Mathematical Model of BCG Immunotherapy in Superficial Bladder Cancer

Immunotherapy with Bacillus Calmette-Guérin (BCG)-an attenuated strain of Mycobacterium bovis (M. bovis) used for anti tuberculosis immunization-is a clinically established procedure for the treatment of superficial bladder cancer. However, the mode of action has not yet been fully elucidated, despite much extensive biological experience. The purpose of this paper is to develop a first mathematical model that describes tumor-immune interactions in the bladder as a result of BCG therapy. A mathematical analysis of the ODE model identifies multiple equilibrium points, their stability properties, and bifurcation points. Intriguing regimes of bistability are identified in which treatment has potential to result in a tumor-free equilibrium or a full-blown tumor depending only on initial conditions. Attention is given to estimating parameters and validating the model using published data taken from in vitro, mouse and human studies. The model makes clear that intensity of immunotherapy must be kept in limited bounds. While small treatment levels may fail to clear the tumor, a treatment that is too large can lead to an over-stimulated immune system having dangerous side effects for the patient.

[The bacillus Calmette-Guérin as immunomodulator in bladder cancer]

The bacillus Calmette-Guérin (BCG) is regarded as the most successful immunotherapy against superficial bladder carcinoma recurrences to date. BCG intravesical therapy for superficial bladder cancer has shown its efficacy and advantage over classical therapeutic strategies. This efficacy is based on complex and long lasting immune activation. The initial step is the binding of mycobacteria to the urothelial lining, which depends on the interaction of a fibronectin attachment protein on the bacteria surface with fibronectin in the bladder wall. Granulocytes and other immunocompetent mononuclear cells became attracted to the bladder wall and a cascade of proinflammatory cytokines sustains the immune response. In the bladder wall a largely TH1 based cytokine milieu and granuloma-like cellular foci are established. Within this scenario, the most important effector mechanisms might be the direct antitumor activity of interferons and the cytotoxic activity of NK cells. Current treatment consists of an induction phase of 6 weeks and a maintenance dose schedule of 3 weeks every three months up to 36. The majority of patients present adverse events related to dose administration due to bladder inflammatory response and on only a few occasions, there are mayor complications like granulomatous prostatitis. Among all the neoplasms only in superficial bladder cancer the BCG is proved to be effective.

[Metastatic transitional cell carcinoma with high CA 19.9 serum levels]

We report the case of a 75-year-old woman with liver metastases of a urothelial carcinoma accompanied by a marked increased in CA 19-9 serum level. The mechanisms leading to this elevation, similar to that observed in biliary tract diseases, are discussed.

Immunotherapeutic effect of Concholepas hemocyanin in the murine bladder cancer model: evidence for conserved antitumor properties among hemocyanins

PURPOSE

We determined the antitumor properties of a newly available hemocyanin obtained from the Chilean gastropod Concholepas concholepas (Biosonda Corp., Santiago, Chile) in a syngeneic heterotopic mouse bladder carcinoma model. Since keyhole limpet hemocyanin (Pierce, Rockford, Illinois) is used increasingly in biomedicine as a carrier for vaccines and an immunotherapeutic agent for bladder transitional cell carcinoma, there is a growing interest in finding new substances that share its potent immunomodulatory properties. Considering that keyhole limpet hemocyanin and Concholepas concholepas hemocyanin differ significantly, it was not possible to predict a priori the antitumor properties of Concholepas concholepas hemocyanin.

MATERIALS AND METHODS

C3H/He mice were primed with Concholepas concholepas hemocyanin before subcutaneous implantation of mouse bladder tumor-2 cells. Treatment consisted of a subcutaneous dose of Concholepas concholepas hemocyanin (1 mg or 100 mug) at different intervals after implantation. Keyhole limpet hemocyanin and phosphate buffered saline served as positive and negative controls, respectively. In addition, experiments were designed to determine which elements of the immune response were involved in its adjuvant immunostimulatory effect.

RESULTS

Mice treated with Concholepas concholepas hemocyanin showed a significant antitumor effect, as demonstrated by decreased tumor growth and incidence, prolonged survival and lack of toxic effects. These effects were similar to those achieved with keyhole limpet hemocyanin. We found that each hemocyanin increased natural killer cell activity but the effect of Concholepas concholepas hemocyanin was stronger. Analysis of serum from treated mice showed an increased interferon-gamma and low interleukin-4, which correlated with antibody isotypes, confirming that hemocyanins induce a T helper type 1 cytokine profile.

