LncRNAs Expression Profiles In Plasma Exosomes Of Lung Adenocarcinoma And The Diagnostic Value Of RP11-466L17.1 In Lung Adenocarcinoma

Objective To study the expression profiles of long non-coding RNAs(lnc RNAs)in the plasma exosomes from lung adenocarcinoma(LUAD)patients and explore the possible mechanism of differentially expressed lnc RNAs in the development of LUAD.To find lnc RNAs with diagnostic potential for LUAD.Methods1.Morphological observation of exosomes was carried out by transmission electron microscope(TEM),and their molecular markers were identified by western blot.2.High-throughput sequencing was used to screen out differentially expressed lnc RNAs in plasma exosomes of five LUAD patients and five healthy controls.GO analysis and KEGG signaling pathway analysis of target genes of differentially expressed lnc RNAs were used to predict the possible functions of lnc RNAs.3.Differentially expressed lnc RNAs were verified by quantitative real-time PCR(qRT-PCR).Chi-square test was used to explore the correlation between the expression levels of differentially expressed lnc RNAs and various clinical parameters.4.Using electrochemiluminescence technology to detect serum carcinoembryonic antigen(CEA)levels in LUAD patients and healthy controls.Receiver operating characteristic curves(ROC)were used to evaluate the diagnostic efficacy of lnc RNA and CEA for LUAD.Results1.Transmission electron microscopy(TEM)observed that the size of plasma exosomes was between 40 nm to 120 nm.Western blot showed that they expressed CD9 and CD63.2.The results of high-throughput sequencing showed that compared with healthy people,the expression levels of 18 lnc RNAs in plasma exosomes of LUAD patients were up-regulated and the expression levels of 431 lnc RNAs were down-regulated.The results of GO analysis showed that the differentially expressed lnc RNAs were related to the regulation of protein phosphorylation,the postive regulation of cannonical Wnt,setretory granule lumen,the integrin binding,and platelet-derived growth factor.KEGG signaling pathway analysis showed that differentially expressed lnc RNAs are related to PI3K-Akt signaling pathway.3.The results of qRT-PCR showed that the expression level of RP11-466L17.1 was significantly lower in plasma and plasma-derived exosomes from case group than from healthy control group,and the expression level of RP11-466L17.1 in LUAD cell A549 was also lower than that in normal bronchial epithelial cells Beas-2b.The expression level of RP11-466L17.1 in plasma had no significant correlation with gender,age,smoking and TNM stage of LUAD patients.4.The area under the ROC curve(AUC)of plasma RP11-466L17.1 and serum CEA was 0.724(95% CI: 0.625～0.808)and 0.755(95% CI: 0.659～0.835),respectively.The area under the ROC curve was 0.788(95% CI: 0.718～0.897)when the two were combined,and the combined diagnostic efficacy was higher than the single index.Conclusion The expression profiles of plasma exosomes lnc RNAs in LUAD patients and healthy controls are different.The differentially expressed lnc RNAs may be associated with the occurrence of LUAD.The expression levels of RP11-466L17.1 in LUAD patients’ plasma and plasma-derived exosomes were significantly lower than those in healthy controls.RP11-466L17.1 is expected to become a molecular marker for the diagnosis of LUAD.