Study Of RNAi Silencing CXCR4Gene Inhibits The Invasion And Metastasis Of Gastric Cancer Cell SGC7901

ObjectiveGastric cancer is a common malignant tumor of the digestive tract,itsincidence rate in malignant tumor is the fourth and the fatality rate is thesecond.Even throught surgery, the5-year survival rate is only20%. The leadingcause of death is gastric tissue invasion and metastasis. Recent studies havefound that the expression of CXCR4in a variety of tumor cell is high, which isclosely related with tumor invasion and metastasis. The study had confirmedthat expression of CXCR4in gastric cancer tissue is high too and theirexpression levels is closely related with node metastasis and peritonealmetastasis. In this study,by building CXCR4-shRNA adenovirus vector andtransfected CXCR4-shRNA adenovirus vector into gastric cancer SGC7901cell;secondly built the model of peritoneal metastases in nude mice, thenobserved the CXCR4-shRNA adenovirus vector’s effect on metastatic tumorgrowth in nude mice and demonstrated the role of CXCR4in gastric cancerinvasion and metastasis.Methods1.Construction of CXCR4-shRNA adenovirus vector, the adenovirus vectorwas transfected into gastric cancer cells,western blot was used to detect theCXCR4protein expression level of gastric cancer cell after transfected; 2.Construction of the three nude mice peritoneal metastasis models: gastriccancer group,empty virus group, CXCR4-shRNA group;then compared thetumor volume, weight, metastasis tumor number, the survival time, the survivalrate,life prolongation rate of three nude mice groups.3.Western Blot was used to detect the VEGF-C, MMP-2protein expression ingastric carcinoma.Result1.Successfully constructed CXCR4-shRNA adenovirus vector andsuccessfully transfected constructed CXCR4-shRNA adenovirus vector intogastric cancer SGC7901, the cells do not appear obvious cythpathiceffect(CPE).2. western blot was used to detect the CXCR4protein expression level ofgastric cancer cell SCG7901after transfected,the results showed that proteinlight in CXCR4was thin, dull colored and the expression level was significantlyreduced.3. Successfully constructed three groups of nude mice gastric cancer cellabdominal cavity situ xenograft model. Compared CXCR4group with the gastriccancer group and empty virus group, tumor number, tumor weight, volume ofceliac metastasis tumor of CXCR4group were lower than the latter two. CXCR4group tumor inhibition rate reached69.4%, the difference is significant, hasstastistical significance(P0.05); CXCR4group nude mice survived significantlylonger time, five nude mices survived after30days and the survival rate was83.3%,the life extension rate was59.3%, the difference was significant and hasstatistical significance(P0.05); Compared the gastric cancer group with emptyvirus group, the experimental results showed no significant difference(P0.05).4.Western Blot was used to detect CXCR4, VEGF-C and MMP-2proteinexpression of three groups of metastatic tumor tissue, the results showed that:VEGF-C, MMP-2protein light in CXCR4group was thin, dull colored and the CXCR4group VEGF-C, MMP-2protein expression level was significantlyreduced, compared with the gastric cancer group and empty virus group, thedifference was significant, has statistical significance(P0.05); Contrast thegastric cancer group and empty virus group, there was no significantdifference(P0.05). Gel imaging system was used to calculate the VEGF-C,MMP-2OD value, VEGF-C OD average values in shRNA group, gastric cancergroup and empty virus group were respectively0.89,0.87,0.23;MMP-2ODaverage values were0.90,0.88,0.21.According to formula, the inhibition ratewere63.1%,67.7%.Conclusion1.CXCR4-shRNA adenovirus vector was successfully constructed andCXCR4-shRNA adenovirus vector was successfully transfected into gastriccancer cell SGC7901.2.Successfully constructed nude mice situ xenograft tumor model.3.CXCR4-shRNA adenovirus vector can effectively inhibit tumor growth andmetastasis to the abdominal viscera,and reduced tumor volume and weight,increase the survival time of nude mice, and reduced mortality.4.VEGF-C, MMP-2protein levels decreased after CXCR4expression levelswas inhibited, the gastric tissue growth, invasion and metastatsis wassuppressed,too.