Oncolytic adenovirus armed with IL-24 Inhibits the growth of breast cancer in vitro and in vivo

Background: interleukin-24 (il-24) is a cytokine that belongs to the il-10 family. it can selectively induce cancer cell apoptosis which has been utilized as a cancer gene therapy strategy. methods. a recombinant type five adenovirus containing il-24 gene (designated cnhk600-il24) was constructed,whose replication is activated only in tumor cells. the replication of cnhk600-il24 in breast tumor cells and fibroblasts were assessed by tcid50 and mtt assay; the secretion of il-24 was measured by elisa and western blotting. the in vivo anti-tumor effect of cnhk600-il24 was investigated in nude mice carrying orthotopic or metastatic breast tumor. results: we observed that cnhk600-il24 could replicate efficiently and resulted in high level il-24 expression and massive cell death in human breast cancer cell mda-mb-231 but not in normal fibroblast cell mrc-5. in addition,orthotopic breast tumor growth in the nude mice model was significantly suppressed when cnhk600-il24 was administered. in the metastatic model generated by tail vein injection,cnhk600-il24 virotherapy significantly improved survival compared with the same virus expressing egfp (median survival cnhk600-il24,55 days vs. cnhk600-egfp,41 day,p<0.05 mantal-cox test). a similar phenomenon was observed in the metastatic model achieved by left ventricular injection as suggested by in vivo luminescence imaging of tumor growth. conclusion: the oncolytic adenovirus armed with il-24,which exhibited enhanced anti-tumor activity and improved survival,is a promising candidate for virotherapy of breast cancer. © 2012 zhu et al.; licensee biomed central ltd.