Orris

Hey πŸ‘‹πŸ‘‹ Can you provide me a short answer (4 mark) on oncogenes πŸ₯ΊπŸ₯Ί

Reading File
Finding Sources
Reading File
Reading File
Here is a concise 4-mark answer on oncogenes:

Oncogenes

Definition: Oncogenes are abnormal or overactive forms of normal cellular genes (called proto-oncogenes) that promote uncontrolled cell growth and contribute to cancer development. They are usually designated by three-letter abbreviations (e.g., ras, myc) and prefixed with "v-" (viral origin) or "c-" (cellular/chromosomal origin).
How Proto-oncogenes Are Activated: Proto-oncogenes can be converted into oncogenes by four main mechanisms:
  1. Translocation - e.g., abl in CML
  2. Point mutation - e.g., ras in colorectal/lung cancer
  3. Gene amplification - e.g., HER2/neu in breast cancer
  4. Promoter insertion - e.g., c-myc
Over 100 oncogenes have been identified.
Functions of Oncogene Products: Oncogene products may function as:
  • Growth factors (e.g., PDGF)
  • Growth factor receptors (e.g., HER2/EGFR family)
  • Intracellular signal transduction molecules (e.g., RAS)
  • Nuclear transcription factors (e.g., c-myc)
Example - RAS Oncogene: KRAS mutations are found in ~25% of lung adenocarcinomas and are common in pancreatic cancer. Mutations at codons 12, 13, or 61 impair GTPase activity, causing constitutive (always-on) activation of downstream proliferation signals, driving uncontrolled cell division.
Sources: Schwartz's Principles of Surgery, 11th Ed.; Goldman-Cecil Medicine

Thank you πŸ€—πŸ€—

You're welcome! 😊 Good luck with your studies! If you need more short answers, diagrams, or any other topic explained, just ask. You've got this! πŸ’ͺπŸ“š
This is a shared conversation. Sign in to Orris to start your own chat.