Oncogenes

Definition

Oncogenes are mutated forms of genes that normally help cells grow. When these genes become mutated, they can promote uncontrolled cell division and lead to cancer. Oncogenes are critical to understanding cancer development because they play a key role in cell signaling pathways that regulate cell growth and proliferation.

5 Must Know Facts For Your Next Test

1. Oncogenes can result from mutations in proto-oncogenes, which are normal genes involved in cell growth and division.
2. Common mechanisms by which oncogenes exert their effects include gene amplification, chromosomal rearrangements, and point mutations.
3. Examples of well-known oncogenes include RAS, MYC, and HER2, each associated with different types of cancers.
4. The activation of oncogenes often leads to increased cell division and survival, contributing to tumor growth.
5. Targeted therapies have been developed to specifically inhibit the functions of certain oncogenes, showcasing the importance of understanding these genes in cancer treatment.

Review Questions

• How do oncogenes differ from tumor suppressor genes in their role in cancer development?
  • Oncogenes promote cancer development through the activation of pathways that lead to uncontrolled cell division. In contrast, tumor suppressor genes normally function to inhibit cell growth and prevent tumor formation. Mutations in oncogenes result in gain-of-function changes that drive excessive proliferation, while mutations in tumor suppressor genes lead to loss-of-function changes that remove the brakes on cell growth. The interplay between these two types of genes is crucial for understanding the mechanisms behind cancer.
• Discuss the various mechanisms by which oncogenes can become activated and their implications for targeted cancer therapies.
  • Oncogenes can become activated through several mechanisms, including gene amplification, where multiple copies of a gene are produced; chromosomal rearrangements that can lead to the fusion of genes; and point mutations that alter the protein's function. These activations often result in proteins that drive excessive cell division or survival. Understanding these mechanisms has led to the development of targeted therapies that specifically inhibit the function of oncogenic proteins, providing more effective treatment options with potentially fewer side effects compared to traditional chemotherapy.
• Evaluate the impact of oncogene research on our understanding of cancer biology and therapeutic advancements.
  • Research into oncogenes has significantly advanced our understanding of cancer biology by elucidating the genetic changes that drive tumorigenesis. By identifying specific oncogenes associated with various cancers, researchers have been able to develop targeted therapies aimed at these genetic alterations. This shift from one-size-fits-all treatments to personalized medicine has improved patient outcomes and transformed how we approach cancer treatment. Moreover, ongoing research continues to reveal new oncogenic pathways and their roles in resistance to existing therapies, highlighting the importance of continued investigation in this field.

Related terms

tumor suppressor genes: Genes that normally help prevent uncontrolled cell growth. When these genes are mutated or lost, it can lead to tumor formation.

mutations:

Changes in the DNA sequence of a gene that can lead to altered protein function and potentially contribute to cancer development.

carcinogenesis: The process by which normal cells transform into cancer cells, often involving a series of genetic mutations including those in oncogenes.