Pharmacophore-Modeled Screening for HbF-Inducing Agents

描述（由申请方提供）：内源性胎儿珠蛋白（HbF）的诱导可改善β珠蛋白疾病的临床严重程度。许多短链脂肪酸和衍生物（SCFAD）刺激胎儿珠蛋白基因启动子的活性，有些通过HDAC抑制和组蛋白超乙酰化产生可接近的染色质结构。然而，现有的SCFA药物需要高剂量或静脉输注，这对许多患者来说难以耐受。对于最佳治疗，仍然需要在较低剂量下口服有效的HbF诱导剂，其通过较高的效力或在血浆中持续较长的持续时间而有效。我们的实验室最初使用药物化学方法鉴定了活性SCFA，并发现了几种抑制或刺激细胞生长的额外作用，从而消极或积极地改变治疗潜力。这些SCFAD被用于创建并随后改进3-D分子模型，或化学结构的药效团，其对于HbF诱导活性是必需的并且其中一些抑制HbF诱导活性。该药效团被用于通过分子建模虚拟筛选13，000种化合物的化学库，并鉴定了28种潜在的候选化合物。在28个预测候选药效团中，有20个被发现诱导HbF（70%的成功率）。虽然一些预测的化合物在体外具有比前几代更高的效力，但许多化合物在体内仍然不具有最佳的药代动力学特征。需要额外的候选人来开发最佳疗法。我们在这里建议使用我们验证的药效团的高通量虚拟筛选的化学库含有200万化合物的额外的HbF诱导剂。将评价所得候选物在报告基因测定中的功能活性和抑制I类HDAC的比活性，其诱导HbF而不引起细胞毒性。这种使用分子建模的虚拟筛选，通过报告基因测定和特异性HDAC活性的选择进行确认，应该产生额外的化合物，用于开发有效终身治疗的最佳HbF诱导剂

DESCRIPTION (provided by applicant): Induction of endogenous fetal globin (HbF) can ameliorate the clinical severity of the beta globin disorders. Many short chain fatty acids and derivatives (SCFADs) stimulate activity from the fetal globin gene promoter, and some create an accessible chromatin structure through HDAC inhibition and histone hyperacetylation. However, the available SCFA drugs require high doses or intravenous infusions, which are difficult for many patients to tolerate. A HbF inducer which is effective orally at lower doses, through higher potency or persistence in plasma for a longer duration of time, is still needed for an optimal therapeutic. Our laboratory initially identified active SCFAs using medicinal chemistry methods, and found several additional actions which inhibit or stimulate cell growth, altering therapeutic potential negatively or positively. These SCFADs were used to create and then refine a 3-D molecular model, or pharmacophore of chemical structures which are essential for and some of which inhibit HbF-inducing activity. This pharmacophore was used to virtually screen a chemical library of 13,000 compounds by molecular modeling, and identified 28 potential candidate compounds. 20 of the 28 pharmacophore-predicted candidates were found to induce HbF (a 70 percent success rate). While some predicted compounds have higher potency in vitro over prior generations, many still do not have optimal pharmacokinetic profiles in vivo. Additional candidates are needed for development of an optimal therapy. We propose here to use our validated pharmacophore for high-throughput virtual screening of chemical libraries containing 2 million compounds for additional HbF-inducers. The resulting candidates will be evaluated for functional activity in reporter gene assays and for specific activity in inhibiting class I HDACs, which induces HbF without causing cellular toxicity. This virtual screening using molecular modeling with confirmation by reporter assay and selection of a specific HDAC activity should generate additional compounds for development of an optimal HbF inducer for an effective life-long treatment