ANP对人胃癌细胞AGS增殖的影响及其机制

Atrial natriuretic peptide modulates the proliferation of human gastric cancer cells via KCNQ1 expression

目的:探讨心房钠尿钛(ANP)对人胃癌AGS细胞增殖的影响及其分子机制。方法:Westernblot检测NPR-A在AGS细胞上的表达;BrdU细胞增殖检测试剂盒检测ANP对胃癌AGS细胞增殖的影响;cGMP检测试剂盒检测ANP对胃癌AGS细胞cGMP水平的影响;Westernblot、RT-QPCR法检测ANP作用AGS细胞后KCNQ1的表达。结果:Westernblot显示NPR-A在AGS细胞上有表达。BrdU细胞增殖检测结果显示高浓度ANP(10-7及10-6mol/L)抑制AGS细胞增殖(P<0.05),而低浓度ANP(10-10及10-9mol/L)促进AGS细胞增殖(P<0.05)。cGMP检测结果显示高浓度ANP通过非cGMP依赖的途径抑制AGS细胞增殖,而低浓度ANP通过cGMP依赖的途径促进AGS细胞增殖。Westernblot及RT-QPCR结果显示高浓度ANP通过下调KCNQ1表达来抑制胃癌AGS细胞增殖,而低浓度ANP通过上调KCNQ1表达来促进胃癌AGS细胞增殖。结论:NPR-A在胃癌AGS细胞上有表达,高浓度ANP通过非cGMP依赖的途径抑制AGS细胞增殖,而低浓度ANP通过cGMP依赖的途径促进AGS细胞增殖。胃癌AGS细胞上存在Kv为KCNQ1,高浓度ANP通过下调KCNQ1表达来抑制AGS细胞增殖,而低浓度ANP通过上调KCNQ1表达来促进AGS细胞增殖。

Objective： To investigate the effect of ANP on the proliferation of human gastric carcinoma cell line AGS and the underlying molecular mechanism. Method： The expression of NPRA in AGS cells was examined by by Western blot. The effect of ANP on cell proliferation was examined by BrdU assay. The effect of ANP on cGMP level was examined by cGMP kit. The ex- pression of KCNQ1 at both mRNA and protein levels in AGS cells treated with ANP was determined by real-time QPCR and Western blot respectively. Result： NPR-A is expressed in human gastric cancer cell line AGS. Lower concentrations of ANP promote proliferation of AGS cells, but higher concentrations decrease proliferation of AGS cells. AGS cells with 10-10, 10-9 and 10-8 mol/L ANP significantly increased the level of cGMP activity compared to control, but no significant difference was found in10-7 and 10-6 mol/L ANP group. The results shown that both in protein and mRNA level 10-10 and 10-9 mol/L ANP significantly upregulate the expression of KCNQ1, but 10^7 and 10^6 mol/L ANP significantly downregulate the expression of KCNQ1. Concluslon： The data we got indicate that lower concentration and higher concentration of ANP have contrary effect on the proliferation of AGS by cGMP denpent or non-cGMP pathway. KCNQ1 upregulation and downregulation by lower and higher concentriaton of ANP take part in the proliferation promotion and inhibition saparately.