A high-throughput assay for the detection of Tyr-phosphorylated proteins in urine of bladder cancer patients

Combination of urinary fibrinogen β-chain and tyrosine-phosphorylated proteins for the detection of bladder cancer

Aim:

To evaluate the performance of urinary fibrinogen β-chain (FBC) – either alone or associated with urinary tyrosine-phosphorylated proteins (UPY) – as bladder cancer (BCa) diagnostic biomarker.

Materials & methods:

164 subjects were tested.

Results:

Significantly different FBC and UPY levels were found between BCa patients and controls, as well as between low-grade and high-grade cancers. The diagnostic accuracy was 0.84 for FBC and 0.87 for UPY. The combination of FBC and UPY improved the accuracy to 0.91. The addition of clinical variables (age, gender, and smoking habit) to FBC and UPY into a model for BCa prediction significantly improved the accuracy to 0.99. The combination of FBC and UPY adjusted for clinical variables associates with the highest sensitivity and good specificity.

Conclusion:

Urinary FBC and UPY could be used as biomarkers for BCa diagnosis.

This research has developed and validated a highly accurate predictive model for BCa diagnosis based on the combination of two urinary biomarkers, fibrinogen β-chain (FBC), and urinary tyrosine-phosphorylated proteins (UPY), and some clinical variables (age, gender and smoking habit). If the preliminary promising results will be confirmed by external validations and prospective trials in selected clinical scenarios, our model could be transferred to clinical practice for screening of high-risk population.

Combined use of Epithelial Membrane Antigen and Nuclear Matrix Protein 52 as Sensitive Biomarkers for Detection of Bladder Cancer

Background

The advent of noninvasive urine-based markers as well as other novel modalities has yielded improved diagnostic accuracy. However, the new markers failed to reach higher sensitivity and specificity. We therefore evaluated the potential role of epithelial membrane antigen (EMA) and nuclear matrix protein 52 (NMP-52) singly and combined as noninvasive biomarkers for the detection of bladder cancer (BC).

Methods

A total of 160 individuals including 66 patients with BC, 54 patients with benign urologic disorders and 40 healthy volunteers were investigated. Urinary EMA at 130 kDa and NMP at 52 kDa were identified, purified and quantified by Western blot, electroelution and enzyme-linked immunosorbent assay (ELISA). The diagnostic performance of each biomarker and their combination were compared using area under receiver operating characteristic curves (AUC).

Results

Mean urinary EMA, 2.42 µg/mL, and NMP-52, 17.85 µg/mL, were significantly elevated in patients with BC compared to controls, 1.18 and 3.44 µg/mL, respectively (p<0.0001). The combined use of these markers yielded values which were increased 4.4- and 13.7-fold in the benign and malignant disease groups, respectively, with respect to the normal group. The values of EMA and NMP-52 were significantly higher in patients with higher-grade tumors than those with lower-grade tumors (p<0.0001). Moreover, this combination could predict all BC stages and grades with 0.91 AUC, 94% sensitivity and 80% specificity.

Conclusions

EMA and NMP-52 in combination could be promising noninvasive biomarkers for BC detection.

Early diagnosis of bladder cancer through the detection of urinary tyrosine-phosphorylated proteins

Background:

A noninvasive, highly sensitive and specific urine test is needed for bladder cancer (BC) diagnosis and surveillance in addition to the invasive cystoscopy. We previously described the diagnostic effectiveness of urinary tyrosine-phosphorylated proteins (UPY) and a new assay (UPY-A) for their measurement in a pilot study. The aim of this work was to evaluate the performances of the UPY-A using an independent cohort of 262 subjects.

Methods:

Urinary tyrosine-phosphorylated proteins were measured by UPY-A test. The area under ROC curve, cutoff, sensitivity, specificity and predictive values of UPY-A were determined. The association of UPY levels with tumour staging, grading, recurrence and progression risk was analysed by Kruskal–Wallis and Wilcoxon's test. To test the probability to be a case if positive at the UPY-A, a logistic test adjusted for possible confounding factor was used.

Results:

Results showed a significant difference of UPY levels between patients with BC vs healthy controls. For the best cutoff value, 261.26 Standard Units (SU), the sensitivity of the assay was 80.43% and the specificity was 78.82%. A statistically significant difference was found in the levels of UPY at different BC stages and grades between Ta and T1 and with different risk of recurrence and progression. A statistically significant increased risk for BC at UPY-A ⩾261.26 SU was observed.

Conclusions:

The present study supplies important information on the diagnostic characteristics of UPY-A revealing remarkable performances for early stages and allowing its potential use for different applications encompassing the screening of high-risk subjects, primary diagnosis and posttreatment surveillance.