Two microRNAs of plasma-derived small extracellular vesicles as biomarkers for metastatic non-small cell lung cancer.

Background: MicroRNAs (miRNAs) of plasma-derived small extracellular vesicles (sEVs) have been proven to be associated with metastasis in several types of cancer. This study aimed to detect miRNAs of plasma-derived sEVs as potential biomarkers for metastatic non-small cell lung cancer (NSCLC).

Methods: We assessed the miRNA profiles of plasma-derived sEVs from healthy individuals as the control group (CT group), NSCLC patients without distant organ metastasis as the NM-NSCLC group and patients with distant organ metastasis as the M-NSCLC group. Next-generation sequencing (NGS) was performed on samples, and differentially expressed miRNAs (DEMs) of the three groups were screened. Kyoto Encyclopedia of Genes and Genomes (KEGG) and ClueGO were used to predict potential pathways of DEMs. MiRNA enrichment analysis and annotation tool (miEAA) was used to understand changes in the tumour microenvironment in NSCLC. Quantitative reverse transcription polymerase chain reaction (qRT‒PCR) analysis was used to validate target miRNAs.

Result: NGS was performed on 38 samples of miRNAs of plasma-derived sEVs, and DEMs were screened out between the above three groups. Regarding the distribution of DEMs in the NM-NSCLC and M-NSCLC groups, KEGG pathway analysis showed enrichment in focal adhesion and gap junctions and ClueGO in the Rap1 and Hippo signaling pathways; miEAA found that fibroblasts were over-represented. From our screening, miRNA-200c-3p and miRNA-4429 were found to be predictive DEMs among the CT, NM-NSCLC and M-NSCLC groups, and qRT‒PCR was applied to verify the results. Finally, it was revealed that expression levels of miR-200c-3p and miR-4429 were significantly upregulated in M-NSCLC patients.

Conclusion: This study identified miRNA-200c-3p and miRNA-4429 as potential biomarkers for NSCLC metastasis.