104. What are proto-oncogenes?
1. They are a type of tumor suppressor genes
2. They stall cancer progression
3. They can become oncogenes
4. They have no relation with cancer progression

Correct Answer:

3. They can become oncogenes

Explanation:

Proto-oncogenes are normal genes that play essential roles in regulating cell growth, differentiation, and survival. Under normal circumstances, they help control the cell cycle and promote healthy cell function. However, when these genes undergo mutations or are overexpressed, they can become oncogenes, which promote cancer development by triggering uncontrolled cell growth. Here’s a breakdown of the options:

1. Tumor suppressor genes:
   Tumor suppressor genes are different from proto-oncogenes. While proto-oncogenes promote growth, tumor suppressor genes inhibit cell division and promote repair mechanisms to prevent cancer. A mutation in tumor suppressor genes, like p53, leads to cancer progression.

2. Stalling cancer progression:
   Proto-oncogenes do not stall cancer progression; they can contribute to it when they become oncogenes. Oncogenes, when mutated, are responsible for driving tumor growth.

3. Becoming oncogenes:
   This is the correct answer. When proto-oncogenes mutate or become overactive, they turn into oncogenes, which contribute to cancer by promoting abnormal cell proliferation. This process can result from mutations such as gene amplification or chromosomal translocation.

4. No relation to cancer progression:
   This statement is false. Proto-oncogenes are directly involved in cancer progression if they mutate to become oncogenes. Therefore, they have a significant relationship with cancer.

Conclusion:

Proto-oncogenes are normal genes that, under certain circumstances, can become oncogenes through mutations. These oncogenes then play a crucial role in driving cancer progression.

Correct Answer: 3. They can become oncogenes