Study Of Functions And Molecular Mechanism Of AdHu5-apoptin In Gastric Cancer

Objective: To investigate the effects and mechanism of apoptincarried by non-proliferation adenovirus on gastric cancer cells,Methods: The use of anticancer therapeutic agents is limited largelydue to their severe toxicity to normal tissues. Development of novel agentswith specific tumor cell killing and gene-effective delivery properties hasbeen much desired for successful cancer treatment. In this study, humanadenovirus serotype5(AdHu5) was used as a vehicle to deliver Apoptin(VP3) gene, which specifically targets gastric cancer through the use ofrecombinant gene-delivery technology. CCK8assay, Colony formationassay, Flow cytometry analysis, Annexin V-FITC/PI staining and animalassay were used to detect the functions of Apoptin in vitro and in vivo.Bioinformatics,westernblot and Immunofluorescence staining methodswere performed to indentify the expression of CARD18.Results: Our results show that the presence of Apoptin proteinencoded by Apoptin gene delivered through adenovirus AdHu5in gastriccancer cells (SGC-7901) significantly inhibited cell proliferation, reducedthe clone number by more than75%, and resulted in47.96%cancer cells being arrested in G2/M phase. It also induced the cleavage of caspases-3,-7and-9of the gastric cancer cells. In vivo animal studies also show thatintratumoral and peritumoral injection of AdHu5-Apoptin into xenogeneictumors significantly suppressed tumor growth and induced apoptosis ofxenogeneic tumors in mice. Furthermore, our findings also indicate that theapoptosis induced by AdHu5-Apoptin was independent of otheranti-apoptotic BcL-2and BcL-xL proteins and p53pathway.In addition，the expression of CARD18in SGC7901exposed to AdHu5-Apoptin wassignificantly down-regulated, And CARD18expression in gastric cancertissues was significantly increased compared with the adjacentnoncancerous tissues(P＜0.05), Besides, the expression levels of CARD18were increasing with more advanced stages and lymph node metastasisTNM stage(P<0.05).Conclusions: Our results show that adenovirus-mediated Apoptin hasa great potential as a therapeutic agent for the effective treatment of gastrictumors.