重组人p53腺病毒联合奥沙利铂对胃癌细胞HGC-27的生长抑制作用

目的观察外源p53基因在胃癌细胞内的表达，研究其对肿瘤细胞生长的影响以及对胃癌细胞化疗敏感性的作用和机制。方法用重组人p53腺病毒注射液（rAd—p53）及奥沙利铂（OXA）单独及联合作用于胃癌细胞株HGC-27不同时间后，MTF法检测其对体外培养细胞的抑制率，免疫组织化学S-P法检测p53蛋白的表达情况，流式细胞仪（FCM）分析其细胞凋亡蛋白caspase-3的表达情况。结果rAd-p53及OXA单独作用时，随药物浓度及作用时间的增加，细胞的生长抑制率逐渐增高；两者联合作用48小时，其在较低浓度时细胞生长抑制率即明显增高（P值均〈0．05），且明显高于单药作用；OXA（3．2μg／m1）与rAd．p63（5×10。、5×107、5×108、5×109vp／m1）联合作用48小时后，与对照组比较，胃癌细胞caspase-3蛋白的含量升高（P值均〈0．05），但p53蛋白无明显升高（P值均〉0．05）。结论OXA和rAd—p53单药可抑制胃癌细胞HGC-27的生长，两者联合应用对胃癌细胞的抑制作用增强；rAd—p53有增强OXA化疗敏感性的作用，其机制与通过线粒体途径激活下游的caspase一3诱导细胞凋亡有关。

Effect of recombinant adenovirus-p53 combined with oxaliplatin on the growth inhibition of human gastric cancer cell line HGC-27

Objective To observe the expression of exogenous p53 gene in gastric cancer cells, study the effects on the growth of tumor ceils, and evaluate the effect of adenovirus mediated p53 gene on chemosensitivity of human gastric cell and the value of gene therapy combined with chemotherapy. Meth- ods Before and after the treatment on the gastric cancer cell line HGC-27 with recombinant adenovirus- p53 （rAd-p53） or oxaliplatin （OXA） alone;or combined these 2 together in different periods, MTI＂ assay was used to examine the suppressive rate of cell growth in cell culture in vitro,p53 protein expression was detected by immunohistochemistry assay, apoptosis protein caspase-3 expression was induced and exam- ined by flow cytometry with administration of different drugs alone or in combination. Results After the treatment of rAd-p53 or OXA alone;or combined on the gastric cancer cell line HGC-27, with the increase of drug concentration and time, the cell growth inhibition rate was gradually increased;Mter treatment with combined drugs in 48 h, the cell growth inhibition rate was gradually increased at the lowest concentration （ P 〈 0.05 ） ; Mter 48 h treatment with rAd-p53 （5 x 106 ,5 x 107 ,5 ~ l0s ~5 x 109 vp/ml） and OXA （3.2 p~g/ml） combined, compared with the control group,the content of caspase-3 protein in gastric cancer cell was gradually increased. Conclusion The proliferation of HGC-27 could be inhibited by rAd-p53, OXA only, but when treatment with rAd-p53 and OXA together, the inhibition of HGC-27 proliferation was high- er than those with single. It is hypothesized that the combination treatment induces cell apoptosis through mitochondrial pathway to activate downstream of caspase-3.