What happens to cells with functional p53 after DNA damage?

The protein p53 plays a crucial role as a tumor suppressor, acting as a guardian of the genome. When DNA damage occurs, functional p53 is activated and triggers a series of cellular responses designed to maintain genomic integrity. One of the primary responses orchestrated by p53 is cell cycle arrest. This pause in the cell cycle allows the cell additional time to activate DNA repair mechanisms before deciding to proceed with division.

If the damage is repairable, cells can fix the DNA before resuming the cell cycle. This effectively prevents the propagation of mutations that might lead to cancer. In the absence of proper p53 function, cells may continue to divide inappropriately despite having damaged DNA, leading to further mutations and an increased risk of tumorigenesis.

In cases where the damage is irreparable, p53 also has the ability to induce programmed cell death, or apoptosis, as a last resort to eliminate the compromised cell. However, the primary immediate response of functional p53 in response to DNA damage is to initiate cell cycle arrest for repair attempts. This process is critical to preventing the development of cancers associated with unregulated cell division and genomic instability.