CONCLUSIONS

To our knowledge our results are the first demonstration of the antitumor effect of a hemocyanin other than keyhole limpet hemocyanin. They suggest that this is an ancient conserved immunogenic mechanism shared by those hemocyanins that is able to enhance T helper type 1 immunity and lead to antitumor activity. Therefore, Concholepas concholepas hemocyanin may be an alternative candidate for providing safe and effective immunotherapy for human superficial bladder cancer.

The role of granulocytes following intravesical BCG prophylaxis

OBJECTIVES

The antitumour effect of bacillus Calmette-Guérin (BCG) still remains relatively undefined. Most investigations on its mechanism of action have focused on mononuclear cells; little consideration has been given to granulocytes. We analysed urine of patients with bladder cancer during 8 wk of intravesical BCG prophylaxis. The number of polymorphonuclear neutrophils (PMNs) and urothelial cells (UCs) was evaluated. We examined the in vitro response of the T24 UC line to human PMNs after BCG treatment.

METHODS

Seventeen patients were enrolled in the study. Cytologic analyses were performed on urine samples collected before each BCG instillation and after 2 h from the first voided urine after BCG instillation. Elastase activity was determined on these samples to evaluate PMN activation. PMN-induced damage was measured on the T24 cell line treated with BCG.

RESULTS

After BCG treatment, a large number of PMNs transmigrated through the urothelium and PMNs adherent to detached UCs were found. One patient, who did not respond with significant PMN transmigration, experienced recurrent disease. The number of eosinophils that transmigrated was low, with the exception of three patients with recurrent disease. In vitro, PMNs adhered to BCG-primed T24 cells and damaged the monolayer.

CONCLUSIONS

The results agree with recent evidence that PMNs may play an important role in the antitumour action of BCG during the BCG induction period. This role is probably nonspecific because both normal UCs in vivo and tumour cells in vitro appeared to be injured. As suggested by results obtained from a limited number of patients, a high number of eosinophils in the urine may indicate therapy failure.

Contemporary Intravesical Treatment Options for Urothelial Carcinoma of the Bladder

To provide a comprehensive review of intravesical treatment options for non–muscle-invasive bladder cancer, we performed a search of the PubMed database for articles between 1980 and 2006 that reported on intravesical agents for treating this disease. Data were compiled and analyzed, emphasizing findings from large multicenter trials, studies providing reproducible results, data that could be confirmed by cross-referencing the literature, and phase I or II studies for pertinent novel agents. A critical analysis of evidence shows that: 1) treatment with Bacillus Calmette-Guérin (BCG), including a maintenance schedule (with or without interferon-α), is the most effective therapy for limiting recurrence, is the only therapy that reduces the incidence of progression, and overall is superior to chemotherapy; 2) mitomycin C, gemcitabine, anthracyclines, and thiotepa provide similar benefits for preventing recurrence in patients with minimal effect on progression; and 3) using chemotherapeutic agents immediately after transurethral resection (when use of BCG is contraindicated because of the risk for systemic absorption) reduces the recurrence rate by up to 50% and seems to be the ideal method of chemotherapy. Although various clinical factors dictate which agent is most appropriate for an individual patient, the current literature supports a single perioperative dose of intravesical mitomycin C followed, in appropriate cases, by induction and maintenance therapy with intravesical BCG.

[Characterization of a novel transplantable orthotopic nude mouse model with xenografted human bladder transitional cell tumor (BIU-87)]

OBJECTIVE

A mouse model of orthotopic bladder cancer simulating its human counterpart is of great importance in preclinical evaluation of new treatment modalities such as immunotxin therapy. The aim of the present study is to establish a novel nude mouse model with xenografted human bladder cancer.

METHODS

Single cell suspension of an established human bladder transitional cell carcinoma (TCC) cell line BIU-87 was instilled into nude mouse bladders which were pretreated with mild acid washing. The tumor growth in mouse bladder was assessed weekly by magnetic resonance imaging (MRI). At intervals following implantation and MRI tumor detection, the animals were sacrificed for necropsy, histological examination and immunocytochemical studies.

RESULTS

The overall tumor establishment was 92.9% (52/56 mice) at 7 - 36 days, while in the subgroup of animals sacrificed at 12 - 13 days, 40 out of 42 animals (95.2%) developed TCC, the majority of which was superficial. The tumor stages were assessed by gross and histopathology. Histological examination confirmed the presence of grade II - III TCC. Immunocytochemistry confirmed that the tumor model maintained the biological and immunological features of BIU-87 cells. The changes seen on MRI images well correlated with the extent of tumor invasion identified by histology. Carcinoma in situ could be detected histologically at 7 - 9 days post-inoculation and progressed into papillary or invasive tumors thereafter.

