Identification of oncogenic long noncoding RNA SNHG12 and DUXAP8 in human bladder cancer through a comprehensive profiling analysis

Bladder cancer is a common urological malignancies world-wide. Recently, a growing number of evidence have highlighted the importance of long noncoding RNAs (lncRNAs) in multiple cancers development and progression. However, the expression pattern of lncRNAs in bladder cancer and their underlying function remain poorly understood. To identify lncRNAs profile alterations and uncover valuable lncRNA candidates for bladder cancer diagnostic, we conducted a comprehensively lncRNAs profiling analyses and explored their clinical relevance using The Cancer Genome Atlas (TCGA) data and three independent microarray profiling data from the Gene Expression Omnibus (GEO). After annotation and analyses of these data, we found that lots of lncRNAs were dysregulated in bladder specimen when compared with normal control specimen. In addition, we found that differential expression of these lncRNAs is accompanied by genomic variations, including genome loci copy number deletion or amplification. Importantly, a part of these lncRNAs are related to bladder cancer patients outcome, such as SNHG10, SNHG12 and LINC00115. Finally, we validated two of these lncRNAs' (DUXAP8 and SNHG12) function in bladder cancer cells by down-regulating their expression with siRNAs, and found that down-regulation of DUXAP8 and SNHG12 could inhibit bladder cancer cells proliferation in vitro. In summary, this study demonstrated that a lot of lncRNAs are dysregulated in bladder cancer, and might provide useful lncRNAs resource for potential prognostic or diagnostic markers for this disease.