Effects of inducers or inhibitors of autophagy and apoptosis combined with ionizing radiation on MCF-7 cells

In order to find sensitive drugs in the radiotherapy of human breast cancer, some experiments were done to detect autophagy and apoptosis on MCF7 cells. MTT method detected cells proliferation; flow cytometry detected cells apoptosis; real-time PCR method analyzed the relative expression amounts of mRNAs. Results showed cells proliferation reduced with the extension of irradiation and apoptosis increased. The apoptosis percentage of the cells in the 4-Gy + rapamycin group increased significantly as compared with that in the 4-Gy + 3-MA and 4-Gy + z-VAD-FMK groups. The relative expressions of LC3B, beclin-1, p53 and Bax mRNA increased significantly in MCF-7 cells treated by irradiation jointing with autophagy inducer, while those of Akt1 and Bcl-2 mRNA decreased significantly. Ionizing radiation can inhibit cells proliferation and promote cells apoptosis. Ionizing radiation jointing with autophagy inducer affects not only the autophagy pathway, but also the apoptosis pathway.