TP53 disruptive mutation predicts platinum-based chemotherapy and PD-1/PD-L1 blockade response in urothelial carcinoma

TP53 mutation is one of the most common genetic alterations in urothelial carcinoma (UrCa), and heterogeneity of TP53 mutants leads to heterogeneous clinical outcomes. This study aimed to investigate the clinical relevance of specific TP53 mutations in UrCa. In this study, a total of eight cohorts were enrolled, along with matched clinical annotation. TP53 mutations were classified as disruptive and nondisruptive according to the degree of disturbance of p53 protein function and structure. We evaluated the clinical significance of TP53 mutations in our local datasets and publicly available datasets. The co-occurring events of TP53 mutations in UrCa, along with their therapeutic indications, functional effects, and the tumor immune microenvironment, were also investigated. TP53 mutations were identified in 49.7% of the UrCa patients. Within this group, 25.1% of patients carried TP53Disruptive mutations, a genetic alteration correlated with a significantly poorer overall survival (OS) when compared to individuals with TP53Nondisruptive mutations and those with wild-type TP53. Significantly, patients with TP53Disruptive mutations exhibit an increased probability of responding favorably to PD-1/PD-L1 blockade and chemoimmunotherapy. Meanwhile, there was no noteworthy distinction in OS among patients with varying TP53 mutation status who underwent chemotherapy. Samples with TP53Disruptive mutations showed an enriched APOBEC- and POLE-related mutational signature, as well as an elevated tumor mutation burden. The sensitivity to immunotherapy in tumors carrying TP53Disruptive mutation may be attributed to the inflamed tumor microenvironment characterized by increased CD8+T cell infiltration and interferon-gamma signaling activation. In conclusion, UrCa patients with TP53Disruptive mutations have shown reduced survival rates, yet they may respond well to PD-1/PD-L1 blockade therapy and chemoimmunotherapy. By distinguishing specific TP53 mutations, we can improve risk stratification and offer personalized genomics-guided therapy to UrCa patients. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

High serum sodium predicts immunotherapy response in metastatic renal cell and urothelial carcinoma

OBJECTIVES

The development of reliable biomarkers for the prediction of immune checkpoint inhibition (ICI) response in patients with metastatic renal cell carcinoma (mRCC) and urothelial carcinoma (mUC) remains an unresolved challenge. Conventional ICI biomarkers typically focus on tumor-related factors such as PD-L1 expression. However, a comprehensive evaluation of the predictive value of serum electrolyte levels, a so far widely unexplored area, is still pending.

METHODS

We conducted a post-hoc analysis of baseline sodium, potassium, chloride, magnesium and calcium levels in two independent phase 3 clinical trials: IMvigor211 for mUC comparing atezolizumab to chemotherapy, and IMmotion151 for mRCC comparing atezolizumab+bevacizumab to sunitinib. This analysis aimed to evaluate the prognostic and predictive value of these electrolyte levels in these clinical settings. A total of 1787 patients (IMvigor211 n = 901; IMmotion151 n = 886) were analyzed.

RESULTS

We found a linear correlation of baseline serum sodium and chloride with prognosis across both trials, which was not found for potassium, magnesium and calcium. In multivariate analysis, the prognostic capacity of sodium was limited to patients receiving ICI as compared to the control group. Interestingly, in both studies, the chance of achieving an objective response was highest in the patient subgroup with high baseline serum sodium levels of > 140 mmol/L (IMmotion151: Complete response in 17.9% versus 2.0% in patients with mRCC with baseline sodium < 135 mmol/L). Serum sodium outperformed tumor PD-L1 expression as a predictor for immunotherapy efficacy.

CONCLUSIONS

Patients exhibiting elevated serum sodium levels derive the greatest benefit from immunotherapy, suggesting that baseline serum concentration could serve as a valuable and cost-effective predictive biomarker for immunotherapy across entities.

The identification of a N6-methyladenosin-modifed immune pattern to predict immunotherapy response and survival in urothelial carcinoma

BACKGROUND

Dysregulation of the immune system and N6-methyladenosine (m6A) contribute to immune therapy resistance and cancer progression in urothelial carcinoma (UC). This study aims to identify immune-related molecules, that are m6A-modified, and that are associated with tumor progression, poor prognosis, and immunotherapy response.

METHODS

We identified prognostic immune genes (PIGs) using Cox analysis and random survival forest variable hunting algorithm (RSF-VH) on immune genes retrieved from the Immunology Database and Analysis Portal database (ImmPort). The RM2Target database and MeRIP-seq analysis, combined with a hypergeometric test, assessed m6A methylation in these PIGs. We analyzed the correlation between the immune pattern and prognosis, as well as their association with clinical factors in multiple datasets. Moreover, we explored the interplay between immune patterns, tumor immune cell infiltration, and m6A regulators.

RESULTS

28 PIGs were identified, of which the 10 most significant were termed methylated prognostic immune genes (MPIGs). These MPIGs were used to create an immune pattern score. Kaplan-Meier and Cox analyses indicated this pattern as an independent risk factor for UC. We observed significant associations between the immune pattern, tumor progression, and immune cell infiltration. Differential expression analysis showed correlations with m6A regulators expression. This immune pattern proved effective in predicting immunotherapy response in UC in real-world settings.

CONCLUSION

The study identified a m6A-modified immune pattern in UC, offering prognostic and therapeutic response predictions. This emphasizes that immune genes may influence tumor immune status and progression through m6A modifications.

Spatial and Temporal Heterogeneity of Tumor-Infiltrating Lymphocytes in Advanced Urothelial Cancer

Checkpoint inhibitors targeting PD-(L)1 induce objective responses in 20% of patients with metastatic urothelial cancer (UC). CD8+ T cell infiltration has been proposed as a putative biomarker for response to checkpoint inhibitors. Nevertheless, data on spatial and temporal heterogeneity of tumor-infiltrating lymphocytes in advanced UC are lacking. The major aims of this study were to explore spatial heterogeneity for lymphocyte infiltration and to investigate how the immune landscape changes during the disease course. We performed multiplex immunohistochemistry to assess the density of intratumoral and stromal CD3+, CD8+, FoxP3+ and CD20+ immune cells in longitudinally collected samples of 49 UC patients. Within these samples, spatial heterogeneity for lymphocyte infiltration was observed. Regions the size of a 0.6 tissue microarray core (0.28 mm2) provided a representative sample in 60.6 to 71.6% of cases, depending on the cell type of interest. Regions of 3.30 mm2, the median tumor surface area in our biopsies, were representative in 58.8 to 73.8% of cases. Immune cell densities did not significantly differ between untreated primary tumors and metachronous distant metastases. Interestingly, CD3+, CD8+ and FoxP3+ T cell densities decreased during chemotherapy in two small cohorts of patients treated with neoadjuvant or palliative platinum-based chemotherapy. In conclusion, spatial heterogeneity in advanced UC challenges the use of immune cell infiltration in biopsies as biomarker for response prediction. Our data also suggests a decrease in tumor-infiltrating T cells during platinum-based chemotherapy.

