Anti-tumor Effects Of A Dual Cancer-specific Oncolytic Adenovirus Carried Apoptin And HTERT Promoter On Lung Cancer

In recent years, Lung cancer ranked the highest of all cancer because of being anupward tendency. Although traditional therapies such as surgery, chemotherapy andradiotherapy are the mainly choice for lung cancer, the novel treatment methods areurgently needed. With the development of molecular cell biology and virological,gene therapy developed is one of the most promising approaches for lung cancer, andadenoviral vectors showed be highly effective and safe. Adenovirus vecters combinedwith standard chemotherapeutics had received extansive attention.There are two anti-tumor gene therapy drugs all over the world. The one isrecombination human adenovirus type5which deleted anti-apoptosis E1B gene andE3gene that promote releasing of virion. Anoher is recombination human adenovirusp53. It is a human type5adenovirus, in which E1gene was replaced with the p53.Adenovirus vectos had become a new weapons for gene transfer. But safety andeffective is evaluated for oncolytic adenovirus as an important indes. First generationadenovirus vecors have a significant immune response because of adenovirus capsidprotein. And this adenovirus which deleted E1A is unable to replicate. On the basis ofRAPAD.I system, oncolytic adenovirus, Ad-Apoptin-hTERTp-E1A, which drivesexpression of Apoptin under the hTRET promoter and expression of E1A under theCMV promoter, took the advantages of cancer-specific changes for replication andsuppression in tumor cells. Ad-ΔE1B55K-ΔE3, Ad-p53and Ad-CMV-EGFP weredesigned as control.In experiments in vitro, lung cancer A549cells was infected with therecombinant adenovirus or adenovirus combined with cisplatin. At various time pointsafter infection, cell viability was assessed by MTT assay. The result performed thatAd-Apoptin-hTERTp-E1A significantly suppressed proliferation. The suppressioneffect was dose-and time-dependent. And the suppression of adenovirus/cisplatin group was higher than adenovirus. The apoptosis of the Ad-Apoptin-hTERTp-E1A-infected A549cells was detected by AO/EB, DAPI and Annexin Vstaining. Infection of A549cells with Ad-Apoptin-hTERTp-E1A resulted in asignificant induction of apoptosis of them. The migratory and invasive of A549cellswhich were inhibited by adenovirus or adenovirus/cisplatin group were detected byTranswell migration assay and Transwell invasion assay. The result showed that A549cells were inhibited by Ad-Apoptin-hTERTp-E1A, and migratory and invasive abilityhad significant effects as compared with the control virus. And the suppression effectwas dose-and time-dependent.In experiments in vivo, the nude mice bearing established subcutaneoustransplantation tumors were treated with adenovirus and adenovirus/cisplatinrespectively. Ad-Apoptin-hTERTp-E1A combined with low-dose cisplatin caninhibited the growth of transplantation tumors obviously, as compared withAd-Apoptin-hTERTp-E1A used alone. All these results indicated that Ad-Apoptin-hTERTp-E1A and it combined with cisplatin have a potential research value, and canprovide a basic theory for clinical gene thrapy.