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 in cancer studies. 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 CAFs and paired normal fibroblasts (NFs) from SLSCC patients were cultured, and exosomes in the culture supernatants were collected and identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting. Exosomal miRNA expression was compared in each pair of CAFs and NFs by next-generation sequencing. 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 thirty 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 target genes may jointly constitute a carcinogenic tumour microenvironment and may play decisive roles in the initiation and progression of SLSCC.