title: Isozyme differentiation of aldolase and pyruvate kinase in fetal, regenerating, preneoplastic, and malignant rat hepatocytes during culture.
abstract: Aldolase and pyruvate kinase isozymes were investigated in cultured hepatocytes from fetal, regenerating, and 2-acetyl-aminofluorene-fed rat liver as well as in some epithelial liver cell lines. Our results show that: (a) cell proliferation and prolonged expression of specific isozymes were found only in cultured hepatocytes from 17-day old fetuses; (b) the fetal type of pyruvate kinase expressed in regenerating and carcinogen-treated liver was temporarily lost only in cultured hepatocytes from regenerating liver; (c) the adult type of aldolase and pyruvate kinase was absent in one epithelial cell line derived from a carcinogen-treated liver and in the hepatoma tissue cell (HTC) line but was found in the Faza clone of the Reuber H35 cell line during the 50 first passages in vitro; and (d) the isozyme pattern of pyruvate kinase was always more strongly shifted than that of aldolase. The observations suggest that: (a) hepatocytes from carcinogen-treated liver exhibit the same lack of ability to proliferate in primary culture as normal adult hepatocytes; (b) adult hepatocytes can produce fetal isozymes without prior cell division; (c) pyruvate kinase is a stronger marker of dedifferentiation (retrodifferentiation) than aldolase; and (d) regulatory processes of isozyme expression are different during ontogenesis, regeneration, and hepatocarcinogenesis.
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D008099:Liver / Q000196:embryology / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology; D008115:Liver Regeneration; D011770:Pyruvate Kinase / Q000378:metabolism*; D051381:Rats
chemical_list: D007527:Isoenzymes; D011770:Pyruvate Kinase; D005634:Fructose-Bisphosphate Aldolase