CONCLUSION

The orthotopic BIU-87 TCC model in nude mice is highly reproducible and is ideal for preclinical studies on experimental intravesical therapies.

[Differential expression of immune-associated genes in two subcloned cell lines from a same human bladder cancer]

AIM

To screen and identify differentially expressed genes in subcloned lines from a same human bladder transitional cell carcinoma (TCC).

METHODS

Two bladder TCC cell lines (BLX and BLS-211) with different phenotypes but same origin were used to screen for differentially expressed genes by suppression subtractive hybridization (SSH).

RESULTS

9 over-expressed genes in BLX and 15 in BLS-211 cells were obtained, respectively. Some Bacillus Galmette-Guerin(BCG)- associated genes, such as BCG induced integral membrane protein(BIGM103), fibronectin(FN), complement factor B(BF), were over-expressed in BLX cells. And 8 new ESTs(Expressed Sequence Tag) in BLS-211 cells were collected by GenBank dbEST database with the accession number of DY505708-13, DY230447-8.

CONCLUSION

SSH is a powerful method for the identification of differentially expressed genes in different cell lines or clones. Some BCG-associated genes, which are differentially expressed in different cells may contribute to the different response to clinical BCG therapy. The identified new ESTs can be cloned for full length to further study their functions.

Establishment and characterization of human urothelial cancer xenografts in severe combined immunodeficient mice

AIM

To establish and characterize a murine xenograft model of human urothelial cancer in severe combined immunodeficient (SCID) mice for therapeutic simulation.

METHODS

Pieces of 30 freshly resected urothelial tumors (24 obtained from bladder and 6 from ureter or pelvis) were implanted subcutaneously into SCID mice, and xenograft tumors were passed in tumorigenic cases. At each passage, histopathology, TP53 mutational status assessed by yeast p53 functional assay, and the Ki-67 labeling index (LI) were examined to evaluate the preservation of original features. A growth delay assay after single-dose irradiation was performed in four representative xenografts.

RESULTS

Tumor growth was observed in 18 mice (60%, 18/30). Histologically, 15 of the 18 were epithelial carcinomas similar to the original tumors, whereas the other 3 were Epstein-Barr virus-associated lymphoproliferative disease, resulting in a 50% (15/30) take rate. No correlation was found between the tumor take rate and the clinicopathologic features, TP53 mutational status, or Ki-67 LI of the patients' tumors. Of these 15 xenografts, 11 xenografts were passed from 3 to 10 generations. TP53 mutational status remained stable during the passages, and the Ki-67 LI of eight xenografts was within a range of 50% of the LI of the original tumors, although the other three xenografts increased by over 50%. Specific growth delay after irradiation, independent of the original tumor growth speed and Ki-67 LI, was observed in four xenografts.

CONCLUSIONS

SCID mice are useful recipients for investigations of human urothelial cancer with a wide biological range. This easy-to-handle xenograft system can help to develop a better in vivo preclinical evaluation system for therapeutic agents as well as the investigation of tumor pathophysiology.

Flow cytometric analysis of Th1 and Th2 cytokines in PBMCs as a parameter of immunological dysfunction in patients of superficial transitional cell carcinoma of bladder

Transitional cell carcinoma (TCC) is the commonest cancer of the bladder. Although majority of TCC can be diagnosed at an early stage and removed easily by transurethral resection of tumor (TURT), the management of this carcinoma is complicated due to frequent recurrences usually within 6 months to one-year period. An imbalance between the Th1 and Th2 immune responses has been attributed to immune dysregulation in various malignancies. The present study aims to evaluate the Th1 and Th2 balance in Peripheral Blood Mononuclear Cells of 41 TCC patients (20 recurrent and 21 non-recurrent) using flow cytometry. It also further assesses immunological and cellular factors influencing the anti-neoplastic activity of the TCC patients and in 21 normal healthy subjects in terms of their cytokine expression and various cell surface markers. The findings of the study revealed that the cell surface markers CD3+, CD4+ and CD8+ along with NK cells were found to be significantly lower in patients than healthy controls (p < 0.01). The mean percent expression of CD4+ was significantly lower in patients showing recurrence (23.9 +/- 9.84) as compared to patients with non-recurrence (31.1 +/- 12.27). The percentage of CD4+T-cells (mean +/- SD) producing IFN-gamma, IL-2 and TNF-alpha were statistically significantly reduced in patients (19.1 +/- 4.94, 52.3 +/- 20.86 and 12.8 +/- 4.49) as compared to healthy controls (23.3 +/- 3.67, 67.5 +/- 12.0 and 17.6 +/- 5.96 respectively), (p < 0.01, 0.018, 0.001). On the contrary, the mean levels of IL-4, IL-6 and IL-10 in patients (63.8+/-17.01, 60.4+/-14.79 and 65.7 +/- 14.84 respectively) were significantly higher as compared to healthy controls (24.4 +/- 8.77, 26.5 +/- 5.28 and 20.6 +/- 3.81 respectively), (p < 0.001). No statistically significant difference was observed in the cytokine expression between patients showing recurrence and non-recurrence. Patients with bladder cancer seem to develop a Th2 dominant status with a deficient type1 immune response. The lymphocyte evaluation along with cytokine measurement can provide a sensitive and valuable tool for evaluating the function of cell-mediated immunity in these patients and can also find application in therapeutic monitoring of bladder cancer patients as new targets for immunotherapy.

