Genome-wide analysis of plasma exosomal microRNA in lung cancer

Purpose: To identify a panel of plasma exosomal miRNAs as potential biomarkers for lung cancer from the genome-wide set of currently known human miRNAs. Methods: Plasma samples from 4 lung cancer patients and 4 patients with benign lung disease were collected, and plasma exosomes were extracted by ultracentrifugation. Exosomal miRNA profiles were generated by deep sequencing based on Illumina NextSeq 500 platform. And differentially expressed exosomal miRNAs between lung cancer and benign lung disease were identified by edgeR with the default threshold of |log2 (fold change) | ≥ 1.5 and P-value < 0.05. Results: A total of 983 detectable exosomal miRNAs were analyzed to identify differentially expressed miRNAs between two groups. There were 6 significantly up-regulated miRNAs and 63 significantly down-regulated miRNAs in lung cancer cases when compared with benign lung disease. Conclusion: The comparative analysis of plasma exosomal miRNAs between lung cancer and benign lung diseases provided a reference for exploring potential biomarkers of lung cancer. And the clinical value of candidate exosomal miRNAs needs to be further verified in lung cancer clinical trials. Expression levels of 983 exosomal miRNAs were investigated in plasma samples from 4 lung cancer cases and 4 patients with benign lung disease.