Role of urothelial cells in BCG immunotherapy for superficial bladder cancer

Epigenetic changes associated with Bacillus Calmette-Guerin (BCG) treatment in bladder cancer

Bacillus Calmette-Guérin (BCG) treatment for non-muscle invasive bladder cancer (NMIBC) is an established immunotherapeutic, however, a significant portion of patients do not respond to treatment. Despite extensive research into the therapeutic mechanism of BCG, gaps remain in our understanding. This review specifically focuses on the epigenomic contributions in the immune microenvironment, in the context of BCG treatment for NMIBC. We also summarise the current understanding of NMIBC epigenetic characteristics, and discuss how future targeted strategies for BCG therapy should incorporate epigenomic biomarkers in conjunction with genomic biomarkers.

Revitalizing Bacillus Calmette-Guérin Immunotherapy for Bladder Cancer: Nanotechnology and Bioengineering Approaches

Bacillus Calmette-Guérin (BCG) immunotherapy has been a cornerstone treatment for non-muscle-invasive bladder cancer for decades and still faces challenges, such as severe immune adverse reactions, which reduce its use as a first-line treatment. This review examines BCG therapy's history, mechanisms, and current status, highlighting how nanotechnology and bioengineering are revitalizing its application. We discuss novel nanocarrier systems aimed at enhancing BCG's efficacy while mitigating specific side effects. These approaches promise improved tumor targeting, better drug loading, and an enhanced stimulation of anti-tumor immune responses. Key strategies involve using materials such as liposomes, polymers, and magnetic particles to encapsulate BCG or functional BCG cell wall components. Additionally, co-delivering BCG with chemotherapeutics enhances drug targeting and tumor-killing effects while reducing drug toxicity, with some studies even achieving synergistic effects. While most studies remain experimental, this research direction offers hope for overcoming BCG's limitations and advancing bladder cancer immunotherapy. Further elucidation of BCG's mechanisms and rigorous safety evaluations of new delivery systems will be crucial for translating these innovations into clinical practice.

Nano-Bacillus Calmette-Guérin immunotherapies for improved bladder cancer treatment

Cancer immunotherapy has rapidly become the fourth mainstream treatment alternative after surgery, radiotherapy, and chemotherapy, with some promising results. It aims to kill tumor cells by mobilizing or stimulating cytotoxic immune cells. However, the clinical applications of tumor immunotherapies are limited owing to a lack of adequate delivery pathways and high toxicity. Recently, nanomaterials and genetic engineering have shown great potential in overcoming these limitations by protecting the delivery of antigens, activating targeted T cells, modulating the immunosuppressive tumor microenvironment, and improving the treatment efficacy. Bacillus Calmette-Guérin (BCG) is a live attenuated Mycobacterium bovis vaccine used to prevent tuberculosis, which was first reported to have antitumor activity in 1927. BCG therapy can activate the immune system by inducing various cytokines and chemokines, and its specific immune and inflammatory responses exert antitumor effects. BCG was first used during the 1970s as an intravesical treatment agent for bladder cancer, which effectively improved immune antitumor activity and prevented tumor recurrence. More recently, nano-BCG and genetically engineered BCG have been proposed as treatment alternatives for bladder cancer due to their ability to induce stronger and more stable immune responses. In this study, we outline the development of nano-BCG and genetically engineered BCG for bladder cancer immunotherapy and review their potential and associated challenges.

Current and Emerging Strategies to Treat Urothelial Carcinoma

Urothelial cell carcinoma (UCC, bladder cancer, BC) remains a difficult-to-treat malignancy with a rising incidence worldwide. In the U.S., UCC is the sixth most incident neoplasm and ~90% of diagnoses are made in those >55 years of age; it is ~four times more commonly observed in men than women. The most important risk factor for developing BC is tobacco smoking, which accounts for ~50% of cases, followed by occupational exposure to aromatic amines and ionizing radiation. The standard of care for advanced UCC includes platinum-based chemotherapy and programmed cell death (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors, administered as frontline, second-line, or maintenance therapy. UCC remains generally incurable and is associated with intrinsic and acquired drug and immune resistance. UCC is lethal in the metastatic state and characterized by genomic instability, high PD-L1 expression, DNA damage-response mutations, and a high tumor mutational burden. Although immune checkpoint inhibitors (ICIs) achieve long-term durable responses in other cancers, their ability to achieve similar results with metastatic UCC (mUCC) is not as well-defined. Here, we discuss therapies to improve UCC management and how comprehensive tumor profiling can identify actionable biomarkers and eventually fulfill the promise of precision medicine for UCC patients.

Emerging applications of cancer bacteriotherapy towards treatment of pancreatic cancer

Pancreatic cancer is a highly aggressive form of cancer with a five-year survival rate of only ten percent. Pancreatic ductal adenocarcinoma (PDAC) accounts for ninety percent of those cases. PDAC is associated with a dense stroma that confers resistance to current treatment modalities. Increasing resistance to cancer treatments poses a challenge and a need for alternative therapies. Bacterial mediated cancer therapies were proposed in the late 1800s by Dr. William Coley when he injected osteosarcoma patients with live streptococci or a fabrication of heat-killed Streptococcus pyogenes and Serratia marcescens known as Coley's toxin. Since then, several bacteria have gained recognition for possible roles in potentiating treatment response, enhancing anti-tumor immunity, and alleviating adverse effects to standard treatment options. This review highlights key bacterial mechanisms and structures that promote anti-tumor immunity, challenges and risks associated with bacterial mediated cancer therapies, and applications and opportunities for use in PDAC management.

Granulomatous prostatitis after bacille Calmette-Guérin instillation resembles prostate carcinoma: A case report and review of the literature

BACKGROUND

Bacille Calmette-Guérin (BCG) instillation is recommended in patients with non-muscle-invasive bladder cancer who have intermediate-risk and high-risk tumors. However, granulomatous prostatitis is a rare complication induced by BCG instillation, which can easily be misdiagnosed as prostate cancer. Here, we report a case of granulomatous prostatitis that resembled prostate cancer.

CASE SUMMARY

A 64-year-old Chinese man with bladder cancer received BCG instillation. Three days later, he stopped BCG instillation and received anti-infective therapy due to the urinary tract infection. Three months after BCG restart, he had rising total prostate-specific antigen (PSA) (9.14 ng/mL) and decreasing free PSA/total PSA (0.09). T2-weighted images of magnetic resonance imaging (MRI) showed a 28 mm × 20 mm diffuse low signal abnormality in the right peripheral zone, which was markedly hyperintense on high b-value diffusion-weighted MRI and hypointense on apparent diffusion coefficient map images. Considering Prostate Imaging Reporting and Data System score of 5 and possibility of prostate cancer, a prostate biopsy was conducted. Histopathology showed typical features of granulomatous prostatitis. The nucleic acid test for tuberculosis was positive. He was finally diagnosed with BCG-induced granulomatous prostatitis. Thereafter, he stopped BCG instillation and received anti-tuberculosis treatment. During 10 mo follow-up, he had no evidence of tumor recurrence or symptoms of tuberculosis.

