【摘要】 最近发现肿瘤微环境内含有较高水平的亚硝酸盐和氨,但是它们对癌细胞的影响还不清楚。本研究旨在探讨亚硝酸盐和铵盐联合暴露对人肝癌细胞侵袭能力的影响及活性氧(ROS)/鸟氨酸脱羧酶(ODC)途径在其中的作用。经亚硝酸钠、氯化铵、亚硝酸钠和氯化铵混合物处理的SMMC-7721细胞,采用MTT实验检测细胞活力,transwell小室检测细胞侵袭能力,ROS检测试剂盒检测细胞内ROS水平,免疫荧光检测细胞内ODC,Western blot检测基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶-9(MMP-9)和ODC的蛋白表达。结果表明,亚硝酸钠和氯化铵混合物能够增强SMMC-7721细胞侵袭能力,促进细胞内ROS水平增加,促进ODC蛋白表达,ROS清除剂N-乙酰半胱氨酸(NAC)可以逆转上述现象;ODC特异性抑制剂二氟甲基鸟氨酸(DFMO)可以增加细胞内ROS水平,降低细胞侵袭能力。综上所述,亚硝酸钠和氯化铵混合物通过增强ROS/ODC途径,促进人肝癌SMMC-7721细胞侵袭。更多还原

【Abstract】 Recent studies have demonstrated that nitrite and ammonia levels are higher in the tumor environment, but their effects on cancer cells remains unclear. The present study was designed to determine the effects of nitrite and ammonia on tumor invasion and the role of reactive oxygen（ROS）/ornithine decarboxylase（ODC） pathway. SMMC-7721 cells were treated with sodium nitrite, ammonium chloride, sodium nitrite and ammonium chloride mixture for 24 h, the cell viability was analyzed using the MTT assay, cell invasion was analyzed with the transwell assay, the intracellular ROS levels were detected with a reactive oxygen species（ROS） test kits, the expression of intracellular ODC was examined with immunofluorescence and Western blot, the expression of matrix metallopeptidase-2（MMP-2） and MMP-9 were analyzed by Western blot. Compared with the control group, SMMC-7721 cells exhibited an increase in cell viability, invasion ability, ROS levels and ODC protein after exposure to 150 μmol·L^-1 sodium nitrite and ammonium chloride mixture for 24 h. The invasive activity was reduced by ROS scavenger N-acetycysteine（NAC） in SMMC-7721 cells. The specific ODC inhibitor difluoromethylornithine（DFMO） increased ROS levels and weakened the ability of sodium nitrite and ammonium chloride mixture in the regulation of invasion of SMMC-7721 cells. These data demonstrated that sodium nitrite and ammonium chloride mixture promote invasion of SMMC-7721 cells by enhancing ROS/ODC pathway.更多还原