Bladder cancer: analysis of miRNA-mRNA interactions

Background: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Their abilyty to affect multiple gene pathways by targeting to various mRNAs makes them to an interesting class of regulators. The interplay between miRNA and mRNA has been proposed as an important process in cancer development and progression. In this study, we analyzed miRNA -mRNA interactions in bladder urothelial carcinoma. Methodology/Principal Findings: We have developed a new algorithm which is capable of identifying altered miRNA-mRNA regulation between tissues samples without preexisting stratification of groups. Microarray expression profiling of both miRNA and mRNA from the same sample were performed using a collective of 24 urothelial carcinoma and normal bladder tissue samples. Using our approach, normal and tumor tissue samples as well as different stages of tumor progression were successfully stratified. Also, we were able to analyzed individual miRNA-mRNA interactions from each patient, focusing on different miRNA families. Conclusions: Just recently, the need for tools that allow an integrative analysis of microRNA and mRNA expression data has been addressed. With this study, we provide an algorithm that considers the special nature of miRNA induced regulation and shows good specificities and sensitivities when applied to bladder cancer expression data. mRNA and microRNA expression data were analyzed together to identify bladder cancer specific micoRNA-mRNA interaction