CONCLUSION

Temporarily elevated PSA and high followed by low signal abnormality on diffusion-weighted MRI are important indicators of BCG-induced granulomatous prostatitis.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

The Urinary Microbiome: Role in Bladder Cancer and Treatment

Commensal microbes have increasingly been found to be involved in the development and progression of cancer. The recent discovery of the urinary microbiome bolstered the notion that microbes might play a role in bladder cancer. Although microbial involvement in bladder neoplastic transformation and metastatic progression, except schisto somiasis, has not been established, accumulating research suggests that dysbiosis of the urinary microbiome can produce a chronically inflammatory urothelial microenvironment and lead to bladder cancer. In this review, we describe how the urinary microbiome might facilitate the development of bladder cancer by altering the host immune system and the kind of cytokines that are directly involved in these responses. We investigated the therapeutic possibilities of modulating the urinary microbiome, including immune checkpoint therapy. The responsiveness of patients to intravesical Bacillus Calmette-Guerin therapy was evaluated with respect to microbiome composition. We conclude by noting that the application of microbes to orchestrate the inflammatory response in the bladder may facilitate the development of treatments for bladder cancer.

Castration immunoregulates toll-like receptor-4 in male bladder cancer

PURPOSE

Among diverse Pattern Recognition Receptors (PRRs), Toll-like receptor-4 (TLR-4) is a key urothelial trigger for innate immune response impacting urothelial bladder carcinoma (BC). Androgen activation promotes immunotolerance, playing an immunoregulatory role by unknown mechanisms. We explored the castration impact on urothelial TLR-4 modulation in carcinogenesis and immunotherapeutic scenario.

METHODS

Intact (SHAM) versus castrated male Fisher-344 rats were evaluated in 2 scenarios: (A) Carcinogenesis: After randomization to SHAM (n = 5) and Castration (n = 5), carcinogenesis was induced by four intravesical doses of 1.5 mg/kg n-methyl-n-nitrosourea (MNU) every 15 days. (B) Treatment: After ultrasonographic confirmed MNU-induced papillary BC on week 8, rats were randomized to SHAM (n = 5) and Castration (n = 5) and offered 6 weekly intravesical treatment of 10⁶ CFU of bacillus Calmette Guerin (BCG) in 0.2 ml saline. After 15 weeks the urinary bladders underwent histopathology. Urothelial cell proliferation was measured by Ki-67 immunohistochemistry (IHC), and TLR-4 expression was quantified by IHC and WB.

RESULTS

Castration induced higher TLR-4 urothelial expression (p = 0.007) and anticarcinogenic effect with fewer urothelial tumors (60 vs. 80%) and lower urothelial cell proliferation compared to intact animals (p = 0.008). In the intravesical BCG treatment setting, castration has potentialized the BCG activation of TLR-4 (p = 0.007) with no residual in situ carcinoma compared to intact animals, suggesting the potential to amplify the BCG immune response.

CONCLUSION

To our knowledge, this is the first description of TLR-4 urothelial expression hormonal modulation. The described castration-mediated immunomodulation will help to improve the knowledge of urothelial cancer gender diversities and PRRs modulations with treatment implications.

Cell-Level Spatio-Temporal Model for a Bacillus Calmette–Guérin-Based Immunotherapy Treatment Protocol of Superficial Bladder Cancer

Bladder cancer is one of the most widespread types of cancer. Multiple treatments for non-invasive, superficial bladder cancer have been proposed over the last several decades with a weekly Bacillus Calmette–Guérin immunotherapy-based therapy protocol, which is considered the gold standard today. Nonetheless, due to the complexity of the interactions between the immune system, healthy cells, and cancer cells in the bladder’s microenvironment, clinical outcomes vary significantly among patients. Mathematical models are shown to be effective in predicting the treatment outcome based on the patient’s clinical condition at the beginning of the treatment. Even so, these models still have large errors for long-term treatments and patients that they do not fit. In this work, we utilize modern mathematical tools and propose a novel cell-level spatio-temporal mathematical model that takes into consideration the cell–cell and cell–environment interactions occurring in a realistic bladder’s geometric configuration in order to reduce these errors. We implement the model using the agent-based simulation approach, showing the impacts of different cancer tumor sizes and locations at the beginning of the treatment on the clinical outcomes for today’s gold-standard treatment protocol. In addition, we propose a genetic-algorithm-based approach to finding a successful and time-optimal treatment protocol for a given patient’s initial condition. Our results show that the current standard treatment protocol can be modified to produce cancer-free equilibrium for deeper cancer cells in the urothelium if the cancer cells’ spatial distribution is known, resulting in a greater success rate.

BCG in Bladder Cancer Immunotherapy

BCG is a live attenuated strain of Mycobacterium bovis that is primarily used as a vaccine against tuberculosis. In the past four decades, BCG has also been used for the treatment of non-muscle invasive bladder cancer (NMIBC). In patients with NMIBC, BCG reduces the risk of tumor recurrence and decreases the likelihood of progression to more invasive disease. Despite the long-term clinical experience with BCG, its mechanism of action is still being elucidated. Data from animal models and from human studies suggests that BCG activates both the innate and adaptive arms of the immune system eventually leading to tumor destruction. Herein, we review the current data regarding the mechanism of BCG and summarize the evidence for its clinical efficacy and recommended indications and clinical practice.

Insights on recent innovations in bladder cancer immunotherapy

Bladder carcinoma is the most common genitourinary cancer, with a high prevalence and global incidence. In addition to early detection by cytology, the management of bladder cancer has recently advanced, not only by improvements in conventional treatments such as surgery and chemotherapy, but also through the introduction of immunotherapeutic strategies. The number of approved immunotherapeutic agents has dramatically increased, with various preclinical and clinical applications in cancer drug discovery. Some bladder cancer immunotherapies include immune checkpoint inhibitors, adoptive cell therapy, cytokine-based therapy, bispecific antibodies, and antibody-drug conjugates. This review provides an overview of some of the innovative immunotherapeutic agents approved and in development that can potentially be used in the treatment of bladder cancer.

FimH confers mannose-targeting ability to Bacillus Calmette-Guerin for improved immunotherapy in bladder cancer

BACKGROUND

Bladder cancer is a common disease worldwide with most patients presenting with the non-muscle-invasive form (NMIBC) at initial diagnosis. Postoperational intravesical instillation of BCG is carried out for patients with high-risk disease to reduce tumor recurrence and progression to muscle invasive disease. However, BCG can also have side effects or be ineffective in some patients because it cannot enter the cancer cells. Thus, to improve the efficacy of BCG immunotherapy is the long-term pursuit of the bladder cancer field.

METHODS

To increase the adhesion of BCG to the urothelium we overexpressed FimH, a mannose binding protein naturally used by uropathogenic Escherichia coli to adhere to human urothelium, onto the surface of BCG. The adhesion/internalization ability of rBCG-S.FimH was examined in mouse bladder by fluorescence microscopy. Preclinical evaluation of antitumor efficacy was carried out in orthotopic mouse models of bladder cancer and in human peripheral blood mononuclear cells. Mechanistic studies were carried out using toll-like receptor 4 (TLR4) knockout mice. Immune cells and cytokines in the serum, tumor and lymph nodes were analyzed by flow cytometry, PCR, ELISA and ELISPOT.

RESULTS

rBCG-S.FimH exhibited markedly improved adhesion and more rapid internalization into urothelial cells than wild-type BCG, resulting in more potent antitumor activity in orthotopic murine models of bladder cancer. To our surprise, rBCG-S.FimH elicited a much more prominent Th1-biased immune response known to be positively correlated with BCG efficacy. Mechanistic studies using TLR4 knockout mouse showed that rBCG-S.FimH could induce enhanced dendritic cell activation and tumor antigen-specific immune response in a TLR4-dependent manner. Furthermore, human peripheral blood mononuclear cells stimulated by rBCG-S.FimH also showed better tumoricidal effects than those using wild-type BCG.

CONCLUSION

rBCG-S.FimH is a novel BCG strain with significantly improved efficacy against bladder cancer. Since intravesical BCG immunotherapy is the first-line treatment for NMIBC, which accounts for more than 70% of all bladder cancer cases, our results provide a compelling rationale for clinical development.

