VHL Gene Restoration Supports RCC Reprogramming to iPSCs but Does Not Ensure Line Stability.

BACKGROUND: Modeling precancerous stages holds the promise to understand early transformation events, thereby offering the potential for personalized, targeted treatment. Because cancer hijacks developmental pathways, precancerous stages could potentially be modeled by reprogramming cancer cells to an induced pluripotent stem cell state and subsequently differentiating them to the target organs using organoid models. METHODS: We attempted reprogramming of patient-derived clear cell renal cell carcinoma (ccRCC) cell lines and adjacent normal renal epithelial cell lines using lentivirus or episomal reprogramming vectors. RESULTS: The cancer cells failed to reprogram while the adjacent normal cells reprogrammed with high efficiency. The von Hippel-Lindau factor (VHL) gene was re-expressed in ccRCC cells in an attempt to restore the wild-type phenotype and restore reprogramming. The VHL gene is the major tumor suppressor in ccRCC pathogenesis and a conductor of oxidative-glycolytic glucose metabolism. While its re-expression did restore the epithelial phenotype and oxidative regulation of ccRCC cells, they still failed to stably reprogram. With an optimized reprogramming workflow, VHL-corrected ccRCC cells generate NANOG+ cells; however, they remained dependent on the ectopic expression of the reprogramming factors. CONCLUSIONS: We concluded that while VHL expression is necessary for cellular reprogramming of ccRCC cells, other genetic lesions in the ccRCC cells could be preventing the stabilization of the pluripotent state.