Correlation between sigma2 receptor protein expression and histopathologic grade in human bladder cancer

Sigma2 (sigma2) receptor proteins are overexpressed in several tissues and tumour cell lines. Although the biomolecular mechanism of this overexpression must be elucidated, sigma2 receptor was considered a potential biomarker for monitoring solid tumour proliferation. In this study, we verified first sigma2 receptor overexpression by saturation analysis with radioligand in six human bladder cancer specimens, then if a possible correlation could be established between sigma2 overexpression and tumour tissue stage and grade. The results displayed that sigma2 receptor protein was normally expressed in human bladder and overexpressed in the case of high-grade transitional cell carcinomas. Moreover, these receptors were undetected in a low-grade squamous cell carcinoma and in a very rare form of anaplastic, large cells plasmacytoid cancer.

LOH at 6p21.3 region and HLA class I altered phenotypes in bladder carcinomas

Alterations in HLA class I antigen expression have been frequently described in different epithelial tumors and are thought to favor tumor immune escape from T lymphocyte recognition. Multiple molecular mechanisms are responsible for these altered HLA class I tumor phenotypes. Some are structural defects that produce unresponsiveness to treatment with interferons. Others include alterations in regulatory mechanisms that can be switched on by treatment of tumor cells with different cytokines. One important mechanism belonging to the first group is loss of heterozygosity (LOH) at chromosome region 6p21.3, which can lead to HLA haplotype loss. In this investigation, the frequency of LOH at 6p21 chromosome region was studied in 69 bladder carcinomas. Short tandem repeat analysis showed that 35% of cases had LOH in this chromosome region. By considering these results together with immunohistological findings previously published by our group, we identified a distribution pattern of HLA class I altered phenotypes in bladder cancer. The most frequently altered phenotype in bladder carcinomas was total loss of HLA class I expression (17 cases, 25%), followed by phenotype II associated with HLA haplotype loss (12 cases, 17.5%), and HLA allelic loss (ten cases, 14.5%). Nine cases (13%) were classified as having a compound phenotype, five cases (7%) as having HLA locus loss, and in 16 cases (23%) no alteration in HLA expression was detected. An important conclusion of this report is that a combination of different molecular and immunohistological techniques is required to precisely define which HLA alleles are lost during tumor progression and to characterize the underlying mechanisms of these losses. These studies should be performed when a cancer patient is to be included in an immunotherapy protocol that aims to stimulate different immune effector mechanisms.

In vivo growth of transitional and renal cell carcinoma cell lines can be suppressed by the adenovirus-mediated expression of a soluble form of vascular endothelial growth factor receptor

Antiangiogenic therapy is a promising strategy for the treatment of cancer since tumor development and metastases require angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most important factors in tumor angiogenesis. In the present study, we investigated the antitumor effect of an adenovirus (AdVEGF-ExR) expressing the extracellular domain of the human VEGF receptor (flt-1) using two different urological tumor/mouse systems. RENCA, a renal cell carcinoma of BALB/c origin, and MBT-2, a poorly differentiated transitional carcinoma of C3H/He origin, were used. Both types of tumor were in vitro infected with AdVEGF-ExR and inoculated subcutaneously into the abdomens of syngenenic mice, and tumor growth was measured twice weekly. In some experiments, BALB/c mice with established RENCA tumors were injected intramuscularly with AdVEGF-ExR as a therapeutic model. The cytotoxicity of spleen cells from the tumor-rejected mice was assessed by 51Cr-release assay. Although the in vitro cell growth of either MBT-2 or RENCA was not affected by infection with AdVEGF-ExR, the in vivo growth of both AdVEGF-ExR-infected tumors was significantly suppressed in the syngeneic mice. In addition, although 2 of 5 mice rejected the AdVEGF-ExR-infected RENCA, tumor-specific cytotoxic T lymphocytes were not generated from their spleen cells, thus suggesting no cellular immune response. In a therapeutic model, intramuscular injections of AdVEGF-ExR at a remote site also significantly suppressed the growth of the subcutaneously established RENCA. These results indicate that the adenovirus-mediated expression of a soluble VEGF receptor can be an effective therapy for urological cancer treatment; however, such VEGF-targeted gene therapy is not necessarily accompanied by subsequent antitumor T cell immunity.