An integrated multi-omics analysis identifies prognostic molecular subtypes of non-muscle-invasive bladder cancer

The molecular landscape in non-muscle-invasive bladder cancer (NMIBC) is characterized by large biological heterogeneity with variable clinical outcomes. Here, we perform an integrative multi-omics analysis of patients diagnosed with NMIBC (n = 834). Transcriptomic analysis identifies four classes (1, 2a, 2b and 3) reflecting tumor biology and disease aggressiveness. Both transcriptome-based subtyping and the level of chromosomal instability provide independent prognostic value beyond established prognostic clinicopathological parameters. High chromosomal instability, p53-pathway disruption and APOBEC-related mutations are significantly associated with transcriptomic class 2a and poor outcome. RNA-derived immune cell infiltration is associated with chromosomally unstable tumors and enriched in class 2b. Spatial proteomics analysis confirms the higher infiltration of class 2b tumors and demonstrates an association between higher immune cell infiltration and lower recurrence rates. Finally, the independent prognostic value of the transcriptomic classes is documented in 1228 validation samples using a single sample classification tool. The classifier provides a framework for biomarker discovery and for optimizing treatment and surveillance in next-generation clinical trials.

Comprehensive integrative profiling of upper tract urothelial carcinomas

BACKGROUND

Crosstalk between genetic, epigenetic, and immune alterations in upper tract urothelial carcinomas and their role in shaping muscle invasiveness and patient outcome are poorly understood.

RESULTS

We perform an integrative genome- and methylome-wide profiling of diverse non-muscle-invasive and muscle-invasive upper tract urothelial carcinomas. In addition to mutations of FGFR3 and KDM6A, we identify ZFP36L1 as a novel, significantly mutated tumor suppressor gene. Overall, mutations of ZFP36 family genes (ZFP36, ZFP36L1, and ZFP36L2) are identified in 26.7% of cases, which display a high mutational load. Unsupervised DNA methylation subtype classification identifies two epi-clusters associated with distinct muscle-invasive status and patient outcome, namely, EpiC-low and EpiC-high. While the former is hypomethylated, immune-depleted, and enriched for FGFR3-mutated, the latter is hypermethylated, immune-infiltrated, and tightly associated with somatic mutations of SWI/SNF genes.

CONCLUSIONS

Our study delineates for the first time the key role for convergence between genetic and epigenetic alterations in shaping clinicopathological and immune upper tract urothelial carcinoma features.

Impact of radiotherapy to the primary tumor on the efficacy of pembrolizumab for patients with advanced urothelial cancer: A preliminary study

Radiotherapy plus immune checkpoint inhibitors can potentially induce synergistic antitumor immune responses. However, little clinical evidence is established regarding their combination therapy. Here, we aimed to assess whether radiotherapy to the primary tumor impacts on the efficacy of pembrolizumab in advanced urothelial cancer. We retrospectively reviewed 98 advanced urothelial cancer patients receiving pembrolizumab in a second- or later-line setting using our multicenter cohort. Patients were categorized according to a history of radiotherapy to the primary tumor: patients previously exposed to radiotherapy to the primary tumor (Radiotherapy group, 17 patients [17%]) and those not (Nonradiotherapy group, 81 patients [83%]). The associations of radiotherapy to the primary tumor with objective response and survival were evaluated. The Radiotherapy group showed a significantly higher objective response ratio than did the Non-radiotherapy group (65% vs 19%; P < .001). The Radiotherapy group had a higher progression-free survival rate compared with the Nonradiotherapy group (52% vs 28% at 12 months; P = .078), but statistical significance was not reached. The Radiotherapy group had a significantly higher overall survival rate compared with the Non-radiotherapy group (77% vs 50% at 12 months; P = .025). From multivariate analysis, radiotherapy to the primary tumor was an independent predictor for longer overall survival (hazard ratio, 0.31; P = .032) along with Eastern Cooperative Oncology Group performance status ≤1 and the absence of visceral metastasis. Therefore, radiotherapy to the primary tumor may enhance the efficacy of pembrolizumab for patients with advanced urothelial cancer.

[Immunotherapy in bladder cancer-quo vadis? Update on current trials and developments]

BACKGROUND

Great advances have been made for the treatment of urothelial carcinoma by the introduction of checkpoint inhibitors (CPI). Single-agent immunotherapy with CPIs has been approved for patients with metastatic or locally advanced inoperable urothelial carcinoma who have either progressed during or after platinum-based chemotherapy or who are cisplatin-ineligible. For cisplatin-ineligible patients, approval is restricted to patients with high programmed cell death ligand 1 (PD-L1) expression. For patients with nonmuscle invasive bladder cancer (NMIBC) or patients with muscle invasive bladder cancer (MIBC) who receive curative therapy, no CPIs have received approval in Germany.

OBJECTIVES

To provide an overview of the current landscape of immunotherapy in patients with urothelial carcinoma.

METHODS

Summary of the therapeutic landscape and resulting challenges based on currently published data using a PubMed search.

RESULTS

In the treatment of metastatic or inoperable urothelial carcinoma, CPIs represent standard treatment. Depending on the results of currently performed trials, an extension of its use to the perioperative setting (neoadjuvant/adjuvant) and to patients with Bacillus Calmette Guérin (BCG) unresponsive NMIBC in the near future is currently being discussed.

CONCLUSIONS

Immuno-oncologic treatment using CPIs has become an integral part of the management of patients with advanced bladder cancer. For biomarker-based patient selection and combination therapies, there is an urgent need for further investigations within clinical trial protocols.

Mitotic activity index and CD25+ lymphocytes predict risk of stage progression in non-muscle invasive bladder cancer

In urothelial cell type non-muscle invasive urinary bladder carcinoma, TNM stage and WHO grade are widely used to classify patients into low and high‑risk groups for prognostic and therapeutic decision-making. However, stage and grade reproducibility and prediction accuracy are wanting. This may lead to suboptimal treatment. We evaluated whether proliferation features, nuclear area of the epithelial cancer cells and the composition of stromal and tumor infiltrating lymphocytes have independent prognostic value. In 183 primary non-muscle invasive bladder cancer patients with long follow-up (median for stage progression cohort: 119 months, range 5-173; median for tumor recurrence cohort: 82, range 3-165) proliferation features Ki67, PPH3 and Mitotic Activity Index (MAI), Mean Nuclear Area (MNA), lymphocyte subsets (CD8+, CD4+, CD25+) and plasma cells (CD138+) were assessed on consecutive sections. Post-resection instillation treatments (none, mitomycin, BCG) were strictly standardized during the intake period. Risk of recurrence was associated with expression of Ki67 (≤ 39 vs. > 39) and Multifocality (p = 0.01). Patients with low Ki67 had a higher recurrence rate than those with high Ki67. Lymphocyte composition did not predict recurrence. Stage progression was strongly associated with high values for MAI (>15) and CD25+ (>0.2%). In a multivariate analysis the combination of MAI and CD25+ was the single most prognostic feature (p<0.001). Validation of these results in additional, independent studies is warranted.

