Qian Long, Ji Zhuqing, Mei Lingyun, Zhao Jun
Department of Thoracic Surgery, The First Affiliated Hospital of Soochow University, No. 899 Pinghai Road, Suzhou, 215006, Jiangsu, China.
Department of Thoracic Surgery, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, 223300, China.
Immunol Res. 2024 Dec 17;73(1):16. doi: 10.1007/s12026-024-09563-9.
Lung adenocarcinoma (LUAD) is the common form of lung cancer and is prone to distant metastasis. IGF2BP2, an m6A modification regulator, is upregulated in lung cancer tissue, but its specific role within the LUAD tumor microenvironment (TME) is unknown. We explored the role of IGF2BP2 in the progression of LUAD. IGF2BP2 expression in LUAD patient specimens and controls was evaluated through bioinformatics, Western blot, and immunohistochemistry. LUAD subcutaneous and orthotopic xenograft tumor models were established, alongside a co-culture system of tumor-associated neutrophils (TANs) and A549 cells. Functional assays assessed IGF2BP2's role under treatment with JX5, an IGF2BP2 inhibitor. Mechanistic assays explored the interaction between IGF2BP2 and LOX1 in 293T cells. IGF2BP2 was significantly upregulated in LUAD tissues, with higher expression levels predicting worse prognosis for patients (p < 0.001). In subcutaneous and orthotopic xenograft models, treatment with JX5, an IGF2BP2 inhibitor, reduced tumor size, volume, and weight (p < 0.001). JX5 also significantly reduced the concentrations of pro-inflammatory cytokines in peripheral blood (p < 0.01 and p < 0.001). Flow cytometry analysis indicated JX5 reduced CD11b+Ly6G+/CD45+ cells (TANs) in the TME (p < 0.001). Mechanistically, JX5 downregulated LOX1 expression in vivo, and co-culture experiments further demonstrated that IGF2BP2 promotes LUAD progression through LOX1-mediated regulation of TAN activity (p < 0.01 and p < 0.001). Overexpression of LOX1 reversed the inhibitory effects of JX5 on TAN infiltration, tumor cell viability, and apoptosis (p < 0.01 and p < 0.001). Additionally, RNA immunoprecipitation revealed that IGF2BP2 binds to LOX1 mRNA at its m6A modification site, stabilizing LOX1 and enhancing its function in the TME. Knockdown of IGF2BP2 accelerated LOX1 mRNA degradation, confirming its role in maintaining LOX1 stability (p < 0.01 and p < 0.001). IGF2BP2 recognizes and stabilizes LOX1 through m6A modification, contributing to TAN-mediated LUAD progression. Overall, these findings offer new insights into LUAD progression and demonstrate that IGF2BP2 is a key regulator that promotes tumor advancement, highlighting the IGF2BP2-LOX1 axis as a potential therapeutic target for LUAD.
肺腺癌（LUAD）是肺癌的常见形式，易于发生远处转移。IGF2BP2是一种m6A修饰调节因子，在肺癌组织中上调，但其在LUAD肿瘤微环境（TME）中的具体作用尚不清楚。我们探讨了IGF2BP2在LUAD进展中的作用。通过生物信息学、蛋白质免疫印迹和免疫组织化学评估LUAD患者标本和对照中IGF2BP2的表达。建立了LUAD皮下和原位异种移植肿瘤模型，以及肿瘤相关中性粒细胞（TANs）与A549细胞的共培养系统。功能试验评估了IGF2BP2抑制剂JX5处理下IGF2BP2的作用。机制试验探讨了IGF2BP2与293T细胞中LOX1的相互作用。IGF2BP2在LUAD组织中显著上调，表达水平较高预示患者预后较差（p<0.001）。在皮下和原位异种移植模型中，IGF2BP2抑制剂JX5处理可减小肿瘤大小、体积和重量（p<0.001）。JX5还显著降低外周血中促炎细胞因子的浓度（p<0.01和p<0.001）。流式细胞术分析表明，JX5减少了TME中CD11b+Ly6G+/CD45+细胞（TANs）（p<0.001）。机制上，JX5在体内下调LOX1表达，共培养实验进一步证明IGF2BP2通过LOX1介导的TAN活性调节促进LUAD进展（p<0.01和p<0.001）。LOX1的过表达逆转了JX5对TAN浸润、肿瘤细胞活力和凋亡的抑制作用（p<0.01和p<0.001）。此外，RNA免疫沉淀显示IGF2BP2在其m6A修饰位点与LOX1 mRNA结合，稳定LOX1并增强其在TME中的功能。敲低IGF2BP2加速了LOX1 mRNA的降解，证实了其在维持LOX1稳定性中的作用（p<0.01和p<0.001）。IGF2BP2通过m6A修饰识别并稳定LOX1，促进TAN介导的LUAD进展。总体而言，这些发现为LUAD进展提供了新的见解，并证明IGF2BP2是促进肿瘤进展的关键调节因子，突出了IGF2BP2-LOX1轴作为LUAD潜在治疗靶点的地位。
