Aberrant wnt/β-catenin signaling and amplification/overexpression of Myc are associated with hepatoblastoma (HB), the most prevalent type of childhood liver cancer. To address their roles in the pathogenesis of HB, we generated mice in which Myc and mutant β-catenin were targeted to immature cells of the developing mouse liver. Perinatal coexpression of both genes promoted the preferential development of HBs over other tumor types in neonatal mice, all of which bore striking resemblance to their human counterparts. Integrated analysis indicated that tumors emerged as a consequence of Myc-driven alterations in hepatoblast fate in a background of pan-hepatic injury, inflammation, and nuclear factor (erythroid-derived 2)-like 2/Nrf2-dependent antioxidant signaling, which was specifically associated with expression of mutant β-catenin but not Myc. Immunoprofiling of human HBs confirmed that approximately 50% of tumors demonstrated aberrant activation of either Myc or Nfe2l2/Nrf2, while knockdown of Nrf2 in a cell line–derived from a human HB with
Sarah A. Comerford, Elizabeth A. Hinnant, Yidong Chen, Hima Bansal, Shawn Klapproth, Dinesh Rakheja, Milton J. Finegold, Dolores Lopez-Terrada, Kathryn A. O’Donnell, Gail E. Tomlinson, Robert E. Hammer
Hepatic expression of mutant β-catenin retards growth and cooperates with Myc to promote HBs and HCCs in neonatal mice.