异柠檬酸脱氢酶突变体特异性抑制剂靶向消除骨髓增生异常综合征干细胞的有效性研究

Clonal heterogeneity Hematopoietic stem / progenitor cells (HSPC) inefficient proliferation is one of the major causes of myelodysplastic syndrome (MDS). Approximately 4-12% of MDS patients have a combination of isocitrate dehydrogenase (IDH) mutations. MDS patient with mutant IDH has a higher percentage of cancer cells in the bone marrow and poor prognosis. IDH mutant-specific inhibitor (IDHi) targeting therapy recently reported can treat IDH mutant AML / MDS, but it is not yet clear whether IDHi can eliminate MDS HSPC. To validate this, we had established a highly efficient and reliable MDS humanized murine model "MDS-MISTRG-PDX" and secondary transplantation method which can be used for MDS HSPC related research and MDS preclinical drug experimental study. We will establish IDH mutant MDS engrafted humanized mouse model and given IDH mutant inhibitor targeted therapy, though measure the changes of 2HG level, analysis the cell differentiation, define differentiation characteristics of HSPC, confirm clonal mutation expression by Targeted Exome Sequencing and define HSPC-differentiated cell population by Single-Cell Sequencing in order to investigate the effectiveness of IDH mutant-specific inhibitor eliminate MDS HSPC. The results of the research can provide new ideas and new methods for MDS laboratory research and provide experimental support for the targeted therapy of MDS.

克隆性异质性造血干／祖细胞（HSPC）无效增生是导致骨髓增生异常综合征(MDS)的主要原因之一。约4-12% MDS病人合并异柠檬酸脱氢酶（IDH）突变，这部分病人骨髓中癌细胞百分比更高，疾病预后极为不良。IDH突变体特异性抑制剂（IDHi）靶向治疗AML/MDS是最新研究热点，但IDHi靶向治疗是否消除MDS HSPC或使其正常，尚未明确。项目团队前期已建立高效可靠的MDS人源化小鼠模型MDS-MISTRG-PDX及二次骨髓移植方法，可用于 MDS HSPC研究及临床前药物实验。本项目拟建立IDH突变MDS-MISTRG-PDX并予IDHi治疗，通过检测IDH 突变产物2HG水平，分析HSPC分化情况及特性，靶向外显子测序验证克隆突变及单细胞测序明确HSPC分化种群变化，进行IDHi靶向消除MDS HSPC的有效性研究。本研究可为MDS研究提供新思路及新方法并为MDS靶向治疗提供支持。

克隆性异质性造血干／祖细胞（HSPC）无效增生是导致骨髓增生异常综合征(MDS)的主要原因之一。约4-12% MDS病人合并异柠檬酸脱氢酶（IDH）突变，这部分病人骨髓中癌细胞百分比更高，疾病预后极为不良。项目组按照原定的研究计划，建立了IDH2体外过表达HEL细胞系，验证了IDH2突变体特异性抑制剂Enasidenib可特异性有效体外抑制IDH2细胞系及原代AML病人细胞增殖，并可促进细胞分化成熟。通过建立的高效可靠MDS-MISTRG-PDX人源化小鼠模型，通过检测Enasidenib治疗前后IDH2突变产物2HG水平，靶向外显子测序验证克隆突变及单细胞测序明确HSPC分化种群变化，CFU检测等分析HSPC分化情况及特性，验证了IDH2突变体特异性抑制剂Enasidenib可抑制IDH2突变MDS/AML病人肿瘤干细胞，同时促进肿瘤干细胞的分化。通过建立的小鼠骨髓二次移植方法，进一步验证了IDH2突变体特异性抑制剂Enasidenib可抑制IDH2突变AML病人肿瘤干细胞的增殖及降低细胞干性的保持。项目组基本完成本项目制定的目标：移植建立了IDH2 突变MDS-MISTRG-PDX人源化小鼠模型，验证了IDH2突变体特异性抑制剂Enasidenib对MDS/AML的治疗效果，并进一步明确IDH2突变体特异性抑制剂Enasidenib靶向治疗MDS/AML HSPC的有效性，为临床MDS/AML治疗提供了实验支持。本项目已发表SCI期刊论文2篇，学术专著1篇。本项目所建立的MDS-MISTRG-PDX人源化小鼠模型可为后续MDS/AML临床转化研究提供良好的动物模型。