What is a consequence of losing both copies of the p53 gene in cancer cells?

The loss of both copies of the p53 gene in cancer cells leads to unregulated cell proliferation. The p53 protein is a crucial tumor suppressor that plays a significant role in cell cycle regulation, DNA repair, and apoptosis (programmed cell death). When p53 is functional, it can activate DNA repair mechanisms, halt the cell cycle to allow for repairs, and induce apoptosis if the damage is irreparable.

However, when both copies of the p53 gene are lost or mutated, these regulatory functions are impaired. This results in a failure to control the cell cycle, allowing cells to divide uncontrollably. Consequently, the lack of p53 function leads to the accumulation of genetic mutations and promotes tumorigenesis, contributing to the development and progression of cancer.

In summary, the absence of p53 stops the normal checks and balances that prevent excessive cell division, resulting in a heightened risk of cancer development through unregulated cell proliferation.