Characterization of six canine prostate adenocarcinoma and three transitional cell carcinoma cell lines derived from primary tumor tissues as well as metastasis

Canine prostate adenocarcinoma (PAC) and transitional cell carcinoma (TCC) of prostate and urinary bladder are highly invasive and metastatic tumors of closely neighbored organs. Cell lines are valuable tools to investigate tumor mechanisms and therapeutic approaches in vitro. PAC in dogs is infrequent, difficult to differentiate from TCC and usually characterized by poor prognosis, enhancing the value of the few available cell lines. However, as cell lines adapt to culturing conditions, a thorough characterization, ideally compared to original tissue, is indispensable. Herein, six canine PAC cell lines and three TCC cell lines were profiled by immunophenotype in comparison to respective original tumor tissues. Three of the six PAC cell lines were derived from primary tumor and metastases of the same patient. Further, two of the three TCC cell lines were derived from TCCs invading into or originating from the prostate. Cell biologic parameters as doubling times and chemoresistances to commonly used drugs in cancer treatment (doxorubicin, carboplatin and meloxicam) were assessed. All cell lines were immunohistochemically close to the respective original tissue. Compared to primary tumor cell lines, metastasis-derived cell lines were more chemoresistant to doxorubicin, but equally susceptive to carboplatin treatment. Two cell lines were multiresistant. COX-2 enzyme activity was demonstrated in all cell lines. However, meloxicam inhibited prostaglandin E2 production in only seven of nine cell lines and did neither influence metabolic activity, nor proliferation. The characterized nine cell lines represent excellent tools to investigate PAC as well as TCC in prostate and urinary bladder of the dog. Furthermore, the profiled paired cell lines from PAC primary tumor and metastasis provide the unique opportunity to investigate metastasis-associated changes PAC cells undergo in tumor progression. The combination of nine differently chemoresistant PAC and TCC cell lines resembles the heterogeneity of canine lower urinary tract cancer.

Enfortumab Vedotin, a fully human monoclonal antibody against Nectin 4 conjugated to monomethyl auristatin E for metastatic urothelial Carcinoma

Introduction: The conventional management of most patients with metastatic urothelial carcinoma (UC) is platinum-based chemotherapy followed by immunotherapy. Erdafitinib is an option in post-platinum patients with activating mutations in fibroblast growth factor receptor (FGFR)-3 and -2. Salvage therapy with taxanes or vinflunine has demonstrated minimal efficacy. Enfortumab Vedotin (EV), a monoclonal antibody-drug conjugate (ADC) targeting nectin-4 is under investigation in patients with advanced UC. Areas covered: This review describes the epidemiology and unmet needs of patients with metastatic UC and is focused specifically on heavily treated patients. We explore the rationale for targeting nectin 4 and the clinical development of EV; efficacy and safety data from the completed phase I and II studies are examined. Ongoing trials to definitively assess clinical outcomes in comparison to current therapy and trials exploring EV in combination are also highlighted. Expert opinion: There is an unmet need for new therapies in most patients with advanced UC and who progress after platinum and immunotherapy. EV has shown promising efficacy and safety in this population in phase 1 and 2 trials including those with poor prognostic factors such as liver metastases. Ongoing trials exploring this agent in combination will continue to advance the treatment of UC.

Evaluation of cancer testis antigen (CT10, PRAME) and MHC I expression in high-grade urothelial carcinoma of the bladder

Immunotherapeutic strategies are increasingly used in the treatment of a number of malignancies including high grade urothelial carcinoma (HGUC) of the bladder. Because of this, detailed and accurate assessment of the tumour immune microenvironment is paramount. In this study, we aimed to correlate the composition of the tumour immune microenvironment with oncologic outcome and the expression of two cancer testis antigens (CTAs), CT10 and PRAME, potential cancer vaccine targets, as well as major histocompatibility complex I (MHC I), a molecule associated with tumour immune escape and resistance to immunotherapy.

Triplicate tissue microarrays (TMAs) were constructed using 207 cases of HGUC of the bladder. Oncologic outcome data was gathered for each case. Consecutive sections from the TMA blocks were stained with CD3, CD4, CD8, FOXP3, PD1, PD-L1, CT10, PRAME, and MHC I. 21% and 15% of cases expressed CT10 and PRAME, respectively. 88% of cases showed absent or decreased MHC I expression. CT10-expressing tumours showed a significantly worse disease specific survival (p = 0.007, hazard ratio 2.245, confidence interval 1.223–4.122). CT10, PRAME, and MHC I expression significantly correlated with other some immune parameters. CT10 and PRAME are expressed in a subset of HGUC and CTA and MHC I expression correlate with a number of important immune parameters. Together, these findings highlight the potential for exploring novel immune therapeutic strategies in HGUC. Additional studies evaluating the clinical relevance of these findings are warranted.

PD-1/PD-L1 Combinations in Advanced Urothelial Cancer: Rationale and Current Clinical Trials

Chemotherapy is no longer the only viable option for patients with locally advanced or metastatic urothelial carcinoma. Immunotherapy, as checkpoint inhibition, has received United States Food and Drug Administration approval in the preceding several years, both in the second-line and first-line for cisplatin-ineligible patients. Those who respond often do so durably; however, response rates in the first line are 23% to 24%, and are lower in the second line. With a focus on urothelial carcinoma, this review discusses the tumor microenvironment and its negative influence on anti-tumor immunity, as well as measures to counteract immune suppression or evasion. The review then describes a range of current clinical trials implementing these measures in the form of programmed death-combination therapy, specifically in advanced bladder and urothelial cancers.

Age and sex have no impact on expression levels of markers of immune cell infiltration and immune checkpoint pathways in patients with muscle-invasive urothelial carcinoma of the bladder treated with radical cystectomy

OBJECTIVES

Advanced age and female sex have been associated with worse outcomes in patients undergoing radical cystectomy for muscle-invasive bladder cancer. A reduced immune response has been implicated as a mechanism. The objective of our study was to analyze the expression patterns of various cellular proteins active in bladder cancer immune pathways, and assess the correlation between age, sex, and the expression of these immune markers.

METHODS

We obtained surgical tissue samples from equally distributed male/female patients with/without lymph node metastasis who had undergone radical cystectomy for urothelial carcinoma (UC) of the bladder (n = 50). Immunohistochemistry (IHC) for CD3 (cluster of differentiation), CD4, CD8, CD56, LAG-3 (lymphocyte-activation gene), TIM-3 (T-cell immunoglobulin and mucin-domain), PD-1 (programmed death) and PD-L1 molecules was performed and scored by a single pathologist (high versus low). Spearman's correlation and Chi square tests investigated the association between age, sex, and IHC results.

RESULTS

Mean age at surgery was 67 years (range 50-78 years); all patients were Caucasians. The following percent of patients scored high for a stain: 18% CD3, 10% CD4, 0% CD8, 0% CD56, 20% LAG-3, 4% TIM-3, 0% PD-1 and 0% PD-L1. There was no association between patients' age, sex, and the expression of any of the immune markers (p > 0.05 for all).

CONCLUSIONS

The association between advanced age, female sex, and worse outcomes in bladder cancer may be independent of the immune pathways active in the disease that we examined in this study.

Anti-PD-1 Immunotherapy-Induced Flare of a Known Underlying Relapsing Vasculitis Mimicking Recurrent Cancer

Safe use of immune checkpoint blockade in patients with cancer and autoimmune disorders requires a better understanding of the pathophysiology of immunologic activation. We describe the immune correlates of reactivation of granulomatosis with polyangiitis (GPA)-an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis-in a patient with metastatic urothelial carcinoma treated with pembrolizumab. After PD-1 blockade, an inflammatory pulmonary nodule demonstrated a granulomatous, CD4+ T-cell infiltrate, correlating with increased CD4+ and CD8+ naïve memory cells in the peripheral blood without changes in other immune checkpoint receptors. Placed within the context of the existing literature on GPA and disease control, our findings suggest a key role for PD-1 in GPA self-tolerance and that selective strategies for immunotherapy may be needed in patients with certain autoimmune disorders. We further summarize the current literature regarding reactivation of autoimmune disorders in patients undergoing immune checkpoint blockade, as well as potential immunosuppressive strategies to minimize the risks of further vasculitic reactivation upon rechallenge with anti-PD-1 blockade. KEY POINTS: Nonspecific imaging findings in patients with cancer and rheumatological disorders may require biopsy to distinguish underlying pathology.Patients with rheumatologic disorders have increased risk of reactivation with PD-(L)1 immune checkpoint blockade, requiring assessment of disease status before starting treatment.Further study is needed to evaluate the efficacy of treatment regimens in preventing and controlling disease reactivation.

