miR-10b调节巨噬细胞极化促进脑胶质瘤免疫逃逸的分子机制

Glioblastoma (GBM) is the most malignant glioma characterized with low cure rate, high recurrence rate and poor prognosis. In recent years, accumulating evidence found that M1/M2 polarization of macrophages (Mφ) located in the tumor microenvironment plays an important role in various tumor immune escape. We found that miR-10b was significantly up-regulated in GBM through microRNA microarray screening. Subsequent studies found that miR-10b can be up-regulated by M2-promoted TGF-β and down-regulated by M1-induced LPS. In addition, several M1/M2 markers like TLR4 are targets of miR-10b. Therefore, we hypothesize that TGF-β can promote the M2 polarization of Mφ by up-regulating miR-10b and thus inhibit the killing effect of Mφ on GBM. While the secretion of TGF-β by M2 cells can exacerbate the expression of miR-10b, leading to the worsening positive feedback pathway of GBM. This project intends to explore the detailed mechanism of miR-10b in GBM immune escape through regulation of Mφ polarization on the basis of previous studies and by using cell fate tracing, myeloid origin Mφ recruitment block and residential Mφ clearance techniques. This study has important theoretical and clinical significance for systematically understanding the molecular mechanism of GBM immune escape.

胶质母细胞瘤（GBM）是恶性程度最高的胶质瘤，治愈率低，复发率高，患者预后差。近年来研究发现肿瘤微环境中巨噬细胞（Mφ）的M1/M2极化在肿瘤免疫逃逸中发挥重要作用。课题组前期通过芯片筛选发现，miR-10b在GBM中显著上调。随后研究发现miR-10b可由促进M2极化的TGF-β上调，并可被促进M1极化的LPS等因子下调；另外TLR4等多种M1/M2标志分子是miR-10b的靶基因。据此，我们推测TGF-β通过上调miR-10b促进Mφ的M2极化，抑制Mφ对GBM的杀伤作用。而M2细胞分泌的TGF-β可加剧miR-10b表达，使GBM进入恶化的正反馈通路。为此，本项目拟在前期基础上，通过体内细胞命运示踪技术、髓系来源Mφ募集阻断和组织定居Mφ清除等技术手段，探讨miR-10b通过调控Mφ极化而参与GBM免疫逃逸的分子机制。该研究对系统理解GBM免疫逃逸的分子机制具有重要的理论和临床意义。

胶质母细胞瘤（GBM）是恶性程度最高的胶质瘤，治愈率低，复发率高，患者预后差。肿瘤微环境中巨噬细胞（Mφ）的M1/M2极化在肿瘤免疫逃逸中发挥重要作用。课题组前期通过芯片筛选发现，miR-10b-5p和miR-103a-3p在GBM中显著上调。机制研究发现miR-10b-5p和miR-103a-3p可由促进M2极化的细胞因子TGF-β1上调，并可被促进M1极化的LPS/IFN-γ等因子下调；GBM细胞中的miR-10b-5p和miR-103a-3p可以外泌体形式进入巨噬细胞中并促进其M2极化，从而促进GBM的免疫逃逸。生信分析表明TGF-β1、miR-10b-5p和miR-103a-3p的水平与GBM的恶性表型紧密相关。课题组利用Crispr-Cas9技术制备了miR-10b-5p和miR-103a-3p基因敲除小鼠，构建了miR-10b-5p和miR-103a-3p基因敲低荧光素酶报告稳转细胞株系，为后期荷瘤模型动物实验奠定了基础。完成了miRNA调控后转录组测序，以期进一步深挖拓展miRNA分子调控GBM进展的分子机制。另外，我们发现miR-10b-5p在胰腺癌中也显著上调，且促进了胰腺癌的克隆形成、增殖、侵袭和迁移。提示我们miR-10b-5p在多种肿瘤进展中可能发挥促进免疫逃逸的共性作用。上述研究有望丰富肿瘤免疫逃逸理论，发现GBM诊断治疗新靶点。最后，2019年以来SARS-CoV-2迅速感染全球，对人民生命安全和医疗卫生系统发出了史无前例的挑战，抑郁、焦虑、脑雾等成为典型新冠后遗症。课题组利用小鼠疾病模型系统性研究了BJ、Delta、Omicron等不同突变株感染机体后的病毒复制水平、对动物行为学的影响、组织病理学变化以及分子水平的改变，初步解析了SARS-CoV-2导致情绪-认知障碍及其潜在的机制，为新冠疫苗、新药研发以及后期恢复治疗奠定了理论基础。