Synergy Effects Research On Combination Of Paclitaxel With Microwave Mild Hyperthermia Induce Human Breast Carcinoma Cell Line MCF-7 Apoptosis

Background:Mild hyperthermia is a method that the patients' local or whole body temperature were elevated up to 39.5-42℃,selectively killing of cancer cells or lead it to apoptosis, controlling the transfer of cancer cells in a wide range through thermal effects and the biological effects of secondary. A large number of research suggests that: hyperthermia(42-45℃)can induce apoptosis of tumor cells with chemotherapy has synergistic anti-tumor effect. However, in clinical studies, we found that when a lot of patients ' body temperature were elevated up to about 39℃,they can obtain good effect. In recent years, there is no research suggests that thermochemotherapy(<41℃)have a direct anti-synergistic sensitizing effect, but only to take effect through the immune regulationt.Objective:This experiment aims to confirm whether chemotherapeutics combined with microwave low-mild hyperthermia will induce synergistic effects, and to explore its mechanism of action.Methods:1.Establishing the human breast carcinoma cells line MCF-7 culture model in vitro, MTT assay were used to measure the proliferati and the invasive capacity, select the effective experimental concentration.2.Flow cytometric analyses were used for detecting the control group,paclitaxel alone group,(40℃-41℃,2h) microwave hyperthermia group and paclitaxel with (40℃-41℃,2h) microwave hyperthermia group in human breast carcinoma MCF-7 cells apoptosis rates changes. Cell apoptosis were detected by AnnexinⅤ-FITC/PI Apoptosis Detection Kit.Results: The proliferati on rate of the human breast carcinoma cell line MCF-7 subjected to paclitaxel decreased significantly. 41℃microwave mild hyperthermia can induce human breast carcinoma cell line MCF-7 apoptosis in vitro, With the time extended, a further increase in apoptosis. Paclitaxel with 40.5℃microwave hyperthermia group compared to paclitaxel alone group or microwave mild hyperthermia alone group, it can induce more apoptosis rates .Hyperthermia has synergistic anti-tumor effect with chemotherapy. With the temperature to 41℃, the synergistic anti-tumor effect with chemotherapy was more pronounced. The proliferati on rate of the human breast carcinoma cell line MCF-7 subjected to combinati on treatment of 5μg/ml paclitaxel with 40℃microwave mild hyperthermia increased significantly.Conclusions:The proliferation rate of the human breast carcinoma cell line MCF-7 subjected to paclitaxel decreases significantly. 41℃,2h,microwave mild hyperthermia can induce apoptosis of human breast carcinoma cell line MCF-7; 40.5℃-41℃,2h,microwave mild hyperthermia has synergistic anti-tumor effect with paclitaxe. The proliferation rate of the human breast carcinoma cell line MCF-7 subjected to 40℃,2h,microwave mild hyperthermia combine with paclitaxel increases.