汉防己甲素对人鼻咽癌细胞株的放射增敏作用及其机制

Tetrandrine enhances radiosensitivity of human nasophayrngeal carcinoma cell lines

目的:探讨汉防己甲素(Tet)对人鼻咽癌细胞株CNE1和CNE2的放射增敏作用及其机制。方法:MTT法检测细胞增殖抑制作用,克隆形成实验比较细胞放射敏感性,流式细胞术检测细胞周期分布。结果:Tet对CNE1和CNE2细胞的最大非细胞毒性剂量分别为1.5μmol/L和1.8μmol/L,该浓度的Tet联合放射线照射与单纯放射线照射相比,在培养至第4～6 d能明显抑制细胞增殖(P<0.01)。CNE1和CNE2细胞单纯放射线照射组平均致死剂量(Do)分别为(1.26±0.02)Gy和(2.27±0.04)Gy,Tet联合放射线照射组Do分别为(0.73±0.05)Gy和(1.61±0.08)Gy,放射增敏比分别为1.73和1.40(P<0.05)。单纯放射线照射组CNE1和CNE2细胞周期分布以G2期为主,分别为(42.62±2.07)%和(34.82±2.74)%,Tet联合放射线照射组CNE1和CNE2 G2期比例分别为(17.02±1.87)%和(19.64±4.82)%(P<0.01)。结论:Tet能增加人鼻咽癌细胞株CNE1和CNE2对放射线照射的敏感性,机制可能与去除放射线照射诱导的G2期阻滞有关。

AIM： To study whether tetrandrine （Tet） enhances the radiosensitivity of human nasopharyngeal carcinoma cell lines in vitro and its mechanism. METHODS ： The inhibitory effect on proliferation was evaluated by MTT assay. The radiosensitivity of the cells was compared by colony formation assay. The cell cycle was analyzed by flow cytom- etry. RESULTS： The maximum non - cytotoxic doses of Tet for CNE1 and CNE2 cells were 1.5 and 1.8 μmol/L,respec- tively. Compared with radiation group, the cell proliferation in Tet plus radiation group was significantly inhibited on the 4th to 6th days （P〈0.01）. The mean lethal doses for CNE1 and CNE2 cells in radiation group were （1.26±0. 02） Gy and （2.27±0.04） Gy, respectively, and the values changed to （0.73±0.05 ） Gy and （1.61±0.08 ） Gy in Tet plus ra- diation group, respectively, resulting in the sensitivity enhancement ratio of 1.73 and 1.40, respectively （P 〈 0.05 ）. The CNE1 and CNE2 cells in G2 phase of the cell cycle in radiation group were （42. 62±2. 07）% and （34. 82±2. 74）%, re- spectively, while those in Tet plus radiation group were （17.02±1. 87）% and （19.64±4.82）%, respectively. CON- CLUSION： Tetrandrine enhances the radiosensitivity of human nasopharyngeal carcinoma cell lines and the mechanism may be related to the abrogation of radiation - induced G2 phase arrest.