Canine invasive transitional cell carcinoma cell lines: In vitro tools to complement a relevant animal model of invasive urinary bladder cancer

Abstract

Urinary bladder cancer is the fifth most common form of cancer in humans in the United States. Urinary bladder cancer also occurs in pet dogs, and naturally-occurring bladder cancer in pet dogs very closely resembles invasive bladder cancer (intermediate to high grade invasive transitional cell carcinoma, InvTCC) in humans. Pet dogs with InvTCC offer a highly relevant resource for preclinical studies in bladder cancer. For translational research in which findings are moved from in vitro experiments through in vivo studies in dogs to human trials, access to human and canine bladder cancer cell lines is important. Cell lines derived from canine InvTCC have been lacking. Here we describe eight such cell lines. Eight cell lines were established from canine InvTCC. Cells were characterized using immunocytochemistry, evaluated for anchorage independent growth in soft agar, and assessed for tumorigenicity in athymic mice. Western blotting was used to identify expression of proteins of interest in human InvTCC. The cell lines were confirmed to be of epithelial origin by their expression of cytokeratin and E-cadherin. Seven cell lines were found to be tumorigenic in athymic mice, and 4 of these cell lines grew in an anchorage independent manner. The cell lines expressed several proteins of interest associated with bladder cancer prognosis and progression in humans, including p53, cox-2, and pRb protein. These established cell lines can be used for comparative bladder cancer research and to evaluate new therapy approaches in vitro prior to in vivo testing.