Oncogenes

Definition

Oncogenes are mutated versions of normal genes, known as proto-oncogenes, that promote cell division and growth. When these genes become activated due to mutations, they can lead to uncontrolled cell proliferation, contributing to the development of cancer. Oncogenes play a crucial role in the regulation of the cell cycle and apoptosis, influencing how cells respond to various growth signals.

5 Must Know Facts For Your Next Test

1. Oncogenes can result from various types of mutations, including point mutations, deletions, or amplifications that enhance their activity or expression.
2. Common examples of oncogenes include RAS, MYC, and HER2, which are often implicated in specific types of cancers.
3. The activation of oncogenes can disrupt normal cell signaling pathways, leading to aberrant cell behavior and evasion of apoptosis.
4. Oncogenes are often identified through their ability to transform normal cells into cancerous cells when introduced into a non-cancerous host.
5. Targeted therapies aimed at inhibiting the activity of oncogenes are being developed as promising cancer treatments.

Review Questions

• How do mutations in proto-oncogenes lead to the formation of oncogenes and contribute to cancer development?
  • Mutations in proto-oncogenes can cause them to become oncogenes by altering their function, often resulting in increased activity or expression. This leads to uncontrolled cell division and growth, overriding normal regulatory mechanisms in the cell cycle. The transition from proto-oncogene to oncogene is a key event in cancer development, as these mutations allow cells to proliferate excessively and evade apoptosis.
• Discuss the relationship between oncogenes and tumor suppressor genes in the context of cell cycle regulation.
  • Oncogenes and tumor suppressor genes work together to maintain a balance in cell cycle regulation. While oncogenes promote cell division and growth, tumor suppressor genes act as brakes that inhibit uncontrolled proliferation. Mutations in either type of gene can disrupt this balance, leading to unchecked cellular growth and the potential development of tumors. The interplay between these two classes of genes is critical for understanding how cancer develops.
• Evaluate the impact of targeted therapies on oncogene-driven cancers and their role in future cancer treatment strategies.
  • Targeted therapies designed to inhibit specific oncogenes have shown promise in treating cancers driven by these mutations. By focusing on the unique molecular characteristics of tumor cells, these therapies can minimize damage to normal cells and improve treatment efficacy. As research continues to uncover new oncogenes and their functions, personalized medicine approaches will likely play a significant role in tailoring treatment strategies for individual patients, potentially leading to better outcomes in oncology.

Related terms

proto-oncogenes: Normal genes that encode proteins responsible for regulating cell growth and division; when mutated, they can become oncogenes.

tumor suppressor genes:

Genes that help regulate cell division and promote apoptosis; mutations in these genes can lead to uncontrolled cell growth and cancer.

apoptosis:

A programmed cell death process that eliminates damaged or unwanted cells; its regulation is vital for maintaining healthy tissue homeostasis.