Lopes Flávia Cristine Mascia, Ferreira Regiane, Albuquerque Dulcinéia Martins, Silveira Angélica A Antoniellis, Costa Raquel, Soares Raquel, Costa Fernando Ferreira, Conran Nicola
INCT de Sangue, Hematology and Hemotherapy Center, School of Medical Sciences, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
Department of Biochemistry (U38-FCT), Faculty of Medicine, University of Porto, Porto, Portugal.
Microvasc Res. 2014 Jul;94:106-13. doi: 10.1016/j.mvr.2014.05.009. Epub 2014 Jun 9.
Hydroxyurea (HU), or hydroxycarbamide, is used for the treatment of some myeloproliferative and neoplastic diseases, and is currently the only drug approved by the FDA for use in sickle cell disease (SCD). Despite the relative success of HU therapy for SCD, a genetic disorder of the hemoglobin β chain that results in red-cell sickling, hemolysis, vascular inflammation and recurrent vasoocclusion, the exact mechanisms by which HU actuates remain unclear. We hypothesized that HU may modulate endothelial angiogenic processes, with important consequences for vascular inflammation. The effects of HU (50-200 μM; 17-24 h) on endothelial cell functions associated with key steps of angiogenesis were evaluated using human umbilical vein endothelial cell (HUVEC) cultures. Expression profiles of the HIF1A gene and the miRNAs 221 and 222, involved in endothelial function, were also determined in HUVECs following HU administration and the direct in vivo antiangiogenic effects of HU were assessed using a mouse Matrigel-plug neovascularization assay. Following incubation with HU, HUVECs exhibited high cell viability, but displayed a significant 75% inhibition in the rate of capillary-like-structure formation, and significant decreases in proliferative and invasive capacities. Furthermore, HU significantly decreased HIF1A expression, and induced the expression of miRNA 221, while downregulating miRNA 222. In vivo, HU reduced vascular endothelial growth factor (VEGF)-induced vascular development in Matrigel implants over 7 days. Findings indicate that HU is able to inhibit vessel assembly, a crucial angiogenic process, both in vitro and in vivo, and suggest that some of HU's therapeutic effects may occur through novel vascular mechanisms.
羟基脲（HU），即羟基尿素，用于治疗某些骨髓增殖性疾病和肿瘤性疾病，目前是美国食品药品监督管理局（FDA）批准用于治疗镰状细胞病（SCD）的唯一药物。尽管HU治疗SCD取得了相对成功，SCD是一种由血红蛋白β链的遗传紊乱导致红细胞镰变、溶血、血管炎症和反复血管阻塞的疾病，但HU发挥作用的确切机制仍不清楚。我们推测HU可能调节内皮血管生成过程，对血管炎症产生重要影响。使用人脐静脉内皮细胞（HUVEC）培养物评估了HU（50 - 200 μM；17 - 24小时）对与血管生成关键步骤相关的内皮细胞功能的影响。在给予HU后，还测定了HUVEC中参与内皮功能的HIF1A基因以及miRNA 221和222的表达谱，并使用小鼠基质胶栓血管生成试验评估了HU的直接体内抗血管生成作用。与HU孵育后，HUVEC表现出高细胞活力，但毛细血管样结构形成速率显著抑制75%，增殖和侵袭能力也显著降低。此外，HU显著降低HIF1A表达，诱导miRNA 221表达，同时下调miRNA 222。在体内，HU在7天内减少了基质胶植入物中血管内皮生长因子（VEGF）诱导的血管发育。研究结果表明，HU在体外和体内均能够抑制血管组装，这是一个关键的血管生成过程，并表明HU的一些治疗作用可能通过新的血管机制发生。
