D/L-2-HG两种对映异构体在AML患者的预后意义及降低高水平2-HG的机制研究

最近发现AML患者具有高频率的IDH1/2突变，突变体使α酮戊二酸转为D-2-羟基戊二酸（D-2-HG）。2-HG有 D-和L-两种不同对映异构体，其溶度总和称总2-HG。我们先前的研究发现AML患者总2-HG升高与IDH1/2突变和谷氨酸酵解通路增强密切相关并且预后差。本实验将分析这两种不同异构体各自的水平及其两者的比值与IDH1/2突变的关系，并分别评估其预后意义。此外，为了寻找降低总2-HG的治疗策略，分别构建IDH1/2突变体和高表达苹果酸脱氢酶(MDH)的32D白血病细胞，采用EGCG和siRNA抑制谷氨酸脱氢酶1表达和活性，在体、内外观察治疗后细胞的D/L-2-HG水平改变和增值、分化、凋亡、耐药、异常甲基化等生物学行为改变。本研究将为AML预后评估添加新的标志物，深化D/L-2-HG在发病机制的理解，并为预后差的部分患者提供新型治疗策略，从而推动临床个体化治疗的进展。

Recently, IDH1/2 mutations were frequently detected in the blasts of AML patients, and these genes mutations caused accumulation of D-2-hydroxyglutarate(D-2-HG) from converting a-ketoglutarate.There are two different enantiomers 2-HG, D-2-HG and L-2-HG,respectively;the total concentration of D-2-HG and L-2-HG represented total 2-HG. Our previous analysis indicated that patients with high level of total 2-HG closely associated with IDH1/2 mutations and the activity of glutamilysis pathway as well as poor clinical outcome. This project aimed to further explore the relationship of D/L-2-HG or the ratio of D-2-HG to L-2-HG and IDH1/2 mutant status in AML patients, further evaluate the prognostic role of D/L-2-HG levels or the ratio as potentional predictors for clinical outcomes.In addition, to explore the treatment stratege in reducing high level of 2-HG,we will construct IDH1/2 mutant 32D cells and malate dehydrogenase (MDH) overexpressed 32D cells respectively, then utility epigallocatechin-3-gallate (EGCG) or siRNA to alter or inhibit the overexpression and/or activity of glutamine dehydrogenase 1, and therefore measure D/L-2-HG levels and observe the biologic behaviors of these cells such as the growth,differentiation, apoptosis,drug resistance and abnormal methylation. Our results will further add the new prognostic biomakers to evalute the prognosis in AML, deepen people's understanding of the pathogenesis of D/L-2-HG, and providing potential new therapeutic strateges for several patients with poor clinical outcomes, thereby promoting the progress of clinical diagnosis and treatment.