Does RNA editing play a role in the development of urinary bladder cancer?

Purpose: A-to-I RNA editing is essential for the development of normal cells and is involved in a wide variety of biological pathways. Currently, limited information suggests linkage between changes in RNA editing levels and the development of cancer. We aimed to explore the possible linkage between altered RNA editing levels and the development of human urinary bladder neoplasms. Materials and methods: Thirty-two patients underwent transurethral resection of bladder tumor. Normal and tumoral urinary bladder tissues were obtained from each patient during surgery. Total RNA was extracted from tissue cells and converted by RT-PCR reaction to cDNA molecules for further analysis. We explored known editing sites in RNA encoding for proteins (BLCAP, Cyfip2, FLNA, GluB Q/R) as well as in RNA transcribed from Alu elements in noncoding regions of the genes encoding for CARD11, FANCC, MDM4, BRCA1, and RBBP9 proteins. Editing levels were determined using Sequenom MassARRAY Compact Analyzer. Results: Eleven tumoral tissues obtained were low grade TCC, 14 high grade TCC, 1 CIS, and another 5 inflammation. One sample contained only normal tissue. We got a total number of 30 normal bladder tissue samples and overall 29 paired samples (i.e., normal and tumoral tissues obtained from the same patient). Statistical analysis revealed no significant changes in editing levels between normal and tumoral tissues. Conclusions: Relying on the results obtained for 9 different editing sites, it can be determined that RNA editing is an epigenetic mechanism that does not participate in the evolution of urinary bladder cancer.