槲皮素对人胃癌MGC-803细胞中瘦素、瘦素受体表达及JAK-STAT通路的影响

Quercetin affects leptin and its receptor in human gastric cancer MGC-803 cells and JAK-STAT pathway

目的:研究槲皮素对人胃癌MGC-803细胞中瘦素、瘦素受体表达及JAK-STAT传导通路的影响。方法:实验分组为胃癌细胞组(只加入MGC-803细胞)、槲皮素处理组(40μmol/L槲皮素)和阳性对照组(40μmol/L AG490,AG490为JAK2激酶抑制剂)。采用免疫组织化学法和Western blot法检测槲皮素对胃腺癌MGC-803细胞中Leptin、Leptin receptor和P-STAT3蛋白阳性表达率的影响。应用半定量逆转录聚合酶链反应(RT-PCR)的方法,检测槲皮素对Leptin、Leptin re-ceptor mRNA表达水平的抑制作用。采用流式细胞术(FCM)测定槲皮素对MGC-803细胞的周期阻滞。应用AnnecxinV标记检测细胞凋亡率。结果:槲皮素处理MGC-803细胞后Lep-tin、Leptin receptor、P-STAT3蛋白水平减少,Leptin、Leptin re-ceptor mRNA水平减少,与对照组相比差异均有统计学意义(P<0.05),瘦素和P-STAT3蛋白之间呈直线相关关系(r=0.741,P<0.05),痩素受体和P-STAT3蛋白之间也呈直线相关关系(r=0.693,P<0.05);FCM显示细胞周期阻滞于G2/M期,凋亡率明显增加;随着槲皮素浓度升高,凋亡细胞和坏死细胞比例增加。结论:槲皮素可能通过JAK-STAT途径有效的下调胃癌中瘦素、痩素受体和P-STAT3表达而发挥抑制细胞增殖和诱导细胞凋亡的作用。

AIM： Quercetin affects the expressions of leptin and its receptor in human gastric cancer MGC-803 cells and JAK-STAT pathway. METHODS： The cultured MGC-803 cells were divided into three groups： Control group： the cultured cells without quercetin, and Quercetin group： the cultured cells with quercetin （40 μmol/L）, and AG490group： the cultured cells with AG490（40 μmol/L）The expressions of Leptin, Leptin receptor and P-STAT3 were detected in protein level by immunocytochemical and Western bloting method respectively. The expressions of Leptin, Leptin receptor were detected in mRNA level by RT-PCR method. MGC-803 cell cycle was arrest by flow cytometry （FCM） ; MGC-803 cell apoptosis ratio by apoptotic marker An-necxinV. RESULTS. The protein expression of Leptin, Leptin receptor, P-STAT3 and the the mRNA expression of Leptin and Leptin receptor were significantly increased （ P 〈 0.05）, compared with the control group. There was the rectilinear correlation relationship not only between Leptin and P-STAT3 protein （ r = 0.741, P 〈 0.05 ） but also between Leptin receptor and P-STAT3 protein （ r = 0.693, P 〈 0.05）. FCM analysis showed that quercetin arrested MGC-803 cells at the G2/M phase, The ratio of apoptoUc and necresic cells increased with added quercetin concentration. CONCLUSION： Quercetin could inhibit the Proliferation of MGC-803 cells. It is probably relevant to the down-regulation the expressions of Leptin and Leptin receptor protein, Leptin mR- NA and Leptin receptor mRNA by JAK-STAT pathway.