Aberrant expression profiles and bioinformatic analysis of CAF‐derived exosomal miRNAs from three moderately differentiated supraglottic LSCC patients

BACKGROUND: Aberrant expression of exosomal miRNAs has emerged as a research hotspot. However, no studies have been conducted on the dysregulation of exosomal miRNAs derived from cancer‐associated fibroblasts (CAFs) in supraglottic laryngeal squamous cell carcinoma (SLSCC). METHODS: Cancer‐associated fibroblasts and paired normal fibroblasts (NFs) from SLSCC patients were cultured, and exosomes in the culture supernatants were collected and identified. Exosomal miRNA expression was compared in each pair of CAFs and NFs by next‐generation sequencing, and expression of selected exosomal miRNAs was validated by reverse transcription‑quantitative PCR. Four online bioinformatic algorithms predicted the potential target genes of aberrantly expressed miRNAs, while gene ontology and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment and network analysis identified downstream target genes and their interactions. RESULTS: Three pairs of CAFs and NFs were successfully cultured and purified. CAF‐derived exosomal miRNAs were mostly downregulated and included miR‐656‐3p, miR‐337‐5p, miR‐29a‐3p and miR‐655‐3p; however, some, including miR‐184‐3p, miR‐92a‐1‐5p, miR‐212‐3p and miR‐3135b, were upregulated. Bioinformatics analysis revealed involvement of these miRNAs in biological processes, cellular components and molecular functions. KEGG analysis revealed the top 30 pathways involvement in cancer initiation and progression and in cell cycle regulation. An interaction network showed miR‐16‐5p, miR‐29a‐3p, miR‐34c‐5p, miR‐32‐5p and miR‐490‐5p as the top five miRNAs and CCND1, CDKN1B, CDK6, PTEN and FOS as the top five target genes. CONCLUSIONS: SLSCC patients showed aberrant expression of CAF‐derived exosomal miRNAs. The top five miRNAs and their target genes may jointly constitute a carcinogenic tumour microenvironment and act as biomarkers for SLSCC intervention.