Involvement of the insulin-like growth factor I receptor and its downstream antiapoptotic signaling pathway is revealed by dysregulated microRNAs in bladder carcinoma

Abstract

Objective: Urothelial carcinoma is one of the most common pathological types of bladder cancer. Several studies have shown that dysregulated microRNAs (miRNAs) play an important role in bladder cancer progression. We performed the present miRNA microarray analysis in samples of urothelial carcinoma of the bladder and adjacent normal bladder tissue from Taiwanese patients to investigate dysregulated miRNAs. Materials and methods: To detect dysregulated miRNAs in urothelial carcinoma of the bladder, samples of tumor and adjacent normal tissues were collected from 10 patients. Tissue samples from three patients were subjected to miRNA microarray analysis, and the remaining tissue samples from the other seven patients were used to validate the results obtained from the microarray data. Potential targets of these dysregulated miRNAs were identified using online databases, including MicroCosm and TargetScan. Results: A panel of 30 differentially expressed miRNAs with at least fourfold differences in expression compared with normal controls, including 19 upregulated and 11 downregulated miRNAs, was generated. The expression levels of miR-30a-5p, miR-30a-3p, miR-99a, miR-130b, miR-133b, miR-135b, miR-145, miR-195, miR-204, and miR-214 were experimentally verified using real-time RT-PCR analysis. Using an online miRNA target database, we discovered that these dysregulated miRNAs potentially control components of the insulin-like growth factor 1 receptor (IGF1R) signaling pathway. Conclusion: Our results indicate that dysregulated miRNAs may be involved in bladder cancer pathogenesis and are potential biomarkers.

Keywords

• bladder cancer
• insulin-like growth factor I receptor (IGF1R)
• microRNA