塞来昔布对肝癌细胞放疗增敏作用研究

目的：探讨塞来昔布（celecoxib）对肝癌细胞放疗增敏作用。方法：用Western blot法检测COX-2在肝癌细胞HepG2中的表达;运用克隆形成试验检测单纯射线照射组和射线联合celecoxib组在不同放射剂量下的细胞存活率,制作细胞生存曲线,比较两组间的放疗敏感性;以流式细胞术检测射线处理后细胞周期变化情况。结果：COX2在肝癌细胞中明显高表达,较正常细胞差异有统计学意义,celecoxib能明显下调COX2的表达。射线联合celecoxib组的细胞存活率、放疗敏感性指标Do、Dq、SF2较单纯射线处理组明显降低,联合组HepG2细胞停滞在G1期者明显增多,而S1期细胞则明显减少,差异有统计学意义。结论：celecoxib能增加肝癌HepG2细胞的放疗敏感性,其机制与celecoxib通过特异性抑制COX-2以影响肝癌细胞亚致死性放射损伤修复和调节细胞周期有关。

Radiosensitivity effect of celecoxib on hepatocelluar carcinoma cell HepG2

Objective： To explore the radiosensitivity effect of celecoxib on the hepatocelluar carcinoma cell. Methods： Expression of COX-2 protein in HepG2 treated with or without Celecoxib were analysed by Western blot. The radiosensitivity was assessed according to the cell survival rate of the clone formation test in the radiation exposure group and the radiation exposure with celecoxib group. Cell cycle were detected by flow cytometry. Results： The expression of COX-2 protein was significantly increased in the radiation exposure group compared with control group （P〈0.05）, whereas the expression of COX-2 protein was downregulated when cells were treated with celecoxib. The cell survival rate and the radiosensitivty target including Do, Dq, and SF2 were significantly reduced in the combination group compared with control group, cell cycle were arrested in G1 in the combination group. Conclusion： Celecoxib can enhance radiosensitivity on hepatocelluar carcinocelluar cell （HepG2）, the mechanism lies in it＇s special inhibition effect on COX-2 protein expression which control the damage repair of tumor cell and cell cycle.