Analysis of Autoantibodies Related to Tumor Progression in Sera from Patients with High-grade Non-muscle-invasive Bladder Cancer.

BACKGROUND/AIM: Bladder cancer (BC) has a high recurrence rate and may progress to being a muscle-invasive lesion, that is potentially associated with a poor prognosis. We identified tumor-associated proteins that were recognized by autoantibodies in sera from patients with high-grade non-muscle-invasive bladder cancer (HG-NMIBC) by proteomic analysis. MATERIALS AND METHODS: The serum levels of these autoantibodies against identified proteins were validated by dot blot analysis with sera from 95 patients with BC and 35 healthy controls. The expression of identified proteins was immunohistochemically analyzed in 115 BC tissues. RESULTS: Autoantibody against protein phosphatase 1, catalytic subunit, alpha isoform (PPP1CA) protein was detected in pretreated sera from patients with HG-NMIBC who showed progression. The serum IgG level of anti-PPP1CA autoantibody was significantly correlated with pathological stage, grade, lymphovascular invasion, and prognosis. The immunoreactions for PPP1CA protein in BC was significantly correlated with pathological stage, grade, and lymphovascular invasion. CONCLUSION: PPP1CA is a candidate sero-diagnostic and prognostic marker for patients with BC.

Nestin is an independent predictor of cancer-specific survival after radical cystectomy in patients with urothelial carcinoma of the bladder.

OBJECTIVES: To investigate the association between the expression of nestin, a class VI intermediate filament protein, and pathologic features or survival in patients with urothelial carcinoma of the bladder (UCB). METHODS: Nestin expression in tumor cells was immunohistochemically studied in 93 patients with UCB who underwent radical cystectomy with pelvic lymphadenectomy. The associations with clinicopathologic parameters were evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of nestin expression on survival. RESULTS: Nestin expression in cystectomy specimens was observed in 13 of 93 patients (14.0%). Nestin expression was associated with pathologic tumor stage (p = 0.006). Nestin-negative patients had better overall survival compared with nestin-positive patients (log-rank p = 0.0148). Univariable analysis indicated that nestin expression, lymphovascular invasion, and lymph node status were significantly associated with cancer-specific survival (hazard ratios, 2.78, 2.15, and 2.80, respectively). On multivariable analysis, nestin expression and lymph node status were independent prognostic factors in cancer-specific survival (hazard ratios, 2.45 and 2.65, respectively). CONCLUSIONS: The results suggest that nestin expression is a novel independent prognostic indicator for patients with UCB and a potentially useful marker to select patients who may be candidates for adjuvant chemotherapy.

Detection of tumor-associated antigens in culture supernatants using autoantibodies in sera from patients with bladder cancer.

Secreted proteins play essential roles in the process of tumorigenesis, and the analysis of tumor-secreted proteins has been suggested as a promising strategy for identifying cancer biomarkers. In this study, we performed proteomic analysis to identify proteins secreted from bladder cancer cell lines that are recognized by autoantibodies in sera from patients with bladder cancer. In addition,autoantibodies against the identified proteins were validated using a dot-blot array with sera from patients with bladder cancer and normal controls. As the results, we detected twenty-five and thirty-two immunoreactive spots in sera from patients with high- and low-grade bladder cancer, respectively.In addition, validation analysis revealed that serum IgG levels of anti-calreticulin and matrix metalloproteinase-2 (MMP2) autoantibodies were significantly higher in bladder cancer patients than in normal controls (both P < 0.05). Furthermore, the serum IgG level of anti-MMP2 autoantibody was significantly higher in patients with high- compared to low-grade bladder cancer(P < 0.05). On multivariate analysis, the serum IgG level of anti-MMP2 autoantibody was an independent predictor of cancer-specific survival (P < 0.05). Based on these findings, serum IgG levels of anti-calreticulin and MMP2 autoantibodies may be novel biomarker candidates for bladder cancer and its clinical outcome.

Proteomic study of sera from patients with bladder cancer: usefulness of S100A8 and S100A9 proteins.

To effectively obtain tumour-specific markers, fractionated proteins obtained using reversed-phase high-performance liquid chromatography for patient-matched pre- and postoperative sera from bladder cancer patients were compared by two-dimensional gel electrophoresis. The usefulness of the identified proteins was confirmed immunohistochemically. S100A8 and S100A9 were identified as tumour-associated proteins. The increased immunoreactive expression of S100A8 protein was associated with bladder wall muscle invasion of the tumour and cancer-specific survival (p<0.05), and the increased immunoreactive expression of S100A9 protein was associated with the tumour grade (p<0.05). In addition, increased expressions of both proteins was associated with recurrence-free survival at a median follow-up of 32.9 months (both p<0.05). On multivariate analysis, the expression of S100A8 was a significant predictor of recurrence (p<0.05). These findings may help to identify biologically aggressive tumors and, thus, patients who might benefit from more intensive adjuvant therapy.