Abstract: | Oncolytic virotherapy is a new strategy for cancer treatment for humans and
dogs. Reovirus has been proven to be a potent oncolytic virus in human medicine. Our
laboratory has previously reported that canine mast cell tumor and canine lymphoma were
susceptible to reovirus. In this study, canine solid tumor cell lines (mammary gland
tumor, osteosarcoma and malignant melanoma) were tested to determine their susceptibility
towards reovirus. We demonstrated that reovirus induces more than 50% cell death in three
canine mammary gland tumors and one canine malignant melanoma cell line. The
reovirus-induced cell death occurred via the activation of caspase 3. Ras activation has
been shown to be one of the important mechanisms of reovirus-susceptibility in human
cancers. However, Ras activation was not related to the reovirus-susceptibility in canine
solid tumor cell lines, which was similar to reports in canine mast cell tumor and canine
lymphoma. The results of this study highly suggest that canine mammary gland tumor and
canine malignant melanoma are also potential candidates for reovirus therapy in veterinary
oncology. |