X线照射对胆囊癌GBC-SD细胞增殖周期的影响

Effects of X-ray irradiation on the cell cycle of gallbladder cancer cell line GBC-SD

目的:探讨X线照射对胆囊癌细胞系GBC-SD的生长及对细胞增殖周期的影响。方法:分别给予体外培养的人胆囊癌细胞系GBC-SD以0,5,10,20GyX线照射。通过MTT方法测定在不同剂量X线照射下的细胞生长变化。通过流式细胞仪检测胆囊癌细胞于照射后增殖周期时相的变化。结果:较大剂量的X线能抑制胆囊癌GBC-SD细胞系的生长,24h表现出明显的抑制作用(P=0.002);72h抑制作用更加显著(P<0.001);其作用呈现效应-剂量依赖性。流式细胞仪检测发现不同的剂量照射后,处于细胞周期不同阶段的细胞会发生不同的变化。24h:胆囊癌细胞的G0～G1、S期细胞比例减少,G2～M期细胞比例增加。72h:胆囊癌细胞的G0～G1细胞比例增加,S期、G2～M期细胞比例减少。实验同时发现小剂量的照射可刺激胆囊癌细胞的增殖,使S、G2～M期细胞增加;而提高照射剂量,使胆囊癌细胞生长停滞在G0～G1期,而S期、G2～M细胞百分比减少。结论:X线照射可通过改变细胞增殖周期分布比例抑制胆囊癌GBC-SD细胞的生长;增加照射剂量可提高胆囊癌的治疗疗效。

Objectives To observe the effects of X-ray irradiation on the growth and the cell cycle of gallbladder cancer cell line GBC-SD. Methods X-ray irradiation with series dosages of 0 Gy,5Gy,10Gy and 20Gy were respectively administrated to the GBC-SD cells cultured in vitro. The cell growth and cell cycle were detected by MTr assay and flowcytometry, respectively. Results The growth of gallbladder cancer cells was inhibited after exposure to a high dose of X-ray, which was demonstrated time-dependent and dose-dependent patterns. The results of flow-cytometry also demonstrated that the proportions of cells in G0-G1 and S stages were decreased at 24 hours after radiation, while G2-M stage cells were increased. In contrast, the proportions of cells in G0-G1 stage was increased, and the S and G2-M stages were decreased at 72 hours after exposure. It was also observed that the cell proliferation was induced after low dose X-ray exposure, which was demonstrated as increased proportions of cells both in S and G2-M stages. Conclusions The therapeutic effects of X-ray irradiation could be enhanced by dose escalation. The potential mechanism might be associated with the changes in cell cycle and cell growth.