Cell density dependent effect of a tumor promoter on proliferation and chondrogenesis of limb bud mesenchymal cells.
When limb bud mesenchymal cells are cultured at high density, chondrogenesis takes place in vitro. Treatment of such cultures with the tumor promoter 12-O-tetradecanoyl phorbol 13-acetate (TPA) resulted in complete inhibition of chondrogenesis as indicated from staining the cultures for proteoglycans and from RNA hybridization to cDNA probes specific for four cartilage macromolecules. The effect of TPA varied depending on the initial plating density. At high density, TPA inhibited cell proliferation. At low density, cell proliferation was stimulated by TPA and above a certain cell density, chondrogenesis took place even in the presence of TPA. These results are interpreted to mean that the effect of TPA on chondrogenesis is indirect, possibly through its influence on cell proliferation.
Department of Biology, University of Dayton, Ohio 45469-0001.
P A
PA
Tsonis
P F
PF
Goetinck
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002356:Cartilage / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002452:Cell Count / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D005121:Extremities / Q000196:embryology; D008648:Mesoderm / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D013755:Tetradecanoylphorbol Acetate; D002118:Calcium