title: Human melanoma proteoglycan: expression in hybrids controlled by intrinsic and extrinsic signals.
abstract: Human malignant melanoma cells express specific chondroitin sulfate proteoglycans (mel-CSPG) on the surface, both in vivo and in vitro. Melanocytes in normal skin show no detectable mel-CSPG but can be induced to express the antigen when cultured in the presence of cholera toxin and the tumor promoter 12-O-tetradecanoylphorbol-13-acetate. Most other cell types do not express mel-CSPG either in vivo or in vitro. A study was designed to examine regulatory signals controlling mel-CSPG expression. The gene encoding mel-CSPG was mapped to human chromosome 15, and this chromosome was introduced into rodent cells derived from distinct differentiation lineages. Three types of mel-CSPG--expressing hybrids were found: (i) hybrids derived from human melanomas; (ii) hybrids derived from human cells that do not express mel-CSPG; and (iii) hybrids derived from human cells expressing mel-CSPG that are antigen-negative but that are induced to express mel-CSPG when cultured on extracellular matrix instead of plastic surfaces. Thus, mel-CSPG expression can be controlled both through intrinsic signals, provided by the differentiation program of the rodent fusion partner, and through extrinsic signals, provided by specific cell-matrix interactions.
mesh_terms: D053674:Aggrecans; D000818:Animals; D000911:Antibodies, Monoclonal; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D002874:Chromosome Mapping; D002901:Chromosomes, Human, 13-15; D006224:Cricetinae; D003412:Cricetulus; D016326:Extracellular Matrix Proteins; D005786:Gene Expression Regulation / Q000187:drug effects; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D006822:Hybrid Cells / Q000187:drug effects / Q000378:metabolism*; D037181:Lectins, C-Type; D008214:Lymphocytes / Q000378:metabolism; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism*; D051379:Mice; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009447:Neuroblastoma / Q000378:metabolism; D011509:Proteoglycans; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: C508320:Acan protein, mouse; C508321:Acan protein, rat; D053674:Aggrecans; D000911:Antibodies, Monoclonal; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D037181:Lectins, C-Type; D009363:Neoplasm Proteins; D011509:Proteoglycans; D002772:Cholera Toxin; D013755:Tetradecanoylphorbol Acetate