A Novel Multiepitope Vaccine Against Bladder Cancer Based on CTL and HTL Epitopes for Induction of Strong Immune Using Immunoinformatics Approaches

Bladder cancer is well-known cancer in two forms of muscle-invasive and non-muscle-invasive bladder cancer which is responsible for annual deaths worldwide. Common therapies methods are somewhat successful; however, these methods have the limitations such as the side effects of chemotherapy which necessitate the requirement for new preventive methods against bladder cancer. Hence, we explain a novel designed multi-epitope vaccine against bladder cancer using the immunoinformatics tool. Three well-known BLCAP, PRAM, and BAGE4 antigens were evaluated due to most repetitive CTL and HTL epitopes binding. IFNγ and IL10 inducer potential of selected epitopes were investigated, as well as liner and conformational B-cell epitopes. Human beta-defensin 3 and PADRE sequence were added to construct as adjuvants, along with EAAAK, AAY, and GGGS linkers to fuse CTL and HTL epitopes. Results showed this construct encodes a soluble, non-toxic, and non-allergic protein with 70 kDa molecular weight. Modeled 3D structure of vaccine was docked whit Toll-Like Receptors (TLR) of 7/8. Docking, molecular dynamics simulation and MMBPSA analysis confirmed stability of vaccine-TLR complexes. The immunogenicity showed this construct could elicit humoral and cellular immune responses. In silico and immunoinformatics evaluations suggest that this construct is a recombinant candidate vaccine against bladder cancer.

Novel molecules as the emerging trends in cancer treatment: an update

As per World Health Organization cancer remains as a leading killer disease causing nearly 10 million deaths in 2020. Since the burden of cancer increases worldwide, warranting an urgent search for anti-cancer compounds from natural sources. Secondary metabolites from plants, marine organisms exhibit a novel chemical and structural diversity holding a great promise as therapeutics in cancer treatment. These natural metabolites target only the cancer cells and the normal healthy cells are left unharmed. In the emerging trends of cancer treatment, the natural bioactive compounds have long become a part of cancer chemotherapy. In this review, we have tried to compile about eight bioactive compounds from plant origin viz. combretastatin, ginsenoside, lycopene, quercetin, resveratrol, silymarin, sulforaphane and withaferin A, four marine-derived compounds viz. bryostatins, dolastatins, eribulin, plitidepsin and three microorganisms viz. Clostridium, Mycobacterium bovis and Streptococcus pyogenes with their well-established anticancer potential, mechanism of action and clinical establishments are presented.

Bacterial cancer therapy in autochthonous colorectal cancer affects tumor growth and metabolic landscape

Bacterial cancer therapy (BCT) shows great promise for treatment of solid tumors, yet basic mechanisms of bacterial-induced tumor suppression remain undefined. Attenuated strains of Salmonella enterica serovar Typhimurium (STm) have commonly been used in mouse models of BCT in xenograft and orthotopic transplant cancer models. We aimed to better understand the tumor epithelium-targeted mechanisms of BCT by using autochthonous mouse models of intestinal cancer and tumor organoid cultures to assess the effectiveness and consequences of oral treatment with aromatase A-deficient STm (STmΔaroA). STmΔaroA delivered by oral gavage significantly reduced tumor burden and tumor load in both a colitis-associated colorectal cancer (CAC) model and in a spontaneous Apcmin/+ intestinal cancer model. STmΔaroA colonization of tumors caused alterations in transcription of mRNAs associated with tumor stemness, epithelial-mesenchymal transition, and cell cycle. Metabolomic analysis of tumors demonstrated alteration in the metabolic environment of STmΔaroA-treated tumors, suggesting that STmΔaroA imposes metabolic competition on the tumor. Use of tumor organoid cultures in vitro recapitulated effects seen on tumor stemness, mesenchymal markers, and altered metabolome. Furthermore, live STmΔaroA was required, demonstrating active mechanisms including metabolite usage. We have demonstrated that oral BCT is efficacious in autochthonous intestinal cancer models, that BCT imposes metabolic competition, and that BCT has direct effects on the tumor epithelium affecting tumor stem cells.

Effects of Mycobacterium bovis Calmette et Guérin (BCG) in oncotherapy: Bladder cancer and beyond

The Mycobacterium bovis Bacillus Calmette et Guérin (BCG) vaccine was generated in 1921 with the efforts of a team of investigators, Albert Calmette and Camille Guérin, dedicated to the determination to develop a vaccine against active tuberculosis (TB) disease. Since then, BCG vaccination is used globally for protection against childhood and disseminated TB; however, its efficacy at protecting against pulmonary TB in adult and aging populations is highly variable. Due to the BCG generated immunity, this vaccine later proved to have an antitumor activity; though the standing mechanisms behind are still unclear. Recent studies indicate that both innate and adaptive cell responses may play an important role in BCG eradication and prevention of bladder cancer. Thus, cells such as natural killer (NK) cells, macrophages, dendritic cells, neutrophils but also MHC-restricted CD4 and CD8 T cells and γδ T cells may play an important role and can be one the main effectors in BCG therapy. Here, we discuss the role of BCG therapy in bladder cancer and other cancers, including current strategies and their impact on the generation and sustainability of protective antitumor immunity against bladder cancer.

MyD88-dependent BCG immunotherapy reduces tumor and regulates tumor microenvironment in bladder cancer murine model

Bacillus Calmette-Guerin (BCG) is the only FDA approved first line therapy for patients with nonmuscle invasive bladder cancer. The purpose of this study is to better understand the role of innate immune pathways involved in BCG immunotherapy against murine bladder tumor. We first characterized the immunological profile induced by the MB49 mouse urothelial carcinoma cell line. MB49 cells were not able to activate an inflammatory response (TNF-α, IL-6, CXCL-10 or IFN-β) after the stimulus with different agonists or BCG infection, unlike macrophages. Although MB49 cells are not able to induce an efficient immune response, BCG treatment could activate other cells in the tumor microenvironment (TME). We evaluated BCG intratumoral treatment in animals deficient for different innate immune molecules (STING-/-, cGAS-/-, TLR2-/-, TLR3-/-, TLR4-/-, TLR7-/-, TLR9-/-, TLR3/7/9-/-, MyD88-/-, IL-1R-/-, Caspase1/11-/-, Gasdermin-D-/- and IFNAR-/-) using the MB49 subcutaneous mouse model. Only MyD88-/- partially responded to BCG treatment compared to wild type (WT) mice, suggesting a role played by this adaptor molecule. Additionally, BCG intratumoral treatment regulates cellular infiltrate in TME with an increase of inflammatory macrophages, neutrophils and CD8+ T lymphocytes, suggesting an immune response activation that favors tumor remission in WT mice but not in MyD88-/-. The experiments using MB49 cells infected with BCG and co-cultured with macrophages also demonstrated that MyD88 is essential for an efficient immune response. Our data suggests that BCG immunotherapy depends partially on the MyD88-related innate immune pathway.

