HEPATOCYTIC TRANSCRIPTION FACTOR EXPRESSION IN HUMAN EMBRYONAL CARCINOMA AND YOLK-SAC CARCINOMA CELL-LINES - EXPRESSION OF HNF-3-ALPHA IN MODELS OF EARLY ENDODERMAL CELL-DIFFERENTIATION

Retinoic acid treatment of the multipotent human embryonal carcinoma c ell line GCT 27 X-1 induced differentiation into an epithelial cell ty pe which morphologically resembled rodent visceral endoderm in vitro. The differentiated cells expressed some markers characteristic of yolk sac, such as cytokeratin 19 and extracellular matrix proteins, but no ne of the secreted serum proteins produced by normal yolk sac or liver . HNF-3 alpha expression increased upon retinoic acid-induced GCT 27 X -1 differentiation. This increase in HNF-3 alpha expression may charac terize an early stage in the differentiation of extraembryonic endoder m. In support of this hypothesis, we found that a yolk sac carcinoma c ell line with a phenotype similar to rodent visceral endoderm expresse d transcripts for HNF-1 alpha, -1 beta, -3 alpha, -3 beta, -3 gamma, a nd 4, whereas yolk sac carcinoma cell lines resembling rodent parietal endoderm expressed transcripts for HNF-3 alpha. The results support t he conclusion that hepatocytic transcription factors, particularly HNF -3 alpha, may play an important role in early endodermal differentiati on in man. (C) 1994 Academic Press, Inc.