Cancer-specific apoptosis induction in canine lymphoma cell lines by the endocytosis inhibitor dynasore

Canine lymphoma is the most common cancer in dogs and has a poor prognosis. We recently found that the endocytosis inhibitor dynasore suppresses the viability of human cancer cell lines, especially hematopoietic cancers, by inducing apoptosis. In the present study, we examined the anticancer effects of dynasore on five previously established canine lymphoma cell lines (CLBL-1, Ema, Nody-1, CLC, and GL-1). Dynasore suppressed cell viability in these canine lymphoma cell lines more effectively than in human cancer cell lines. It also induced apoptosis in CLBL-1 and Ema cells but not in peripheral blood mononuclear cells in healthy dogs or in Madin-Darby canine kidney (MDCK) cells, suggesting that the ability of dynasore to induce apoptosis is cancer-specific. Furthermore, dynasore induced a DNA damage response in CLBL-1 and Ema cells, suggesting that it acts as a genotoxic agent in canine lymphoma cell lines. These findings suggest that endocytosis inhibitors may provide a new anticancer treatment for canine lymphoma.