title: Mouse embryos contain polypeptide growth factor(s) capable of inducing a reversible neoplastic phenotype in nontransformed cells in culture.
abstract: A growth-factor-like substance capable of inducing nontransformed mouse AKR-2B, rat NRK, and EGF-receptorless mouse NR6 cells to form progressively growing colonies in soft agar was identified in acid/ethanol extracts of 17-day mouse embryos. This "mouse embryo factor" (MEF) is similar to previously described transforming growth factors in that it is capable of stimulating DNA synthesis and conferring a reversible transformed morphology on nontransformed cells in vitro. Passage of crude embryo extracts over a Bio-Gel P-60 column gave a major peak of soft agar growth-stimulating activity in the 15,000 molecular weight range with a minor peak at about 22,000. This biological activity was sensitive to treatment with either trypsin or dithiothreitol, but was unaffected by heat (56 degrees C for 30 minutes or 100 degrees C for 3 minutes), indicating that the activity is due to a heat-stable polypeptide(s) with disulfide bonds. Separation of these polypeptide(s) by chromatography on carboxymethyl cellulose revealed two peaks of soft agar growth-stimulating activity which did not cochromatograph with a peak of epidermal growth factor receptor-competing activity. The similarities of this mouse embryo-derived growth factor to previously identified transforming growth factors suggest that both fetal development and neoplastic transformation may be affected by similar mechanisms.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002455:Cell Division; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004247:DNA / Q000096:biosynthesis; D004229:Dithiothreitol / Q000494:pharmacology; D066246:ErbB Receptors; D005347:Fibroblasts / Q000378:metabolism; D006133:Growth Substances / Q000302:isolation & purification*; D006358:Hot Temperature; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains / Q000196:embryology*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D014357:Trypsin / Q000494:pharmacology
chemical_list: D006133:Growth Substances; D011956:Receptors, Cell Surface; D004247:DNA; D066246:ErbB Receptors; D014357:Trypsin; D004229:Dithiothreitol