The long, noncoding RNA (lncRNA) is an important epigenetic regulator with a critical role in human tumors. Here, we aimed to investigate the clinical application and the potential molecular mechanisms of in gastric cancer tumorigenesis and progression. The expression level of was determined by RT-qPCR analysis in 190 pairs of gastric cancer tissues and adjacent normal gastric mucosa tissues (ANT). The biologic functions of were assessed by and functional experiments. RNA protein pull-down assays and LS/MS mass spectrometry analysis were performed to detect and identify the interacting protein FOXM1. Protein-RNA immunoprecipitation assays were conducted to examine the interaction of FOXM1 and Chromatin immunoprecipitation (ChIP) and luciferase analyses were utilized to identify the binding site of FOXM1 on the promoter. The lncRNA was significantly upregulated in gastric cancer tissues compared with ANTs. High expression of predicted poor prognosis in patients with gastric cancer. enhanced gastric cancer cell proliferation and invasion and directly bound FOXM1 protein and increased FOXM1 posttranslationally. Moreover, is also a FOXM1-responsive lncRNA, and FOXM1 directly binds to the promoter to activate its transcription. Finally, fulfilled its oncogenic functions in a FOXM1-mediated manner. Our study suggests that promotes tumor progression by interacting with FOXM1. may be a valuable prognostic predictor for gastric cancer, and the positive feedback loop of -FOXM1 could be a therapeutic target in pharmacologic strategies..

The examination of circulating nucleic acids (CNAs) is an emerging noninvasive diagnostic technique. However, it is unclear if serum long noncoding RNAs (lncRNAs) represent a novel marker to detect gastric cancer (GC). In this study, we measured 39 candidate cancer-associated lncRNAs by reverse transcription and quantitative polymerase chain reaction (RT-qPCR) in sera from 110 patients with GC, 106 age-and sex-matched healthy subjects and 15 patients with gastric peptic ulcer, markers were validated and assessed by RT-qPCR. The correlation of the expression levels of the candidate serum lncRNAs with clinical parameters of GC patients was performed. A three-lncRNA signature, including CUDR, LSINCT-5 and PTENP1, was identified that may be potential diagnostic marker for GC. The areas under the receiver operating characteristic (ROC) curve for this serum three-lncRNA signature were 0.920 and 0.829 for the two sets of serum samples. Moreover, a risk model for the serum three-lncRNA signature demonstrated that healthy samples can be distinguished from early GC samples. Three-lncRNA signature in serum was identified as diagnostic marker for GC. This work may facilitate the detection of GC and serve as the basis for further studies of the clinical value of serum lncRNAs in maintaining surveillance and forecasting prognosis.Gastric cancer (GC) is the fourth most common type of cancer and the second leading cause of cancer-related deaths worldwide. 1 Surgical resection is the most effective treatment and prolongs the survival of patients with early GC; however, the prognosis for patients with advanced GC is poor, despite recent improvements in chemotherapy and radiotherapy. 2 Improvements in diagnosis are urgently needed to increase the long-term survival of patients with resectable-stage GC.Ideally, biomarkers should be easily accessible and sampled noninvasively. Circulating nucleic acids (CNAs) are extracellular nucleic acids found in cell-free sera, plasma and other bodily fluids of healthy subjects and cancer patients. We have previously demonstrated that human serum or plasma contains microRNAs (miRNAs) that are significantly up-regulated or down-regulated in various types of cancer and are of good diagnostic value for screening. 3-5 However, the identification of miRNAs as biomarkers has yielded inconsistent results. Thus, the discovery of alternative or complementing biomarkers is essential; other types of circulating noncoding RNAs (ncRNAs) may also be stable and have diagnostic potential in cancer management. Long noncoding RNAs (lncRNAs) are a newly discovered class of ncRNAs that are longer than 200 nucleotides. Changes in the expression levels of lncRNAs have been increasingly reported in a variety of cancer types, suggesting a connection between