Influence Of Concurrent NP Chemotherapy And Radiotherapy Upon Radiosensitivity And Apoptosis Of Breast Cancer Cell

Objective TO evaluate the effect of a concomitant treatment with vinorelbine (NVB) cisplatin (DDP) and radiation on the radiosensitivity and apoptosis of human breast cancer cell line MCF-7.Methods Two groups (a radiation alone or combination DDP plus NVB with radiation)were studied by cologenic formation assay. Cologenic formation assay was used for cell survival curves in vitro. The difference of radio sensitivities was analyzed by the special parameters of curves. The effect of radiochemotherapy on apoptosis induction in MCF-7 cells was also studied. Quantitation of the apoptotic cells was performed by Flow cytometry measurements. For the qualitative detection, fluorescence microscopy analysis was used.Results The value of Do, Dq, N and SF2 of radiochemotherapy group were smaller than that of radiation alone. Apoptosis index of radiation group alone, (DDP+NVB) chemotherapy group alone and untreated control group increase with time extending. Radiation alone caused accumulation of MCF-7 cells in the G2 / M phase of the cell cycle. In radiochemotherapy groups, at 24 hours after radiation apoptotic peak reached at the dose of 4Gy. Up to 36 hours following irradiation, apoptotic peak values appeared at the dose of 8Gy.Conclusion Vinorelbine and cisplatin can raise the radiosensitivity, resist the repair of sub-lethal damage. There is selectivity of time-dose on apoptotic peak values of radio-chemotherapy groups.