大腸癌におけるレーザー温熱療法(レーザーサーミア)の検討

Abstract

In order to investigate the influence of Nd: YAG laser on hyperthermia in cultured colonic cancer cells (HT 29), we performed flow cytometric DNAanalysis. HT 29 cells were cultured in 24-well dishes in RPMI 1640 medium supplemented with 10% fetal calf serum. A hyperthermia group was heated by a 5%-CO/95%-air incubator at 42°C for 20 minutes. A laser-treatment group was exposed to Nd:YAG laser with output power of 2W for 10 minutes in a fixed-temperature water bath (37°C). A combined therapy group was heated by the incubator after the laser irradiation.In the laser experiments the temperature in the wells ranged from 37.0°C to 38.0°C. On the fifth day of culture, both in the laser-treatment group and the hyperthermia group, no significant changes were observed in the viability of the cells, but the proportion of DNA synthesis phase S was relatively larger than in the control group, suggesting the kinetics of an increase after the completion. In the combined therapy group, the viable-cell number was significantly decreased (P<0.05), and no cells in G2/Mphase were found.This suggests that the tumor-killing effect of hyperthermia on colorectal carcinoma can be potentiated by laser light.