Background: Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in urothelial carcinoma of the bladder (UC) are unclear.
Methods: In this study, the methods of reverse transcription-PCR, immunohistochemistry, and fluorescence in situ hybridization were used to examine mRNA/protein expression and amplification of eIF-5A2 in a large cohort of UCs treated with radical cystectomy.
Results: Up-regulated expression of eIF-5A2 mRNA was observed in 50% (8 of 16) of UCs, when compared with adjacent normal bladder tissues. Overexpression of EIF-5A2 protein and amplification of eIF-5A2 was examined informatively in 45.3% (39 of 86) and 10.6% (5 of 47) of UCs, respectively. In univariate survival analysis of the UC cohorts, a significant association of overexpression of EIF-5A2 with shortened patient survival (mean, 38.2 months versus 52.9 months, P = 0.001, log-rank test) was shown. In different subsets of UC patients, overexpression of EIF-5A2 was also a prognostic indicator in grade 1/2 (P = 0.0009) and grade 3 (P = 0.016) tumor patients, and in pT1 (P = 0.0089), pT2 (P = 0.0354), pT3/4 (P = 0.0058), pN0 (P = 0.0039), and pN1-2 (P = 0.0093) tumor patients. Importantly, EIF-5A2 expression (P = 0.0007) together with pT stage (P = 0.0001) provided significant independent prognostic variables in multivariate analysis.
Conclusions: These findings indicate that overexpression of EIF-5A2 in UCs is coincident with acquisition of a poor prognostic phenotype, suggesting that the expression of EIF-5A2, as detected by immunohistochemistry, is an independent molecular marker for shortened survival time of UC patients treated with radical cystectomy.