too much of a protein, constantly signaling the cell to divide, even when it shouldn't.
Oncogenes: A Closer Look
| Feature | Description |
|---|---|
| Definition | A mutated gene with the potential to cause cancer. |
| Origin | Arises from a mutation in a proto-oncogene. |
| Function | Contributes to uncontrolled cell growth and division. |
| Proto-oncogene | Normal gene involved in regulating cell division; the precursor to an oncogene. |
From Proto-oncogene to Oncogene: What Causes the Change?
Several factors can cause a proto-oncogene to mutate into an oncogene:
- Genetic Mutations: Errors during DNA replication can lead to changes in the gene's sequence.
- Chromosomal Abnormalities: Rearrangements or duplications of chromosomes can activate proto-oncogenes.
- Viral Infections: Some viruses insert their genetic material into a cell's DNA, potentially disrupting proto-oncogenes.
- Environmental Factors: Exposure to carcinogens (cancer-causing substances) can damage DNA and lead to mutations.
Examples of Oncogenes
While there are many different oncogenes, some well-known examples include:
- MYC: Involved in cell growth, proliferation, and differentiation.
- RAS: A family of genes involved in cell signaling pathways.
- ERBB2 (HER2): A receptor tyrosine kinase involved in cell growth and survival.
The Role of Oncogenes in Cancer Development
Oncogenes contribute to cancer development by disrupting the normal balance of cell growth and division. Because oncogenes promote uncontrolled cell growth and division, they can lead to the formation of tumors and ultimately, cancer.
