The significance of the expression of interferon regulatory factor 3 and its alternative splicing isoforms in bladder cancer

Abstract

Objective To evaluate the role of interferon regulatory factor 3 (IRF-3) and its alternative splicing isoforms in bladder cancer.Methods RNA was isolated from 3 cell lines (normal human urothelium cells,769-P,EJ) and 48 cases of bladder cancer tissues and adjacent normal tissues from Peking university first hospital between Jun.2012 to Jan.2013 by Trlzol method.RT-PCR was used to examine IRF-3 and its four alternative splicing isoforms (IRF-3a,-3c,-3d,-3e).Sequencing technology was used to find the point mutations in open reading frame of IRF-3 cDNA.Results The expression of IRF-3d is negative in normal human urothelium cells and the level of IRF-3d is lower than that in 769-P and EJ cell lines.In the 48 cases of pathological specimens,IRF-3 and IRF-3a expressed widely and no significant difference was observed between tumor and normal tissues.IRF-3d and-3e showed tumor-specific expression (P＜0.05).Although IRF-3c expressed more widely in tumor than in normal tissues,no statistical significance was observed.There was a correlation between IRF-3a and bladder tumor staging.Conclusions IRF-3 ubiquitously expressed in tumor and normal tissue (P =0.01).Its alternative splicing isoforms IRF-3d and-3e had significant correlations with bladder tumor occurrence.IRF-3a expression was also associated with bladder tumor staging. Key words: Interferon regulatory factor 3; Alternative splicing isoforms; Point mutation; Bladder tumor