Gene expression profiling of microRNAs associated with UCA1 in bladder cancer cells.

Emerging evidence indicates that non-coding RNAs, such as lncRNAs and microRNAs, play important roles in diverse diseases, such as cancer, immune diseases and cardiovascular diseases. Interestingly, lncRNAs could directly or indirectly regulate the expression of miRNAs. However, the expression profiling of miRNAs associated with UCA1 in bladder cancer remains unknown. Here, we used Illumina deep sequencing to sequence miRNA libraries from both the UCA1 knockdown and normal high-expression 5637 cells. We identified 225 and 235 miRNAs expressed in 5637 cells of normal high-expression and knockdown of UCA1, respectively. Overall, expression of 75 miRNAs showed significant difference associated with UCA1, of which 38 were upregulated and 37 downregulated with UCA1 knockdown. GO analysis of the host target genes revealed that these aberrantly regulated miRNAs were involved in complex cellular pathways, including biological process, cellular component and molecular function. We selected 8 candidate miRNAs associated with UCA1 and predicted their targeted mRNAs, and found that p27kip1 was a crucial downstream molecule for these 8 miRNAs, especially for miR-196a. KEGG pathway analysis showed that PI3K-Akt signaling pathway was involved in regulating these 8 candidant miRNAs. Among these 8 candidant miRNAs, we observed the correlation among UCA1, miR-196a and the host target mRNA, p27kip1, in bladder cancer cells and tissues. UCA1 was upregulated by miR-196a and positively correlated with miR-196a, whereas UCA1 and miR-196a were negatively correlated with p27kip1, which was downregulated in bladder cancer patients. Thus, our findings provided valuable information on miRNAs associated with UCA1 in bladder cancer, which could be helpful to further explore the related genes and molecular networks fundamental in bladder cancer progression.