Mechanisms of microRNA-mediated regulation of cellular proliferation in vascular malformations

血管畸形是淋巴管或血管内皮系统的先天性异常，其特征是内皮细胞过度增殖，导致扩张的静脉、动脉和淋巴通道的形成。这些病变有扩大的倾向，侵袭附近的解剖结构，出血，感染，引起严重的疼痛和毁容，并转移重要器官的血液供应，因此可导致严重的发病率。这些病变的治疗传统上依赖于手术切除或硬化治疗，这些方法复发率和并发症都很高。控制增殖的基因的几个体细胞功能获得突变与这些病变的内皮细胞有关，使这些基因及其下游信号级联成为分子药物治疗的有吸引力的靶点。在初步实验中，我们发现已知的内皮细胞增殖调节因子microRNA-21(miR-21)在淋巴管畸形组织中上调，导致MAPK过度磷酸化，促进细胞生长。在这个方案中，我们将确定血管畸形组织和内皮细胞的整个miRNA表达谱，以识别所有异常表达的miRNAs并确定 它们对细胞增殖和异常血管形成的影响。我们将利用之前收集的冰冻组织标本、新鲜采集的血管异常组织和分离的内皮细胞，以及现有的正常内皮细胞系，进行miRNA测序、蛋白质组学分析以及体外和体内生长分析。长期目标是确定潜在的以miRNA为基础的针对血管异常血管内皮细胞增殖的治疗方法，并确定对诊断和治疗监测有用的血管异常循环生物标志物。

Vascular malformations are congenital anomalies of the lymphatic or vascular endothelial system and are characterized by a hyperproliferative phenotype of endothelial cells, which leads to the formation of ectatic veins, arteries, and lymphatic channels. These lesions can cause significant morbidity due to their propensity to enlarge, encroach on nearby anatomical structures, hemorrhage, become infected, cause significant pain and disfigurement, and divert blood supply from vital organs. Treatments for these lesions has traditionally relied on surgical excision or sclerotherapy, which have high rates of recurrence and complications. Several somatic, gain-of-function mutations in genes which control proliferation have been implicated in the endothelium of these lesions, making these genes and their downstream signaling cascades attractive targets for molecular pharmacotherapies. In preliminary experiments, we have identified microRNA-21 (miR-21), a known regulator of endothelial cell proliferation, as upregulated in lymphatic malformation tissue, leading to hyperphosphorylation of MAPK and increased cell growth. In this proposal, we will determine the entire miRNA expression profile of vascular malformation tissue and endothelial cells to identify all aberrantly expressed miRNAs and determine their effects on cellular proliferation and abnormal vessel formation. We will utilize previously collected frozen tissue specimens, freshly harvested vascular anomaly tissue and isolated endothelial cells, and existing normal endothelial cell lines which will undergo miRNA sequencing, proteomics analysis, and in vitro and in vivo growth assays. The long term goals are to identify potential miRNA-based treatments which target vascular anomaly endothelial proliferation and identify circulating biomarkers of vascular anomalies which are useful for diagnostics and treatment monitoring.