The Study On Plasma-Derived Exosomal MiRNA As Diagnostic Biomarkers For Early-Stage Lung Adenocarcinoma

Background:Lung cancer is one of the most common malignancies in the world with high morbidity and mortality.Although great progress has been made in the treatment of lung cancer,especially the TKI treatment of lung adenocarcinoma in recent years,this still couldn’t improve the situation of poor prognosis of lung cancer.Early diagnosis is an effective way to improve the prognosis of cancer.Current methods for early diagnosis of lung cancer are mainly spiral CT scans.Detection of tumor markers by peripheral blood is a more acceptable method for patients,however there are currently no biomarkers with satisfactory sensitivity and specificity for lung cancer.Recently,breakthroughs have been made in the study of exosomes and Micro RNA(miRNA).Many studies have found that both are involved in almost every progress of tumor development.Thus,Micro RNA(miRNA)has the potential to become a new biomarker.Objective:1.Master the experimental methods for separating and extracting exosomes from peripheral blood and extracting miRNA from exosomes.2.To determine the expression of miRNA in exosomes of patients with early lung adenocarcinoma before and 7 days after surgery and in normal human plasma.3.Find differentially expressed miRNAs and verify their differential expression in early-stage lung adenocarcinoma and normal subjects;4.Explore the possibility of screening miRNAs as biomarkers for early-stage lung adenocarcinoma.Method:1.The exosomes were separated and extracted by ultra-low temperature centrifugation,and the miRNA was extracted from the exosomes using an extraction kit.2.The extracted miRNA was sequenced using the next-generation sequencing technology(Illumina Genome Analyzer Ⅱx gene analysis system).3.SPSS software for statistical analysis,and Graphpad prism7.0 software for charting;4.qRT-PCR technology to verify miRNA expression.Result:The expression of hsa-mir-10b-5p,hsa-mir-192-5p,hsa-mir-151 a-5p was significantly up-regulated in lung adenocarcinoma samples.The expression of hsa-mir-10b-5p was significantly lower than that before surgery,and the expression of hsa-mir-192-5p and hsa-mir-151a-5p before and after surgery were not obvious.In addition,the expression of these three miRNAs was significantly associated with the survival prognosis of lung adenocarcinoma.This miRNA also showed the same expression in the comparison validation experiments between normal and early lung adenocarcinoma patients.Conclusion:The expression of these three miRNAs,which were selected,hsa-mir-10b-5p,hsa-mir-192-5p and hsa-mir-151a-5p,were significantly different in early lung cancer and normal human samples.These differential expressions were confirmed to be credible by validation experiments.Their target genes and possible signaling pathways are further predicted.These three miRNAs are likely to be involved in tumor cell metabolic pathways,PI3K-Akt signaling pathway and MAPK signaling pathway.These signaling pathways are involved in tumorigenesis,and play a vital role in the development process,which confirms their potential to become a tumor diagnostic marker.