Oncogene

Definition

An oncogene is a gene that has the potential to cause cancer when mutated or expressed at high levels. Oncogenes are involved in the regulation of cell growth, division, and survival, and their dysregulation can lead to the uncontrolled proliferation of cells, a hallmark of cancer.

5 Must Know Facts For Your Next Test

1. Oncogenes can be activated through various mechanisms, such as point mutations, gene amplification, chromosomal rearrangements, and viral integration.
2. Oncogenes typically promote cell proliferation, inhibit apoptosis, and induce angiogenesis, all of which contribute to the development and progression of cancer.
3. Examples of well-known oncogenes include RAS, MYC, HER2/ERBB2, and BRAF, which are frequently mutated in various types of cancer.
4. Oncogenes can act in a dominant fashion, meaning that a single mutated allele is sufficient to drive the transformation of a normal cell into a cancer cell.
5. Targeting oncogenes and their signaling pathways is a major focus of cancer therapy, as it can disrupt the fundamental mechanisms that drive tumor growth and survival.

Review Questions

• Explain the role of oncogenes in the development of cancer.
  • Oncogenes are genes that, when mutated or overexpressed, can drive the transformation of normal cells into cancer cells. These genes typically promote uncontrolled cell proliferation, inhibit apoptosis, and induce angiogenesis, all of which are hallmarks of cancer. Oncogenes can be activated through various mechanisms, such as point mutations, gene amplification, chromosomal rearrangements, and viral integration. Examples of well-known oncogenes include RAS, MYC, HER2/ERBB2, and BRAF, which are frequently mutated in various types of cancer. Targeting oncogenes and their signaling pathways is a major focus of cancer therapy, as it can disrupt the fundamental mechanisms that drive tumor growth and survival.
• Describe the relationship between oncogenes and tumor suppressor genes in the context of cancer development.
  • Oncogenes and tumor suppressor genes work in a delicate balance to regulate cell growth and division. Oncogenes promote cell proliferation, inhibit apoptosis, and induce angiogenesis, leading to the uncontrolled growth of cells and the development of cancer. In contrast, tumor suppressor genes normally act to inhibit cell division, promote apoptosis, and maintain genomic stability. Mutations or inactivation of tumor suppressor genes, such as TP53 and RB1, can contribute to the development of cancer by removing the brakes on cell division. The interplay between the dysregulation of oncogenes and the loss of tumor suppressor gene function is a key driver of carcinogenesis, the process by which normal cells are transformed into cancer cells through genetic and epigenetic changes.
• Evaluate the importance of understanding oncogenes in the context of cancer therapy and personalized medicine.
  • Understanding the role of oncogenes in cancer is crucial for the development of effective cancer therapies and the implementation of personalized medicine approaches. Oncogenes are often the key drivers of tumor growth and survival, making them attractive targets for cancer therapy. By targeting the specific oncogenes that are mutated or overexpressed in a patient's cancer, healthcare providers can design more personalized and effective treatment strategies. This has led to the development of targeted therapies, such as tyrosine kinase inhibitors and monoclonal antibodies, that selectively inhibit the activity of oncoproteins. Additionally, the identification of oncogene mutations can help guide the selection of appropriate treatments and predict the response to therapy. This knowledge is essential for the practice of personalized medicine, where treatment decisions are tailored to the unique genetic and molecular profile of an individual's cancer, ultimately improving patient outcomes and reducing the risk of adverse effects.

Related terms

Tumor Suppressor Gene: Genes that normally act to inhibit cell division, promote apoptosis, and maintain genomic stability. Mutations in tumor suppressor genes can contribute to the development of cancer.

Proto-Oncogene: The normal, non-mutated version of a gene that can become an oncogene when it is mutated or overexpressed.

Carcinogenesis: The process by which normal cells are transformed into cancer cells through genetic and epigenetic changes.