Influence of p53 expression on radiosensitivity of human normal and tumor cells

The radiosensitivity of normal human fibroblasts is p53 dependent and associated with the loss of cells from the cycling population as the result of an irreversible G1 arrest; cells lacking normal p53 function show no arrest and are more radioresistant. Under conditions in which the repair of potentially lethal radiation damage is facilitated, the fraction of cells arrested in G1 is reduced and survival is enhanced. The response of human tumor cells differs significantly. The radiation-induced G1 arrest is minimal or absent in p53⁺ tumor cells, and loss of normal p53 function has no consistent effect on their radiosensitivity. These results suggest that p53 status may not be a useful predictive marker for the response of human solid tumors to radiation therapy.

Duke Scholars

Author Chuan-Yuan Li Dermatology