Question

The event(s) that lead(s) to inactivation of tumor suppressor genes in cancer cells is(are)

• A. gene amplification
• B. promoter methylation
• C. loss of heterozygosity
• D. histone acetylation

Hint:

- Tumor suppressor gene inactivation often involves epigenetic changes such as promoter methylation or genetic alterations like loss of heterozygosity.
- Gene amplification and histone acetylation are generally associated with oncogenes, not tumor suppressor genes.

Answer 1

The Correct Option is B, C

Step 1: Tumor suppressor genes normally protect against cancer by regulating cell growth. Their inactivation is a common event in cancer.
Step 2: The inactivation of tumor suppressor genes occurs through several mechanisms:
- Gene amplification (A) usually leads to the overexpression of oncogenes, not inactivation of tumor suppressor genes.
- Promoter methylation (B) causes gene silencing by preventing transcription, thus inactivating the tumor suppressor gene.
- Loss of heterozygosity (C) occurs when one allele of a tumor suppressor gene is lost or mutated, leading to inactivation.
- Histone acetylation (D) generally activates gene expression and is not associated with tumor suppressor gene inactivation.
Final Answer: The correct events are promoter methylation and loss of heterozygosity.
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