Circulating Long Non-coding RNA GAS5 Is A Novel Biomarker For The Diagnosis Of Non-small Cell Lung Cancer

Background and Objective:Non small cell lung cancer(NSCLC)is one of the most common causes of cancer death with a high mortality rating in global.Long non coding RNAs(lncRNAs)are new-founding RNAs that regulate many biological processes such as cellular differentiation regulation,proliferation,transport,chromatin modification and transcription.Recent studies have shown that IncRNAs involves the development of human diseases,especially expressed abnormally in cancer.Accumulating reports suggest that IncRNAs are engaged in the development of NSCLC.Our previous studies have shown that IncRNAs GAS5 significantly lower in NSCLC tissues that lead to the proliferation and invasion of NSCLC.Moreover,GAS 5 is associated with the prognosis of patients with lung cancer.Plasma samples are easier and more convenient to collect than tissues which conducive to for clinical application.Currently the diagnostic importance of GAS5 has not been reported.This study is to explore the GAS5 expression in the plasma of NSCLC patients,and to identify the relationship between the GAS5 and clinical pathological features;and to get clear the potential significance of GAS5 in the plasma diagnosis for NSCLC patients,by identifying the differences of GAS5 in NSCLC patients and in normal people though qPCR.Materials and Methods:A total of 90 peripheral blood samples were well collected from patients with NSCLC from Nanjing University School of Medicine and Respiratory Department of the General Hospital of Nanjing Military Region during March 2014 to November 2014.Another 33 control samples were collected from healthy donors without cancers.Free RNAs are extracted from the supernatant fluid of the centrifugal Peripheral blood.The expression GAS5 from all plasma samples are to detected by the real-time fluorescent quantitative reverse transcription PCR.The Receiver-Operating Characteristics(ROC)curves were established to evaluate the sensitivity and specificity of GAS5 in diagnosing non-small cell lung cancer,and clinical application value and efficiency of circulating IncRNAs GAS5 as the NSCLC plasma molecular diagnostic markers were studied.All involved cancer patients had not been treated by surgery chemotherapy or radiation therapy before blood collection.Results:The expression of IncRNAs GAS5 in the plasma is stable.The results of GAS5 of the 90 plasma samples suggest that the GAS5 expression in the NSCLC plasma is significantly lower than that of healthy donors(P<0.000).Moreover,a marked increase in the plasma GAS 5 expression could be observed after the radical resection of pulmonary carcinoma.In addition,GAS5 curve area is 0.832 according to ROC curve analysis,(P<0.0001;sensitivity,81.1%;specificity,72.7%).What is more important is that,compared with CEA in combination,the area under the curve(AUC)is 0.909,the combination of GAS5 and CEA could can provide better diagnostic efficiency for detecting non-small cell lung cancer.The plasma levels of GAS5 may be more valuable than the levels of CEA for NSCLC diagnosis,and GAS5 levels may be useful for evaluating the tumor dynamics of NSCLC.Conclusions:We have demonstrated that GAS5 was decreased in NSCLC plasma expression and the plasma samples were more easily available than the tissue sample in the clinic,thus GAS5 is likely to be the ideal diagnostic biomarker in the early diagnosis for NSCLC.