An armed oncolytic adenovirus ZD55-IL-24 combined with ADM or DDP demonstrated enhanced antitumor effect in lung cancer

Abstract

Purpose. Oncolytic adenovirus such as ZD55 has become a promising anticancer agent for its efficient tumor-targeted replication and lysis capability. Armed with therapeutic gene IL-24 to generate a novel oncolytic adenovirus ZD55-IL-24, the antitumor efficiency of ZD55 is greatly increased. To explore the clinical application of ZD55-IL-24 in cancer therapy, the combination of gene-virotherapy (ZD55-IL-24) with chemotherapy was performed in this paper. Methods. The effect of this gene-virotherapy with chemotherapy on cell proliferation was determined by MTT assay in four types of cancer cell lines and one human normal cell line. Real-time PCR was performed to detect the replication of ZD55-IL-24 when adriamycin (ADM) or cisplatin (DDP) was administrated. The changes in caspase pathway were analyzed by Western blot. We further identify the combinational therapy in Balb/c nude mice with NCI-H460 xenograft. Results. ADM and DDP enhanced cell killing/inhibiting effects of ZD55-IL-24 in all the tumor cell lines, while no overlapping toxicity was observed in the normal liver cell line L-02. These chemo-agents inhibited the propagation of ZD55-IL-24 in NCI-H460 cells, but did not influence the expression of IL-24. Consistent with the results in vitro, the tumor growth of co-administration group was remarkably delayed, compared with single treatment groups (p<0.05). Conclusion. ZD55-IL-24 combined with ADM demonstrates improved killing effects against lung tumor xenograft.