M2 macrophage-derived exosomal EHF transcriptionally activates FGFR1 to promote malignant phenotypes and glycolysis in NSCLC.

backgroundNon-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide, largely due to the supportive role of the tumor microenvironment (TME). Tumor-associated macrophages, particularly the M2 phenotype, are pivotal in promoting NSCLC progression. Exosomes, key mediators of intercellular communication, can transfer functional cargo from M2 macrophages to cancer cells, thereby regulating malignant behaviors. However, the specific mechanisms by which M2 macrophage-derived exosomes modulate NSCLC progression are not fully understood.

methodsBioinformatics analyses were initially performed to identify differentially expressed genes (DEGs) in M2 macrophages and NSCLC tissues using the GSE159112 and GSE268175 datasets. THP-1 cells were induced to differentiate into M2 macrophages, from which exosomes were isolated and characterized via nanoparticle tracking analysis, transmission electron microscopy, and western blotting. NSCLC cell lines (A549 and H23) were co-cultured with these exosomes to assess the transfer of ETS homologous factor (EHF). Functional assays, including 5-Ethynyl-2'-deoxyuridine (EdU), Transwell, flow cytometry, and sphere formation assays, were conducted to evaluate cell proliferation, migration, invasion, apoptosis, and stemness. Glycolytic capacity was determined by measuring glucose uptake, lactate production, and ATP levels. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were employed to verify the transcriptional regulation of FGFR1 by EHF. Rescue experiments involving FGFR1 overexpression were performed to validate the signaling axis, and a xenograft mouse model was established to confirm the in vivo findings.

resultsEHF was identified as a critical upregulated transcription factor in both M2 macrophages and NSCLC tissues. M2 macrophage-derived exosomes were efficiently internalized by NSCLC cells, resulting in subsequent upregulation of its expression in recipient cells. Mechanistically, EHF transcriptionally activated fibroblast growth factor receptor 1 (FGFR1) by binding to its promoter region. Functionally, exosomes derived from EHF-deficient M2 macrophages significantly suppressed NSCLC cell proliferation, migration, invasion, and sphere formation, while promoting apoptosis. Concurrently, the loss of exosomal EHF inhibited glycolysis, evidenced by reduced glucose uptake, lactate production, and ATP levels. Crucially, restoring FGFR1 expression reversed the suppressive effects induced by EHF-deficient exosomes, confirming that the EHF/FGFR1 axis drives these malignant phenotypes. In vivo experiments further demonstrated that exosomes from EHF-silenced M2 macrophages inhibited tumor growth and downregulated proliferation markers.

conclusionM2 macrophage-derived exosomal EHF promoted NSCLC progression and glycolysis by transcriptionally activating FGFR1. These findings highlight the EHF/FGFR1 axis as a novel molecular link between macrophages and NSCLC cells.