Mathematical model of tumor immunotherapy for bladder carcinoma identifies the limitations of the innate immune response

Treatment for non-muscle invasive carcinoma of the bladder represents one of the few examples of successful tumor immunity. Six weekly intravesical instillations of Bacillus Calmette-Guerin (BCG), often followed by maintenance schedule, result in up to 50-70% clinical response. Current models suggest that the mechanism of action involves the non-specific activation of innate effector cells, which may be capable of acting in the absence of an antigen-specific response. For example, recent evidence suggests that BCG-activated neutrophils possess anti-tumor potential. Moreover, weekly BCG treatment results in a prime-boost pattern with massive influx of innate immune cells (107-108 PMN/ml urine). Calibrating in vivo data, we estimate that the number of neutrophil degranulations per instillation is approximately 106-107, more than sufficient to potentially eliminate ~106 residual tumor cells. Furthermore, neutrophils, as well as other innate effector cells are not selective in their targeting-thus surrounding cells may be influenced by degranulation and / or cytokine production. To establish if these observed conditions could account for clinically effective tumor immunity, we built a mathematical model reflecting the early events and tissue conditioning in patients undergoing BCG therapy. The model incorporates key features of tumor growth, BCG instillations and the observed prime / boost pattern of the innate immune response. Model calibration established that each innate effector cell must kill 90-95 bystander cells for achieving the expected 50-70% clinical response. This prediction was evaluated both empirically and experimentally and found to vastly exceed the capacity of the innate immune system. We therefore conclude that the innate immune system alone is unable to eliminate the tumor cells. We infer that other aspects of the immune response (e.g., antigen-specific lymphocytes) decisively contribute to the success of BCG immunotherapy.

The Urinary Microbiome and Bladder Cancer: Susceptibility and Immune Responsiveness

Bladder cancer is a highly prevalent disease worldwide and is associated with a high mortality rate. Across all stages of bladder cancer, immunotherapy has now become the cornerstone of treatment. The commensal microbiome has become a major focus of research given its impact on numerous states of human health and disease. Many links between commensal microbes and immune function have been reported. Recently a commensal urinary microbiome has been identified and characterized in healthy individuals by several research groups. The urinary microbiome is now emerging as an important factor influencing bladder cancer development and therapeutic responsiveness. In this report, we identify findings from important clinical and mechanistic studies on the urinary microbiome and future opportunities to impact prevention and treatment of bladder cancer.

Impact of chronic kidney disease on oncological outcomes in patients with high-risk non-muscle-invasive bladder cancer who underwent adjuvant bacillus Calmette-Guérin therapy

OBJECTIVES

To investigate the impact of chronic kidney disease (CKD) on oncological outcomes in patients with high-risk non-muscle invasive bladder cancer (NMIBC) who underwent adjuvant induction bacillus Calmette-Guérin (BCG) therapy after transurethral resection of bladder tumor (TURBT).

MATERIALS AND METHODS

We conducted a multi-institutional retrospective study assessing 209 patients with high-risk NMIBC who underwent TURBT and subsequent adjuvant induction BCG therapy from December 1998 to April 2019. Patients were divided into 2 groups: those with preoperative estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m² (non-CKD group), and those with eGFR < 60 ml/min/1.73 m² (CKD group). Primary endpoints were intravesical recurrence-free survival (RFS) and muscle-invasive bladder cancer (MIBC)-free survival. Background-adjusted multivariate analyses with the inverse probability of treatment weighting (IPTW) method using the propensity score were performed to evaluate the impact of CKD on intravesical RFS, MIBC-free survival, metastasis-free survival, cancer-specific survival, and overall survival. Moreover, multivariable analyses were performed to assess the impact of CKD on intravesical recurrence and MIBC progression, adjusting for the competing risk of death using the Fine-Gray competing risk regression model.

RESULTS

Median age and follow-up period after TURBT were 72 years and 45 months, respectively. Of 209 patients, 71 (34%) were diagnosed with CKD before TURBT. Background-adjusted multivariate analyses with the IPTW method indicated that CKD was significantly associated with shorter intravesical RFS, MIBC-free survival, metastasis-free survival, cancer-specific survival, and overall survival. In the Fine-Gray competing risk regression model, CKD showed significantly higher probabilities of intravesical recurrence and MIBC progression, with an adjusted subdistribution hazard ratio of 1.886 (95% confidence interval 1.069-3.330, P = 0.028) and 3.740 (95% confidence interval 1.060-13.20, P = 0.040), respectively.

CONCLUSIONS

CKD presents a risk factor of poor oncological outcomes in patients with high-risk NMIBC who underwent adjuvant induction BCG therapy after TURBT.

Immunogenomic Analysis of Exceptional Responder to ALT-803 (IL-15 Analogue) in BCG Unresponsive Nonmuscle Invasive Bladder Cancer: A Case Series and Review of the Literature

The clinical validity and utility of complex biomarkers have not been extensively studied in bladder cancer. Three patients with nonmuscle invasive bladder cancer [1 patient with an exceptional response; complete response (CR) for 30 months] who failed intravesical BCG were evaluated using an NYS CLEP approved assay, Immune Report Card, which measures programmed death-ligand 1 expression, CD8 T-cell infiltration pattern, mutational burden, and gene expression of 51 immune-related transcripts using RNA-Seq. Patients were tested before being treated under our expanded access protocol for intravesical BCG with ALT-803. Subject 1 had failed his fourth line of therapy, subject 2 had failed only his first line of therapy, and subject 3 had failed his seventh line of therapy. Surprisingly, subject 1 had an unusually prolonged CR which lasted 30 months; subject 2 had the persistent and recurrent disease until 12 months when he then developed a CR; subject 3 had disease recurrence at 3 months, along with progression noted at 6 months. Immunomutational status was extensively evaluated to identify potential alterations that might play a role as predictive markers for subject 1, who had an exceptional response. Compared with subject 3, tumor in subject 1 demonstrated a high level of expression for CTLA4 (immunosuppression) and CD39 (immunosuppressive). Together, an immunosuppressive tumor environment in nonmuscle invasive bladder cancer that have failed prior BCG may respond better to interleukin-15 immunotherapy compared with tumors without an immunosuppressive environment.

Analysis of risk factors for post-bacillus Calmette-Guerin-induced prostatitis in patients with non-muscle invasive bladder cancer

The objective of this study was to evaluate risk factors for bacillus Calmette–Guerin-induced prostatitis in patients with non-muscle invasive bladder cancer following bacillus Calmette–Guerin therapy. Clinical findings from patients with non-muscle invasive bladder cancer who underwent multi-parametric magnetic resonance imaging before transurethral resection of bladder tumor and post-bacillus Calmette–Guerin therapy from March 2004 to August 2018 were evaluated. The population was grouped into patients with or without newly developed lesions on multi-parametric magnetic resonance imaging performed 3 months after bacillus Calmette–Guerin instillation. Patients with prostate-specific antigen levels ≥ 4 ng/mL or prostate cancer were excluded. Univariable and multivariable analyses were performed to determine the predictors of prostate lesions in patients with prior bacillus Calmette–Guerin exposure. Post bacillus Calmette–Guerin-induced prostatitis was found in 50 of the 194 patients (25.8%). No significant differences were observed between the groups except for prostate volumes (33.8 mL vs. 30.8 mL, P = 0.012) and body mass index (25.2 kg/m² vs. 24.1 kg/m², P = 0.044). After bacillus Calmette–Guerin exposure, no significant differences in prostate-specific antigen levels, international prostate symptom scores, or post-voiding residual volume were noted. Multivariable regression analysis showed that body mass index (odds ratio, OR = 1.115, P = 0.038) and prostate volume (OR = 3.080, P = 0.012) were significant predictors of post-bacillus Calmette–Guerin prostate lesions. Body mass index and prostate volume may be clinical predictors of prostate lesions after bacillus Calmette–Guerin exposure. Awareness of potential risk factors for this entity should contribute to the clinical decision-making process for patients following bacillus Calmette–Guerin therapy.

