重组人p53腺病毒注射液逆转人耐药胃癌MGC-803细胞耐药性的体外试验研究

目的:研究重组人p53腺病毒注射液(rAd-p53)对体外人耐药胃癌MGC-803细胞的逆转作用及其可能的机制。方法:通过紫杉醇由低到高剂量诱导人胃癌MGC-803细胞内多耐药基因表达;不同剂量rAd-p53作用于人耐药胃癌MGC-803细胞不同时间后,MTT法检测细胞增殖抑制率,并计算半数有效抑制浓度(IC50),流式细胞仪检测细胞周期及凋亡情况,免疫组织化学法和蛋白质印迹法测定多药耐药基因mdr1表达蛋白P糖蛋白(MDR1-Pgp)的表达。结果:rAd-p53可明显抑制人耐药胃癌MGC-803细胞增殖,呈时间-剂量依赖关系,作用24、48、72h的IC50分别为1889.85、998.44、354.91MOI;rAd-p53可阻滞人耐药胃癌MGC-803细胞周期于G2/M期并诱导其凋亡,可下调MDR1-Pgp蛋白表达。结论:人耐药胃癌MGC-803细胞的耐药性可能与MDR1-Pgp的高表达有关;rAd-p53可显著抑制人耐药胃癌MGC-803细胞的增殖并诱导耐药细胞凋亡,且呈剂量和时间依赖关系。

Experimental Research on Drug Resistance Reversal of Human Gastric Cancer MGC-803 by Recombinant Human Ad-p53 Injection in Vitro

OBJECTIVE:To discuss the reversal effects and the possible mechanism of recombinant human Ad-p53 injection(rAd-p53) on human gastric cancer MGC-803.METHODS:Drug resistant gene expressions of MGC-803 cells were induced by paclitaxel from low to the high dose.After the application of different concentrations of rAd-p53 on MGC-803 for different time,MTT method was used to measure inhibition rate of cell proliferation to calculate IC50.Cell cycle phase distribution and apoptosis were determined by flow cytometry.Immunohistochemistry and Western blot assay were used to evaluate the level of MDR1-Pgp expression.RESULTS:MTT method showed that rAd-p53 could inhibit the proliferation of MGC-803 in time and dose dependant manner.The inhibiting concentration of 50% cell growth(IC50) at 24 h,48 h and 72 h were 1 889.85,998.44,354.91MOI,respectively.Cell cycle was arrested at the G2/M phase,and apoptosis of cells could be efficiently induced by rAd-p53 at different concentrations.MDR1-Pgp protein expression were down-regulated during rAd-p53 induction.CONCLUSION:Drug resistance of MGC-803 is mainly related with the high expression of MDR1-Pgp;rAd-p53 significantly inhibits the proliferation of MGC-803 and induce cell apoptosis in dose and time dependent manner.