Several factors contribute to oncogenesis, including genetic mutations, epigenetic modifications, and environmental influences. Some of the key factors are:
1. Proto-oncogenes: These are normal genes that play a role in cell growth and division. When mutated, they become oncogenes that can drive the uncontrolled growth of cells. 2. Tumor Suppressor Genes: These genes normally act as brakes on cell proliferation. Mutations can deactivate these genes, removing the checks on cell growth and leading to cancer. 3. DNA Repair Genes: These genes are responsible for repairing damaged DNA. Mutations can impair DNA repair mechanisms, increasing the likelihood of additional genetic alterations. 4. Epigenetic Changes: These are modifications to DNA and histones that do not change the DNA sequence but can affect gene expression. Epigenetic changes can activate oncogenes or silence tumor suppressor genes. 5. Environmental Factors: Exposure to carcinogens like tobacco smoke, radiation, and certain chemicals can damage DNA and contribute to cancer development.