CD163+ macrophages predict a poor prognosis in patients with primary T1 high-grade urothelial carcinoma of the bladder

PURPOSE

Macrophages are a major cell type that can infiltrate solid tumors and exhibit distinct phenotypes in different tumor microenvironments. This study investigates the prognostic value of tumor-infiltrated CD163+ macrophages in patients with T1 high-grade (T1HG) bladder cancer.

METHODS

CD163+ macrophages were assessed by immunohistochemistry in 94 T1HG bladder cancer samples. Kaplan-Meier analyses and Cox proportional hazards' regression models were applied to evaluate recurrence-free survival, progression-free survival and disease-specific survival.

RESULTS

With a median follow-up of 60 months, 37 (39.4%) patients experienced disease recurrence, 14 (14.9%) progression, 11 (11.7%) disease-specific mortality. High CD163+ macrophages were associated with higher risk of disease recurrence and progression (P < 0.05, for both). In multivariate Cox proportional hazards regression analysis, high CD163+ macrophages were a significant negative predictor of recurrence-free survival, progression-free survival and disease-specific survival (P < 0.05 for all).

CONCLUSION

CD163+ macrophages are a poor prognostic factor in T1HG bladder cancer. This finding provide the ground for further testing it in predicting the outcome of this challenging disease.

A multifactorial model of T cell expansion and durable clinical benefit in response to a PD-L1 inhibitor

Checkpoint inhibitor immunotherapies have had major success in treating patients with late-stage cancers, yet the minority of patients benefit. Mutation load and PD-L1 staining are leading biomarkers associated with response, but each is an imperfect predictor. A key challenge to predicting response is modeling the interaction between the tumor and immune system. We begin to address this challenge with a multifactorial model for response to anti-PD-L1 therapy. We train a model to predict immune response in patients after treatment based on 36 clinical, tumor, and circulating features collected prior to treatment. We analyze data from 21 bladder cancer patients using the elastic net high-dimensional regression procedure and, as training set error is a biased and overly optimistic measure of prediction error, we use leave-one-out cross-validation to obtain unbiased estimates of accuracy on held-out patients. In held-out patients, the model explains 79% of the variance in T cell clonal expansion. This predicted immune response is multifactorial, as the variance explained is at most 23% if clinical, tumor, or circulating features are excluded. Moreover, if patients are triaged according to predicted expansion, only 38% of non-durable clinical benefit (DCB) patients need be treated to ensure that 100% of DCB patients are treated. In contrast, using mutation load or PD-L1 staining alone, one must treat at least 77% of non-DCB patients to ensure that all DCB patients receive treatment. Thus, integrative models of immune response may improve our ability to anticipate clinical benefit of immunotherapy.

Effect of BCG Immunotherapy on Cell-Mediated Cytotoxicity in Bladder Cancer Patients following Surgical Treatment

Peripheral blood lymphocytes from bladder cancer patients display in vitro cytotoxicity against established bladder tumor target cells. Following surgery and after separation of lymphocytes in non-T and T with high affinity and low affinity for sheep erythrocytes fractions, the cytotoxic activity was significantly decreased in all subsets. After BCG therapy the cytotoxic capacity was restored and the effect was equally distributed in the different subpopulations. The monocyte-enriched fraction did not show any change in the cytotoxic activity after treatment.

Anti-Programmed Cell Death 1/Ligand 1 (PD-1/PD-L1) Antibodies for the Treatment of Urothelial Carcinoma: State of the Art and Future Development

Immunotherapy with programmed cell death 1/ligand 1 (PD-1/PD-L1) checkpoint inhibitors has expanded a previously limited pool of effective treatment options for patients with metastatic urothelial carcinoma, particularly those with recurring or refractory disease and those who are ineligible for cisplatin. This review reports key findings from completed and ongoing clinical trials that highlight the potential of PD-1/PD-L1 blockade in urothelial carcinoma. A literature search was performed of PubMed, Embase, ClinicalTrials.gov, and selected annual congress abstracts. Prospective studies, reviews, editorials, and descriptions of ongoing anti-PD-1/PD-L1 studies in bladder cancer were included. Anti-PD-1/PD-L1 monoclonal antibodies have shown efficacy and safety across patient subgroups with urothelial carcinoma, including those with poor prognostic factors. Efficacy was similar across different anti-PD-1/PD-L1 agents. Although these antibodies have demonstrated durable responses in a subset of patients with urothelial carcinoma, clinicians are currently unable to predict which patients may derive benefit from immune checkpoint blockade. Anti-PD-1/PD-L1 antibodies have shown favorable clinical activity and tolerability in patients with metastatic urothelial carcinoma refractory to platinum-based therapy or who are ineligible for cisplatin. The activity of PD-1/PD-L1 inhibitors is now also being studied as first-line monotherapy in cisplatin-eligible patients in combination with chemotherapy as maintenance therapy after first-line chemotherapy, and in earlier disease states, such as muscle-invasive and non-muscle-invasive bladder cancer. Better predictive tools to define target patient populations are needed, as are further investigations to define optimal combinations or sequencing of treatments.

Anti-PD-L1/TGFβR2 (M7824) fusion protein induces immunogenic modulation of human urothelial carcinoma cell lines, rendering them more susceptible to immune-mediated recognition and lysis

BACKGROUND

Avelumab has recently been approved by the Food and Drug Administration for the therapy of Merkel cell carcinoma and urothelial carcinoma. M7824 is a novel first-in-class bifunctional fusion protein comprising a monoclonal antibody against programmed death-ligand 1 (PD-L1, avelumab), fused to the extracellular domain of human transforming growth factor beta (TGFβ) receptor 2, which functions as a TGFβ "trap." Advanced urothelial tumors have been shown to express TGFβ, which possesses immunosuppressive properties that promote cancer progression and metastasis. The rationale for a combined molecule is to block the PD-1/PD-L1 interaction between tumor cells and immune cell infiltrate and simultaneously reduce or eliminate TGFβ from the tumor microenvironment. In this study, we explored the effect of M7824 on invasive urothelial carcinoma cell lines.

METHODS

Human urothelial (transitional cell) carcinoma cell lines HTB-4, HTB-1, and HTB-5 were treated with M7824, M7824mut (M7824 that is mutated in the anti-PD-L1 portion of the molecule and thus does not bind PD-L1), anti-PD-L1 (avelumab), or IgG1 isotype control monoclonal antibody, and were assessed for gene expression, cell-surface phenotype, and sensitivity to lysis by TRAIL, antigen-specific cytotoxic T lymphocytes and natural killer cells.

RESULTS

M7824 retains the ability to mediate antibody-dependent cellular cytotoxicity of tumor cells, although in some cases to a lesser extent than anti-PD-L1. However, compared to anti-PD-L1, M7824 increases (A) gene expression of molecules involved in T-cell trafficking in the tumor (e.g., CXCL11), (B) TRAIL-mediated tumor cell lysis, and (C) antigen-specific CD8+ T-cell-mediated lysis of tumor cells.

