RESUMEN
Pingyangmycin (also known as Bleomycin A5) is produced by Streptomyces verticillus var. pingyangensis n.sp., and has antitumor activities against a variety of tumor cells. The aim of the present study was to determine the molecular mechanism(s) underlying the therapeutic effects of pingyangmycin against infantile hemangiomas. Human hemangiomaderived endothelial cells (HemECs) were treated with pingyangmycin at varying concentrations (100, 200 or 300 µg/ml), and the morphological changes and apoptosis levels were assessed. The gene expression changes were determined by cDNA microarray technology. Transmission electron microscopy examination revealed that the pingyangmycintreated HemECs exhibited typical apoptotic characteristics, including chromatin condensation and the formation of apoptotic bodies. AnnexinV staining demonstrated that pingyangmycin caused a significant and dosedependent induction of apoptosis in the HemECs. In the pingyangmycintreated HemECs, 4,752 genes demonstrated at least 2fold expression changes at the mRNA level. Quantitative polymerase chain reaction confirmed that pingyangmycin significantly upregulated the expression of p53, p53induced protein with death domain, Bax, p53 upregulated modulator of apoptosis and p53 inducible gene 3, and downregulated the expression of murine double minute 2. The data demonstrated that the proapoptotic activity of pingyangmycin against infantile hemangiomas involves p53 pathway activation.
Asunto(s)
Antibióticos Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Bleomicina/análogos & derivados , Células Endoteliales/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Bleomicina/toxicidad , Regulación hacia Abajo/efectos de los fármacos , Células Endoteliales/citología , Células Endoteliales/metabolismo , Hemangioma/metabolismo , Hemangioma/patología , Humanos , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , ARN Mensajero/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Regulación hacia Arriba/efectos de los fármacos , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Propranolol, a non-selective ß-blocker, is emerging as an effective treatment for complicated hemangiomas. The aim of this study was to investigate the molecular mechanism(s) underlying the therapeutic effects of propranolol against hemangiomas, using primary infantile hemangioma endothelial cells (IHECs). IHECs were treated with various concentrations of propranolol and morphological changes and apoptosis were assessed. Changes in the expression levels of apoptosis-related genes were examined. Annexin-V staining revealed that propranolol at 40, 50 and 60 µg/ml caused a concentration-dependent increase in the apoptosis of IHECs. Morphological analyses revealed that exposure to 50 µg/ml propranolol resulted in typical apoptotic changes, including shrinkage, the formation of apoptotic bodies and retention of plasma membrane integrity. Gene expression analyses revealed that propranolol treatment led to a marked increase in the expression of caspase-8, cytochrome c, apoptosis-inducing factor, caspase-3 and poly (ADP-ribose) polymerase 1, as well as a concomitant reduction in lamin B1 expression. Our data collectively demonstrate that propranolol induces apoptosis of IHECs through activation of the intrinsic and extrinsic apoptotic pathways, which represents an important mechanism for its therapeutic effects against infantile hemangiomas.