Small interfering RNA targeting decoy receptor 3 sensitizes colon cancer cells (SW480) to radiation treatment

Abstract

AIM:To investigate whether small interfering RNA(siRNA)targeting decoy receptor 3(DcR3) can sensitize colon cancer cells(SW480)to radiation treatment and analyze the significance of DcR3 expression in the prediction of radiation resistance in colon cancer before radiotherapy. METHODS:After SW480 cells were irradiated with different doses of 137 Cs gamma rays for different durations,the expression levels of DcR3 were determined by enzyme-linked immunosorbent assay(ELISA).An expression vector expressing siRNA targeting DcR3 was then constructed.After the expression vector was trans-fected into irradiated and unirradiated SW480 cells,the colony formation ability of these cells was determined by colony formation assay,and cell apoptosis was analyzed by flow cytometry. RESULTS:Compared with unirradiated SW480 cells,the expression level of DcR3 increased in SW480 cells irradiated with different doses of 137 Cs gamma rays for different durations,especially remarkable in cells irradiated with 10 Gy 137 Cs gamma rays(P0.05).Compared with irradiated untransfected SW480 cells and unirradiated transfected SW480 cells,the colony formation was enhanced,the M1 peak in cell cycle was elevated and the number of apoptotic bodies increased in irradiated transfected SW480 cells. CONCLUSION:siRNA targeting DcR3 can sensitize colon cancer cells(SW480)to radiation treatment.High DcR3 expression may predict the development of radiation resistance in colon cancer.