BLZ945通过激活JAK-STAT信号通路抑制恶性胶质瘤生长的作用机制研究

Colony stimulating factor 1 receptor (CSF-1R) is a hot spot of molecular targeted therapy，the molecular targeted drug CSF-1R inhibitor can inhibit tumor growth, but its mechanism is still unclear. Our previous work showed that the CSF-1R inhibitor BLZ945 significantly inhibited the growth of malignant glioma and improved the survival rate of malignant glioma bearing rats. Through RT-PCR and ELISA analysis, it was found that BLZ945 could regulate the expression of SOCS3 and IFN-γ in tumor tissue. Flow cytometry showed that BLZ945 could induce macrophage polarization to M1 type in tumor microenvironment. Therefore, the applicant proposed a scientific hypothesis that BLZ945 may regulate the expression of SOCS3 and IFN-γ by mediating the phosphorylation of macrophage surface molecule CSF-1R, activate JAK-STAT signaling pathway, and induce macrophage polarization to M1 type, thereby inhibit the growth of malignant glioma. In order to verify the above scientific hypothesis, the applicant intends to investigate the effect of BLZ945-induced macrophage polarization on malignant glioma and the mechanism of BLZ945 induced macrophage polarization via in vivo and in vitro, so as to provide a theoretical basis for the clinical application of BLZ945 and a new target for the treatment of malignant glioma.

巨噬细胞集落刺激因子受体（CSF-1R）是分子靶向治疗的热点，分子靶向药物CSF-1R抑制剂可抑制肿瘤生长，但其机制不清。我们的近期研究发现，CSF-1R抑制剂BLZ945可明显抑制恶性胶质瘤生长和提高荷瘤鼠生存率；通过PCR和ELISA分析发现BLZ945可调节肿瘤组织中SOCS3和IFN-γ的表达；而流式细胞术结果表明BLZ945可诱导肿瘤微环境中的巨噬细胞向M1型极化。由此，申请人提出科学假说：BLZ945可能通过介导巨噬细胞表面分子CSF-1R磷酸化，调节SOCS3和IFN-γ的表达，激活JAK-STAT信号通路，诱导巨噬细胞向M1型极化，进而抑制恶性胶质瘤的生长。为验证上述科学假说，申请人拟通过体内外实验研究BLZ945诱导的巨噬细胞极化对恶性胶质瘤的作用，以及BLZ945诱导巨噬细胞极化的分子机制。本项目可为BLZ945的临床应用提供理论依据，并为恶性胶质瘤的治疗提供新的靶点。

为了探讨巨噬细胞集落刺激因子1受体（CSF-1R）抑制剂BLZ945对恶性胶质瘤生长的作用及其相关分子机制，我们开展了本项目的研究工作。本项目主要研究内容包括：（1）构建恶性胶质瘤原位动物模型，研究BLZ945对巨噬细胞分化的作用以及恶性胶质瘤生物学行为的影响；（2）探明BLZ945在体外对巨噬细胞的影响，以及巨噬细胞极化对胶质瘤细胞增殖、侵袭、迁移和凋亡等生物学活性的作用；（3）验证BLZ945是否通过JAK1/STAT1信号通路诱导巨噬细胞极化。我们的研究结果发现：（1）BLZ945在体内通过诱导巨噬细胞向M1型极化，改善肿瘤微环境，从而抑制恶性胶质瘤的生长；（2）BLZ945作用的巨噬细胞在体外能明显抑制胶质瘤细胞的增殖、侵袭和迁移能力，并促进其凋亡；（3）BLZ945通过调节CSF-1R磷酸化，使IFN-γ表达上调，SOCS3表达下调，进而激活JAK1/STAT1信号通路，诱导巨噬细胞极化为M1型。本项目的科学意义在于，通过多层次体内外模型，首次发现了分子靶向治疗药物BLZ945对巨噬细胞极化的影响和巨噬细胞极化对恶性胶质瘤的作用，揭示了BLZ945诱导巨噬细胞极化的分子机制，为恶性胶质瘤生物治疗提供新的路径，并为恶性胶质瘤免疫治疗提供新的靶点。