转录因子BTB-CNC同源体1通过上调赖氨酰氧化酶促进胶质母细胞瘤中巨噬细胞的募集和极化

目的研究转录因子BTB-CNC同源体1（BACH1）通过上调赖氨酰氧化酶（LOX）促进胶质母细胞瘤（GBM）中巨噬细胞的募集和极化。方法基于公共数据库分析BACH1在胶质瘤中的表达特点和预后情况；构建BACH1过表达的稳转GBM细胞系，并对其进行转录组和蛋白质组联合测序分析；利用Transwell共培养体系将GBM细胞与巨噬细胞共培养，观察对巨噬细胞的趋化和极化影响；构建GL261-C57BL/6小鼠脑胶质瘤原位模型，探索靶向调控BACH1对肿瘤生长以及免疫微环境中巨噬细胞的影响。结果首先，相对于正常脑组织，BACH1在胶质瘤中高表达，且在GBM患者中表达最高；同时还发现高表达BACH1的GBM患者预后较低表达BACH1的患者更差。然后，测序结果发现相对于BACH1空载组，BACH1过表达组中肿瘤相关巨噬细胞趋化因子LOX的转录和蛋白水平均显著升高（转录组，P<0.000 1；蛋白组，P=0.001 5）。其次，流式实验结果表明，相对于BACH1空载组，BACH1过表达组中M2型肿瘤相关巨噬细胞（CD11b+CD206+）明显增加(P<0.000 1)，当加入LOX抑制剂后，两组中的M2型肿瘤相关巨噬细胞明显减少且BACH1过表达组减少的更明显（BACH1-Vec，P=0.001 5；BACH1-OE，P=0.001 3）。小鼠脑胶质瘤原位模型结果提示，相对于BACH1空载组，BACH1过表达组中肿瘤体积更大且侵袭能力更强。结论BACH1能够通过促进GBM细胞分泌肿瘤相关巨噬细胞趋化因子LOX进而影响巨噬细胞的募集和极化，最终促进肿瘤的恶性进展。

Objective To investigate how the transcription factor BTB-CNC homology 1(BACH1) upregulates lysyl oxidase(LOX) to promote macrophage recruitment and polarization in glioblastoma(GBM). Methods BACH1 expression and prognosis in gliomas were analyzed using public databases. A stable GBM cell line overexpressing BACH1 was constructed and analyzed by transcriptomics and proteomics. Transwell co-culture experiments were performed to observe the effects on macrophage chemotaxis and polarization. A GL261-C57BL/6 mouse model was used to explore the effects of targeted regulation of BACH1 on tumor growth and macrophages in the immune microenvironment. Results BACH1 was found to be highly expressed in GBM compared to normal brain tissue, and patients with high BACH1 expression had worse prognoses than those with low BACH1 expression. Transcriptomic and proteomic analysis revealed that LOX was significantly upregulated in the BACH1 overexpression group compared to the BACH1 empty vector group (transcriptomics, P<0.000 1; proteomics, P=0.001 5). Flow cytometry experiments showed that M2 macrophages(CD11b+CD206+) were significantly increased in the BACH1 overexpression group compared to the BACH1 empty vector group(P<0.000 1), and that the addition of a LOX inhibitor significantly reduced the number of M2 macrophages, with a greater decrease in the BACH1 overexpression group BACH1-Vec, P=0.001 5; BACH1-OE, P=0.001 3). In the mouse model, tumors in the BACH1 overexpression group were larger and more invasive than those in the BACH1 vector group. Conclusion BACH1 promotes macrophage recruitment and polarization in GBM by upregulating LOX, ultimately leading to malignant progression of the tumor.