Question

How does inactivation of p53 promote cancer?

Loss of Cell Cycle Regulation:

Impaired DNA Repair:

Apoptosis Suppression:

Genomic Instability:

Answer 1

The loss of p53 function promotes cancer through loss of cell cycle regulation, impaired DNA repair, apoptosis suppression, and genomic instability.

Step-by-step explanation:

The loss of p53 function in cells promotes cancer through several mechanisms:

1. Loss of Cell Cycle Regulation: Mutations in p53 may result in the loss of its ability to trigger the production of a protein called p21, which helps block the activation of proteins that drive cell division. Without p21, the G1 checkpoint is compromised, and the cell cycle proceeds directly from G1 to S, leading to uncontrolled cell division and tumor growth.
2. Impaired DNA Repair: Normally, p53 monitors DNA damage and triggers repair mechanisms. Mutated p53 proteins may lose their ability to initiate DNA repair, leading to the accumulation of mutations and genomic instability, which can promote cancer.
3. Apoptosis Suppression: p53 can also initiate apoptosis, a process of programmed cell death, if DNA damage is severe and cannot be repaired. Mutations in p53 can result in abnormal p53 proteins that fail to activate apoptosis, allowing damaged cells to survive and contribute to tumor formation.
4. Genomic Instability: The loss of p53 function and impaired DNA repair can lead to genomic instability, which refers to an increased rate of mutations in the DNA. Genomic instability can accelerate the accumulation of mutations in oncogenes and tumor suppressor genes, further promoting tumor growth and progression.