title: Characterization of intermediate filaments expressed by Ewing tumor cell lines.
abstract: The histogenesis of Ewing sarcoma is still controversial; we therefore studied the expression of intermediate filaments (IF) in cell lines derived from Ewing tumors since identification of IF in tumor cells is considered a reliable marker of tissue origin and differentiation. All nine lines studied expressed vimentin IF; in addition, a small number of Ewing cells from three lines expressed keratin filaments. After treatment with phorbol esters, a high percentage of cells from these three lines synthesize keratin IF identified by immunoblotting as keratin 8 and 18 polypeptides, which are expressed by single epithelia and epithelial cells in early embryonic development. Furthermore cells from a fourth line synthesize keratins after transplantation in nude mice. These data indicate that, under certain conditions, undifferentiated Ewing cells may acquire an IF phenotype related to that of epithelial cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D003599:Cytoskeleton / Q000648:ultrastructure*; D006801:Humans; D007124:Immunoenzyme Techniques; D007382:Intermediate Filaments / Q000648:ultrastructure*; D007633:Keratins / Q000096:biosynthesis; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D012512:Sarcoma, Ewing / Q000648:ultrastructure*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D007633:Keratins; D013755:Tetradecanoylphorbol Acetate