H2O2 generation by bacillus Calmette-Guérin induces the cellular oxidative stress response required for bacillus Calmette-Guérin direct effects on urothelial carcinoma biology

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.

Research progress on the microbiota in bladder cancer tumors

The microbiota, also referred to as the microbial community, is a crucial component of the human microenvironment. It is located predominantly in various organs, including the intestines, skin, oral cavity, respiratory tract, and reproductive tract. The microbiota maintains a symbiotic relationship with the human body, influencing physiological and pathological functions to a significant degree. There is increasing evidence linking the microbial flora to human cancers. In contrast to the traditional belief that the urethra and urine of normal individuals are sterile, recent advancements in high-throughput sequencing technology and bacterial cultivation methods have led to the discovery of specific microbial communities in the urethras of healthy individuals. Given the prevalence of bladder cancer (BCa) as a common malignancy of the urinary system, researchers have shifted their focus to exploring the connection between disease development and the unique microbial community within tumors. This shift has led to a deeper investigation into the role of microbiota in the onset, progression, metastasis, prognosis, and potential for early detection of BCa. This article reviews the existing research on the microbiota within BCa tumors and summarizes the findings regarding the roles of different microbes in various aspects of this disease.

The relationship between BCG immunotherapy and oxidative stress parameters in patients with nonmuscle invasive bladder cancer

INTRODUCTION

Environmental chemicals have been associated with the regulation of oxidative stress markers, which have the potential for the development of bladder cancer. However, limited studies on the function of oxidative stress parameters and nonmuscle invasive bladder cancer (NMIBC) in therapy response are available. Here we studied the oxidative stress parameters in response to BCG immunotherapy in NMIBC patients.

MATERIAL AND METHODS

A total of 120 patients with NMIBC and treatment with BCG were enrolled and categorized into 2 groups on BCG response, 50 patients were BCG-responsive (BCG-R) and 70 were BCG-nonresponsive (BCG-N). BCG-R have no evidence of tumor recurrence or advancement after 1 year of BCG immunotherapy, but BCG-N has a recurrence of tumor after 3 to 6 months cycles of BCG instillation, as determined by cystoscopy. In all groups, we measured the levels of oxidative stress markers- malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT).

RESULTS

The levels of oxidative stress markers viz. MDA, NO, and SOD in the BCG-N group were significantly higher (P < 0.001) than in the BCG-R group. Furthermore, the data demonstrated a significant correlation between oxidative stress marker and NMIBC T1 high grade and tumor size >2.5 cm. However, no statistically significant difference was found between studied groups with CAT.

CONCLUSION

The findings suggest that the carcinogenesis of NMIBC is associated with oxidative damage of biomolecules and indicates the involvement of oxidative stress markers in the development and recurrence of NMIBC.; Therefore, it is critical to ensure the management for T1 high grade and tumor size of >2.5 cm for antioxidant protection.

Immune mechanisms and molecular therapeutic strategies to enhance immunotherapy in non-muscle invasive bladder cancer: Invited review for special issue "Seminar: Treatment Advances and Molecular Biology Insights in Urothelial Carcinoma"

Intravesical immunotherapy with Bacillus Calmette-Guérin (BCG) has been the standard of care for patients with high-risk non non-muscle invasive bladder cancer (NMIBC) for over four decades. Despite its success as a cancer immunotherapy, disease recurrence and progression remain common. Current efforts are focused on developing effective and well-tolerated alternatives to BCG and salvage bladder preservation therapies after BCG has failed. The focus of this review is to synthesize our current understanding of the molecular biology and tumor immune microenvironment of NMIBC to provide rationale for existing and emerging therapeutic targets. We highlight recent and ongoing clinical trials and define the current treatment landscape, challenges, and future directions of salvage treatment. Combination regimens that are rationally designed will be needed to make meaningful therapeutic advancements. Investigations into the molecular underpinnings of NMIBC are leading to the emergence of predictive molecular biomarkers that provide greater insight into the clinical heterogeneity of NMIBC and enable us to identify drivers of treatment resistance and new therapeutic targets.

