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Induction and Analysis of Epithelial to Mesenchymal Transition
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Induction and Analysis of Epithelial to Mesenchymal Transition

Published on: August 27, 2013

Transforming growth factor-beta and retinoic acid modulate phenotypic transformation of normal rat kidney cells

E J van Zoelen, T M van Oostwaard, S W de Laat

    The Journal of Biological Chemistry
    |April 15, 1986
    PubMed

    Insights

    Phenotypic transformation of normal rat kidney (NRK) cells can be induced by various combinations of growth factors like epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) with retinoic acid (RA). Transforming growth factor-beta (TGF-β) and RA show similar modulation effects.

    Area of Science:

    • Cell biology
    • Molecular biology
    • Cancer research

    Background:

    • Normal rat kidney (NRK) cells are a model system for studying cellular transformation.
    • Growth factors like EGF, PDGF, and TGF-β play critical roles in cell growth and differentiation.
    • Retinoic acid (RA) is a key signaling molecule involved in various developmental processes.

    Purpose of the Study:

    • To investigate the ability of EGF, PDGF, and TGF-β, in combination with RA, to induce phenotypic transformation in NRK cells.
    • To determine if TGF-β or EGF receptor ligands are essential for NRK cell transformation.
    • To compare the modulatory effects of TGF-β and RA on NRK cell transformation.

    Main Methods:

    • Utilized a growth factor-defined medium with chemically inactivated serum to eliminate serum-derived growth factor effects.
    • Assayed the induction of anchorage-independent growth in NRK cells using combinations of growth factors and RA.
    • Quantified EGF and PDGF receptor numbers on NRK cells following treatment.

    Main Results:

    • Phenotypic transformation of NRK cells can be induced by EGF + RA and PDGF + RA + TGF-β, indicating neither TGF-β nor EGF receptor ligands are essential.
    • TGF-β and RA exhibit similar modulatory roles in phenotypic transformation.
    • Both TGF-β and RA increase EGF receptor numbers in NRK cells, but not PDGF receptors.
    • TGF-β is mitogenic for Swiss 3T3 fibroblasts without insulin, while RA requires insulin for mitogenic effects on these cells.

    Conclusions:

    • Phenotypic transformation of NRK cells requires specific combinations of polypeptide growth factors and modulating agents.
    • The process of phenotypic transformation can be induced under a broader range of conditions than previously understood.
    • TGF-β and RA share both similarities and differences in their biological activities and modulatory functions.

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