CONCLUSIONS

These studies demonstrate the immunomodulatory properties of M7824 on both tumor cell phenotype and immune-mediated lysis. Compared to anti-PD-L1 or M7824mut, M7824 induces immunogenic modulation of urothelial carcinoma cell lines, rendering them more susceptible to immune-mediated recognition and lysis. These findings show the relevance of the dual blockade of PD-L1 and TGFβ in urothelial carcinoma cell lines and thus support the rationale for future clinical studies of M7824 in patients with urothelial cancer.

Phase 1 study of intravenous administration of the chimeric adenovirus enadenotucirev in patients undergoing primary tumor resection

BACKGROUND

Enadenotucirev (formerly ColoAd1) is a tumor-selective chimeric adenovirus with demonstrated preclinical activity. This phase 1 Mechanism of Action study assessed intravenous (IV) delivery of enadenotucirev in patients with resectable colorectal cancer (CRC), non-small-cell lung cancer (NSCLC), urothelial cell cancer (UCC), and renal cell cancer (RCC) with a comparator intratumoral (IT) dosed CRC patient cohort.

METHODS

Seventeen patients scheduled for primary tumor resection were enrolled. IT injection of enadenotucirev (CRC only) was administered as a single dose (≤ 3 × 1011 viral particles [vp]) on day 1, followed by resection during days 8-15. IV infusion of enadenotucirev was administered by three separate doses (1 × 1012 vp) on days 1, 3, and 5, followed by resection during days 8-15 (CRC) or days 10-25 (NSCLC, UCC, and RCC). Enadenotucirev activity was measured using immunohistochemical staining of nuclear viral hexon and quantitative polymerase chain reaction for viral genomic DNA.

RESULTS

Delivery of enadenotucirev was observed in most tumor samples following IV infusion, with little or no demonstrable activity in normal tissue. This virus delivery (by both IV and IT dosing) was accompanied by high local CD8+ cell infiltration in 80% of tested tumor samples, suggesting a potential enadenotucirev-driven immune response. Both methods of enadenotucirev delivery were well tolerated, with no treatment-associated serious adverse events.

CONCLUSIONS

This study provides key delivery and feasibility data to support the use of IV infusion of enadenotucirev, or therapeutic transgene-bearing derivatives of it, in clinical trials across a range of epithelial tumors, including the ongoing combination study of enadenotucirev with the checkpoint inhibitor nivolumab. It also provides insights into the potential immune-stimulating properties of enadenotucirev.

TRIAL REGISTRATION

This MOA study was a phase 1, multicenter, non-randomized, open-label study to investigate the administration of enadenotucirev in a preoperative setting (ClinicalTrials.gov: NCT02053220).

Three Drugs Approved for Urothelial Carcinoma by FDA

The FDA has approved one PD-1 checkpoint inhibitor, pembrolizumab, and two PD-L1 checkpoint inhibitors, avelumab and durvalumab, to treat metastatic urothelial carcinoma in patients whose disease continues to progress despite platinum-based chemotherapy. This brings the total number of checkpoint inhibitors for the disease to five, prompting questions about how best to use them.

[YB-1-based virotherapy: A new therapeutic intervention for transitional cell carcinoma of the bladder?]

Therapeutic intervention using oncolytic viruses is called virotherapy. This type of virus is defined by the ability to replicate in tumor cells only and to destroy these cells upon replication. In addition, this virus type is able to induce a tumor-directed immune response. Early clinical trials have confirmed the safety profile of oncolytic viruses. Currently, different groups are working on the development of oncolytic viruses with a focus on treatment of nonmuscle invasive bladder cancer (NMIBC). A preliminary active recruiting clinical phase II/III trial ongoing in patients with a NMIBC was recently implemented in the United States. Our research group developed an oncolytic adenovirus that will soon enter a clinical phase I trial in patients diagnosed with glioma. This virus is being further modified for the treatment of NMIBC. In this review article, recent developments in the design and use of virotherapy in bladder cancer are summarized.

High CD4⁺ T cell density is associated with poor prognosis in patients with non-muscle-invasive bladder cancer

PURPOSE

The aim of this study was to investigate the clinical significance of CD4(+) T cells in non-muscle-invasive bladder cancer (NMIBC) tissues in situ.

METHODS

Immunohistochemistry was used to examine the distribution of CD4(+) T cells in 131 NMIBC tissues. Kaplan-Meier analysis and Cox proportional hazards regression models were applied to estimate overall survival (OS) and recurrence-free survival (RFS).

RESULTS

NMIBC patients were divided into two groups based on the median frequency of CD4(+) T cells (median, 1/×400 high resolution). On univariate analysis, CD4(+) T cell density was inversely associated with overall survival (P = 0.01). In those patients with high CD4(+) T density, 5-year OS rates was only 77%, compared with 86% in those with low density, respectively. Although CD4(+) T cell density showed no prognostic significance for RFS (P = 0.36), 5-year RFS rates of patients with high CD4(+) T density (58%) was lower than those of patients with low CD4(+) T density (65%, respectively). By multivariate analysis, tumor infiltrating CD4(+) T cell density emerged as an independent prognostic factor for OS (HR, 2.75; P = 0.004). In addition, no association was found between CD4(+) T cell density and any clinicopathological variables (P > 0.05).

CONCLUSION

Our findings suggest that CD4(+) T cells could potentially serve as a poor prognostic marker for patients with NMIBC.

Emerging immunotherapies for bladder cancer

PURPOSE OF REVIEW

Inhibition of immune escape mechanisms, such as the programed death-ligand 1 pathway, has demonstrated rapid, durable responses in multiple tumor types, including advanced urothelial carcinoma. This review discusses emerging immunotherapies for urothelial carcinoma in various stages of clinical development.

RECENT FINDINGS

Urothelial carcinoma has a high mutational burden, which may increase the number of tumor antigens and potentially enhance the ability of the immune system to recognize tumor cells as foreign. However, urothelial carcinoma can evade the immune system by downregulating tumor-antigen presentation, upregulating various immune checkpoints, and inactivating cytotoxic T cells. Immunotherapies for urothelial carcinoma target each of these steps to restore immune-mediated cytotoxicity. Many of these agents are in clinical trials for urothelial carcinoma.

SUMMARY

Immunotherapies are active in urothelial carcinoma, but only in a fraction of patients, implying the presence of persistent immune escape. Identifying the mechanisms of immune escape and developing rational combinatorial regimens may make the benefit of immunotherapy accessible to a broader population.

An anti-ubiquitin antibody response in transitional cell carcinoma of the urinary bladder

Background

To use combinatorial epitope mapping (“fingerprinting”) of the antibody response to identify targets of the humoral immune response in patients with transitional cell carcinoma (TCC) of the bladder.

Methods

A combinatorial random peptide library was screened on the circulating pool of immunoglobulins purified from an index patient with a high risk TCC (pTa high grade plus carcinoma in situ) to identify corresponding target antigens. A patient cohort was investigated for antibody titers against ubiquitin.

Results

We selected, isolated, and validated an immunogenic peptide motif from ubiquitin as a dominant epitope of the humoral response. Patients with TCC had significantly higher antibody titers against ubiquitin than healthy donors (p<0.007), prostate cancer patients (p<0.0007), and all patients without TCC taken together (p<0.0001). Titers from superficial tumors were not significantly different from muscle invasive tumors (p = 0.0929). For antibody response against ubiquitin, sensitivity for detection of TCC was 0.44, specificity 0.96, positive predictive value 0.96 and negative predictive value 0.41. No significant titer changes were observed during the standard BCG induction immunotherapy.

