汉防己甲素对人肺腺癌细胞的放射增敏作用及其机制的实验研究

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

目的探讨汉防己甲素(Tet)对人肺腺癌SPC-A1细胞的放射敏感性的影响及其作用机制。方法 MTT法检测Tet对SPC-A1细胞的增殖抑制作用,比较单纯照射组(4 Gy)、照射(4 Gy)+Tet(1μmol/L)组、单用Tet组(1μmol/L)及空白对照组间SPC-A1细胞增殖抑制率的差异。采用克隆形成实验来计算受照射后的细胞存活率,拟合细胞存活曲线,计算D0、Dq、SF2。流式细胞术检测照射前后SPC-A1细胞周期的分布情况。结果 Tet对SPC-A1细胞的24、48和72 h半数抑制浓度(IC50)分别为10.77、5.78、和3.89μmol/L。照射+Tet组24、48、72 h的细胞增殖抑制率均高于单纯照射组,差异有统计学意义(P<0.05)。克隆形成实验显示照射+Tet组的D0、Dq和SF2值分别为(1.551±0.045)Gy、(0.522±0.023)Gy和0.503±0.008,均低于单纯照射组。放射增敏比(SER)为1.48。流式细胞仪检测结果显示照射导致了SPC-A1细胞G2期阻滞(P<0.05)。联合Tet后可以降低G2期阻滞细胞比例(P<0.05)。结论 Tet可以有效增加人肺腺癌SPC-A1细胞的放射敏感性,其机制可能是通过降低放射导致的G2期阻滞细胞比例,从而使DNA的损伤固定,发生增殖性死亡。

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.