中文摘要：

采用不同浓度梯度的蛋氨酸脑啡肽（methionine enkephalin,MENK）体外作用于人胃癌细胞BGC823后,探讨对其增殖影响及其作用机制,为胃癌的免疫治疗提供理论依据。体外培养人胃癌细胞株BGC823,PCR检测阿片受体OGFr的表达;用不同浓度（0、1、2、3、4 mg/mL）的MENK体外作用于BGC823细胞24、48、72、96 h后,MTS检测MENK对其增殖影响;流式细胞术和Annexin V-FITC/PI双染法检测4 mg/mL MENK体外处理48、72 h后BGC823细胞凋亡变化。结果显示,人胃癌BGC823细胞有阿片受体OGFr的表达;MENK可抑制BGC823细胞增殖,且随着剂量的增加和时间的延长,其抑制作用逐渐增强（P〈0.05）;4 mg/mL MENK48 h处理组与空白组相比细胞凋亡率增加,72 h处理组与48 h处理组结果一致（P〈0.05）。结果表明,MENK可抑制BGC823细胞增殖,具有显著的剂量依赖性和时间依赖性,且可通过诱导细胞凋亡抑制BGC823细胞的增殖。

英文摘要：

The effect of different concentration gradients of methionine enkephalin （MENK） on human gastric cancer cell line BGC823 in vitro was investigated its effects on proliferation and its affecting mechanism on gastric cancer, and provided theoretical foundation for gastric cancer immunotherapy. Human gastric cancer cell line BGC823 was cultured in vitro, PCR to detect the expression of opioid growth factor receptor （OGFr） , 24, 48, 72, 96 h after different con- centrations （0, 1 , 2, 3,4 mg/mL） of MENK were reacted in vitro on BGC823 cells, MTS to determine the effect of MENK on their proliferation. The apoptosis changes was detected 48 h and 72 h after treated with 4 mg/mL MENK in vitro by flow eytometry and Annexin V-FITC/PI double staining BGC823 cells. The results showed that human gastric cancer cell line BGC823 had the expression of OGFr. MENK could inhibit the proliferation of BGC823 cells, and with the increase of close and the extension of time, the inhibition strengthened gradually （P 〈 0.05 ）. As compared with the blank groups, apoptosis rate of the group treated with 48 h with 4 mg/mL MENK increased, and the result was ac- cord with the one treated 72 h with 4 mg/mL MENK （ P 〈 0.05 ）. Therefore, the proliferation Of BGC823 cells could be inhibited by MENK, and had significant dose-dependency and time-dependency. In addition, the BGC823 cellsproliferation could be inhibited through the induction of cell apoptosis.