[Effect of different heating methods combined with neferine on the expressions of γH2AX and mdr-1/P-gp in MCF-7/Adr breast cancer cells].

OBJECTIVE: To determine the effect of different heating Methods combined with neferine(Nef) on the proliferation and expressions of γH2AX and mdr-1/P-gp in MCF-7/Adr breast cancer cells.
METHODS: MTT assay was used to determine block heating, water submerged heating, medium heating, and oven heating combined with 10 μg/mL Nef on adriamycin cultured MCF-7/Adr cell proliferation. The mdr-1mRNA expression was detected by real-time quantitative PCR. γH2AX and P-gp expressions were detected by Western blot.
RESULTS: The absorbance values of MCF-7/Adr cells in different heating groups at 42 degree and 45 degree were significantly decreased, the mdr-1/P-gp expression was decreased, and γH2AX expression was upregulated compared with those of the 37 degree control group (all P<0.01). The absorbance values (P<0.01) and mdr-1/P-gp expression(P<0.05) were significantly lower and γH2AX expression(P<0.05) was significantly higher in the hyperthermia combined with 10 μg/mL Nef group than those of 10 μg/mL Nef group and hyperthermia group in MCF-7/Adr cells. The water submerged heating group had the lowest P-gp expression and the highest γH2AX expression among different heating groups at 42 degree and 45 degree in MCF-7/Adr cells (P<0.05).
CONCLUSION: Hyperthermia can increase the cell toxicity of adriamycin to multidrug resistant breast cancer cells. Hyperthermia significantly damages DNA of MCF-7/Adr cells and the higher temperature, the worse effect. Multidrug resistant breast cancer cells may respond differently to the different heating methods. Combined treatment of hyperthermia with Nef can increase the sensitivity in adriamycin chemotherapy.