ALCAM (CD166): its role in hematopoietic and endothelial development

A critical role for the endothelium of yolk sac and dorsal aorta has been s hown in embryonic hematopoiesis. A stromal cell line derived from yolk sac, YSCL-72, has been chosen to search for a novel molecule associated with em bryonic hematopoiesis. Analysis between YSCL-72 and an adult aorta-derived endothelial cell line, EOMA, demonstrated that activated leukocyte cell adh esion molecule (ALCAM, or CD166) was specifically expressed in YSCL-72 but not in EOMA. Immunohistochemical study showed that ALCAM was expressed In t he endothelium of yolk sac and dorsal aorta but not In adult aorta. ALCAM-t ransfected EOMA cells supported development of hematopoietic progenitor cel ls compared with vector-transfected EOMA cells, suggesting that ALCAM appea red to be crucial for hematopoiesis. In addition, ALCAM was found to be inv olved in capillary tube formation and hemangioblast differentiation. Taken together with these findings, ALCAM is highly associated not only with embr yonic hematopoiesis but also vasculoangiogenesis. (C) 2001 by The American Society of Hematology.