Conclusions

This is the first report to demonstrate an anti-ubiquitin antibody response in patients with TCC. Although sensitivity of antibody production was low, a high specificity and positive predictive value make ubiquitin an interesting candidate for further diagnostic and possibly immune modulating studies.

Assessment of tumoral PD-L1 expression and intratumoral CD8+ T cells in urothelial carcinoma

OBJECTIVE

To evaluate programmed death ligand 1 (PD-L1) expression in urothelial carcinoma of the bladder in relationship with tumor-infiltrating CD8+ T cells.

MATERIALS AND METHODS

Tissue microarrays were prepared from 56 cystectomy specimens performed at our hospital (1994-2002). PD-L1 immunoexpression was assessed using the murine antihuman PD-L1 monoclonal antibody 5H1. Extent of membranous PD-L1 expression was assigned in each spot. Spots showing ≥5% expression were considered positive. Average PD-L1 expression per tumor was also calculated (5% positivity cutoff). "High CD8 density" was defined as the presence of ≥60 CD8+ intraepithelial lymphocytes per high power field in a given spot. A tumor was considered high density if ≥50% of its spots were of high density.

RESULTS

PD-L1 expression was positive in approximately 20% of tumors. None of the benign urothelium spots expressed PD-L1. High CD8 density was observed in approximately 20% of cases. CD8 density did not correlate with PD-L1 expression. Overall survival (OS) and disease-specific survival (DSS) rates were 14% and 28%, respectively (median follow-up, 31.5 months). PD-L1 expression was associated with age at cystectomy (P = .01). Remaining clinicopathologic parameters were not associated with PD-L1 expression or CD8 density. High CD8 density was associated with favorable OS (P = .02) and DSS (P = .02). The same was true when CD8 density was adjusted for demographic and clinicopathologic parameters. There was no correlation between PD-L1 expression and outcome.

CONCLUSION

High intratumoral CD8+ T cell density is associated with better OS and DSS in invasive urothelial carcinoma of the bladder. We found no correlation between PD-L1 expression and outcome.

Validation of pretreatment neutrophil-lymphocyte ratio as a prognostic factor in a European cohort of patients with upper tract urothelial carcinoma

OBJECTIVE

To investigate the potential prognostic significance of the neutrophil-lymphocyte ratio (NLR) in a large European cohort of patients with upper urinary tract urothelial cell carcinoma (UUT-UCC).

PATIENTS AND METHODS

We retrospectively evaluated data from 202 consecutive patients with non-metastatic upper urinary tract urothelial cell carcinoma (UUT-UCC), who underwent surgery between 1990 and 2012 at a single tertiary academic centre. Patients' cancer-specific survival (CSS) and overall survival (OS) were assessed using the Kaplan-Meier method. To evaluate the independent prognostic significance of the NLR, multivariate proportional Cox regression models were applied for both endpoints.

RESULTS

A higher NLR was significantly associated with shorter CSS (P = 0.002, log-rank test), as well as with shorter OS (P < 0.001, log-rank test). Multivariate analysis identified a high NLR as an independent prognostic factor for patients' CSS (hazard ratio 2.72, 95% CI 1.25-5.93, P = 0.012), and OS (hazard ratio 2.48, 95% CI 1.31-4.70, P = 0.005).

CONCLUSIONS

In the present cohort, patients with a high preoperative NLR had higher cancer-specific and overall mortality after radical surgery for UUT-UCC, compared with those with a low preoperative NLR. This easily identifiable laboratory measure should be considered as an additional prognostic factor in UUT-UCC in future.

Types of HLA in the bladder transitional cell carcinoma (TCC)

HLA plays a complementary role in the interaction between tumor and body immunology. The aim of this study was to determine the existence of the association between the HLA system and transitional cell carcinoma (TCC). Using standard micro-lymphocytotoxic method of Terasaki, HLA-A, B, DR and DQ antigen types of 30 patients with TCC of the bladder were compared with the control group (30 healthy people). In the TCC patient group, HLA -DQ6(1) and HLA -DQ7(3) antigens were detected with a significantly higher frequency than in the control group (p=0.018 and p=0.038, respectively), whereas HLA-A10, B4, DR53 and DQ1 antigens were detected with significantly higher frequency in the control group (p less 0.05 in all). It suggests that patients who had the antigens detected were at higher risk of TCC, and the ones who had the antigens displaying protective features as were detected in the control group, were at lesser risk.

[Glycosyl-phosphatidylinositol-anchored interleukin-2 expressed on tumor-derived exosomes induces anti-tumor immune response]

OBJECTIVE

To prepare IL-2-anchored and tumor-derived exosomes vaccine, and investigate the antitumor efficiency of the special cytotoxic T-lymphocytes induced by Ex/GPI-IL-2.

METHODS

To construct pEGFP-N1-IL2gpi plasmid coding a fusion gene of a DNA oligo encoding GPI-anchor signal sequence attaching to human IL-2 cDNA. Then T24 cell lines stably expressing GPI-IL-2 proteins (T24/GPI-IL-2) were established. Ex/GPI-IL-2 were isolated and purified by ultrafiltration and sucrose gradient centrifugation, and the morphology and molecule markers were analyzed. The mixed lymphocyte reaction study and cytotoxic study were performed to determine the proliferative effect of T lymphocytes and the cytotoxicity induced by Ex/GPI-IL-2.

RESULTS

The pEGFP-N1-IL2gpi plasmid was successfully constructed, and cell lines stably expressing GPI-IL-2 fusion proteins were established. Ex/GPI-IL-2 were small vesicular and saucer-shaped in diameter of 30-90 nm, containing heat shock protein 70, intercellular adhesion molecule-1, MAGE-1 and GPI-IL-2. Ex/GPI-IL-2-pulsed could dendritic cells induce proliferation of T cells and cytotoxic immune response more efficiently (P<0.05).

CONCLUSIONS

GPI-IL-2 gene-modified tumor cells can make the exosomes containing GPI-IL-2 with an increased anti-tumor effect. Our study provides a feasible approach for exosome-based tumor immunotherapy of bladder transitional cell tumors.

BCG prophylaxis in bladder cancer produces activation of recruited neutrophils

INTRODUCTION

Bacillus Calmette-Guerin (BCG) is used to treat high risk superficial bladder cancer, but its anti-tumor effect remains incompletely defined. Recently a role for polymophonuclear (PMN) neutrophils has been suggested. To investigate the role of granulocytes, we monitored the activation state of these cells in the urine of BCG-treated patients.

MATERIALS AND METHODS

Ten patients with stage T1, grade 3 (T1G3) transitional cell carcinoma received an 8 week course of BCG after undergoing transurethral resection of the bladder. Cytological and enzymatic analyses of urine samples collected before and 2 hours after the physiological expulsion of BCG were performed. The activation state of urine granulocytes and the presence of activating factors within the urine samples were monitored.

RESULTS

BCG immunotherapy stimulated, through soluble factors, the activation of PMN neutrophils, which transmigrated into the bladder, and the degree of activation of the PMN neutrophils was related directly to the number of epithelial cells detached from the urothelial layer.

CONCLUSIONS

This study suggests that PMN neutrophils can participate in reducing the recurrence of bladder cancer by promoting urothelial cell turnover proportionally to their degree of activation. Our results provide further evidence to support the role of PMN neutrophils in BCG immunotherapy.

