Conclusions
All proteins previously detected in urine from patients with bladder cancer were also expressed in bladder cancer tissue. The expression of APOE, FGB and POLR1E increased with stage and they are potential diagnostic markers. SERPINA1 was identified as a prognostic marker candidate.
Methods
Urine samples, 16 from patients with bladder cancer and 26 from controls, were used in Western Blotting experiments. Tissue microarrays with bladder tissue from 344 patients diagnosed with bladder cancer between 1984 and 2005 was used in immunohistochemistry experiments. The proteins apolipoprotein E (APOE), fibrinogen β chain precursor (FGB), leucine-rich α2-glycoprotein (LRG1), polymerase (RNA) I polypeptide E (POLR1E), α1-antitrypsin (SERPINA1) and topoisomerase 2A (TOP2A) were probed with antibodies validated by the Human Protein Atlas.
Results
Increased expressions of APOE, FGB and POLR1E were correlated with increased tumour stage (P < 0.001). Expression of SERPINA1 in Ta and T1 tumours was found to increase the risk of tumour progression (hazard ratio 2.57, 95% confidence interval 1.13-5.87; P = 0.025) CONCLUSIONS: All proteins previously detected in urine from patients with bladder cancer were also expressed in bladder cancer tissue. The expression of APOE, FGB and POLR1E increased with stage and they are potential diagnostic markers. SERPINA1 was identified as a prognostic marker candidate.