Cao Chengzhang, Lai Haiyin, Shi Yuzhen
Department of Thoracic Surgery, Longyan First Affiliated Hospital of Fujian Medical Univensity, Longyan, China.
Department of Critical Care Medicine, Longyan First Affiliated Hospital of Fujian Medical Univensity, Longyan, China.
J Biochem Mol Toxicol. 2025 Apr;39(4):e70251. doi: 10.1002/jbt.70251.
Enhanced macrophage M2 polarization and CD8 T cell dysfunction contribute to the pathophysiology of non-small cell lung cancer (NSCLC). Motor neuron and pancreatic homeobox 1 (MNX1) has emerged as a potential tumor-promoting player. Here, we clarified the activity of MNX1 in NSCLC. PMA-induced THP-1 M0-like macrophages or CD8 T cells were co-cultured with NSCLC cells. Cell colony formation, migration, proliferation, apoptosis, and invasiveness were assessed by colony formation, wound healing, CCK-8, flow cytometry, and transwell assays, respectively. The ratio of CD206 macrophages was analyzed by flow cytometry. Ki-67 expression was tested by immunofluorescence. ChIP and luciferase assays were used to evaluate the relationship between MYCN and MNX1. MNX1 was highly expressed in NSCLC, and its loss-of-function suppressed cell growth, motility, and invasiveness in NSCLC cells. MNX1 depletion also diminished macrophage M2 polarization and CD8 T cell apoptosis. Mechanistically, MYCN increased MNX1 expression at the transcriptional level. MNX1 increase reversed the impact of MYCN depletion on NSCLC cell malignant behaviors, macrophage M2 polarization, and CD8 T cell viability. MYCN depletion diminished the in vivo growth of A549 subcutaneous xenografts. Additionally, MNX1 increase counteracted the impact of MYCN depletion on the Wnt/β-catenin pathway. Our findings elucidate the oncogenic role of the MYCN/MNX1/Wnt/β-catenin pathway in NSCLC by driving macrophage M2 polarization and diminishing CD8 T cell viability. Our study thus uncovers a novel mechanism underlying NSCLC development and highlights potential targets for combating NSCLC.
增强的巨噬细胞M2极化和CD8 T细胞功能障碍促成了非小细胞肺癌（NSCLC）的病理生理学。运动神经元和胰腺同源盒1（MNX1）已成为一个潜在的促肿瘤因子。在此，我们阐明了MNX1在NSCLC中的活性。将佛波酯（PMA）诱导的THP-1 M0样巨噬细胞或CD8 T细胞与NSCLC细胞共培养。分别通过集落形成、伤口愈合、CCK-8、流式细胞术和Transwell实验评估细胞集落形成、迁移、增殖、凋亡和侵袭能力。通过流式细胞术分析CD206巨噬细胞的比例。通过免疫荧光检测Ki-67表达。采用染色质免疫沉淀（ChIP）和荧光素酶实验评估MYCN与MNX1之间的关系。MNX1在NSCLC中高表达，其功能丧失抑制了NSCLC细胞的生长、运动和侵袭能力。MNX1缺失还减少了巨噬细胞M2极化和CD8 T细胞凋亡。机制上，MYCN在转录水平上增加MNX1表达。MNX1表达增加逆转了MYCN缺失对NSCLC细胞恶性行为、巨噬细胞M2极化和CD8 T细胞活力的影响。MYCN缺失减少了A549皮下异种移植瘤的体内生长。此外，MNX1表达增加抵消了MYCN缺失对Wnt/β-连环蛋白信号通路的影响。我们的研究结果阐明了MYCN/MNX1/Wnt/β-连环蛋白信号通路通过驱动巨噬细胞M2极化和降低CD8 T细胞活力在NSCLC中的致癌作用。因此，我们的研究揭示了NSCLC发生发展的一种新机制，并突出了对抗NSCLC的潜在靶点。
