Shields Down: A cancer-fighting gene declines in old age
As people age, their risk of cancer increases, primarily because cancer-causing damage to DNA accumulates over time. A new study suggests another possible reason for the increased risk. Experiments in mice show that a key tumor-suppressing gene is less active in old age.
The gene, called p53, is one of the most important and thoroughly studied anticancer genes. When a cell’s DNA becomes damaged, p53 orchestrates a response that either repairs the cell or causes it to self-destruct, thus preventing the cell from growing into a tumor. More than half of all tumors in people are estimated to have mutations in p53.