Expression and antigenicity of survivin, an inhibitor of apoptosis family member, in bladder cancer: Implications for specific immunotherapy

OBJECTIVES

To assess the expression of survivin in transitional cell carcinoma of the bladder and to study whether survivin is a transitional cell carcinoma-specific antigen that could be a target for immunotherapy. Survivin, an inhibitor of apoptosis family member, has been reported to be expressed in various cancers but not in normal adult tissues.

METHODS

Immunohistochemical staining for survivin and human leukocyte antigen (HLA) class I was performed on specimens from 88 patients who underwent transurethral resection and radical cystectomy. To determine whether survivin was recognized as a tumor antigen by the host immune system, we assessed anti-survivin antibodies in the sera of 52 patients and 18 healthy volunteers with an enzyme-linked immunosorbent assay using recombinant survivin.

RESULTS

Survivin and HLA class I were expressed in 77 (87.5%) and 59 (67.0%) of the 88 bladder cancer specimens, respectively, and 56 (63.6%) expressed both survivin and HLA class I. The absorbance values of anti-survivin antibodies in patients with bladder cancer were significantly greater than those in the healthy volunteers. A relationship was found between the level of serum anti-survivin antibodies and the staining intensity of survivin in the specimen.

CONCLUSIONS

Survivin is expressed in carcinoma of the bladder with high sensitivity. It is suggested that survivin is presented on HLA class I molecules of antigen-presenting cells in 64% of patients with bladder cancer. Therapeutic targeting of survivin in bladder cancer is a future possibility.

Expresión inmunohistoquímica de p53, p21, p16 y Ciclina D1 en el cáncer de vejiga superficial. Estudio en un soporte de tissue microarray

INTRODUCTION AND OBJECTIVES

To retrospectively assess the relationship between immunohistochemical expression of p53, p21, p16, and cyclin D1, with recurrence, progression and survival in superficial bladder cancer.

METHODS

163 patients undergoing transurethral resection for superficial bladder cancer between February 1995 and March 2004. Tumor samples were included in a tissue microarray support that was serially sectioned for immunohistochemical staining. Grade and stage associations for each marker were evaluated by the Chi-square test. Assessment of the relationship with recurrence, progression, and survival Kaplan-Meier curves and log-rank test were used.

RESULTS

There were no statistically significant differences in marker expression depending on tumor grade and stage, with the exception of Cyclin D1, that was significantly different depending on tumor stage (p=0.030). p21 expression was related to tumor recurrence (p=0.035), progression (p=0.008) and survival (p=0.034). p16 expression was also related to recurrence (p=0.048) and survival (p=0.047), but not to tumor progression (p=0.116). p53 and Cyclin D1 were not statistically associated with tumor recurrence, progression or survival.

CONCLUSIONS

In our experience, only p16 and p21 may be useful in the management of superficial bladder tumors, as they are predictors of recurrence and survival in Ta and T1 patients.

Value of clusterin immunoreactivity as a predictive factor in muscle-invasive urothelial bladder carcinoma

OBJECTIVES

To determine whether clusterin immunoreactivity of muscle-invasive bladder carcinoma can predict disease-related survival of patients treated by radical cystectomy.

METHODS

Multi-tissue arrays were constructed from 132 tumors and stained immunohistochemically using a mouse monoclonal antibody (clone 7D1). Positive clusterin staining was defined as immunoreactivity in more than 10% of tumor cells. We also studied tumor proliferation (Ki-67 antigen), p53, and Her2 expression. Immunoreactivity was compared with disease-related survival. Univariate and multivariate analyses were performed.

