Stem cells in infantile hemangioma

Background:Infantile hemangioma(IH)is the most common tumor of infancy and the pathogenesis is still unclear.Recent new evidences have been shown that IH arises from stem cells.Data sources:Based on recent original publications from Pub Med,Elsevier and Google Scholar,a large number of articles about pathogenesis and treatment of IH were selected by their titles and abstracts.Results:The hemangioma-derived stem cells expressed stem cell-specific marker CD133 and mesenchymal markers CD29,CD44,and comprised between 0.1%and 1%of the cells in proliferating-phase IH.During the proliferative phase,stem cells differentiated into large amounts of endothelial cells and pericytes;while during the involuting phase,stem cells became less and predominantly differentiated toward adipocytes.Signaling pathways like VEGF/VEGFR,Notch signaling,were found to be related to these processes.Corticosteroids,Rapamycin and propranolol had a significant effect on stem cells by inhibiting the cell growth or differentiation,or participating in maintaining the cell stability.Conclusions:Stem cells derived from hemangioma play an important role in the pathogenesis of IH,and may be important targets of therapy.