中文摘要：

目的探讨乳铁蛋白抗菌肽（Lfcin B）对人胃癌细胞株MGC803细胞增殖和细胞凋亡的影响。方法用CCK-8法测定不同浓度Lfcin B对胃癌细胞株MGC803 24、48和72h细胞增殖影响。用流式细胞术检测胃癌MGC803细胞凋亡的变化。用RT-PCR检测凋亡相关基因bcl-2、bax和caspase-3 mRNA的变化情况。用Western blot检测MGC803细胞中的Bcl-2、Bax和Caspase-3蛋白表达。结果 Lfcin B对胃癌细胞株MGC803的增殖具有抑制作用,促进胃癌细胞株MGC803细胞凋亡,并且具有时间和剂量依赖性（P〈0.05,P〈0.01）;Lfcin B能显著抑制胃癌细胞株MGC803 bcl-2 mRNA表达,同时促进bax和caspase-3 mRNA表达,并且随着Lfcin B浓度的增高相关基因下降或上升越明显（P〈0.05,P〈0.01）;Western blot结果也显示,Lfcin B能抑制Bcl-2蛋白表达,促进Caspase-3和Bax蛋白表达,其变化规律与mRNA相同（P〈0.05,P〈0.01）。结论 Lfcin B通过调控相关基因,抑制胃癌细胞MGC803增殖,并诱导其细胞凋亡。

英文摘要：

Objective To explore the effect of the lactoferrin peptides（LfcinB） on human gastric cancer MGC803 cells proliferation and apoptosis. Methods The proliferation of MGC803 cells at different concentrations of LfcinB were evaluated by CCK-8 assay for 24, 48 and 72 h, respectively. Flow cytometry（FCM） was performed to detect the effect of LfcinB on MGC803 cells apoptosis. The expression of apoptotic-specific genes, such as bcl-2, bax and caspase-3 was assessed by RT-PCR and Western blot analysis. Results LfcinB obviously inhibited the proliferation and promoted apoptosis of gastric cancer MGC803 cells （P 〈 0. 05, P 〈 0. 01 ） with a time- and dose-dependent manner. LfcinB could markedly inhibit MGC803 cells bcl-2 gene mRNA expression, while promoting bax and caspase-3 mRNA expression, and with the increase of concentration LfcinB that related genes decreased or in- creased more significantly （P 〈0. 05, P 〈0. 01 ）. Western blot also showed that LfcinB inhibited Bcl-2 protein ex- pression and promoted Caspase-3, Bax protein expression, in line with mRNA results （P 〈 0. 05, P 〈 0. 01 ）. Con- clusion LfcinB can efficiently inhibit proliferation and induce apoptosis of human gastric cancer MGCS03 cells through altering the expression of bcl-2, bax and caspase-3 genes.