The osteoblast-like differentiated phenotype of a variant of MG-63 osteosarcoma cell line correlated with altered adhesive properties.
A cell line, called MG-63.3A, was selected for its resistance to detachment from cell culture by a synthetic peptide containing the fibronectin cell-attachment sequence, Arg-Gly-Asp-Ser. The mechanism of this resistance is probably the 6-fold overproduction of the cell surface fibronectin receptor in MG-63.3A cells (Dedhar et al, J. Cell. Biol. 105, 1175-1182, (1987]. Compared to the parental, tumorigenic MG-63 cells, the non-tumorigenic MG-63.3A cells display strikingly different properties. These include an altered morphology, a slower proliferation rate, ability to form a calcified matrix in vitro, increased synthesis of type I collagen and expression of bone type alkaline phosphatase activity. Studies with purified growth factors indicate that the MG-63 and MG-63.3A cell lines respond to differentially to growth factors; the growth of MG-63 cells if stimulated by PDGF and GM-CSF and inhibited IL-1 beta, whereas the growth of MG-63.3A is unaffected by GM-CSF and IL-1 beta but is stimulated by PDGF and estradiol. We conclude from these data that the MG-63.3A cells may represent a more differentiated cell type with osteoblast-like properties. Studies are currently underway to further characterize, by electron microscopy, the calcified matrix formation by MG-63.3A cells.
Dedhar
S
S
Department of Advanced Therapeutics, Cancer Control Agency of British Columbia, Vancouver, Canada.
Mitchell
M D
MD
Pierschbacher
M D
MD
D000469:Alkaline Phosphatase / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation; D002455:Cell Division; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D009842:Oligopeptides / Q000494:pharmacology; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D010641:Phenotype; D011453:Prostaglandins / Q000378:metabolism; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure
D005353:Fibronectins; D009842:Oligopeptides; D011453:Prostaglandins; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic; D003094:Collagen; C058161:glycyl-arginyl-glycyl-aspartyl-seryl-proline; D000469:Alkaline Phosphatase