Question

P53 is a tumor suppressor gene: mutations in p53 are seen in more than 50% of all cancers. Which of the following mutations in p53 would likely increase cell division rate, predisposing an individual to cancer? Sort each mutation into the correct bin to identify it as cancer-causing or non-cancer-causing.

a. Nonsense mutation close to the start codon of p53
b. Deletion of the p53 gene
c. Translocation that puts the p53 gene near an active repressor region of DNA
d. Viral insertion of a p53-like gene
e. Methylation of CpG islands near the p53 promoter region
f. Missense mutation that increases the activity of p53
g. Duplication of the p53 gene Cancer-causing Non-cancer-causing

Answer 1

A missense mutation that increases the activity of p53 would likely increase cell division rate, predisposing an individual to cancer.

Step-by-step explanation:

The mutation in p53 that would likely increase cell division rate and predispose an individual to cancer is a missense mutation that increases the activity of p53. This type of mutation leads to a hyperactive p53 protein, which can result in excessive cell cycle arrest and DNA repair, leading to unregulated cell division and the accumulation of mutations.

In contrast, the other mutations listed do not directly increase cell division rate:

• Nonsense mutation close to the start codon of p53 - This mutation would result in a truncated and non-functional p53 protein.
• Deletion of the p53 gene - This mutation would completely eliminate the p53 protein.
• Translocation that puts the p53 gene near an active repressor region of DNA - This mutation may lead to reduced or impaired expression of the p53 gene.
• Viral insertion of a p53-like gene - This mutation may introduce a new gene into the genome but does not directly affect p53 function.
• Methylation of CpG islands near the p53 promoter region - This mutation may result in reduced expression of the p53 gene.
• Duplication of the p53 gene - This mutation would result in an increased amount of p53 protein but does not necessarily increase its activity.