title: Hypoxia, hormones, and endothelial progenitor cells in hemangioma.
abstract: Hemangiomas are the most common tumor of infancy, and although the natural history of these lesions is well described, their etiology remains unknown. One current theory attributes the development of hemangiomas to placentally-derived cells; however, conclusive evidence to support a placental origin is lacking. While placental tissue and hemangiomas do share molecular similarities, it is possible that these parallels are the result of analogous responses of endothelial cells and vascular progenitors to similar environmental cues. Specifically, both tissue types consist of actively proliferating cells that exist within a low oxygen, high estrogen environment. The hypoxic environment leads to an upregulation of hypoxia inducible factor-1alpha (HIF-1alpha) responsive chemokines such as stromal cell derived factor-1alpha (SDF-1alpha) and vascular endothelial growth factor (VEGF), both of which are known to promote the recruitment and proliferation of endothelial progenitor cells. Increased hormone levels in the postpartum period further potentiate the growth of these lesions. In this model, increased stabilization of HIF-1 in concert with increased levels of estrogen create a milieu that promotes new blood vessel development, ultimately contributing to the pathogenesis of infantile hemangiomas.
authors: Stanford University Medical Center, Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford, CA 94305-5148, USA.
authors: Edward I
authors: EI
authors: Chang
authors: Eric I
authors: EI
authors: Chang
authors: Hariharan
authors: H
authors: Thangarajah
authors: Cynthia
authors: C
authors: Hamou
authors: Geoffrey C
authors: GC
authors: Gurtner
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D042783:Endothelial Cells / Q000473:pathology / Q000502:physiology*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006391:Hemangioma; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007223:Infant; D007231:Infant, Newborn; D009389:Neovascularization, Pathologic; D010920:Placenta; D011247:Pregnancy; D013234:Stem Cells / Q000473:pathology / Q000502:physiology*
chemical_list: D004967:Estrogens; D051795:Hypoxia-Inducible Factor 1, alpha Subunit