The Role And The Effect To HSP70 Of Hyperthermia Chemotherapy For The Colorectal Cancer Cell

Objective To study the best acting-time and temperature of Hyperthermia Chemotherapy to colorectal cancer cell lines(CT26),and analysis the role of Hyperthermia Chemotherapy and the changing of HSP70mRNA.Method using the colorectal cancer cell lines of the BALB/C mice (CT26),when it in logarithmic phase,dividing it into six teams according to its time point(0.5h,1h,1.5h,2h,2.5h and 3h),then treating the six groups separately with chemotherapy,hyperthermia and Hyperthermia Chemotherapy. The temperature of chemotherapy group is at 37℃,and the temperature of hyperthermia group and Hyperthermia Chemotherapy group is at 42℃,43℃, 44℃and 45℃.We also set up a negative control.(1)to compare the growth inhibiting of tumor cell of each approaching using MTT;(2)to analyze the expressing of HSP70mRNA in each cell group using RT-PCR.Results The average inhibition rate of 0.5h,1h,1.5h,2h,2.5 and 3h is 58.64±17.67%,63.76±18.19%,72.09±19.75%,74.47±19.77%,73.41±20.47% and 71.85±21.09%separately.The average inhibition rate of 1.5h is higher than 0.5h 58.64±17.67%(p=0.001)and 1h 63.76±18.19%(p=0.007),but there is no statistics differentiation compared with 2h,2.5h and 3h(p＞0.05).The average inhibition rate of 42℃,43℃,44℃and 45℃is 57.24±19.57%,58.07±19.95%,82.62±13.22%and 83.65±11.12%.The average inhibition rate of 44℃is higher than 42℃57.24±19.57%(p=0.000)and 43℃58.07±19.95%(p=0.001).but there is no statistics differentiation compared with 45℃(p＞0.05).When the heating temperature is up to 44℃,and the time is up to 1.5h,the inhibition rate of Hyperthermia Chemotherapy group can be up to 93.35%,evidengly is higher than the inhibition rate of chemotherapy group and hyperthermia group 74.9±14.45%(p＜0.01),59.3±0.95%(p＜0.01).From the mRNA level,the expression of HSP70 is low for the negative control,higher than negative control under the chemotherapy,and increased gradually with temperature increased under hyperthermia,and decreased gradually with temperature increased under hyperthermia chemotherapy,especially,the effect is more obvious at the temperature of 44℃,45℃.Conclusion:①the best condition of effect to hyperthermia chemotherapy is at 44℃,1.5h;②hyperthermia chemotherapy can not only inhibit the growth of CT26 tumor cell effectively,but also lower the expression of the HSP70mRNA.