Small Cell-Penetrating Glyco-Decoys Sidetrack Selectin Ligand Biosynthesis

我们有一种小分子糖诱饵的初步数据，它可以特异性地侧轨配体的生物合成以进行e选择，并且是一种新型抗炎药的候选药物。选择家族的三个成员E、L和P是组成性表达在血液白细胞表面和活化的内皮细胞和血小板上的炎症粘附分子。作为黏液蛋白糖蛋白配体的糖基硅烷酸LeX和硅烷酸Lea的发现激起了人们对小分子治疗炎症、血管和癌症疾病的极大兴趣。潜在的前提是，通过拮抗选择素-配体相互作用来控制白细胞粘附率可以导致对抗这些疾病的新疗法。2011年，GlycoMimetics公司以3.4亿美元的价格将一种selectin配体衍生物授权给辉瑞公司，用于首个镰状细胞炎症适应症，这是该领域新发现的商业价值的一个例子。我们采取了一种不同的方法，专注于构建天然配体的酶的特异性。在PSGL1、E选择和L选择中，已知L选择结合硫酸粘蛋白聚糖。我们的发现导致了磺胺- lex，磺胺- lea和各种核心2 （Galss3 [Galss4GlcNAcss6]GalNAc¿）聚糖作为这些细胞粘附蛋白的配体的发现。在另一种方法中，我们专注于合成修饰的单糖类似物，如4-氟- glcnac醋酸酯和4-氟- galnac醋酸酯，作为选择配体组装酶的细胞穿透代谢抑制剂。我们还合成了小分子作为糖诱饵来破坏这些选择的天然配体的生物合成。一个小的合成糖诱饵与天然受体底物竞争，从而将糖链的合成从内源性糖蛋白和糖脂转移到可溶性配体上，后者作为细胞结合配体选择结合的抑制剂。其次，在糖诱饵存在的情况下，细胞结合分子上配体的缺失阻止了开始炎症过程的粘附事件。该策略的潜在主题是，关于关键酶特异性的生物合成知识是开发基于抑制选择粘附系统的小分子治疗发现的迫切要求。我们研究了n -聚糖配体的酶组装对E选择的特异性。初步，我们发现了一种新的化合物，它可以破坏糖聚糖的生物合成以进行E选择（专利申请）。在第一阶段，主要目标是合成类似物和相关化合物，并测试作为HL60细胞中E选择配体生物合成的抑制剂。CD44具有E选择的配体，也具有透明质酸的特异性受体，促进正常细胞的迁移。CD44在多种癌细胞中高度表达。一个小分子抑制E选择特异性n-聚糖的生物合成，如CD44，为减轻炎症疾病和癌症中的粘附事件带来了新的潜在工具。这个第一阶段的提案符合SBIR计划的核心原则，即有前景的商业产品。

DESCRIPTION: We have preliminary data for a small molecule glyco-decoy that specifically side-tracks the biosynthesis of the ligand for E-selection, and is a candidate for a novel anti-inflammatory. The three members E, L and P of the selection family are inflammatory adhesion molecules expressed constitutively on the surface of blood leukocytes and on activated endothelial cells and platelets. Discoveries of glycans sialyl LeX and sialyl Lea as mucin glycoprotein ligands for the selection family of cell adhesion proteins has stirred immense interest in pursuit of small molecules for treatment of inflammatory, vascular and cancer diseases. The underlying premise is that controlling the rate of leukocyte adhesion by antagonizing selectin-ligand interactions can lead to new therapies to combat these diseases. GlycoMimetics, Inc., has licensed a selectin ligand derivative to Pfizer in 2011 for $340M with the first indication sickle cell inflammation, as an example of the newly perceived commercial value in this area. We took a different approach, focusing on specificities of sets of enzymes that construct the native ligands. Among PSGL1, E selection and L selection, the latter is known to bind sulfated mucin-glycans. Our findings led to the discovery of sulfo-LeX, sulfo-Lea and various core 2 (Galss3 [Galss4GlcNAcss6]GalNAc¿) glycans as the ligands for these cell adhesion proteins. In another approach, we focused on synthesis of modified analogs of monosaccharides such as 4-fluoro-GlcNAc acetates and 4-fluoro-GalNAc acetates as cell-penetrating metabolic inhibitors of the selection ligand assembly enzymes. We also synthesized small molecules as glyco-decoys to disrupt biosynthesis of natural ligands of these selections. A small synthetic glyco-decoy competes with the natural acceptor-substrate and thus diverts the synthesis of the glycan chains from endogenous glycoproteins and glycolipids to soluble ligands, which act as inhibitors of selection binding to cell-bound ligand. Secondarily, ligand absence on cell-bound molecules in the presence of the glyco-decoy precludes adhesion events that begin the inflammatory process. The underlying theme of this strategy is that biosynthetic knowledge about specificity of key enzymes as "hits" is a compelling requirement for developing small molecules for therapeutic discoveries based on inhibiting selection adhesion systems. We have examined specificity of enzyme assembly of N-glycan ligands for E selections. Preliminarily, we have discovered a novel compound that disrupts the biosynthesis of glycans for E selections (patent submitted). In Phase I, the prime objective is to synthesize analogs and related compounds and test as inhibitors of E selection ligand biosynthesis in HL60 cells. CD44 is endowed with a ligand for E selection, and also has a specific receptor for hyaluronic acid, promoting migration in normal cells. CD44 is highly expressed in various cancer cells. A small molecule inhibiting biosynthesis of E selection-specific N-glycans such as in CD44 brings new potential tools for mitigation of inflammatory disorders and adhesion events in cancer. This Phase I proposal meets the central tenet of the SBIR program for promising commercial products.