Overexpression of long non-coding RNA n346372 in bladder cancer tissues is associated with a poor prognosis

Accumulating evidence has confirmed that dysregulated long non-coding RNAs (lncRNAs) participate in the initiation and progression of a number of solid tumors and have potential applications for early diagnosis, targeted therapy, and the prognosis of patients with bladder cancer. In the present study, via high-throughput sequencing technology and bioinformatics analysis, a total of 169 lncRNAs with significantly differential expression between bladder cancer tissues and paired adjacent normal tissues (n=10) were initially identified by screening. Reverse-transcription-quantitative polymerase chain reaction was carried out to validate the expression levels of lncRNA-n346372 in 60 pairs of tissue samples from bladder cancer patients. The results indicated that lncRNA-n346372 was upregulated in bladder cancer tissues compared with the matched adjacent normal tissues (P<0.05). In addition, the results of fluorescence in situ hybridization analysis of bladder cancer cells and tissues demonstrated that lncRNA-n346372 is located in the cytoplasm, and the expression of lncRNA-n346372 in bladder cancer tissues was significantly increased compared with the paired normal tissues. Following a χ(2) test with common clinical variables among the patients, the expression level of lncRNA-n346372 was demonstrated to be positively associated with advanced tumor stage and poor histological differentiation of bladder cancer. Kaplan-Meier survival analysis revealed that patients with high expression of n346372 were more likely to have a poor prognosis compared with patients with low n346372 expression. Finally, univariate and multivariate analyses indicated that the relative level of n346372, apart from tumor stage and histological grade, may serve as an independent prognostic factor of bladder cancer. To the best of the authors' knowledge, this is the first study to verify the dysregulated expression of lncRNA-n346372 in bladder cancer; an association of this lncRNA with overall survival of bladder cancer patients was also uncovered in the present study, suggesting that lncRNA-n346372 may contribute to the initiation and/or progression of bladder cancer with potential applications in the clinic.