HUMAN OMENTAL MICROVASCULAR ENDOTHELIAL AND MESOTHELIAL CELLS - CHARACTERIZATION OF 2 DISTINCT MESODERMALLY DERIVED EPITHELIAL-CELLS

Human omental microvascular endothelial (HOME) and mesothelial (MESO) cells share many phenotypic properties, but can be characterized from one another based upon a comprehensive panel of endothelial and mesoth elial markers. Traditional cell markers such as vonWillebrand factor, DiI-Ac-LDL, and Ulex europaeus I lectin are not sufficient to distingu ish between HOME and MESO cells. Furthermore, immunoreactivity to a pa nel of endothelial cell-specific monoclonal antibodies, including repr esentatives from the known clusters of differentiation (CD), indicate that some of these antigens are coexpressed in HOME and MESO cells, In distinguishing between the two cell types, HOME and not MESO cells ex press E-selectin, E/P-selectin, P-selectin (CD62), Le-y, anti VLA-6 (C Dw49f). Moreover, HOME cells and not MESO cells form tube-like struct ures when cultured on Matrigel. MESO cells differ from HOME cells base d upon (I) the expression of cytokeratins; (2) their rapid proliferati on in response to platelet-derived growth factor; and (3) a change fro m an epitheliod to fibroblast-like morphology in response to tumor nec rosis factor and epidermal growth factor. Both HOME and MESO cells exp ress tissue plasminogen activator and plasminogen activator inhibitor, but urokinase activity is only expressed by MESO cells. As there is n o one universal endothelial or mesothelial cell marker that can specif ically confirm the identity of these cells, it appears necessary to em ploy a comprehensive panel of cell markers to rule out the possibility of misidentifying a cell culture. (C) 1997 Academic Press.