An orthotropic mouse model of combined hepatocellular-cholangiocarcinoma derived from oncogene transformed hepatoblasts

Objective To establish an orthotropic mouse model of combined hepatocellular-cholangiocarcinoma. Methods Hepatoblasts were isolated by E-cadherin conjugated microbeads from E13.5 fetal liver of C57BL/6J mice. After culture for several days, expended hepatoblasts were transfected with retrovirus encoding c-Myc mutant T58A. Then 1×106 modified hepatoblasts were delivered into portal system of retrosine pretreated mice by splenic injection (c-Myc mutant T58A group, n=6). Non-modified hepatoblasts served as control for injection (wildtype group, n=6). Eight weeks after surgery, all 12 recipient mice were sacrificed for pathological examination. Immunohistochemistry and double-fluorescence immunostaining were performed on 4 μm sections to determine the phenotype of tumors. Results Mice delivered with hepatoblasts constructively expressing c-Myc mutant T58A showed high incidence of hepatocarcinogenesis (4 in 6 mice, 66.7%), while those delivered with wildtype hepatoblasts showed no tumor (0 in 6 mice, 0.0%). The tumors pathologically mimicked human combined hepatocellular-cholangiocarcinoma. By immunohistochemistry and double-fluorescence immunostaining, the tumor cells were confirmed with colocalization of ALB and K19. Conclusion We generated an orthotropic mouse model of combined hepatocellular-cholangiocarcinoma derived from oncogene transformed hepatoblasts. Key words: Combined hepatocellular-cholangiocarcinoma; Hepatoblast; Retrovirus; Model, animal; Oncogene