title: Lowered antioxidant enzymes in spontaneously transformed embryonic mouse liver cells in culture.
abstract: Normal embryonal mouse liver cells in culture were shown to undergo spontaneous transformation during prolonged subculture. The spontaneously transformed cells lost their anchorage dependence, as measured by a soft agar assay, and gave rise to tumors in nude mice. Accompanying this transformation, the antioxidant enzymes, copper- and zinc-containing superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT) and glutathione reductase, decreased significantly in activity; the decline in enzymatic activity of CuZnSOD, MnSOD and CAT was due to a decline in the levels of immunoreactive protein. These spontaneously transformed high passage in vitro liver cells appeared similar in morphology, antioxidant enzyme activity and tumorigenicity to their counterparts transformed by N-methyl-N-nitro-N-nitrosoguanidine and Simian virus 40. These data provide experimental evidence that changes in antioxidant enzymes are associated with spontaneous in vitro cellular transformation of mouse embryonal liver cells.
authors.affiliation: Radiation Research Laboratory, University of Iowa, Iowa City 52242.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: L W
authors.initials: LW
authors.lastname: Oberley
authors.forename: T D
authors.initials: TD
authors.lastname: Oberley
authors.forename: J H
authors.initials: JH
authors.lastname: Elwell
authors.forename: E
authors.initials: E
authors.lastname: Sierra-Rivera
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015153:Blotting, Western; D002374:Catalase / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D002478:Cells, Cultured; D002875:Chromosomes; D005980:Glutathione Reductase / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000196:embryology / Q000201:enzymology*; D008113:Liver Neoplasms / Q000201:enzymology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase