1. Gastric cancer-derived exosomal let-7 g-5p mediated by SERPINE1 promotes macrophage M2 polarization and gastric cancer progression.
- Author
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Ye Z, Yi J, Jiang X, Shi W, Xu H, Cao H, Qin L, Liu L, Wang T, Ma Z, and Jiao Z
- Subjects
- Humans, Mice, Animals, Male, Female, Cell Line, Tumor, Tumor-Associated Macrophages metabolism, Tumor-Associated Macrophages immunology, Macrophage Activation genetics, Stomach Neoplasms genetics, Stomach Neoplasms pathology, Stomach Neoplasms metabolism, Plasminogen Activator Inhibitor 1 metabolism, Plasminogen Activator Inhibitor 1 genetics, MicroRNAs genetics, MicroRNAs metabolism, Exosomes metabolism, Exosomes genetics, Macrophages metabolism, Disease Progression
- Abstract
Background: Tumor-associated macrophages (TAMs), particularly M2-polarized TAMs, are significant contributors to tumor progression, immune evasion, and therapy resistance in gastric cancer (GC). Despite efforts to target TAM recruitment or depletion, clinical efficacy remains limited. Consequently, the identification of targets that specifically inhibit or reprogram M2-polarized TAMs presents a promising therapeutic strategy., Objective: This study aims to identify a dual-function target in GC cells that drives both malignant phenotypes and M2 macrophage polarization, revealing its molecular mechanisms to provide novel therapeutic targets for selectivly targeting M2-polarized TAMs in GC., Methods: Transcriptomic and clinical data from GC and adjacent tissues were utilized to identify mRNAs associated with high M2 macrophage infiltration and poor prognosis. Single-cell sequencing elucidated cell types expressing the target gene. Transwell co-culture and exosome intervention experiments demonstrated its role in M2 polarization. Small RNA sequencing of exosomes, western blotting, and CoIP assays revealed the molecular mechanisms underlying exosome-mediated M2 polarization. Protein array, ChIP and dual-luciferase reporter assays clarified the molecular mechanisms by which the target gene regulated exosomal miRNA. In vivo validation was performed using xenograft tumor models., Results: SERPINE1 was identified as a highly expressed mRNA in GC tissues and cells, significantly associated with advanced clinical stages, worse prognosis, and higher M2 macrophage infiltration in patients with GC. SERPINE1 overexpression in GC cells promoted tumor growth and M2 macrophage polarization. SERPINE1 facilitated the transfer of let-7 g-5p to macrophages via cancer-derived exosomes, inducing M2 polarization. Exosomal let-7 g-5p internalized by macrophages downregulated SOCS7 protein levels, disrupting its interaction with STAT3 and relieving the inhibition of STAT3 phosphorylation, thereby leading to STAT3 hyperactivation, which consequently drove M2 polarization. Additionally, in GC cells, elevated SERPINE1 expression activated JAK2, enhancing STAT3 binding to the let-7 g-5p promoter and promoting its transcription, thereby increasing let-7 g-5p levels in exosomes., Conclusion: GC cell-derived SERPINE1, functioning as a primary driver of GC growth and TAM M2 polarization, promotes M2 polarization through the regulation of exosomal let-7 g-5p transfer via autocrine activation of the JAK2/STAT3 signaling pathway. These findings elucidate a novel mechanism of SERPINE1-induced M2 polarization and highlight SERPINE1 as a promising target for advancing immunotherapy and targeted treatments in GC., Competing Interests: Declarations. Ethics approval and consent to participate: The Ethics Committee of The Second Hospital of Lanzhou University approved the study (No. 2024 A-662), with informed consent from all participants. Animal experiment was approved by Animal Ethics Committee of Gansu University of Chinese Medicine followed the guidelines for the Care and Use of Laboratory Animals (No. 2021-063). Consent for publication: All authors contributed significantly to the conception, design, execution, and interpretation of the research. They reviewed and approved the manuscript and agreed to be listed as co-authors. Competing interests: All authors declare no confict of interest., (© 2024. The Author(s).)
- Published
- 2025
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