Autopahgic Modulation Enhanced The Radiosensitivity Of Colorectal Cancer

Purpose :We aimed to observe the effect of radiosensitivity of colorectal cancer by the autophagic status of colorectal cancer and to explore the possibility and the potential mechanisms.Methods:The colorectal cancer cell CCL-244 were treaded with rapamycin and exposure to4 Gy irradiation. Untreated CCL-244, rapamycin pretreated CCL-244、4Gy irradiation pretreated CCL-244 and rapamycin joint 4Gy irradiation. CCK-8 assay and cell wound healing assay were used to observe the proliferation and migration with different treatment groups on CCL-244. Colony forming assay and cell apoptotic analysis with flow cytometry were performed after exposure to 4Gy irradiation to observe the effects of the radiosensitivity of colorectal cancer cells. Western blot analysis of autophagy proteins LC3 and Beclin-1expression were carried out to analyze the autophagic levels of CCL-244 induced by rapamycin.Results:After exposure to 4Gy irradiation,the rapamycin pretreated CCL-244 proliferative ability was significantly inhibited and the migratory ability was improved. The rapamycin pretreated CCL-244 had the minimun numbers of clones from the results of Colony forming assay and had the highest apoptotic rate. Cancer cells from the rapamycin pretreated group exposure to 4Gy irradiation demonstrated suppressed colony forming abilities and promoted apoptosis. In the rapamycin pretreated group after 4Gy irradiation,expression of LC3 and Beclin-1 more higher than the rapamycin pretreated group.Conclusions :Rapamycin can up-regulation autophagic on CCL-244 cell line and to promote radiosensitivity of colorectal cancer cells. The autophagy of colorectal cancer cells may bea potential target for radiosensitization in cancer therapy and worth further study.