title: Increased proteoglycan synthesis following the differentiation of F9 embryonal carcinoma cells: formation of a differentiation-specific proteoheparan sulfate.
abstract: We have examined changes in proteoglycan synthesis by F9 embryonal carcinoma cells after the cells have been treated with retinoic acid or retinoic acid plus cholera toxin. Retinoic acid is known to stimulate the differentiation of this cell type to a primitive endoderm-like cell characterized by the production of basement membrane components such as type IV collagen, laminin and proteoglycans. We have now demonstrated that proteoglycan synthesis and secretion were further stimulated when cholera toxin was added in addition to retinoic acid. Moreover, media of these fully differentiated cells was found to contain a different species of proteoheparan sulfate not produced by stem cells or retinoic acid-treated cells. This proteoheparan sulfate had a high density upon CsCl gradient centrifugation. The protein core of this proteoheparan sulfate was estimated by SDS gel electrophoresis to be approximately 15,000 daltons.
authors.affiliation: Collagen and Connective Tissue Laboratories, Veterans Administration Outpatient Clinic, Boston, MA 02108.
authors.forename: C T
authors.initials: CT
authors.lastname: Baldwin
authors.forename: J E
authors.initials: JE
authors.lastname: Silbert
authors.forename: D E
authors.initials: DE
authors.lastname: Humphries
authors.forename: J N
authors.initials: JN
authors.lastname: Cogburn
authors.forename: B D
authors.initials: BD
authors.lastname: Smith
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002499:Centrifugation, Density Gradient; D002772:Cholera Toxin / Q000494:pharmacology; D054278:Embryonal Carcinoma Stem Cells; D006025:Glycosaminoglycans / Q000096:biosynthesis / Q000493:pharmacokinetics; D006493:Heparin / Q000031:analogs & derivatives* / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000502:physiology*; D011509:Proteoglycans / Q000096:biosynthesis* / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D006025:Glycosaminoglycans; D011509:Proteoglycans; C036090:heparin proteoglycan; D014212:Tretinoin; D006493:Heparin; D002772:Cholera Toxin