Epstein-Barr virus-infected cell line TCC36B derived from B lymphocytes infiltrating renal pelvis urothelial carcinoma

This study reports an initial analysis of an EBV-infected B cell line (TCC36B), established from an urothelial carcinoma (UC) lesion of the renal pelvis.

MATERIALS AND METHODS

Cytofluorometric and G-banding analyses were performed for phenotyping and cytogenetics. PCR was used to detect EBV DNA, and sequence analysis to investigate mutations and deletions of the latent membrane protein (LMP)-1 gene of EBV.

RESULTS

TCC36B cells proliferated in vitro and showed positivity for surface CD19, CD20, HLA-DR and IgG(λ), indicating that they belong to B-cells. Cytogenetic analysis showed 46,XX with a unique clonal abnormality of dup(2)(p13p25). EBV DNA was detected in TCC36B cells. Sequence analysis revealed a 30-bp deletion and 7 point mutations on the LMP-1 gene in TCC36B cells.

CONCLUSION

These results suggest the involvement of an EBV variant in the pathogenesis of UC. This cell line should thus facilitate further investigations on the aetiological role of EBV in urothelial cancer.

[Immobilization of streptavidin-tagged bioactive hTNF-alpha on biotinylated mucosal surface of the bladder wall for treatment of superficial bladder cancer in mice]

OBJECTIVE

To investigate a novel immunotherapy through immobilization of streptavidin-tagged hTNF-alpha on the biotinylated mucosal surface of the bladder wall for bladder cancer treatment in mice.

METHODS

A total of 120 female C57BL/6j mice were randomized into 5 equal groups, namely blank control, PBS, soluble hTNF-alpha, SA-GFP, and SA-hTNF-alpha treatment groups. Twenty-four hours after establishment of a mouse model of orthotopic superficial bladder cancer, SA-hTNF-alpha fusion protein was immobilized on the biotinylated mucosal surface of the bladder wall, which was repeated every 4 days for a total of 6 sessions. Immunohistochemistry was performed to detect the retention time of SA-hTNF-alpha fusion protein in the biotinylated mouse bladder mucosa and the distribution of CD4(+) and CD8(+) lymphocytes in the mucosa and tumor tissues, with the tumor growth and mouse survival also observed. The cytotoxiciy of the tumor-specific lymphocytes was evaluated. The mice responding well to the treatment were re-challenged by MB49 and monitored for survival.

RESULTS

SA-hTNF-alpha could be efficiently and stably immobilized on the bladder mucosal surface for as long as 7 days. On day 60 after MB49 implantation, 18 out of 22 SA- hTNF-alpha-treated mice survived, with 9 appearing tumor-free, but all the mice in PBS control group died. Five out of 9 tumor-free mice in SA-hTNF-alpha group showed resistance to a re-challenge with intravesical MB49. The numbers of CD4(+) and CD8(+) lymphocytes were significantly greater in SA-hTNF-alpha group than in the other groups (P<0.05). The cytotoxicity of the tumor-specific lymphocytes was significantly stronger in SA-hTNF-alpha group than in the other groups (P<0.05).

CONCLUSION

SA-hTNF-alpha immobilized on the biotinylated mucosal surface of the bladder wall can significantly inhibit the tumor growth and promote the survival of the mice bearing orthotopic superficial bladder cancer.

[De novo urological neoplasms in kidney transplant patients: experience in 1,751 patients]

INTRODUCTION

Immunosuppressive treatment promotes development of neoplasms in kidney transplant patients. Cancer prevalence in these patients is 4 to 5 times higher as compared to the general population. Tumors are also known to behave more aggressively in transplant patients.

OBJECTIVE

To perform a descriptive analysis of de novo urological tumors in kidney transplant patients and to analyze patient survival.

MATERIALS AND METHODS

A retrospective study was conducted in 1751 transplant patients from January 1980 to December 2006. Patients in whom the tumor occurred in the first year after transplantation were excluded. The primary variables considered included sex, age at transplant, age at cancer diagnosis, site, clinical stage, treatment, and outcome. A Chi-square test was used for univariate statistical analysis. Survival was assessed using the Kaplan-Meier method.

RESULTS

Twenty-nine de novo tumors (1.6%) were diagnosed in the 1751 transplanted patients, with a median follow-up of 35.28 months (2-121) from tumor diagnosis. Tumors were found in 24 males (82%) and 5 females (18%). Median age at transplantation was 50.8 (17-70) years, and median age at tumor diagnosis was 56.4 (19-79) years. Eleven patients (38%) were diagnosed with prostate cancer, seven (24%) with bladder tumors, 4 (60%) with non-muscle invasive tumors, and 3 (40%) with muscle invasive tumors. A renal adenocarcinoma in the primitive kidney was diagnosed in 6 patients (20%). Five patients (18%) were detected a tumor in the transplanted kidney. Median survival was 75 months for patients with bladder tumors, 82 months for prostate cancer, 59 months for tumors in the native kidney, and 86 months for graft tumors.

CONCLUSIONS

In our series, de novo urological tumors in kidney transplant recipients were more common in males. Prostate cancer is the most common tumor and renal cell carcinoma of the native kidney has the worst survival rate.

Construction of a DNA vaccine encoding Flk-1 extracellular domain and C3d fusion gene and investigation of its suppressing effect on tumor growth

Although the critical role of complement component C3d as a molecular adjuvant in preventing virus infection is well established, its role in cancer prophylaxis and treatment is unclear. In this study, we constructed a recombinant plasmid encoding Flk-1 and C3d3 fusion proteins and investigated its transient expression in vitro in transfected eukaryotic cells and its antibody response in immunized mice. Subsequently, we investigated the vaccine's ability to elicit an immune response leading to suppression of angiogenesis and tumor growth in mice bearing bladder transitional cell carcinoma. Using Western blotting, immunocytochemistry, and flow cytometry, we detected the expression of Flk-1 and C3d3 fusion proteins in COS-7 cells transfected with these recombinant plasmids. Further binding experiment using CR2 (C3d receptor) positive Raji cells that were incubated with transfected COS-7 supernatant indicated that C3d was successfully fused to Flk-1. Although both vaccines elicited peak antibody levels at 5 weeks, Flk-1-specific antibody titer in pSG.SS.Flk-1(ECD).C3d3.YL-immunized mice was significantly higher when compared to pSG.SS.Flk-1(ECD).YL-immunized mice. The results of experiments with bladder tumor-bearing mice showed that the vaccine inhibited tumor growth significantly. These results suggest that C3d plays a critical role in tumor immunotherapy by promoting antibody response in Flk-1-based DNA vaccines. This approach may provide a new strategy for the rational design of anti-angiogenic therapies for the treatment of solid tumors and provide a basis for the further exploitation and application of the anti-angiogenesis DNA vaccines.

[Level of CD4(+) CD25(high) CD127(low/-) regulatory T cells in transitional cell carcinoma patients and its clinical significance]

OBJECTIVE

To evaluate the expressions of CD4+ CD25high CD127low/- regulatory T cells (Treg) in peripheral blood from patients with transitional cell carcinoma (TCC) in urinary system.

METHODS

The proportion of Treg population in CD4+ T cells from 93 patients with transitional cell carcinoma was evaluated. And flow cytometry was employed to analyze different clinicopathologic characteristics and detect the pre- and post-operative changes in 38 patients with benign urinary diseases and 37 healthy subjects.

