Effects of tetrandrine on radiosensitvity of lung adenocarcinoma cell line and it's mechanism

DING Wei; YANG Aizhen; XV Haijun; CHEN Longhua

Abstract：Objective To investigate the effects of tetrandrine(Tet) on radiosensitivity of human lung adenocarcinoma SPC-A1 cells and its mechanism. Methods MTT assay was used to evaluate the cytotoxicity of Tet on SPC-A1. MTT assay were used to e-valuate the inhibition ratio of irradiation group(X-ray 4 Gy), Tet (1 μmol/ L) +irradiation (X-ray 4 Gy) group and Tet group (1μmol/ L). Cell viability after radiation was calculated by clonogenic assay. According to cell survival curve, the parameters including D0 , Dq ,SF2 were calculated. Flow cytometry was used to detect the cell cycle distribution of irradiation group and Tet+irradiation group. Results The IC50 of Tet on SPC-A1 cells at 24, 48 and 72 h were 10. 77, 5. 78 and 3. 89 μmol/ L, respectively. The values of D0 , Dq ,and SF2 of Tet+irradiation group were(1. 551±0. 045)Gy, (0. 522±0. 023)Gy and 0. 503±0. 008, which were lower than those of irradiation group, and SER was 1. 48. Flow cytometry showed that exposure of SPC-A1 cells to 4 Gy of X-rays caused G2 / M arrests (P<0. 05). The arrests were abrogated by treated with Tet(P<0. 05). Conclusion Tet can efficiently enhance the radiosensitivity of SPC-A1 cell. The mechanism maybe abrogating the radiation-induced G2 phase arrest. It fixes the damage of DNA,and causes reproduc-tive cell death.