Mechanisms of BCG in the treatment of bladder cancer-current understanding and the prospect

Over 30 years' successful application of Bacillus Calmette Guerin (BCG) to the clinical treatment of bladder cancer has proved it one of the most promising immunotherapies for cancer. However, the applications and achievements have failed to uncover the mechanism of BCG works on bladder cancer fully. Clinically, the administration of BCG on patients results in no effect, or apparent resistance, and even severe adverse reactions, which are inexplicable. At present, the widely confirmed and accepted immunity mechanism of BCG fall in the processes of the absorption after the instillation of BCG, the internalization of BCG, cytokine release induced by a series of signal transduction pathways, and the effect stage of innate and acquired immune responses. Nonetheless, the limited ascertainments of the mechanism of BCG action cannot fully explain the clinical phenomenon caused by BCG. Therefore, the other mechanisms of BCG action have remained the research hotspot aiming to explore more targeted treatments or to initiate new therapeutic methods avoiding harm. By summarizing the recent research achievements of the mechanism of BCG works on bladder cancer, this review aims to provide clues for researchers to quest more valuable ideas.

Toll-like Receptors from the Perspective of Cancer Treatment

Toll-like receptors (TLRs) represent a family of pattern recognition receptors that recognize certain pathogen-associated molecular patterns and damage-associated molecular patterns. TLRs are highly interesting to researchers including immunologists because of the involvement in various diseases including cancers, allergies, autoimmunity, infections, and inflammation. After ligand engagement, TLRs trigger multiple signaling pathways involving nuclear factor-κB (NF-κB), interferon-regulatory factors (IRFs), and mitogen-activated protein kinases (MAPKs) for the production of various cytokines that play an important role in diseases like cancer. TLR activation in immune as well as cancer cells may prevent the formation and growth of a tumor. Nonetheless, under certain conditions, either hyperactivation or hypoactivation of TLRs supports the survival and metastasis of a tumor. Therefore, the design of TLR-targeting agonists as well as antagonists is a promising immunotherapeutic approach to cancer. In this review, we mainly describe TLRs, their involvement in cancer, and their promising properties for anticancer drug discovery.

Enhanced Intracellular Delivery of BCG Cell Wall Skeleton into Bladder Cancer Cells Using Liposomes Functionalized with Folic Acid and Pep-1 Peptide

Although bacillus Calmette–Guérin cell wall skeleton (BCG-CWS) might function as a potential substitute for live BCG, its use in the treatment of bladder cancer remains limited owing to issues such as insolubility and micrometer-size following exposure to an aqueous environment. Thus, to develop a novel nanoparticulate system for efficient BCG-CWS delivery, liposomal encapsulation was carried out using a modified emulsification-solvent evaporation method (targets: Size, <200 nm; encapsulation efficiency, ~60%). Further, the liposomal surface was functionalized with specific ligands, folic acid (FA), and Pep-1 peptide (Pep1), as targeting and cell-penetrating moieties, respectively. Functionalized liposomes greatly increased the intracellular uptake of BCG-CWS in the bladder cancer cell lines, 5637 and MBT2. The immunoactivity was verified through elevated cytokine production and a THP-1 migration assay. In vivo antitumor efficacy revealed that the BCG-CWS-loaded liposomes effectively inhibited tumor growth in mice bearing MBT2 tumors. Dual ligand-functionalized liposome was also superior to single ligand-functionalized liposomes. Immunohistochemistry supported the enhanced antitumor effect of BCG-CWS, with IL-6 production and CD4 infiltration. Thus, we conclude that FA- and Pep1-modified liposomes encapsulating BCG-CWS might be a good candidate for bladder cancer treatment with high target selectivity.

Predictors of Response to Intravesical Therapy

Despite the 40-year reign of bacillus Calmette-Guérin (BCG) as the most effective immunotherapy in urologic cancers, a lack of clinical tools to predict treatment response has hampered progress in the field. Acting as an immunostimulatory agent against a multitude of phenotypically diverse non-muscle-invasive bladder cancers, response to BCG likely depends on both tumor characteristics as well as host factors. With a deeper understanding of the tumor biology as well as the mechanism of action underpinning immunotherapy, newer and more effective clinical tools are being constructed to improve patient selection.

Engineering bacteria for cancer therapy

The engineering of living cells and microbes is ushering in a new era of cancer therapy. Due to recent microbiome studies indicating the prevalence of bacteria within the human body and specifically in tumor tissue, bacteria have generated significant interest as potential targets for cancer therapy. Notably, a multitude of empirical studies over the past decades have demonstrated that administered bacteria home and grow in tumors due to reduced immune surveillance of tumor necrotic cores. Given their specificity for tumors, bacteria present a unique opportunity to be engineered as intelligent delivery vehicles for cancer therapy with synthetic biology techniques. In this review, we discuss the history, current state, and future challenges associated with using bacteria as a cancer therapy.

Structure establishment of three-dimensional (3D) cell culture printing model for bladder cancer

Purpose

Two-dimensional (2D) cell culture is a valuable method for cell-based research but can provide unpredictable, misleading data about in vivo responses. In this study, we created a three-dimensional (3D) cell culture environment to mimic tumor characteristics and cell-cell interactions to better characterize the tumor formation response to chemotherapy.

Materials and methods

We fabricated the 3D cell culture samples using a 3D cell bio printer and the bladder cancer cell line 5637. T24 cells were used for 2D cell culture. Then, rapamycin and Bacillus Calmette-Guérin (BCG) were used to examine their cancer inhibition effects using the two bladder cancer cell lines. Cell-cell interaction was measured by measuring e-cadherin and n-cadherin secreted via the epithelial-mesenchymal transition (EMT).

Results

We constructed a 3D cell scaffold using gelatin methacryloyl (GelMA) and compared cell survival in 3D and 2D cell cultures. 3D cell cultures showed higher cancer cell proliferation rates than 2D cell cultures, and the 3D cell culture environment showed higher cell-to-cell interactions through the secretion of E-cadherin and N-cadherin. Assessment of the effects of drugs for bladder cancer such as rapamycin and BCG showed that the effect in the 2D cell culture environment was more exaggerated than that in the 3D cell culture environment.

Conclusions

We fabricated 3D scaffolds with bladder cancer cells using a 3D bio printer, and the 3D scaffolds were similar to bladder cancer tissue. This technique can be used to create a cancer cell-like environment for a drug screening platform.

Mechanisms of BCG immunotherapy and its outlook for bladder cancer

BCG immunotherapy is the gold-standard treatment for non-muscle-invasive bladder cancer at high risk of recurrence or progression. Preclinical and clinical studies have revealed that a robust inflammatory response to BCG involves several steps: attachment of BCG; internalization of BCG into resident immune cells, normal cells, and tumour urothelial cells; BCG-mediated induction of innate immunity, which is orchestrated by a cellular and cytokine milieu; and BCG-mediated initiation of tumour-specific immunity. As an added layer of complexity, variation between clinical BCG strains might influence development of tumour immunity. However, more than 40 years after the first use of BCG for bladder cancer, many questions regarding its mechanism of action remain unanswered. Clearly, a better understanding of the mechanisms underlying BCG-mediated tumour immunity could lead to improved efficacy, increased tolerance of treatment, and identification of novel immune-based therapies. Indeed, enthusiasm for bladder cancer immunotherapy, and the possibility of combining BCG with other therapies, is increasing owing to the availability of targeted immunotherapies, including checkpoint inhibitors. Understanding of the mechanism of action of BCG immunotherapy has advanced greatly, but many questions remain, and further basic and clinical research efforts are needed to develop new treatment strategies for patients with bladder cancer.