Bladder Tissue Microbiome Composition in Patients of Bladder Cancer or Benign Prostatic Hyperplasia and Related Human Beta Defensin Levels

Balance between the microbiome associated with bladder mucosa and human beta defensin (HBD) levels in urine is a dynamic, sensitive and host-specific relationship. HBD1—possessing both antitumor and antibacterial activity—is produced constitutively, while the inducible production of antibacterial HBD2 and HBD3 is affected by bacteria. Elevated levels of HBD2 were shown to cause treatment failure in anticancer immunotherapy. Our aim was to assess the relationship between microbiome composition characteristic of tumor tissue, defensin expression and HBD levels measured in urine. Tissue samples for analyses were removed during transurethral resection from 55 bladder carcinoma and 12 prostatic hyperplasia patients. Microbiome analyses were carried out with 16S rRNS sequencing. Levels of HBD mRNA expression were measured with qPCR from the same samples, and urinary amounts of HBD1, 2 and 3 were detected with ELISA in these patients, in addition to 34 healthy volunteers. Mann–Whitney U test, Wilcoxon rank sum test (alpha diversity) and PERMANOVA analysis (beta diversity) were performed. Defensin-levels expressed in the tumor did not clearly determine the amount of defensin measurable in the urine. The antibacterial and antitumor defensin (HBD1) showed decreased levels in cancer patients, while others (HBD2 and 3) were considerably increased. Abundance of Staphylococcus, Corynebacterium and Oxyphotobacteria genera was significantly higher, the abundance of Faecalibacterium and Bacteroides genera were significantly lower in tumor samples compared to non-tumor samples. Bacteroides, Parabacteroides and Faecalibacterium abundance gradually decreased with the combined increase in HBD2 and HBD3. Higher Corynebacterium and Staphylococcus abundances were measured together with higher HBD2 and HBD3 urinary levels. Among other factors, defensins and microorganisms also affect the development, progression and treatment options for bladder cancer. To enhance the success of immunotherapies and to develop adjuvant antitumor therapies, it is important to gain insight into the interactions between defensins and the tumor-associated microbiome.

Estradiol inhibits autophagy of Mycobacterium tuberculosis‑infected 16HBE cells and controls the proliferation of intracellular Mycobacterium tuberculosis

Tracheobronchial tuberculosis (TBTB) is most common in young, middle-aged females. Despite adequate anti-tuberculosis therapy, >90% of patients develop tracheobronchial stenosis, which has a high rate of resulting in disability. The present study aimed to explore the effect of estradiol on the development of TBTB. Estrogen receptor (ER) expression in granulomatous tissue was assessed via immunofluorescence. In order to determine whether estrogen affected the proliferation of intracellular Mycobacterium tuberculosis (Mtb), 16HBE cells were infected with Mtb in vitro, followed by estradiol treatment. Intracellular Mtb was quantified via colony counting. The effect of estradiol on autophagy of infected 16HBE cells was determined via western blotting and transmission electron microscopy. Necrosis assays of infected 16HBE cells were analyzed using propidium iodide staining and assessing lactate dehydrogenase (LDH) release. To determine how estradiol affects autophagy, infected 16HBE cells were treated with ER-specific and non-specific modulators. Reactive oxygen species (ROS) levels were analyzed via flow cytometry. Additionally, the protein expression levels of autophagy-associated proteins were determined via western blotting. Mtb could enter human lobar bronchial goblet cells and ciliated cells in patients with TBTB. The results also demonstrated that ERα was expressed in granulomatous tissue from patients with TBTB. Administration of 10⁻⁶ M estradiol reduced the number of intracellular Mtb colony-forming units in vitro in the 16HBE human bronchial epithelial cell line at day 3 after infection. Furthermore, cells treated with estradiol and infected with Mtb released less LDH at 72 h and exhibited reduced necrosis levels at 24 h compared with the untreated cells. In addition, autophagy of infected 16HBE cells was inhibited by estradiol. Estradiol and the specific ERα agonist had similar effects on autophagy in infected 16HBE cells. Additionally, treatment with the ERα antagonist abolished the inhibition of autophagy by estradiol in infected 16BHE cells. Compared with the untreated infected 16HBE cells, the ROS levels in the infected 16HBE cells treated with estradiol and the ERα agonist significantly decreased. The levels of phosphorylated (p)-mTOR and p-AKT notably increased in estradiol- and ERα agonist-treated infected 16HBE cells. In summary, estradiol may serve a key role in the development of TBTB through binding to ERα.

