Expression of Glypican-3 in Mouse Embryo Stem Cells and its Derived Hepatic Lineage Cells Treated with Diethylnitrosamine in vitro

To clarify the role of stem cells in hepatocarcinogenesis, glypican-3 (GPC-3) and E-cadherin expression wasinvestigated in embryonic cell lineages. Mouse embryonic stem cells (ESCs), hepatic progenitor cells (HPCs) andhepatocyte like cells (HCs), representing 0, 22 and 40 days of differentiation, respectively, were treated in vitro withdiethylnitrosamine (DEN) at four doses (0, 1, 5 and 15 mM; G1, G2, G3 and G4, respectively) for 24 h and GPC-3 and E-cadherin expression was examined by relative quantitative real-time PCR and immunocytochemistry.GPC-3 mRNA expression was significantly different for G4 at day 0 (p<0.001) and for G4 at day 22 (p<0.01)compared with the control (G1). E-cadherin mRNA expression was significantly different for G3 and G4 atday 0 (p<0.05 and p<0.001, respectively), for G2 and G4 (p<0.05 and p<0.001, respectively) at day 22 and forG2 and G4 (p<0.01 and p<0.001, respectively) at day 40 compared with G1. Immunofluorescence staining forGPC-3 showed a membranous and/or granular expression in cytoplasm of ESCs and HPCs and granular and/ordiffuse expression in cytoplasm of HCs, which were also stained by E-cadherin. DEN treatment increased GPC-3 expression in ESCs, HPCs and HCs, with increase of E-cadherin expression. Taken together, the expressionof GPC-3 was altered by DEN treatment. However, its expression pattern was different at the stage of embryostem cells and its derived hepatic lineage cells. This suggests that GPC-3 expression may be modulated in theprogeny of stem cells during their differentiation toward hepatocytes, associated with E-cadherin expression.