Low serum 25-hydroxyvitamin D is associated with increased bladder cancer risk: A systematic review and evidence of a potential mechanism

The development of some cancers is associated with vitamin D deficiency. We suggest that reduced conversion of 25-hydroxyvitamin D (25(OH)D) to 1,25-dihydroxyvitamin D (1,25(OH)₂D) and the resulting modification of tissue specific immune responses may be key. Non-muscle-invasive bladder cancer is highly immunoresponsive and stimulation of an inflammatory response by intravesical bacillus Calmette-Guerin (BCG) treatment prevents recurrence. To assess the relationship between serum 25(OH)D and bladder cancer risk we conducted a systematic review. To test our hypothesis, the synthesis of 1,25(OH)₂D by human bladder epithelial cell lines (T24/83 and RT4) was examined. Studies were identified from Medline, Web of Science, Embase and Cochrane library (limited to English language, humans and 1990-2018). After removal of duplicates, title and abstract review 6 full papers were appraised. Low vitamin D levels were associated with bladder cancer risk in 5/6 of the studies. Both cell lines express the vitamin D receptor, 25-hydroxyvitamin D 1α-hydroxylase (1α-OHase) and 24-hydroxylase (24-OHase) mRNA, which was induced by 1,25(OH)₂D. 24-OHase mRNA was also increased by 25(OH)D indicating 1α-OHase activity. Both cell types expressed TLR1,2,4 and the TLR partners MyD88 and CD14mRNA. Cathelicidin mRNA was undetectable in both cell lines but was induced by 1,25(OH)₂D and 25(OH)D in RT4 cells. The systematic review demonstrated that bladder cancer risk correlates with serum 25(OH)D levels. In addition, we have shown that transitional epithelial cells express functional vitamin D signaling and can synthesize sufficient 1,25(OH)₂D to stimulate a local immune response. We suggest that in order to maintain optimal immune surveillance within the bladder adequate levels of serum 25(OH)D are required for direct synthesis of 1,25(OH)₂D by bladder epithelial cells.

Cold Tumors: A Therapeutic Challenge for Immunotherapy

Therapeutic monoclonal antibodies targeting immune checkpoints (ICPs) have changed the treatment landscape of many tumors. However, response rate remains relatively low in most cases. A major factor involved in initial resistance to ICP inhibitors is the lack or paucity of tumor T cell infiltration, characterizing the so-called “cold tumors.” In this review, we describe the main mechanisms involved in the absence of T cell infiltration, including lack of tumor antigens, defect in antigen presentation, absence of T cell activation and deficit of homing into the tumor bed. We discuss then the different therapeutic approaches that could turn cold into hot tumors. In this way, specific therapies are proposed according to their mechanism of action. In addition, ‘‘supra-physiological’’ therapies, such as T cell recruiting bispecific antibodies and Chimeric Antigen Receptor (CAR) T cells, may be active regardless of the mechanism involved, especially in MHC class I negative tumors. The determination of the main factors implicated in the lack of preexisting tumor T cell infiltration is crucial for the development of adapted algorithms of treatments for cold tumors.

Intravesical Mycobacterium brumae triggers both local and systemic immunotherapeutic responses against bladder cancer in mice

The standard treatment for high-risk non-muscle invasive bladder cancer (BC) is the intravesical administration of live Mycobacterium bovis BCG. Previous studies suggest improving this therapy by implementing non-pathogenic mycobacteria, such as Mycobacterium brumae, and/or different vehicles for mycobacteria delivery, such as an olive oil (OO)-in-water emulsion. While it has been established that BCG treatment activates the immune system, the immune effects of altering the mycobacterium and/or the preparation remain unknown. In an orthotopic murine BC model, local immune responses were assessed by measuring immune cells into the bladder and macromolecules in the urine by flow cytometry and multiplexing, respectively. Systemic immune responses were analyzed by quantifying sera anti-mycobacteria antibody levels and recall responses of ex vivo splenocytes cultured with mycobacteria antigens. In both BCG- and M. brumae-treated mice, T, NK, and NKT cell infiltration in the bladder was significantly increased. Notably, T cell infiltration was enhanced in OO-in-water emulsified mycobacteria-treated mice, and urine IL-6 and KC concentrations were elevated. Furthermore, mycobacteria treatment augmented IgG antibody production and splenocyte proliferation, especially in mice receiving OO-in-water emulsified mycobacteria. Our data demonstrate that intravesical mycobacterial treatment triggers local and systemic immune responses, which are most significant when OO-in-water emulsified mycobacteria are used.

Oxidative damage and response to Bacillus Calmette-Guérin in bladder cancer cells expressing sialyltransferase ST3GAL1

Background

Treatment with Bacillus Calmette-Guérin (BCG) is the gold standard adjuvant immunotherapy of non-muscle invasive bladder cancer (NMIBC), although it fails in one third of the patients. NMIBC expresses two tumor-associated O-linked carbohydrates: the disaccharide (Galβ1,3GalNAc) Thomsen-Friedenreich (T) antigen, and its sialylated counterpart (Siaα2,3Galβ1,3GalNAc) sialyl-T (sT), synthesized by sialyltransferase ST3GAL1, whose roles in BCG response are unknown.

Methods

The human bladder cancer (BC) cell line HT1376 strongly expressing the T antigen, was retrovirally transduced with the ST3GAL1 cDNA or with an empty vector, yielding the cell lines HT1376_sT and HT1376_T, that express, respectively, either the sT or the T antigens. Cells were in vitro challenged with BCG. Whole gene expression was studied by microarray technology, cytokine secretion was measured by multiplex immune-beads assay. Human macrophages derived from blood monocytes were challenged with the secretome of BCG-challenged BC cells.

Results

The secretome from BCG-challenged HT1376_sT cells induced a stronger macrophage secretion of IL-6, IL-1β, TNFα and IL-10 than that of HT1376_T cells. Transcriptomic analysis revealed that ST3GAL1 overexpression and T/sT replacement modulated hundreds of genes. Several genes preserving genomic stability were down-regulated in HT1376_sT cells which, as a consequence, displayed increased sensitivity to oxidative damage. After BCG challenge, the transcriptome of HT1376_sT cells showed higher susceptibility to BCG modulation than that of HT1376_T cells.

Conclusions

High ST3GAL1 expression and T/sT replacement in BCG challenged-BC cancer cells induce a stronger macrophage response and alter the gene expression towards genomic instability, indicating a potential impact on BC biology and patient’s response to BCG.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4107-1) contains supplementary material, which is available to authorized users.

BCG immune activation reduces growth and angiogenesis in an in vitro model of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers worldwide and is associated with poor survival and significant treatment morbidity. The immune profile in patients with HNSCC is immunosuppressive and presents cytokine-mediated adaptive immune responses, triggered apoptosis of T cells, and alterations in antigen processing machinery. Bacille Calmette-Guerin (BCG) immunotherapy has been used successfully as a treatment for several types of cancer. In the present study, we sought to determine the antitumor effect of soluble mediators from peripheral blood mononuclear immune cells (PBMCs) activated with BCG vaccine in a three-dimensional coculture model of HNSCC growth using FaDu hypopharynx carcinoma squamous cells. BCG activation of PBMCs led to an increase in CD4+ and CD8+ lymphocyte subsets concomitant with an elevation in the levels of the antitumor cytokines IL-6, TNF-α and IFN-γ, and a EGFR in FaDu cells. In addition, coculture with BCG-activated PBMCs reduced FaDu proliferation and increased cytotoxicity and apoptosis in parallel with an increase in caspase-3 activity and p53 expression. Finally, conditioned medium from BCG-activated PBMCs reduced the levels of the angiogenic factors vascular endothelial growth factor and angiopoietin-2 produced by human aortic endothelial cells (HAECs), and inhibited their proliferation and differentiation into capillary-like structures. Taken together, these results demonstrate that BCG vaccination induces antitumor responses in an HNSCC in vitro model and suggest that the BCG vaccine could be an effective alternative therapy for the treatment of HNSCC.