From Interferon to Checkpoint Inhibition Therapy—A Systematic Review of New Immune-Modulating Agents in Bacillus Calmette–Guérin (BCG) Refractory Non-Muscle-Invasive Bladder Cancer (NMIBC)

Background: In Bacillus Calmette–Guérin (BCG) refractory non-muscle-invasive bladder cancer (NMIBC), radical cystectomy is the gold standard. The advent of immune checkpoint inhibitors (CPIs) has permanently changed the therapy landscape of bladder cancer (BC). This article presents a systematic review of immune-modulating (IM) therapies (CPIs and others) in BCG-refractory NMIBC. Methods: In total, 406 articles were identified through data bank research in PubMed/Medline, with data cutoff in October 2021. Four full-text articles and four additional congress abstracts were included in the review. Results: Durvalumab plus Oportuzumab monatox, Pembrolizumab, and Nadofaragene firadenovec (NF) show complete response (CR) rates of 41.6%, 40.6%, and 59.6% after 3 months, with a long-lasting effect, especially for NF (12-month CR rate of 30.5%). Instillations with oncolytic viruses such as NF and CG0070 show good efficacy without triggering significant immune-mediated systemic adverse events. Recombinant BCG VPM1002BC could prove to be valid as an alternative to BCG in the future. The recombinant pox-viral vector vaccine PANVAC™ is not convincing in combination with BCG. Interleukin mediating therapies, such as ALT-803, are currently being studied. Conclusion: CPIs and other IM agents now offer an increasing opportunity for bladder-preserving strategies. Studies on different substances are ongoing and will yield new findings.

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.

Immune escape mechanisms and immunotherapy of urothelial bladder cancer

BACKGROUND AND AIM

Urothelial bladder cancer (UBC) is a common malignant tumor of the urogenital system with a high rate of recurrence. Due to the sophisticated and largely unexplored mechanisms of tumorigenesis of UBC, the classical therapeutic approaches including transurethral resection and radical cystectomy combined with chemotherapy have remained unchanged for decades. However, with increasingly in-depth understanding of the microenvironment and the composition of tumor-infiltrating lymphocytes of UBC, novel immunotherapeutic strategies have been developed. Bacillus Calmette-Guerin (BCG) therapy, immune checkpoint blockades, adoptive T cell immunotherapy, dendritic cell (DC) vaccines, etc., have all been intensively investigated as immunotherapies for UBC. This review will discuss the recent progress in immune escape mechanisms and immunotherapy of UBC.

METHODS

Based on a comprehensive search of the PubMed and ClinicalTrials.gov database, this review included the literature reporting the immune escape mechanisms of UBC and clinical trials assessing the effect of immunotherapeutic strategies on tumor or immune cells in UBC patients published in English between 1999 and 2020.

RESULTS

Immune surveillance, immune balance, and immune escape are the three major processes that occur during UBC tumorigenesis. First, the role of immunosuppressive cells, immunosuppressive molecules, immunosuppressive signaling molecules, and DCs in tumor microenvironment is introduced elaborately in the immune escape mechanisms of UBC section. In addition, recent progress of immunotherapies including BCG, checkpoint inhibitors, cytokines, adoptive T cell immunotherapy, DCs, and macrophages on UBC patients are summarized in detail. Finally, the need to explore the mechanisms, molecular characteristics and immune landscape during UBC tumorigenesis and development of novel and robust immunotherapies for UBC are also proposed and discussed.

CONCLUSION

At present, BCG and immune checkpoint blockades have been approved by the US Food and Drug Administration for the treatment of UBC patients and have achieved encouraging therapeutic results, expanding the traditional chemotherapy and surgery-based treatment for UBC.

RELEVANCE FOR PATIENTS

Immunotherapy has achieved desirable results in the treatment of UBC, which not only improve the overall survival but also reduce the recurrence rate and the occurrence of treatment-related adverse events of UBC patients. In addition, the indicators to predict the effectiveness and novel therapy strategies, such as combination regimen of checkpoint inhibitor with checkpoint inhibitor or chemotherapy, should be further studied.

The Dependence between Urinary Levels of Angiogenesis Factors, 8-Iso-prostaglandin F2α, ɣ-Synuclein, and Interleukin-13 in Patients with Bladder Cancer: A Pilot Study

