The Expression And Clinical Significance Of Exosomal MiRNA In NSCLC Patients

Objective:To investigate the expression and clinical significance of serum Exosomal miRNA in non-small cell lung cancer (NSCLC) patients.Methods:The serum from 76 pairs of NSCLC patients and healthy subjects is our research object.1) Determined the presence of Exosomes by Western blot.2) The latest results of miRNA chip analys show:ten kinds of miRNAs including Let-7a, miR-21, miR-19b, miR-146a, miR-182, miR-451, miR-486, miR-210, miR-205 and miR-155 are strongly associated with NSCLC. Quantified the relative expression level of these Exosomal miRNAs in 10 pairs of NSCLC patients and healthy subjects with RT-PCR.3) Differentially expressed Exosomal miRNAs are selected for further analyzed in serum from 66 pairs of NSCLC patients and healthy subjects. Analyzed correlation between the expression level and clinicopathologic features of NSCLC patients.4) Download the date of miRNA expression from TCGA database and compare it with our study.Results:1) The result of western blot shows:CD63, Exosomal marker proteins, identified in the pellet using western blot, for which we could ensure the pellet as Exosome. The levels of Exosomes are significantly higher(P<0,05) in NSCLC patient than that in the healthy subjects.2) The screening results of above-mentioned 10 kinds of Exosomal miRNAs show: serum Exosomal Let-7a, miR-21, miR-19b, miR-146a, miR-182, miR-486, miR-205 and miR-155 are higher in NSCLC patients than that in healthy subjects(P<0.05), while Exosomal miR-451 and miR-210 are lower in NSCLC patients (P<0.05).3) Exosomal Let-7a, miR-21, miR-19b, miR-205, miR-451 and miR-210 are selected for further validation study. The study show that serum Exosomal Let-7a, miR-21, miR-19b and miR-205 are higher in NSCLC patients than that in healthy subjects(P<0.05). Nevertheless, Exosomal miR-451 and miR-210 are lower in NSCLC patients(P<0.05). The expression level of Exosomal Let-7a and miR-21 are higher in NSCLC patients with stagesⅢand Ⅳ(P<0.05), while the Exosomal miR-451 and miR-210 are lower(P<0.05). The expression level of Exosomal Let-7a, miR-19b, miR-205 are higher in NSCLC patients with lymph node metastasis than the patients without (P<0.05). The expression level of Exosomal Let-7a, miR-21, miR-19b, miR-205, miR-210 are obviously higher in adenocarcinoma(AD) than in squamous cell carcinoma (SCC)(P<0.05). High level of Exosomal Let-7a, miR-21, miR-19b and miR-205 and lower level of Exosomal miR-451 and miR-210 are significantly correlated with metastasis(P<0.05). High level of Exosomal Let-7a, miR-21, miR-19b and miR-205 and lower level of Exosomal miR-210 are significantly correlated with the size of tumor(P<0.05).4) The result of our study, compared with the TCGA database, shows that:Compared with the high expression of Exosome in peripheral blood serum, Let-7a in NSCLC tissue is low expression. Compared with the low expression of Exosome in peripheral blood serum, miR-210 is high expression in NSCLC tissue. While the expression of miR-21, miR-19b, miR-205, miR-451 are not differ significantly between tissue and serum (P>0.05).Conclusion:The serum Exosomal miRNA are significantly dysregulated in NSCLC and show closely related to clinicopathologic features, which provide significant diagnostic values for NSCLC. Examination of serum Exosomal miRNA presents us a useful serum bio-marker for NSCLC classification.