Characterization of inflammasome-related genes in urine sediments of patients receiving intravesical BCG therapy

BACKGROUND

Nowadays, the intravesical Bacillus Calmette-Guérin (BCG) instillation is the method of choice for the postsurgical treatment of high-grade nonmuscle-invasive bladder cancer , to reduce both recurrence rate and risk of progression. BCG is hypothesized to correct the immune system disequilibrium occurring during carcinogenesis, through an immunostimulation with detrimental effects for tumoral cells. Inflammation plays a crucial role in tumor progression. The deregulation of inflammasomes upon carcinogenesis underlines its importance both in physiologic and pathologic human conditions. Nucleotide oligomerization domain-like receptors (NLRs) are key components of this molecular platform and the increase in expression of some members of nucleotide oligomerization domain-like receptors family (NLRP3, NLRP4, NLRP9, and NLR family apoptosis inhibitory protein [NAIP]) in urothelial carcinoma was already demonstrated in our previous work. The first aim of the present work was to estimate whether these inflammasome-related genes show alterations during BCG instillations. The expression levels of NLRP3, NLRP4, NLRP9, and NAIP were assessed in the urine sediments from patients, which underwent surgery for superficial high-grade bladder cancer and further subjected to serial BCG instillations. The eventual association between NLR expression and recurrence was also evaluated. The expression of CK20 mRNA as confirmed marker of bladder cancer was also assayed.

METHODS

Urine were sampled from patients harboring high-grade superficial bladder cancer and treated postsurgically with weekly BCG instillations for 6 weeks (induction cycle, I). Urine sediments were processed and resulting RNA was reverse transcribed and used for amplification by real-time PCR.

RESULTS

After surgery, CK20 levels decreased significantly whereas NLRP4 and NLRP9 genes showed an increase. NLRP3 and NAIP remained substantially unmodified. CK20 mRNA decreased at the end of the induction cycle. NLRP3 did not show relevant modifications. The expression levels of NLRP4 and NLRP9 decreased significantly after 2 BCG administrations and remained substantially downregulated during the whole induction cycle. CK20 was higher in recurrence cases before BCG administration compared to the recurrence-free group, while no significant difference after BCG therapy was recorded. NLRP4 and NLRP9 were higher in patients with recurrence before BCG administration.

CONCLUSIONS

The study underlines the importance of NLRP4 and NLRP9 in urothelial carcinoma and if these preliminary data will be confirmed in larger cohort studies, the assessment of NLRP4 and NLRP9 expression levels could help to predict the BCG failure, playing a relevant role in decision making for early radical surgery.

Expression of sialyl-Tn sugar antigen in bladder cancer cells affects response to Bacillus Calmette Guérin (BCG) and to oxidative damage

The sialyl-Tn (sTn) antigen is an O-linked carbohydrate chain aberrantly expressed in bladder cancer (BC), whose biosynthesis is mainly controlled by the sialyltransferase ST6GALNAC1. Treatment with Bacillus Calmette-Guérin (BCG) is the most effective adjuvant immunotherapy for superficial BC but one third of the patients fail to respond. A poorly understood correlation between the expression of sTn and BC patient's response to BCG was previously observed. By analyzing tumor tissues, we showed that patients with high ST6GALNAC1 and IL-6 mRNA expression were BCG responders. To investigate the role of sTn in BC cell biology and BCG response, we established the cell lines MCR_sTn and MCR_Nc by retroviral transduction of the BC cell line MCR with the ST6GALNAC1 cDNA or with an empty vector, respectively. Compared with MCR_Nc, BCG-stimulated MCR_sTn secreted higher levels of IL-6 and IL-8 and their secretome induced a stronger IL-6, IL-1β, and TNFα secretion by macrophages, suggesting the induction of a stronger inflammatory response. Transcriptomic analysis of MCR_Nc and MCR_sTn revealed that ST6GALNAC1/sTn expression modulates hundreds of genes towards a putative more malignant phenotype and down-regulates several genes maintaining genomic stability. Consistently, MCR_sTn cells displayed higher H₂O₂ sensitivity. In MCR_sTn,, BCG challenge induced an increased expression of several regulatory non coding RNA genes. These results indicate that the expression of ST6GALNAC1/sTn improves the response to BCG therapy by inducing a stronger macrophage response and alters gene expression towards malignancy and genomic instability, increasing the sensitivity of BC cells to the oxidizing agents released by BCG.

Topical and systemic immunoreaction triggered by intravesical chemotherapy in an N-butyl-N-(4-hydroxybutyl) nitorosamine induced bladder cancer mouse model

Intravesical bacillus Calmette-Guerin (BCG) treatment is the most common therapy to prevent progression and recurrence of non-muscle invasive bladder cancer (NMIBC). Although the immunoreaction elicited by BCG treatment is well documented, those induced by intravesical treatment with chemotherapeutic agents are much less known. We investigated the immunological profiles caused by mitomycin C, gemcitabine, adriamycin and docetaxel in the N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced orthotopic bladder cancer mouse model. Ninety mice bearing orthotopic bladder cancer induced by BBN were randomly divided into six groups and treated with chemotherapeutic agents once a week for four weeks. After last treatment, bladder and serum samples were analyzed for cell surface and immunological markers (CD4, CD8, CD56, CD204, Foxp3, and PD-L1) using immunohistochemistry staining. Serum and urine cytokine levels were evaluated by ELISA. All chemotherapeutic agents presented anti-tumor properties similar to those of BCG. These included changes in immune cells that resulted in fewer M2 macrophages and regulatory T cells around tumors. This result was compatible with those in human samples. Intravesical chemotherapy also induced systemic changes in cytokines, especially urinary interleukin (IL)-17A and granulocyte colony stimulating factor (G-CSF), as well as in the distribution of blood neutrophils, lymphocytes, and monocytes. Our findings suggest that intravesical treatment with mitomycin C and adriamycin suppresses protumoral immunity while enhancing anti-tumor immunity, possibly through the action of specific cytokines. A better understanding of the immunoreaction induced by chemotherapeutic agents can lead to improved outcomes and fewer side effects in intravesical chemotherapy against NMIBC.

Turning tumour cells into antigen presenting cells: The next step to improve cancer immunotherapy?

Downregulation/loss of the antigen presentation is a major immune escape mechanism in cancer. It allows tumour cells to become 'invisible' and avoid immune attack by antitumour T cells. In tumour harbouring properties of professional antigen presenting cells (i.e. tumour B cells in lymphoma), downregulation/loss of the antigen presentation may also prevent direct priming of naïve T cells by tumour cells. Here, we review treatments that may induce/restore antigen presentation by the tumour cells. These treatments may increase the generation of antitumour T cells and/or their capacity to recognise and eliminate tumour cells. By forcing tumour cells to present their antigens, these treatments may sensitise patients to T cell-based immunotherapies, including checkpoint inhibitors.

