Exosonal MicroRNA-744-5p Serves As A New Biomarker For Non-small-cell Lung Cancer

BACKGROUND&OBJECTIVELung cancer is the most common malignant tumor,among which non-small cell lung cancer(NSCLC)accounts for about 85%of primary lung cancer.Early stage NSCLC has a good prognosis,but most of the patients in clinical work are in the advanced stage of the disease.At present,there is no clinical biomarker that can effectively detect NSCLC.Exosomes are extracellular vesicles with a diameter of 40-150 nm released by cells.Nucleic acids and proteins encapsulated in exosomes can reflect the internal changes of cells and play an important role in the development of diseases.In this study,we attempted to identify exosomal microRNA differentially expressed in NSCLC,especially early stage NSCLC,and healthy people,then screened out biomarkers for the diagnosis of early stage NSCLC.METHODFirstly,the exosomes sequencing results of serum and cell supernatants were analyzed,and microRNAs differentially expressed in lung cancer exosomes were screened.Exosomes in serum were extracted by Exoquick isolation kit.The expression of microRNA in serum exosomes of NSCLC and healthy control group was analyzed by real-time fluorescence quantitative PCR.The diagnostic efficacy of candidate biomarkers was evaluated by calculating ROC curve.The expression level of potential microRNA in lung cancer tissues and lung cancer cells was observed by real-time fluorescent quantitative PCR.Cell proliferation kit was used to detect the effect of microRNA on the proliferation of cancer cells.Cell invasion experiment and cell migration experiment were used to verify the change of the migration and invasion ability of the target gene.RESULT1 The expression of microRNA-192-5p,microRNA-320a,microRNA-484,microRNA-2110 and microRNA-744-5p in serum exosomes of patients with NSCLC was low,and the difference was statistically significant.2 Exosomal microRNA-744-5p has good diagnostic efficacy for early stage NSCLC,and the area under ROC curve is 0.943.3 microRNA-744-5p is highly expressed in lung cancer tissues and cells,promoting the proliferation,migration and invasion of lung cancer cells.CONCLUSIONThe low expression of exosomal microRNA-744-5p in plasma can be used as a biomarker for the diagnosis of early stage NSCLC.MicroRNA-744-5p is highly expressed in lung cancer tissues and cells,which promotes cell proliferation,migration and invasion.