Oncogenes and tumor suppressor genes play important roles in cancer, helping us understand how it develops. They work against each other in a complicated way.
Oncogenes:
- What They Are: Oncogenes are bad versions of normal genes called proto-oncogenes. They help cells grow and survive.
- How They Work: When these genes change (mutate), they can become too active. This means cells can divide wildly and out of control.
- Important Facts:
- About 15% of human cancers are linked to certain oncogenes.
- For example, RAS mutations are found in around 30% of all cancers.
- Another example is HER2/neu, which is seen more in 20-30% of breast cancers.
Tumor Suppressor Genes:
- What They Are: Tumor suppressor genes (TSGs) usually stop cells from dividing too much and help keep our DNA stable.
- How They Work: If these genes are mutated or deleted, they can’t do their job. This can lead to cancer.
- Important Facts:
- TP53 (also known as p53) mutations are found in more than 50% of human tumors.
- Changes in RB1 (Retinoblastoma gene) are linked to hereditary retinoblastoma and other cancers.
How They Work Together:
- Finding Balance: Cancer often happens when there’s a problem with both oncogenes and tumor suppressor genes. When oncogenes become active and tumor suppressor genes stop working, it can lead to cancer.
- Two-Hit Hypothesis: This idea suggests that both parts of a tumor suppressor gene must be damaged (or "hit") to help cancer grow. This shows how important it is for tumor suppressor genes to stop working alongside oncogenes becoming too active.
Knowing how oncogenes and tumor suppressor genes interact is key to creating better treatments for cancer. This understanding can lead to more targeted therapies and improve cancer treatment strategies.