High CD204+ tumor-infiltrating macrophage density predicts a poor prognosis in patients with urothelial cell carcinoma of the bladder

Macrophages (Mφs) are a major cell type that can infiltrate solid tumors and exhibit distinct phenotypes in different tumor microenvironments. This study attempted to investigate the prognostic values of various tumor-infiltrating Mφ phenotypes in patients with urothelial cell carcinoma of the bladder (UCB), with a focus on Mφ tissue microlocalization. Mφs were assessed by immunohistochemistry in tissues from 302 UCB patients using CD68 as a pan-Mφ marker, and CD204 and CD169 as robust pro- and anti-tumoral Mφ phenotype markers, respectively. Our data showed that these Mφ phenotypes were predominately distributed in stromal (ST) rather than in intratumoral (INT) regions (all P < 0.0001). Surprisingly, CD204 and CD169 can be co-expressed by the same CD68⁺ Mφs. Kaplan-Meier analysis revealed that all INT- and ST-infiltrating CD204⁺ or CD169⁺ Mφ densities were inversely associated with overall survival (all P < 0.01). By multivariate analysis, ST-infiltrating CD204⁺ Mφ density emerged as an independent prognostic factor for overall survival (HR, 1.981; P = 0.022). Moreover, the density of ST-infiltrating CD204⁺ Mφs was positively associated with the tumor size (P = 0.001), tumor stage (P < 0.0001), nodal metastasis (P < 0.0001), and histological grade (P < 0.0001). Our findings suggest that CD204⁺ Mφs might play detrimental protumoral roles and represent the predominant Mφ phenotype in human bladder cancer.

Mycobacteria emulsified in olive oil-in-water trigger a robust immune response in bladder cancer treatment

The hydrophobic composition of mycobacterial cell walls leads to the formation of clumps when attempting to resuspend mycobacteria in aqueous solutions. Such aggregation may interfere in the mycobacteria-host cells interaction and, consequently, influence their antitumor effect. To improve the immunotherapeutic activity of Mycobacterium brumae, we designed different emulsions and demonstrated their efficacy. The best formulation was initially selected based on homogeneity and stability. Both olive oil (OO)- and mineral oil-in-water emulsions better preserved the mycobacteria viability and provided higher disaggregation rates compared to the others. But, among both emulsions, the OO emulsion increased the mycobacteria capacity to induce cytokines’ production in bladder tumor cell cultures. The OO-mycobacteria emulsion properties: less hydrophobic, lower pH, more neutralized zeta potential, and increased affinity to fibronectin than non-emulsified mycobacteria, indicated favorable conditions for reaching the bladder epithelium in vivo. Finally, intravesical OO-M. brumae-treated mice showed a significantly higher systemic immune response, together with a trend toward increased tumor-bearing mouse survival rates compared to the rest of the treated mice. The physicochemical characteristics and the induction of a robust immune response in vitro and in vivo highlight the potential of the OO emulsion as a good delivery vehicle for the mycobacterial treatment of bladder cancer.

Poly(I:C) potentiates Bacillus Calmette-Guérin immunotherapy for bladder cancer

Non-specific immunotherapy consisting of intravesical instillation of Bacillus Calmette-Guérin (BCG) is currently the best available treatment to prevent non-muscle-invasive bladder tumor recurrence and progression. This treatment however is suboptimal, and more effective immunotherapeutic approaches are needed. Toll-like receptors (TLRs) play a major role in the activation of the immune system in response to pathogens and danger signals but also in anti-tumor responses. We previously showed that human urothelial cells express functional TLRs and respond to TLR2 and TLR3 agonists. In this study, we analyzed the potential of polyinosinic:polycytidylic acid [poly(I:C)], a TLR3 agonist, to replace or complement BCG in the treatment of non-muscle-invasive bladder cancer. We observed that poly(I:C) had an anti-proliferative, cytotoxic, and apoptotic effect in vitro on two low-grade human bladder cancer cell lines, MGH-U3 and RT4. In MGH-U3 cells, poly(I:C) induced growth arrest at the G1-S transition. Poly(I:C) also increased the immunogenicity of MGH-U3 and RT4 cells, inducing the secretion of MHC class I molecules and of pro-inflammatory cytokines. By comparison, poly(I:C) had less in vitro impact on two high-grade human bladder cancer cell lines, 5637 and T24, and on MBT-2 murine high-grade bladder cancer cells. The latter can be used as an immunocompetent model of bladder cancer. The combination poly(I:C)/BCG was much more effective in reducing MBT-2 tumor growth in mice than either treatment alone. It completely cured 29% of mice and also induced an immunological memory response. In conclusion, our study suggests that adding poly(I:C) to BCG may enhance the therapeutic effect of BCG.

Granulomatous Prostatitis After Intravesical Bacillus Calmette-Guérin Instillation Therapy: A Potential Cause of Incidental F-18 FDG Uptake in the Prostate Gland on F-18 FDG PET/CT in Patients with Bladder Cancer

PURPOSE

This study aimed to evaluate the possibility that Bacillus Calmette-Guérin (BCG)-induced granulomatous prostatitis can be a potential cause of benign F-18 FDG uptake.

METHODS

A total of 395 bladder cancer patients who underwent F-18 FDG PET/CT (PET/CT) were retrospectively evaluated. Patients were divided into two groups according to BCG therapy status. Elapsed time after BCG therapy, serum PSA level, results of prostate biopsy, and the SUVmax and uptake pattern in the prostate gland were reviewed. For patients who underwent follow-up PET/CT, the changes in SUVmax were calculated.

RESULTS

While 35 % of patients showed prostate uptake in the BCG therapy group, only 1 % showed prostate uptake in the non-BCG therapy group (p < 0.001). Among 49 patients with FDG-avid prostate lesions, none had suspected malignancy during the follow-up period (median: 16 months). Five patients revealed granulomatous prostatitis on biopsy. The incidence of FDG-avid prostate lesions was significantly higher if the elapsed time after BCG therapy was less than 1 year compared to more than 1 year (p < 0.001). Serum PSA was normal in 88 % of patients. All patients with incidental F-18 FDG uptake in the prostate gland showed focal or multifocal prostate uptake, and median SUVmax was 4.7. In 16 patients who underwent follow-up PET/CT, SUVmax was decreased in 14 patients (88 %) without treatment, and no patients demonstrated further increased prostate uptake (p < 0.001).

CONCLUSIONS

BCG-induced granulomatous prostatitis can be a potential cause of benign F-18 FDG uptake, especially in those with a history of bladder cancer treated with BCG. In BCG-induced granulomatous prostatitis, focal or multifocal prostate uptake is frequently seen within 1 year after BCG therapy, and the intensity of prostate uptake is decreased on the follow-up PET/CT without any treatment.

T-cell immunoglobulin mucin-3 expression in bladder urothelial carcinoma: Clinicopathologic correlations and association with survival

BACKGROUND

T cell immunoglobulin mucin-3 (Tim-3) was initially recognized as a pivotal immune checkpoint inhibitor that maintains immune homeostasis and tolerance. Recently, Tim-3 has been demonstrated to play an important role in tumor-associated immune suppression and aberrant Tim-3 expression has been reported in several human malignancies. However, the role of Tim-3 in bladder urothelial carcinoma (BUC) remains largely unknown. The present study aims to investigate Tim-3 expression in BUC and analyze correlations with clinicopathologic outcomes and postoperative survival.

METHODS

Tim-3 protein expressions were detected in paraffin embedded sections from 100 patients with BUC by immunohistochemistry. Expressions were correlated with clinicopathologic outcomes and postoperative survival.

RESULTS

Tim-3 protein was over-expressed in bladder cancer cells, tumor infiltrating lymphocytes and endothelial cells from patients with BUC. The expression levels of Tim-3 were significantly correlated with advanced pathological grade and T stage. Moreover, another immune checkpoint molecule programmed death receptor-1(PD-1) was also over- expressed in BUC tissues and had a significant correlation with Tim-3. Multivariate analysis showed that Tim-3 expression, as well as PD-1 expression was both independent predictors of disease-free survival and overall survival in patients with BUC.

CONCLUSION

Tim-3 over-expression implies adverse clinical outcomes for BUC, which suggests it is a potential prognostic biomarker and a novel therapeutic target in BUC.