RESULTS

Positive immunohistochemical clusterin expression was found in 25% of the tumors. On univariate analysis, clusterin immunoreactivity (P = 0.048), tumor stage (P = 0.011), nodal status (P = 0.0001), sex (P = 0.039), Ki-67 antigen index (P = 0.011), and Her2 expression (P = 0.020) were significantly associated with disease-related survival. On multivariate analysis, tumor stage (P = 0.01), nodal status (P = 0.0001), Ki-67 antigen (P = 0.0001), and Her2 expression (P = 0.001) were identified as significant independent predictive factors; clusterin expression missed the level of statistical significance by only a narrow margin (P = 0.058).

CONCLUSIONS

Although clusterin immunoreactivity showed only a trend towards an independent prognostic relevance in this study, we conclude that it may be used, in addition to conventional and other immunohistochemical prognosticators, as a supplementary tool to provide more prognostic information in patients undergoing cystectomy for muscle-invasive bladder cancer.

Superantigen-activated mononuclear cells induce apoptosis in transitional cell carcinoma

BACKGROUND

Superantigens are among the most potent T-cell mitogens known. Since T-cell activation and T-cell-derived cytokines play a role in the immune response associated with intravesical Bacillus Calmette-Guerin (BCG) application, this study was initiated to explore the fundamental aspects of a potential new immunomodulatory therapy for superficial bladder cancer. Since Superantigen-induced cytotoxicity is mediated by apoptosis, the effects of SEB (staphylococcal enterotoxin B)-Superantigen-activated PBMC (peripheral blood mononuclear cells) on bladder cancer cells were evaluated with regard to Fas/Fas-ligand-based interactions.

MATERIALS AND METHODS

Whether SEB can induce Fas-ligand expression on PBMC and the extent of cytokine secretion were examined by flow cytometry and specific ELISA. In addition, whether the SEB-activated PBMC are able to induce apoptosis in transitional cell carcinoma cells (TCC) was evaluated in co-culture experiments.

RESULTS

It was shown that SEB induced pronounced time- but not dose-dependent specific Fas-ligand expression on PBMC, lasting 1 h to 7 h after initiation of the experiment. Cleaved soluble Fas-ligand was detected in the culture supernatants 24 h after stimulation, but not earlier. Further, a strong time-dependent secretion of cytokines IL-2, IFN-gamma and TNF-alpha released from the SEB-stimulated PBMC was shown. In co-culture experiments, it was demonstrated that SEB-activated PBMC significantly induced apoptosis in TCC cells. The released cytokines from SEB-treated PBMC demonstrated only a minor, not significant, apoptotic response in TCC cells.

CONCLUSION

This first evaluation of the possible mode of action of a Superantigen opens the door for extended studies of this interesting approach to the treatment of bladder cancer.

CpG oligonucleotide therapy cures subcutaneous and orthotopic tumors and evokes protective immunity in murine bladder cancer

Bacillus Calmette-Guerin (BCG) instillation is standard immunotherapy for superficial bladder carcinoma. However, many patients become refractory to BCG, giving impetus to the development of alternative therapies. CpG oligodeoxynucleotide (ODN) therapy has been shown to promote T(H)1-oriented antitumor responses in various tumor models. To investigate its therapeutic effect in bladder cancer, we used different CpG ODNs to treat C57BL/6 mice bearing the subcutaneous murine bladder tumor MB49. CpG type B ODN 1668 was superior at inhibiting tumor growth, leading to complete regression of large tumors. More importantly, CpG ODN 1668 also regressed orthotopically growing MB49 tumors for the first time. Rechallenge of CpG ODN-cured mice with MB49 showed that a majority of the mice were protected long term, demonstrating that CpG ODN therapy evokes a memory response. Adenoviral vectors (Ad) encoding CD40L, tumor necrosis factor-related activation-induced cytokine, lymphotactin, interleukin (IL) 2, and IL-15 were also investigated. AdCD40L and AdIL-15 transduction could abolish MB49 tumorigenicity, and these vectors were combined with CpG ODN 1668 to investigate any enhanced effects. No such effects were seen. All groups of mice treated with CpG ODNs, alone or in combination with adenoviral vector, exhibited increased serum concentrations of IL-12, indicative of a T(H)1 response. Our results show that CpG ODN therapy cures established subcutaneous and orthotopic bladder cancer via a T(H)1-mediated response and provides long-lasting protective immunity.

