Abstract
It is well known that hyperthermia of 42-43oC shows higher lethal sensitivity to a certain specific cancer cell. This heat treatment does not have an influence on normal tissue very much from experience. This becomes a base of cancer therapy by cancer hyperthermia. However, it is not clear why hyperthermia sensibility is higher in cancer tissue than normal tissue. Researchers have reported several reasons for hyper-lethal sensitivity of cancer cells, such as anoxia, low pH, and deficiency of repair system of heat damage. Our previous results shows that target of hyperthermia is centrosome. There is no difference in heat sensitivity of centrosome between normal and cancer cells. Structural aberration of centrosome induces abnormal division in mitotic period, and the cell that caused abnormal division dies with high frequency. In other words, lethal sensitivity of cells is controlled by the frequency of centrosome aberration when cells are going into mitosis after heat-treatment. On the other hand, we have reported that low dose radiation exposure of a cGy level is not accompanied with derivation of p53 and promotes cellular proliferation potency. By taken together our results, it is expected that a cancer cell increase heat sensitivity than normal cells by combination of low dose radiation and hyperthermia. This time, I will report the possibility of combined treatment of hyperthermia and low dose radiation.
