We investigated the effects of embryoid body (EB) forming conditions on the expression of hepatocyte marker genes such as alpha-fetoprotein, albumin and CYP7A1 in cells cultured on Matrigel-coated plates for 15 d. The expression levels of hepatocyte marker genes in the cells cultured for 2 d for EB formation from cynomolgus monkey embryonic stem (cmES) cells was higher than those in cells cultured for 5 d. However, the fragment-size of cmES colonies did not markedly affect the expression levels. The expression levels of hepatocyte marker genes, and CYP1A1 and CYP2C43 in cells cultured on Matrigel were considerably higher than those on Matrigel reduced and collagen I. CYP1A1 and CYP3A8 mRNAs were significantly induced by 3-methylcholanthrene and rifampicin, respectively. However, CYP2C43 and CYP2D17 were not induced by these compounds. These results suggested that the differentiation into hepatocytes is affected by the incubation period for EB formation, and that Matrigel successfully promoted in vitro differentiation of cmES cells to hepatocytes.
