Oncolytic activity of Canine Distemper virus in human ductal breast carcinoma cells

Oncolytic virotherapy is a novel strategy for cancer treatment in humans and companion animals. Canine distemper virus (CDV) is known to induce apoptosis in tumor cells, thus serving as a potential candidate for oncolytic therapy. However, the mechanism of viral oncolytic activity is less studied and varies depending on the type of cancer and cell lines. In the present study, the susceptibility of the MCF-7 cell line to CDV infection was assessed using the CDV strain which was confirmed previously through sequence analysis in the Vero cell line. The impact of CDV infection on cell proliferation and apoptosis was studied by evaluating the expression of four target genes including the myeloid cell leukemia 1 (MCL-1), phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), Transcription Factor (SP1) and DNA (cytosine-5)-methyltransferase 3A (DNMT3A). CDV replication in the cells induced cytopathic effect and decreased in the cell proliferation rates compared to the uninfected control. MCL-1, SP1 and PIK3R1 gene expression was down-regulated, while the expression of DNMT3A was upregulated 3-days post infection. The expression levels of the target genes suggests that CDV may be inducing the intrinsic apoptotic pathway in the cancer cell-line. Overall, the results strongly propose Canine distemper virus (CDV) strain as a potential candidate for cancer therapy after detailed studies.