Novel insights into the mechanism of action of intravesical immunomodulators

To date, the precise mechanism of intravesical immunomodulators remains unknown. In vitro, interferon alpha (IFN-alpha) acts directly on neoplastic cells and inhibits their proliferation while it induces their differentiation. Urothelium and transitional cell carcinoma (TCC) cells express IFN-alpha receptor, the density of which correlates with lesion grade. IFN-alpha reduces neo-microvascular density in the normal urothelium adjacent to the tumor after transurethial resection (TUR), possibly via inhibition of COX-1. Moreover, IFN-alpha induces the membrane expression of tumor-related antigens and MHC antigens, providing a basis for a cellular immune response. When given intravesically, IFN-alpha may result in local and systemic T cell and NK cell activation. By monitoring nitric oxide (NO) end-products in urine and evaluating inducible nitric oxide synthase (iNOS) expression immunohistochemically, we were able to show that IFN-alpha may induce urothelial iNOS expression with subsequent formation of peroxynitrite, which might contribute to the antineoplastic action of IFN-alpha. Bacillus Calmette-Guerin (BCG) is thought to bind to the bladder wall via interaction between the bacterial antigen 85 complex and fibronectin. Although systemic reactions (evolution of cellular immune response, systemic production of cytokines and oxygen free radicals) have been reported, a likely scenario is that exposure to BCG results in a massive local immune response, characterized by induced expression of cytokines in the urine and in the bladder wall, and by a marked infiltration of the bladder wall by granulocytes and mononuclear cells. BCG-induced changes in tumor cell phenotype render them able to act both as lymphokine-alphactivated killer cell targets and antigen presenting cells. Although BCG may act directly on the proliferation of tumor cells, helper and cytotoxic T cells and, most probably, NK cells are absolutely necessary for any antitumor effects. Tumor cell killing is mediated through FasLigand, perforin and TNF-alpha. In a recent study, we found that BCG up-regulated iNOS expression in normal human urothelium in vivo, suggesting a role for NO in BCG-mediated antitumor activity.

Association of positive serum anti-p53 antibodies with poor prognosis in bladder cancer patients

AIMS

To assess the association of serum anti-p53 antibodies and overexpression of tumor p53 protein with survival and prognostic factors in patients with urinary bladder tumors.

METHODS

Seventy-six patients with transitional cell carcinoma of the urinary bladder were assessed prospectively (Ta, 18; T(1), 30; > or =T(2), 28). Serum anti-p53 antibodies were detected by enzyme-linked immunosorbent assay. Tumor p53 gene overexpression was assessed by immunohistochemical staining. The mean follow-up time was 34 months.

RESULTS

Serum anti-p53 antibodies were positive in 25 patients (33%). Overexpression of tumor p53 protein was positive in 41 patients (54%). There was an association between the presence of serum anti-p53 antibodies and tumor p53 gene overexpression (P = 0.001). The total survival of the patients with positive serum anti-p53 antibodies was shorter than the patients with positive tumor p53 gene overexpression (P < 0.001, P = 0.344, respectively). In the multivariate survival analysis, both tumor stage and serum-p53 antibodies were found to be independent survival predictors (P = 0.004, P = 0.006, respectively).

CONCLUSION

Serum anti-p53 antibody positive tumors had a worse prognosis than those with negative serum levels, regardless of the p53 status of the tumor.

A novel expression of macrophage derived chemokine in human bladder cancer

PURPOSE

Successful bacillus Calmette-Guerin (BCG) immunotherapy for bladder cancer is associated with proper induction of T helper (Th)1 immunity. Unfortunately, 30% to 40% of bladder tumors never respond to BCG. We sought evidence of antagonistic Th2 chemokine production by bladder tumors as a potential cause of BCG nonresponsiveness.

MATERIALS AND METHODS

Expression of interferon-gamma inducible protein-10 (IP-10), a Th1 chemokine, and macrophage derived chemokine (MDC), a Th2 chemokine, was examined in 9 clinical bladder tumor specimens and 7 human bladder cancer lines by sandwich enzyme-linked immunosorbent assay, immunohistochemistry and immunofluorescence. Regulation of these chemokine expressions in the human RT4 bladder cancer line was also explored by reverse transcription-polymerase chain reaction and electrophoretic mobility shift assay.

RESULTS

Eight of 9 clinical specimens expressed IP-10 and 5 expressed MDC. However, of 7 cancer lines only 1 low grade line (RT4) expressed IP-10 and MDC, and 1 high grade line (T24) expressed IP-10. Histological staining demonstrated MDC and IP-10 expression in human bladder tumors. Interestingly interferon-gamma and tumor necrosis factor-alpha up-regulated and synergized the expression of these 2 chemokines in RT4 cells. Such positive effects appeared to be mediated by nuclear factor-kappaB but not by the AP-1 signaling pathway.

CONCLUSIONS

These results indicate that certain bladder tumors produce the Th2 chemokine MDC, which may antagonize the local Th1 environment induced by BCG. MDC production by bladder tumors appears to be mediated by signals distinct from those identified in macrophages.

Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis

AIM

To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC).

METHODS

Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available.

RESULTS

The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples.

CONCLUSION

The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.

P16 immunoreactivity is an independent predictor of tumor progression in minimally invasive urothelial bladder carcinoma

OBJECTIVE

To evaluate the prognostic impact of p16 immunoreactivity in minimally invasive transitional cell bladder carcinomas (stage T1).

METHODS

Multi-tissue-arrays containing 73 samples of T1 bladder carcinomas were stained immunohistochemically for p16. Additionally, p53 and Ki-67 antigen expression were examined. A multivariate analysis including other prognostically relevant factors like tumor grade and sub-stage was performed.

RESULTS

Loss of p16 expression occurred in 54% of cases and was significantly associated with reduced progression-free (p=0.018 by univariate analysis), but not with recurrence-free survival (p=0.341). Median Ki-67 antigen and p53 index were 51% (range, 1-93%) and 10% (range, 0-100%), respectively. Both indices correlated significantly (p=0.041 and p=0.024, respectively) with recurrence-free, but not with progression-free survival. Also tumor grade was significantly associated with tumor recurrence (p=0.006). By multivariate analysis, tumor grade (p=0.008) was identified as an independent predictor of tumor recurrence, whereas p16 expression (p=0.009) was identified as an independent predictor of tumor progression.

CONCLUSION

According to our data, there is a significant correlation between loss of p16 expression and tumor progression in patients with minimally-invasive bladder cancer. Immunohistochemical p16 staining may therefore represent a useful tool of providing additional information on the clinical outcome of these patients.

[The prognostic value of KI-67 proliferation index in transitional cell carcinoma of renal pelvis and ureter]

The investigation deals with Ki-67 immunoreactivity assay in upper urinary tract transitional cell carcinoma (TCC) with respect to grade, stage and survival after radical surgery. In a retrospective study (5yrs) of 37 patients with TCC of the renal pelvis and ureter, who had undergone radical nephroureterectomy and bladder resection, pT1-pT4 lesions and G1-G3 tumors were identified. Ki-67 expression was evaluated by immunohistological staining (1:100; MIB-1; Immunotech. Inc., Westbrook, USA). By using fifteen x600 visual fields, Ki-67 labeling index (number of positive cells per 100 tumor cells) was found (mean +SD--29.7 +/- 9.22). There was a correlation between the index and tumor stage (p < 0.001) and grade (p = 0.002). The Ki-67 values in excess of 27 corresponded to high risk of bladder recurrence (p < 0.001) and short duration of recurrence development (p = 0.067) whereas, for the index of under 22, five-year progression-free survival was more frequent (p < 0.001). Having been tested in that study, discriminative modeling yielded the following parameters: sensitivity and specificity for bladder recurrence was 93% and 79% while for 5-year progression-free survival- 89% and 100%.

Overexpression of human carcinoma-associated antigen in urothelial carcinoma of the bladder

CONTEXT

Human carcinoma-associated antigen (HCA) is a mucin protein whose level is increased in the sera of patients with a variety of carcinomas. We have previously shown that prostatic carcinoma overexpresses HCA in comparison to benign prostatic tissue. To our knowledge, expression of HCA in other tumors has not been reported previously.

OBJECTIVE

The current study was designed to determine if HCA is overexpressed in urothelial carcinoma (UCa) of the bladder.

DESIGN

Forty cystectomy specimens with UCa were selected, of which 27 cases had invasive UCa, 21 cases had a noninvasive component, and 36 cases had benign urothelium. Seven cystectomy specimens with benign conditions were chosen as controls. Anti-HCA monoclonal antibody HAE3 was used for immunohistochemical staining. Results were recorded as positive (> or =5% of cells staining and staining intensity 2+ or 3+) or negative (<5% of cells staining or staining intensity <2+) and analyzed using the Fisher exact test.

RESULTS

HAE3 staining was positive in 67% of invasive UCa, 29% of noninvasive UCa, but only 5% of benign urothelium specimens. The difference in HCA expression between benign urothelium and UCa and that between invasive and noninvasive UCa was statistically significant (P =.008). No statistically significant difference was found between low-grade and high-grade noninvasive papillary UCa (P =.06).

CONCLUSIONS

Human carcinoma-associated antigen is selectively overexpressed in a significant number of cases of UCa of the bladder, suggesting the potential utility of monitoring the serum and/or urine levels of HCA in monitoring patients with HCA-positive UCa for recurrence or progression.