Exosomal AC068768.1 enhances the proliferation, migration, and invasion of laryngeal squamous cell carcinoma through miR-139-5p/NOTCH1 axis

Abstract

Objective: Long non-coding RNAs (lncRNAs) are closely associated with the pathogenesis of laryngeal squamous cell carcinoma (LSCC). This study aimed to investigate the roles of AC068768.1 in LSCC. Methods: Exosomes were extracted by ultracentrifugation and identified by transmission electron microscopy (TEM) assay. The expression levels of mRNA and miRNA were determined by real-time quantitative polymerase chain reaction (RT-qPCR). Cellular functions were assesses through immunofluorescence, flow cytometry, colony formation, wound healing and transwell assays. Chromatin immunoprecipitation (ChIP) and luciferase assays were conducted to verify the binding of AC068768.1 by signal transducer and activator of transcription 3 (STAT3). Xenograft assays were performed to confirm the roles of AC068768.1 in LSCC, and hematoxylin-eosin (HE) staining was applied for histological analysis. Results: LSCC cell-derived exosomes induced M2-like tumor-associated macrophages (TAM2) polarization, which promoted the proliferation, migration, and invasion of LSCCs. Knockdown of exosomal AC068768.1 inhibited M2 polarization and suppressed LSCC aggressiveness both in vitro and in vivo. Moreover, AC068768.1 sponged miR-139-5p, inducing the upregulation of neurogenic locus notch homolog protein 1 (NOTCH1). LSCCs adapted to TAM2 polarization in the tumor microenvironment via AC068768.1-mediated activation of the NOTCH1 pathway. Additionally, NOTCH1 activated STAT3. Conclusion: The AC068768.1/miR-139-5p/NOTCH1/STAT3 axis promotes the metastasis of LSCC. This finding may provide a novel target for LSCC therapy.