Endothelial progenitor cells in infantile hemangioma.
Infantile hemangioma is an endothelial tumor that grows rapidly after birth but slowly regresses during early childhood. Initial proliferation of hemangioma is characterized by clonal expansion of endothelial cells (ECs) and neovascularization. Here, we demonstrated mRNA encoding CD133-2, an important marker for endothelial progenitor cells (EPCs), predominantly in proliferating but not involuting or involuted hemangioma. Progenitor cells coexpressing CD133 and CD34 were detected by flow cytometry in 11 of 12 proliferating hemangioma specimens from children 3 to 24 months of age. Furthermore, in 4 proliferating hemangiomas, we showed that 0.14% to 1.6% of CD45(-) nucleated cells were EPCs that coexpressed CD133 and the EC marker KDR. This finding is consistent with the presence of KDR(+) immature ECs in proliferating hemangioma. Our results suggest that EPCs contribute to the early growth of hemangioma. To our knowledge, this is the first study to show direct evidence of EPCs in a human vascular tumor.
Program in Vacular Biology, Department of Surgery, Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA. ying.yu@tch.harvard.edu
Ying
Y
Yu
Alan F
AF
Flint
John B
JB
Mulliken
June K
JK
Wu
Joyce
J
Bischoff
D000071916:AC133 Antigen; D015703:Antigens, CD; D015152:Blotting, Northern; D002455:Cell Division; D002675:Child, Preschool; D004730:Endothelium, Vascular / Q000473:pathology* / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D006023:Glycoproteins / Q000235:genetics; D006391:Hemangioma / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D008297:Male; D010455:Peptides / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D013234:Stem Cells / Q000473:pathology* / Q000502:physiology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics; D019043:Vascular Neoplasms / Q000473:pathology* / Q000503:physiopathology
D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D012333:RNA, Messenger; D040301:Vascular Endothelial Growth Factor Receptor-2