title: Tumorigenic conversion of endothelial cells.
abstract: Tumors of endothelial origin develop rarely. Until now, only two angiosarcoma (AS)-derived endothelial cell lines have been be isolated, ISO-HAS and AS-M. Both AS-derived endothelial cell lines presented the typical endothelial characteristics, such as the expression of CD31 and von Willebrand factor, but differed from normal endothelial cells in a nuclear expression of p53, in a delayed angiogenic reaction, and a reduced expression of caveolin. In addition, differences in the expression of cytokines and cell adhesion molecules responsive to proinflammatory stimuli were observed. While AS-M showed an expression pattern similar to that of human umbilical vein endothelial cells (HUVEC), ISO-HAS clearly differed from primary endothelial cells by a constitutive expression of E-selection, granulocyte macrophage colony-stimulating factor, and vascular endothelial cell adhesion molecule-1. Even though the telomeres of both AS-derived established cell lines were longer than telomeres of freshly isolated HUVEC, neither transcripts encoding telomerase nor telomerase activity were detected, suggesting that the tumor cells of endothelial origin may use a telomerase-independent mechanism for maintaining the telomere length. This observation has implications for development of therapeutic approaches for angiosarcoma.
mesh_terms: D000328:Adult; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism; D002448:Cell Adhesion; D002467:Cell Nucleus / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: C495540:CAV1 protein, human; D051242:Caveolin 1; D022461:Caveolins; D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D016159:Tumor Suppressor Protein p53; D019010:Vascular Cell Adhesion Molecule-1; D014841:von Willebrand Factor; D018799:Intercellular Adhesion Molecule-1; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019098:Telomerase