Heat-induced p53-dependent signal transduction and its role in hyperthermic cancer therapy

A tumour suppressor gene product, p53, is well known to be activated by genotoxic stress such as radiation and DNA damaging agents. Recently, it has been found that non-genotoxic physiological stresses such as heat, cold and low pH also activate p53, which regulates the expression of downstream genes. p53 was found to contribute to heat sensitivity through Bax-mediated apoptosis via activation of caspase-3 in the human cancer cells. This study reviews heat-induced p53-dependent signal transduction and heat sensitivity via a p53-regulated pathway for apoptosis in human cancer cells with identical genetic backgrounds except for p53 status. Furthermore, based on recent reports, it is proposed that p53 status could be a useful indicator in predictive assays for hyperthermic cancer therapy. Hyperthermia treatment based on such predictive assays might improve the outcome and efficiency of cancer therapy in the future. It is further proposed that manipulation of mp53 by glycerol as a chemical chaperone may provide a new cancer therapy for patients with mp53-tumours.