Yap/Taz介导的髓源性抑制细胞（MDSC）生成在急性髓系白血病监测中的临床和机制研究

It is important to look for molecular or immune markers related to the progression of acute myeloid leukemia (AML) and monitoring of minimal residual disease. Ours previous study has found that marrow-derived suppressor cells (MDSC) in bone marrow of adult patients with AML were significantly increased, and affected the clinical course and prognosis. In recent years, it has been found that YAP/Taz in Hippo pathway is a key factor in the regulation of immune microenvironment. Our preliminary experiment showed YAP/Taz signal is activated in bone marrow of AML patients. So we hypothesized that the inactivation of Hippo pathway in AML leukemia cells resulting in the binding of Yap / Taz to the nucleus with TEAD，the expression of gene transcription, the induction of cytokines/chemokine expression and secretion in extracellular vesicles, which mediated the induction of MDSCs, the inhibition of T Cells on the killing of tumor cells, thus promote the progress of AML. This study is to determine the expression of Hippo pathway in clinical AML bone marrow samples, the localization of Yap / Taz and its relationship with the proportion of MDSCs and clinical prognosis. The important role of Yap / Taz is determined at the cellular level by co-culturing leukemia cells with PMBC cells by RNA interference techniques. Molecular mechanisms is determined by Separation of extracellular vesicles and detection of the contents changes. It will provides new ideas for AML treatment and monitoring.

寻找急性髓系白血病（AML）疾病进展和微小残留病灶监测相关分子或免疫标记有重要意义。申请者前期研究发现成人AML患者骨髓中髓源性抑制细胞（MDSC）明显增高，并影响临床病程和预后。近年来研究发现Hippo通路中YAP/Taz是调节免疫微环境的关键因素。本课题组预实验显示AML患者骨髓细胞中存在YAP/Taz信号激活。据此提出假设：AML白血病细胞中Hippo通路失活，Yap/Taz进入核内与TEAD结合，促进基因转录，诱导细胞外囊泡中细胞/趋化因子的表达分泌，介导MDSC生成，抑制T细胞对肿瘤细胞的杀伤作用，促进AML进展。本研究拟检测临床骨髓样本中Hippo通路的表达，Yap/Taz的定位及其与MDSCs比例和临床预后的相关性。在细胞水平通过白血病细胞和PMBC细胞共培养及RNA干扰技术确定Yap/Taz的重要作用。分离细胞外囊泡，检测内容物研究分子机制，为AML治疗和监测提供新思路。

急性髓系白血病（AML）完全缓解后复发是一大难题，我们前期研究发现成人AML患者骨髓中髓源性抑制细胞（MDSC）明显增高，并影响临床病程和预后。我们的预实验显示AML患者骨髓细胞中存在YAP/Taz信号激活。所以，我们假设：AML白血病细胞中Hippo通路失活，Yap/Taz进入核内与TEAD结合，促进基因转录，诱导细胞外囊泡中细胞/趋化因子的表达分泌，介导MDSC生成，抑制T细胞对肿瘤细胞的杀伤作用，促进AML进展。为了验证此假设，我们用Q-PCR检测了AML骨髓标本中Hippo通路的变化，并用流式细胞术检测了PMN-MDSC和M-MDSC两个亚型的变化。并用慢病毒毒感染AML细胞系MOLM-13，再通过嘌呤霉素筛选稳定细胞株后与健康志愿者PBMC同培养，用流失细胞术检测MPN-MDSC和M-MDSC的变化。我们的研究发现，AML患者中PMN-MDSC比例明显较正常对照组高，并且AML细胞系MOLM-13明显诱导人PBMC中PMN-MDSC的分化。