Biological effects of Tween-80 in combination with hyperthermia on human stomach cancer cell line BGC-823

Various biological indices were used to observe the effects of Tween-80 in combination with hyperthermia at different temperature (39–43°C for different period of time (20–100 minutes) on human stomach cell line BGC-823. The results showed that Tween-80 obviously reduced the activation energy of BGC-823 cells. Synergistic effect was observed if applied with heat at 39°C with the increase in temperature and time, the inhibitory effect on the cancer cells was gradually intensified. The lethal rate of BGC-823 cells treated by heat at 41°C in combination with Tween-80 was around 5.2 times as that treated by hyperthermia alone. The synergistic effect of heat at 41°C for 100 min. in combination with Tween-80 was equivalent to the effect of 43° C for 100 min.. In other words, the critical temperature for BGC-823 cells was hereby reduced about 2°C. The measurement of membrane mobility, SDH activity etc. also showed that at 41°C the synergistic effect of hyperthermia in combination with Tween-80 was the best, it exceeding the single effect of these factors in combination and showing effect of multiplication. The synergistic effect of heat at 41°C in combination with Tween-80 was higher than that of heat at 41°C in combination with MMC. It also demonstrated that the specific and sustained action on the inhibition of cancer cells did exist. These studies suggested that the synergistic mechanism of Tween-80 and hyperthermia probably was that both of them acted on the cell membrane system.