塞来昔布对结肠癌细胞株HT-29的放射增敏研究

目的研究塞来昔布对结肠癌细胞株HT-29的放射增敏效应,并初步探讨其作用机制。方法体外培养结肠癌细胞株HT-29,用不同浓度的塞来昔布作用于HT-29细胞,以成克隆实验检测细胞辐射敏感性;建立结肠癌荷瘤裸鼠模型,不同实验条件下观察肿瘤体积变化并绘制肿瘤生长曲线;采用免疫组织化学方法检测肿瘤组织中血管内皮生长因子（VEGF）的表达。结果克隆形成实验结果显示,塞来昔布30μmol/L和50μmol/L作用后的放射增敏比分别为1.304和1.475;肿瘤生长曲线表明,联合治疗组的肿瘤增长最缓慢;塞来昔布组可致肿瘤组织中VEGF表达下降（P〈0.05）。结论塞来昔布在体内和体外实验中均可增强结肠癌细胞HT-29细胞的放射敏感性,其机制可能与其抑制肿瘤新生血管形成相关。

Study on Enhancement of Radiosensitivity in Colon Cancer Carcinoma Cell Line HT-29 by Celecoxib in vitro and in vivo

Objective To evaluate the radiosensitizing effect of Celecoxib,a selective cyclooxygenase-2 inhibitor,on colonic carcinoma cell line HT-29 in vivo and in vitro,and to probe the underlying mechanisms.Methods Colonic carcinoma cell line HT-29 was managed in vitro,and was treated by different concentration of Celecoxib,and the cell radiosensitivity was analyzed by colony formation unit assays;the change of tumor volume was observed by establishing the bear-tumor mice model of colonic carcinoma and drawing the tumor growth curve under different conditions;the expression of VEGF in colonic carcinoma tissues was detected by Immunohistochemistry assay.Results The colony formation unit assays showed SER was respectivly1.304 and 1.475 in different groups which were combined with Celecoxib（30μmol/ L and 50 μmol/ L）.The tumor growth curve was used to do determination in these groups.When radiation was used combined with Celecoxib increase of tumor volume was the slowest.The expression level of VEGF in group Celecoxib was proved lower than that in the other groups（P0.05）.Conclusion Celecoxib in vitro and in vivo could enhance the radiosensitivity in colon cancer carcinoma cell line HT-29 and inhibiting tumor angiogenesis maybe one of the underlying mechanisms.