RESULTS

The proportion of Treg population in CD4+ T cells in peripheral blood of patients with TCC significantly increased as compared with those with benign urinary diseases and healthy subjects. There was a strong correlation between the proportion of Treg and tumor recurrence, quantity, lymph node metastasis (P < 0. 01) as well as pathological stage; no correlation was found between the proportion of Treg and clinical TNM stage (P > 0. 05). The proportion of Treg was also different at pre- and post-operation (P < 0. 05).

CONCLUSION

CD4+ CD25high CD127low/- regulatory T cells in peripheral blood from patients with TCC significantly increased as compared with that in patients with benign urinary diseases and in healthy subjects. It may be responsible for immune suppression in TCC patients. Tumor resection could decrease the proportion of Treg in peripheral blood, but the long-term change in immune function requires further investigations.

Intravesical immunotherapy of superficial bladder cancer with chitosan/interleukin-12

Intravesical BCG has been used successfully to treat superficial bladder cancer for three decades. However, 20% to 30% of patients will fail initial BCG therapy and 30% to 50% of patients will develop recurrent tumors within 5 years. Alternative or complementary strategies for the management of superficial bladder cancer are needed. Interleukin-12 (IL-12) is a potent T(H)1 cytokine with robust antitumor activity and the ability to potentiate immunologic memory. Unfortunately, intravesical IL-12 did not show antitumor efficacy in a recent clinical study of patients with recurrent superficial bladder cancer. We hypothesized that coformulation of IL-12 with chitosan, a biocompatible, mucoadhesive polysaccharide, could improve intravesical IL-12 delivery and provide an effective and durable alternative for the treatment of superficial bladder cancer. In antitumor studies, 88% to 100% of mice bearing orthotopic bladder tumors were cured after four intravesical treatments with chitosan/IL-12. In contrast, only 38% to 60% of mice treated with IL-12 alone and 0% treated with BCG were cured. Antitumor responses following chitosan/IL-12 treatments were durable and provided complete protection from intravesical tumor rechallenge. Urinary cytokine analysis showed that chitosan/IL-12 induced multiple T(H)1 cytokines at levels significantly higher than either IL-12 alone or BCG. Immunohistochemistry revealed moderate to intense tumor infiltration by T cells and macrophages following chitosan/IL-12 treatments. Bladder submucosa from cured mice contained residual populations of immune cells that returned to baseline levels after several months. Intravesical chitosan/IL-12 is a well-tolerated, effective immunotherapy that deserves further consideration for testing in humans for the management of superficial bladder cancer.

[Oncolytic vesicular stomatitis viruses as intravesical agents against non-muscle-invasive bladder cancer]

Patients with high-risk bladder cancer who do not respond to bacillus Calmette-Guerin (BCG) immunotherapy represent a significant therapeutic challenge. The addition of interferon to BCG has recently evolved as a second-line treatment option; however, many high-grade tumors are nonresponsive to interferon. Thus, replication-competent oncolytic vesicular stomatitis viruses (VSV) that selectively target interferon-refractory tumors are promising intravesical agents. In vitro, wild-type VSV as well as a mutant variant (AV3) that has an impaired ability to shut down innate immunity preferentially killed undifferentiated, interferon-nonresponsive bladder cancer cells. Testing of these viruses in an orthotopic murine model of high-grade bladder cancer, which we have recently validated, revealed that both AV3 and wild-type VSV significantly inhibited orthotopic tumor growth. Despite the use of immunocompromised nude mice, there was no evidence of toxicity. In conclusion, VSV instillation therapy demonstrated strong antitumor activity and safety in an orthotopic model of high-risk disease. These findings provide preclinical proof-of-principle for the intravesical use of VSV, especially in interferon-refractory patients.

The role of TGF-beta-1 protein and TGF-beta-R-1 receptor in immune escape mechanism in bladder cancer

BACKGROUND

Tumor cells have numerous immune surveillance escape mechanisms as well as means of resistance to apoptosis. This study tried to clarify one of these mechanisms in bladder cancer with the hope of being able to develop targeted therapy that will sensitize the tumor cells to immune-mediated apoptosis.

METHODS

In this study, electron microscopic examination and expression of TGF-beta-1 protein and TGF-beta-R-1 receptor using immunoelectronmicroscopic and immunocytochemical techniques were investigated in urine and peripheral blood mononuclear cells (PBMNCs). Samples were obtained from 5 healthy controls (Group 1) and 60 study patients who were classified according to the cytopathologic examination of their urine into 2 main subgroups: chronic cystitis (bilharzial and nonbilharzial, Group 2, n = 15) and bladder cancer (transitional cell carcinoma and squamous cell carcinoma, Group 3, n = 45).

RESULTS

Examination of PBMNCs by immunoelectronmicroscopic and immunocytochemical techniques showed a significant increase in the percentage of positive cases expressing both TGF-beta-1 protein and TGF-beta-R-1 receptors in bladder cancer in comparison with the control (P < .01 and P < .05, respectively) and with chronic cystitis (P < .05). By electron microscopic examination, 42 out of 45 bladder cancer cases (93.3%) revealed remarkable apoptotic changes represented by cell shrinkage, surface blebs, nuclear chromatin condensation, and vacuolated cytoplasm. Urine examination by immunoelectronmicroscopic and immunocytochemical techniques revealed a statistically significant decrease in the percentage of positive cases expressing TGF-beta-R1 receptor in bladder cancer in comparison with either chronic cystitis cases or controls (P < .01), while TGF-beta-1 protein was significantly increased (P < .01). By electron microscopic examination, exfoliated necrotic malignant epithelial (urothelial) cells and many inflammatory cells were detected.

CONCLUSIONS

This work helps researchers and clinicians to better understand one of the escape mechanisms in bladder cancer that may facilitate the reverse of tumor escape from the immune system. It also draws attention to TGF-beta-1 protein and TGF-beta-R1 receptor; TGF-beta-1 protein can be used as an attractive target for anticancer therapy, and the absence of TGF-beta-R1 can be considered a marker for malignant transformation of urothelial cells in bladder cancer.

Immunotherapeutic strategies for high-risk bladder cancer

Transitional cell carcinoma (TCC), which is the pathological diagnosis for the majority of bladder cancers, is a solid tumor entity that is responsive to immunotherapy as evidenced by a substantial cure rate documented with the use of intravesical bacillus Calmette-Guérin (BCG) therapy in selected patients with high-grade superficial disease. The nonspecific immune modulation that occurs as a result of BCG therapy is not well understood; however, the success of BCG therapy provides a basis for the exploration of mechanisms related to immune responses and the development of novel immunotherapeutic agents for the treatment of high-risk disease. In this review, we discuss the complexity of the immune system and therapies that are considered capable of manipulating it to potentially benefit patients with bladder cancer.

Nephrotic syndrome as a complication of intravesical BCG treatment of transitional cell carcinoma of urinary bladder

Nephrotic syndrome can be associated with various neoplasms, especially solid tumors and lymphomas. This patient presented with painless hematuria of transitional cell carcinoma of urinary bladder, underwent transurethral resection, but developed recurrence 16 months later. Repeat resection was done and intravesical Bacillus Calmette-Guerin (BCG) injections were started. After six months, the patient developed hypertension and nephrotic syndrome with a biopsy revealing membranous glomerulonephritis, though there was no radiological evidence of tumor. This is the first case of nephrotic syndrome with intravesical BCG instillation in a bladder carcinoma patient.

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.