LMO1基因在胃癌侵袭转移中的作用及其机制

The effect and mechanism of LMO1 on the invasion and metastasis of gastric cancer

目的 观察LMO1在胃癌组织和人胃癌细胞株中的表达水平,探讨LMO1基因沉默对人胃癌MKN28细胞侵袭转移的影响.方法 采用免疫组化技术检测30例胃癌和癌旁组织中LOM1蛋白表达.实时定量PCR和Western blot检测人胃癌细胞株AGS、BGC-823、SGC-7901、MKN28和正常人胃黏膜上皮细胞GES中LMO1 mRNA和蛋白表达及LMO1特异性siRNA对LMO1mRNA和蛋白表达的影响.Transwell小室实验检测MKN28侵袭转移能力,Western blot检测E-钙黏蛋白、基质金属蛋白酶-9（matrix metalloproteinase-9,MMP-9）、血管内皮生长因子（vascular endothelialgrowth factor,VEGF）蛋白的表达.结果 胃癌组织中LMO1蛋白表达阳性率（77％）高于癌旁组织（17％）（x2=21.70,P＜0.01）.淋巴结转移阳性胃癌患者LOM1蛋白阳性率高于无淋巴结转移患者（x2=5.83,P=0.02）.胃癌细胞株AGS、BGC-823、SGC-7901、MKN28的LMO1mRNA和蛋白表达水平均较正常人胃黏膜上皮细胞GES升高,以MKN28细胞升高最为明显（均P＜0.01）.与阴性转染组比较,LMO1-siRNA转染组LMO1 mRNA和蛋白表达水平均降低（均P＜0.01）.LMO1基因沉默降低了胃癌MKN28细胞的侵袭转移能力（t=-11.53,P＜0.01;t=-10.68,P＜0.01）.与阴性转染组比较,LMO1-siRNA转染组E-钙黏蛋白表达水平升高,MMP-9和VEGF表达水平降低（均P＜0.01）.结论 LMO1基因在胃癌组织和胃癌细胞株中高表达,可能通过调控E-钙黏蛋白、MMP-9和VEGF表达参与胃癌的侵袭转移过程.

Objective To investigate the expression level of LMO1 in gastric cancer tissues and human gastric cancer cell lines,and explore the invasive and metastatic potential of LMO1 gene silencing by small interfering RNA on the human gastric cancer cell line MKN28.Methods Immunohistochemical technique was applied to detect the expression of LOM1 protein in gastric cancer tissues and tumor adjacent tissues of paraffin specimens in 30 cases.The expression levels of LMO1 in human gastric cancer cell lines AGS,BGC-823,SGC-7901,MKN28 and human gastric mucosal epithelial cells GES were detected by realtime-PCR and Western blot.Using LipofectamineTM 2000,LMO1 siRNA was transfected into MKN28 cellsin vitro （siRNA transfect group）.Negative control was established.Real time-PCR and Western blot was used to examine the difference of LMO1 expression.Transwell assays were performed to identify the differences and changes of invasive and metastatic ability in gastric cancer cell line MKN28.Western blot was used to examine the expression levels of E-cadherin,MMP-9 and VEGF.Results Positive rate of LOM1 protein in gastric cancer tissues（77%）was higher than that in tumor adjacent tissues （17%） （x2 =21.70,P 〈 0.01）.Positive rate of Vavl protein was higher in lymphatic metastasis group than in non-lymphatic metastasis group（x2 =5.83,P =0.02）.Compared with GES,the expression level of LMO1 increased significantly in gastric cancer cell lines,especially in MKN28 （P 〈 0.01）.The expression levels of LMO1 mRNA and protein in LMO1-siRNA transfected MKN28 cells were lower than the matched negative control cells （P 〈0.01）.The invasive and metastatic potentials of LMO1-siRNA transfected MKN28 cellssignificantly decreased （t =-11.53,P 〈0.01;t =-10.68,P 〈0.01）.The expression levels of E-cadherin were higher than the matched negative control cells;and MMP-9,VEGF protein in LMO1-siRNA transfected MKN28 cells were lower than the matched negative control cells （P 〈 0.01）.Conclusions LMO1 has higher expression level in gastric cancer tissues and some gastric cancer cell lines,and down-regulation of LMO1 can inhibit the invasion and metastasis ability of gastric cancer.