Efficient derivation of immortalized, isogenic cell lines from genetically defined murine hepatoblastomas.

Hepatoblastoma (HB), the most common childhood liver cancer and the simplest of human neoplasms molecularly, commonly deregulates Wnt/β-catenin (B), Hippo/YAP (Y) and/or NFE2/NRF2 (N) signaling. Murine HBs that closely resemble human tumors can be generated by over-expressing pairwise or triple combination of mutant forms of B,Y and N. However, research is hampered by a paucity of established cell lines from either species. We show here that immortalized cell lines can be routinely established from murine HBs that over-express oncogenic B + Y and B + Y + N if the Cdkn2a tumor suppressor locus is concurrently mutated as also commonly occurs in human HBs. Eight BY and 3 BYN cell lines are characterized here, 10 of which can be regrown as subcutaneous and metastatic lung tumors in the immune-competent mice from which they originated. During maintenance as hypoxic spheroids in vitro, tumor cells express endothelial cell markers. In vivo, similar cells appear adjacent to blood vessels. The ability to routinely generate isogenic HB cell lines with defined oncogenic drivers should facilitate studies that are best performed in vitro. The approach may also be useful for deriving HB cell lines associated with less common molecular drivers and from human tumors.