Intrinsic regulation of hemangioma involution by platelet-derived growth factor.
Infantile hemangioma is a vascular tumor that exhibits a unique natural cycle of rapid growth followed by involution. Previously, we have shown that hemangiomas arise from CD133+ stem cells that differentiate into endothelial cells when implanted in immunodeficient mice. The same clonally expanded stem cells also produced adipocytes, thus recapitulating the involuting phase of hemangioma. In the present study, we have elucidated the intrinsic mechanisms of adipocyte differentiation using hemangioma-derived stem cells (hemSCs). We found that platelet-derived growth factor (PDGF) is elevated during the proliferating phase and may inhibit adipocyte differentiation. hemSCs expressed high levels of PDGF-B and showed sustained tyrosine phosphorylation of PDGF receptors under basal (unstimulated) conditions. Inhibition of PDGF receptor signaling caused enhanced adipogenesis in hemSCs. Furthermore, exposure of hemSCs to exogenous PDGF-BB reduced the fat content and the expression of adipocyte-specific transcription factors. We also show that these autogenous inhibitory effects are mediated by PDGF receptor-β signaling. In summary, this study identifies PDGF signaling as an intrinsic negative regulator of hemangioma involution and highlights the therapeutic potential of disrupting PDGF signaling for the treatment of hemangiomas.
Department of Pathology, University of Western Ontario, London, Ontario, Canada.
E E
EE
Roach
R
R
Chakrabarti
N I
NI
Park
E C
EC
Keats
J
J
Yip
N G
NG
Chan
Z A
ZA
Khan
D000071916:AC133 Antigen; D017667:Adipocytes / Q000378:metabolism / Q000473:pathology; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000077214:Becaplermin; D002454:Cell Differentiation; D049109:Cell Proliferation; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D006391:Hemangioma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D009365:Neoplasm Regression, Spontaneous / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism; D015398:Signal Transduction
D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D010982:Platelet-Derived Growth Factor; C000606024:Prom1 protein, mouse; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D017479:Receptors, Platelet-Derived Growth Factor