Alterations of gene expression in endoderm differentiation of F9 teratocarcinoma cells

During the endoderm differentiation of F9 mouse embryonal carcinoma cells, as induced by sodium butyrate (NaBu) or retinoic acid (RA), gene expression s of alkaline phosphatase (AL-Pase), pyruvate kinase (PKase) and 5' ribonuc leotide phosphohydrolase (5'-Nase) were examined. The specific activity of ALPase was found to increase by 3.5-fold after 48 hr treatment with NaBu. I n contrast, specific activity of PKase were decreased by 63%. Northern blot analysis revealed that the elevation of ALPase activity resulted from an i ncrease in the level of liver/bone/kidney (L/B/K)-type ALPase mRNA and that the decrease of PKase activity was dependent on a reduction in the level O f M-2-PKase mRNA. Interestingly, when NaBu was removed from the culture med ium, the levels of these mRNAs reverted to their original levels after 16 h . During these processes, the specific activity of 5'-Nase and the level of its mRNA remained unchanged. In contrast, when F9 cells were treated with RA, only the level of L/B/K-type ALPase mRNA increased. Lastly, we examined the issue of whether an increase in the level of ALPase mRNA is dependent on the transcriptional activation of the mouse L/B/K-type ALPase gene. Tran sient transfection assays using luciferase reporter constructs showed that the promoter activity increased as the result of treatment with RA but not with NaBu. Mol. Reprod. Dev. 60: 165-171, 2001. (C) 2001 Wiley-Liss, Inc.