title: Comparison of intra- and extracellular transforming growth factors from nontransformed and chemically transformed mouse embryo cells.
abstract: Multiple transforming growth factors (TGFs) have been isolated from the serum-free conditioned media and acid-ethanol cell extracts of nontransformed AKR-2B and chemically transformed AKR-MCA mouse cells. The TGF activity was analyzed using Bio-Gel P-60 chromatography in 1 M acetic acid and tested for colony-stimulating activity in soft agar using AKR-2B, AKR-2B (clone 84A), NRK, and AKR-MCA cells as indicators. Both intracellular and extracellular TGF activity from AKR-MCA and AKR-2B cells show a major peak of AKR-2B and epidermal growth factor-potentiated NRK colony-stimulating activity that coelute in the 13,000 +/- 2,000 molecular weight region. In the 24,000 +/- 7,000 molecular weight range, AKR-MCA cells produce intracellular and extracellular NRK colony-stimulating activity that is not potentiated by epidermal growth factor, while the intracellular and extracellular NRK colony-stimulating activity produced by AKR-2B cells requires added epidermal growth factor for colony formation. Also important in determining the growth and morphological characteristics of a cell line, besides the production of a TGF, is the ability of a cell to respond to TGF activity. We have shown that the transformed AKR-MCA cells form more colonies than AKR-2B cells in response to certain TGF activities. This suggests that the increased responsiveness of AKR-MCA cells to TGFs may be important in determining its phenotype.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D004622:Embryo, Mammalian; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors; D051379:Mice; D008806:Mice, Inbred AKR; D008970:Molecular Weight; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism; D015291:Transforming Growth Factors
chemical_list: D010455:Peptides; D011956:Receptors, Cell Surface; D004815:Epidermal Growth Factor; D015291:Transforming Growth Factors; D066246:ErbB Receptors