Introduction of 65 kDa Antigen ofMycobacterium tuberculosisto Cancer Cells Enhances Anti-Tumor Effect of BCG Therapy

Discovering Therapeutic Protein Targets for Bladder Cancer Using Proteomic Data Analysis

BACKGROUND

Bladder cancer accounts for almost 54% of urinary system cancer and is the second most frequent cause of death in genitourinary malignancies after prostate cancer. About 70% of bladder tumors are non-muscle-invasive, and the rest are muscle-invasive. Recurrence of the tumor is the common feature of bladder cancer. Chemotherapy is a conventional treatment for MIBC, but it cannot improve the survival rate of these patients sufficiently. Therefore, researchers must develop new therapies. Antibody-based therapy is one of the most important strategies for the treatment of solid tumors. Selecting a suitable target is the most critical step for this strategy.

OBJECTIVE

The aim of this study is to detect therapeutic cell surface antigen targets in bladder cancer using data obtained by proteomic studies.

METHODS

Isobaric tag for relative and absolute quantitation (iTRAQ) analysis had identified 131 overexpressed proteins in baldder cancer tissue and reverse-phase proteomic array (RPPA) analysis had been done for 343 tumor tissues and 208 antibodies. All identified proteins from two studies (131+208 proteins) were collected and duplicates were removed (331 unique proteins). Gene ontology study was performed using gene ontology (GO) and protein analysis through evolutionary relationships (PANTHER) databases. The Human Protein Atlas database was used to search the protein class and subcellular location of membrane proteins obtained from the PANTHER analysis.

RESULTS

Membrane proteins that could be suitable therapeutic targets for bladder cancer were selected. These included: Epidermal growth factor receptor (EGFR), Her2, Kinase insert domain receptor (KDR), Heat shock protein 60 (HSP60), HSP90, Transferrin receptor (TFRC), Activin A Receptor Like Type 1 (ACVRL1), and cadherin 2 (CDH2). Monoclonal antibodies against these proteins or their inhibitors were used for the treatment of different cancers in preclinical and clinical trials.

CONCLUSION

These monoclonal antibodies and inhibitor molecules and also their combination can be used for the treatment of bladder cancer.

Effect of human leukocyte antigen class I expression of tumor cells on outcome of intravesical instillation of bacillus calmette-guerin immunotherapy for bladder cancer

PURPOSE

Various immune systems play important roles in the clinical efficacy of intravesical Bacillus Calmette-Guerin (BCG) instillation for bladder cancer. However, human leukocyte antigen (HLA) class I molecules on tumor cells and various immune system cells infiltrating to/around the tumor have not been evaluated, although many prognostic factors, including clinical, pathologic, and molecular ones, have been investigated. The aim of this study was to determine immunologic prognostic factors of BCG immunotherapy for bladder cancer.

EXPERIMENTAL DESIGN

Immunohistochemical staining for HLA class I, CD4, CD8, CD20, CD68, TIA-1, S-100, and FOXP3 was carried out on specimens from 30 patients who underwent BCG immunotherapy from whom both pretreatment and posttreatment specimens were obtained. We did univariate and multivariate analyses of factors affecting recurrence-free survival. The positive, weakly positive, and negative groups of cells that infiltrated to/around the tumor were compared with recurrence-free survival using the Kaplan-Meier method and log-rank test.

RESULTS

HLA class I was a significant prognostic factor both in univariate and multivariate analyses. The 5-year recurrence-free survivals of the patients with HLA class I-positive tumors and those with HLA class I-negative tumors were 55.7% and 19.1%, respectively (P = 0.019). There was a significant association between infiltration of CD8, CD20, and CD68-positive cells after BCG therapy and therapeutic effects.

CONCLUSIONS

Our data show that expression of HLA class I molecules on tumor cells contributes significantly to the therapeutic effect of BCG immunotherapy for bladder cancer. It is suggested that CTLs may be one of main effectors in this therapy.

HSP90 expression: a new predictive factor for BCG response in stage Ta-T1 grade 3 bladder tumours

OBJECTIVES

Although Bacillus Calmette-Guérin (BCG) instillations are considered as the adjuvant treatment of choice for stage Ta-T1 grade G3 bladder tumours, there is no consensus for a predictive factor to assess BCG success. This study attempted to evaluate if heat shock proteins (HSPs) could be useful predictive markers in BCG responses.

METHODS

Thirty-three primary resected G3 superficial bladder tumours were included in the study. All patients received adjuvant BCG instillations. The mean follow-up was 56 mo (range: 24-132 mo). HSP expression was evaluated by immunochemistry.

RESULTS

In the 33 patients, 18 had no recurrence (group 1), 9 had recurrence with no muscular invasion (group 2), and 6 had an invasive recurrence (group 3). A significant correlation was found between lack of expression of HSP90 and BCG response: the mean HSP expression was 92.7%, 84.4%, and 26.7% for groups 1, 2 and 3 tumours, respectively (p<0.0001). For the 6 patients who did not positively respond to BCG, HSP expression was <40%. All the tumours with a HSP90 expression >40% positively responded to BCG, corresponding to group 1 or 2 patients. In contrast, HSP60 expression was not correlated to the BCG response.

CONCLUSIONS

HSP90 could be considered as a very promising marker to assess BCG treatment response. Low HSP90 expression (<40%) could be useful to predict BCG failure and early stage cystectomy could be proposed for these selected patients with primary high-risk grade 3 superficial bladder tumours.

Reactive arthritis following BCG immunotherapy for urinary bladder carcinoma: a systematic review

Intravesical instillation of Bacillus Calmette-Guerin (BCG) is used with efficacy and safety in the treatment of patients with intermediate and high-risk superficial bladder carcinoma. Arthralgia and/or arthritis is one of the rare severe complications following intravesical BCG immunotherapy. We searched MEDLINE in order to analyze the frequency of this clinical complication, its pathogenesis and outcome. The electronic search was conducted using the following key words: "BCG immunotherapy" and "Arthritis, arthralgias and BCG immunotherapy". At the end of a process of abstract analysis, 48 papers were included in the systematic review. All the selected papers, except one that was a clinical review, described at least one case of arthritis after BCG therapy. The BCG immunotherapy resulted to be safe and efficacious in the treatment of bladder cancer; the development of reactive arthritis is rare and can evolve in a chronic process. The review of the literature highlighted that reactive arthritis following BCG intravesical instillation is a complication usually well controlled with the discontinuation of the immunotherapy and nonsteroidal anti-inflammatory drugs (NSAIDs) treatment. Only a small portion of patients with a particular genetic background will develop a chronic process.