During the last decade, a significant increase in the incidence of bladder cancer (BC) has been observed. Angiogenesis plays a key role in the process of tumor growth and metastasis. Additionally, the participation of oxidative stress and chronic inflammation in BC pathogenesis is indicated. The aim of the study was to evaluate the urinary levels of parameters of angiogenesis, stimulating angiogenin (ANG) and inhibiting angiostatin (ANGST), 8-iso-prostaglandin F2α (8-iso-PGF2α) as a marker of oxidative stress, ɣ-synuclein (SNCG) as a cancer progression parameter, and interleukin-13 (IL-13) as an anti-inflammatory immunomodulator. The levels of ANG, ANGST, 8-iso-PGF2α, SNCG, and IL-13 in the urine of BC patients and healthy controls were measured by the enzyme-linked immunosorbent assay. These parameters were examined in the whole group of BC patients and in subgroups depending on the clinical stage: nonmuscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC); histopathologic malignancy: low grade (LG) and high grade (HG) and in primary and recurrent BC. Significantly, higher urinary parameters were found in BC patients in comparison to controls. Levels of all parameters increased with the development of cancer, with the exception of 8-iso-prostaglandin F2α, in which the level was higher in the early stages of the disease, but these differences were not statistically significant. Some correlations have been demonstrated between parameters in BC patients. Based on the receiver operating characteristic curves, ANG and ANGST had the best diagnostic value for BC. The obtained results indicate the important role of the examined parameters of angiogenesis, oxidative stress, and inflammation in the pathogenesis and development of BC. It is reasonable to continue research in order to thoroughly assess the impact of various associated processes on the course of BC. It is also important to carry out similar tests in patients with other urological diseases.

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.

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.

IGF-1 may predict the severity and outcome of patients with sepsis and be associated with microRNA-1 level changes

IGF-1 functions as an anti-oxidative stress molecule and some critical patients with sepsis have a lower level of serum IGF-1. However, the association between IGF-1 and the severity or prognosis of sepsis remains unclear. This study aimed to elucidate the relationship between serum IGF-1 levels and the severity and prognosis of sepsis, and the possible mechanism was analyzed. Clinical characteristics of patients with sepsis were recorded and analyzed. Serum IGF-1 levels and micro (mi)RNA-1 levels were tested using radioimmunoassay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, respectively. The A549 cell line and HKC cell line were cultured in vitro and exposed to H₂O₂ with or without IGF-1 treatment. Cell death was detected by analyzing cell death markers via ELISA kits, and miRNA-1 levels were detected after H₂O₂ exposure using RT-qPCR analysis. miRNA-1 in cells was upregulated by transfection and IGF-1 mRNA was detected to determine its relationship with miRNA-1. Once again, cell ELISA kits were used to analyze cell death markers after transfection. Serum IGF-1 levels were reduced in patients with sepsis, whereas miRNA-1 levels were higher (P<0.05 vs. healthy control). Patients in the septic shock subgroup or dead patients had the lowest IGF-1 levels and the highest miRNA-1 levels (P<0.05 vs. sepsis and severe sepsis). IGF-1 levels were inversely proportional to the miRNA-1 level. In vitro, IGF-1 reduced the cell death caused by H₂O₂. miRNA-1 transfection effectively increased the sensitivity of cells to H₂O₂ damage by reducing the expression of IGF-1, which was able to prevent cells from injury caused by H₂O₂. The transfection of negative control miRNA did not influence the level of IGF-1 miRNA and the sensitivity to H₂O₂ damage. In conclusion, low IGF-1 levels in patients with sepsis may predict increased severity of the condition and poor prognosis. The possible mechanism is that the excessive miRNA-1 levels reduce IGF-1 levels, resulting in insufficient anti-oxidative action by IGF-1 which increases the injury caused by oxidative stress in patients with sepsis.

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.

Targeting Hsp90 in urothelial carcinoma

Urothelial carcinoma, or transitional cell carcinoma, is the most common urologic malignancy that carries significant morbidity, mortality, recurrence risk and associated health care costs. Despite use of current chemotherapies and immunotherapies, long-term remission in patients with muscle-invasive or metastatic disease remains low, and disease recurrence is common. The molecular chaperone Heat Shock Protein-90 (Hsp90) may offer an ideal treatment target, as it is a critical signaling hub in urothelial carcinoma pathogenesis and potentiates chemoradiation. Preclinical testing with Hsp90 inhibitors has demonstrated reduced proliferation, enhanced apoptosis and synergism with chemotherapies and radiation. Despite promising preclinical data, clinical trials utilizing Hsp90 inhibitors for other malignancies had modest efficacy. Therefore, we propose that Hsp90 inhibition would best serve as an adjuvant treatment in advanced muscle-invasive or metastatic bladder cancers to potentiate other therapies. An overview of bladder cancer biology, current treatments, molecular targeted therapies, and the role for Hsp90 inhibitors in the treatment of urothelial carcinoma is the focus of this review.