Propranolol has been widely used in treating infantile hemangiomas (IHs). But recurrence of IHs was found in some cases on cessation of propranolol treatment. The other is that Chinese individuals reacted to propranolol differently from American Whites. Whether the difference of sensitivity is due to the beta adrenoceptor (beta-AR) expression pattern of hemangioma initiating cells remains unclear. In the present study, we isolated hemangioma-derived stem cells (hemSCs) from proliferative IHs and analyzed the biological characteristics and beta-AR expression pattern of hemSCs by immunostaining, Western blotting and multilineage differentiation assay as well. We also tested the effects of propranolol on hemSCs by evaluating VEGF expression, proliferation and apoptosis related parameters. Our results indicated that CD133(+) hemSCs located pre-vascular in proiferative IH tissues. Both beta 1 and beta 2-AR were expressed, while beta 2-AR was dominant on hemSCs. Propranolol at 100-150 mu M inhibited proliferation of hemSCs, not did 50 mu M. Propranolol down-regulated VEGF expression of hemSCs, instead of inducing apoptosis. The adipogenic potential was enhanced by propranolol. Therefore, our current results suggested propranolol could not induce apoptosis of hemSCs, but played a curative role though suppressing VEGF synthesis and enhancement of adipogenesis of hemSCs. Our results might partially provide the insight of mechanism of relapse in some cases on cessation of propranolol treatment.
[1]Shanghai Jiao Tong Univ, Sch Med, Xinhua Hosp, Dept Plast & Reconstruct Surg, Shanghai 200030, Peoples R China.
[2]Shanghai Fudan Univ, Huadong Hosp, Dept Nursing, Shanghai, Peoples R China.
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