Comprehensive analysis of aberrantly expressed profiles of lncRNAs and miRNAs with associated ceRNA network in muscle-invasive bladder cancer

// Hanbo Wang 1, * , Leilei Niu 2, * , Shaobo Jiang 1 , Jing Zhai 3 , Ping Wang 4 , Feng Kong 5 , Xunbo Jin 1 1 Minimally Invasive Urology Center, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China 2 Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Sha Tin, New Territories, Hong Kong SAR, China 3 Department of Biochemistry, School of Basic Medical Sciences, Taishan Medical University, Taian, China 4 Department of Surgery, Qilu Hospital, Shandong University, Jinan, China 5 Central Laboratory, The Second Hospital of Shandong University, Jinan, China * These authors contributed equally to this work Correspondence to: Feng Kong, email: kongfeng@sdu.edu.cn Xunbo Jin, email: jinxunbo@163.com Keywords: muscle-invasive bladder cancer, lncRNA, ceRNA, miRNA, TCGA Received: August 20, 2016 Accepted: November 07, 2016 Published: November 15, 2016 ABSTRACT Although initially thought to be transcriptional noise, long noncoding RNAs (lncRNAs) are gaining increased attention in human cancers as its diversity function. At present, lncRNAs are regarded as the main part of competing endogenous RNA (ceRNA) network due to its regulation on protein-coding gene expression by acting as miRNA sponges. However, functional roles of lncRNA-mediated ceRNAs in muscle-invasive bladder cancer remain unclear. To clarify relevant potential mechanisms, here we comprehensively compared the expression profiles of mRNAs, lncRNAs and miRNAs between 322 muscle-invasive bladder cancer tissues and 19 non-tumor bladder tissues, based on the Cancer Genome Atlas (TCGA). A total of 22 lncRNAs were identified as aberrantly expressed and had correlations with tumorigenesis and/or progression of muscle-invasive bladder cancer (|log2FoldChange| > 1.5, corrected P value < 0.01). 6 out of the 22 dysregulated lncRNAs functioned as prognostic biomarkers for patients with muscle-invasive bladder cancer according to the overall survival analysis ( P value < 0.05). Finally, a dysregulated lncRNA-associated ceRNA network was successfully constructed, which inculdes five muscle-invasive bladder cancer-specific lncRNAs, nine miRNAs and 32 mRNAs. In summary, our study identified novel lncRNAs as candidate prognostic biomarkers and potential therapeutic targets for muscle-invasive bladder cancer, based on large-scale sample size. More importantly, the newly identified ceRNA network will be beneficial for improving the understanding of lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of muscle-invasive bladder cancer.