Urothelial carcinoma (UC), more commonly known as bladder cancer, affects approximately 81,000 people a year in the United States and is the fourth most common type of cancer among men. Age also plays a tremendous factor, as 90% of people affected by bladder cancer are older than 55, and if the cancer has metastasized the 5-year survival rate is 35%. This requires the advancement of early detection and treatment methods for bladder cancer. The development of clinically relevant systems to serve as a bridge between preclinical murine studies and human clinical practice is of vital importance. The Oncopig Cancer Model (OCM) is a novel transgenic swine platform that recapitulates human cancer through development of site/cell specific tumors after Cre recombinase induced expression of heterozygous KRASG12D and TP53R167H transgene. In this study, we standardized a protocol for the development and growth of Oncopig UC cell lines that faithfully recapitulates in vitro and in vivo features of human bladder cancer.
The focus of this preliminary research was to successfully create OCM UC cell lines that mimic features of human UC. OCM urothelial cell lines (n=7) were isolated from whole bladders collected from male Oncopigs at euthanasia. OCM urothelial cell lines were exposed to Cre recombinase 48 hours post isolation to induce expression of KRASG12D and TP53R167H transgenes, resulting in development of OCM UC cell lines. Differences in migration rates were observed between OCM urothelial and UC cell lines, confirming cellular invasiveness. RT-PCR was performed after several passages to confirm KRASG12D and TP53R167H gene expression, which was observed in OCM UC but not urothelial cell lines. Uroplakin II and pan- Cytokeratin (PCK-26) are markers for UC and urothelial cells, respectively, and are used to diagnose UC clinically. OCM UC cells stained positively for Uroplakin II and PCK-26, confirming their identity as malignant UC cells. Future work is needed to confirm OCM and human UC display similar histological and molecular features, and to develop strategies for in vivo OCM UC tumor development.