The role of the p53 molecule in cancer therapies with radiation and/or hyperthermia.

In recent years, cancer-related genes have been analyzed as predictive indicators for cancer therapies. Among those genes, the gene product of a tumor suppressor gene p53 plays an important role in cancer therapy, because the p53 molecule induces cell-cycle arrest, apoptosis and depression of DNA repair after cancer therapies such as radiation, hyperthermia and anti-cancer agents. An abnormality of the p53 gene might introduce low efficiency in their cancer therapies. Mutations of p53 are observed at a high frequency in human tumors, and are recognized in about half of all malignant tumors in human. In the both systems of a human cell culture and their transplanted tumor, the sensitivities to radiation, heat and anti-cancer agents were observed in wild-type p53 cells, but not in mutated or deleted p53 cells. In this review, we discuss the p53 activation signaling pathways through the modification of p53 molecules such as phosphorylation after radiation and/or hyperthermia treatments.