BCG therapy downregulates HLA-I on malignant cells to subvert antitumor immune responses in bladder cancer

Identification and validation of sialyltransferase ST3Gal5 in bladder cancer through bioinformatics and experimental analysis

BACKGROUND

Bladder cancer (BLCA) is one of the top ten most common cancers in the world. Aberrant sialylation is a common feature in tumorigenesis and tumor immunity. This study seeks to explore the potential impact of sialyltransferase ST3Gal5 on BLCA.

METHODS

Initially, glycosyltransferase-related DEGs (GRDEGs) were identified using multiple bioinformatics approaches in TCGA-BLCA cohort and validated using GEO databases. Clinical prognosis integration facilitated the determination of ST3Gal5 as an independent prognostic factor in BLCA, employing univariate and multivariate Cox regression analyses. Immune cell infiltration was assessed via CIBERSORT and ssGSEA analyses, while HLA and immune checkpoint genes' levels, along with drug sensitivity, were evaluated in low- and high-ST3Gal5 groups. The TIDE and IPS scores were used to gauge the immune checkpoint blockade (ICB) response. Furthermore, functional experiments, both in vivo and in vitro, were conducted to elucidate the biological roles of ST3Gal5.

RESULTS

In agreement with bioinformatics findings, ST3Gal5 expression was down-regulated in BLCA tissues and cells, correlating with poorer prognostic outcomes. The StromalScore, ImmuneScore, and ESTIMATEScore were significantly elevated in low-ST3Gal5 group. Moreover, the levels of HLA and immune checkpoint genes were upregulated in low-ST3Gal5 group. Down-regulated ST3Gal5 promoted the proliferation, migration, and invasion of BLCA cells in vivo and in vitro.

CONCLUSION

Our findings demonstrated that low ST3Gal5 level promoted tumorigenesis and progression of BLCA, implying its potential as a predictive biomarker and therapeutic target.

Mechanoimmune-Driven Backpack Sustains Dendritic Cell Maturation for Synergistic Tumor Radiotherapy

Cell backpacks present significant potential in both therapeutic and diagnostic applications, making it essential to further explore their interactions with host cells. Current evidence indicates that backpacks can induce sustained immune responses. Our original objective was to incorporate a model antigen into the backpacks to promote dendritic cell maturation and facilitate antigen presentation, thereby inducing immune responses. However, we unexpectedly discovered that both antigen-loaded backpacks and empty backpacks demonstrated comparable abilities to induce dendritic cell maturation, resulting in nearly identical potency in T-cell proliferation. Our mechanistic studies suggest that the attachment of backpacks induces mechanical forces on dendritic cells via opening the PIEZO1 mechanical ion channel. This interaction leads to the remodeling of the intracellular cytoskeleton and facilitates the production of type I interferons by dendritic cells. Consequently, the mechano-immune-driven dendritic cell backpacks, when combined with radiotherapy, induce a robust antitumor effect. This research presents an avenue for leveraging mechanotransduction to enhance combination immunotherapeutic strategies, potentially leading to groundbreaking advancements in the field.

Developments in conservative treatment for BCG-unresponsive non-muscle invasive bladder cancer

INTRODUCTION

To reduce the risk of disease recurrence and progression of intermediate and high-risk Non-Muscle Invasive Bladder Cancers (NMIBCs), intravesical adjuvant treatment with Bacillus Calmette-Guerin (BCG) represents the standard of care, although up to 50% of patients will eventually recur and up to 20% of them will progress to Muscle Invasive Bladder Cancer (MIBC). Radical Cystectomy (RC) is the treatment of choice in this setting; however, this represents a major and morbid surgery, thus meaning that not all NMIBCs patient could undergo or may refuse this procedure or may refuse. The search for effective bladder sparing strategies in NMIBCs BCG-unresponsive patients is a hot topic in the urologic field.

AREAS COVERED

We aimed to review the most important bladder-preserving strategies for BCG unresponsive disease, from those used in the past, even though rarely used nowadays (intravesical chemotherapy with single agents), to current available therapies (e.g. intravesical instillation with Gemcitabine-Docetaxel), and to future upcoming treatments (Oportuzumab Monatox).

EXPERT OPINION

At present, bladder-preserving treatments in BCG-unresponsive patients are represented by the use of intravesical instillations, systemic immunotherapies, both with good short-term and modest mid-term efficacy, and numerous clinical trials ongoing, with encouraging initial results, in which patients could be recruited.

The combination of immune checkpoint inhibitors and antibody-drug conjugates in the treatment of urogenital tumors: a review insights from phase 2 and 3 studies

With the high incidence of urogenital tumors worldwide, urinary system tumors are among the top 10 most common tumors in men, with prostate cancer ranking first and bladder cancer fourth. Patients with resistant urogenital tumors often have poor prognosis. In recent years, researchers have discovered numerous specific cancer antigens, which has led to the development of several new anti-cancer drugs. Using protein analysis techniques, researchers developed immune checkpoint inhibitors (ICIs) and antibody-conjugated drugs (ADCs) for the treatment of advanced urogenital tumors. However, tumor resistance often leads to the failure of monotherapy. Therefore, clinical trials of the combination of ICIs and ADCs have been carried out in numerous centers around the world. This article reviewed phase 2 and 3 clinical studies of ICIs, ADCs, and their combination in the treatment of urogenital tumors to highlight safe and effective methods for selecting individualized therapeutic strategies for patients. ICIs activate the immune system, whereas ADCs link monoclonal antibodies to toxins, which can achieve a synergistic effect when the two drugs are combined. This synergistic effect provides multiple advantages for the treatment of urogenital tumors.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer

The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.

Autophagy flux in bladder cancer: Cell death crosstalk, drug and nanotherapeutics

Autophagy, a self-digestion mechanism, has emerged as a promising target in the realm of cancer therapy, particularly in bladder cancer (BCa), a urological malignancy characterized by dysregulated biological processes contributing to its progression. This highly conserved catabolic mechanism exhibits aberrant activation in pathological events, prominently featured in human cancers. The nuanced role of autophagy in cancer has been unveiled as a double-edged sword, capable of functioning as both a pro-survival and pro-death mechanism in a context-dependent manner. In BCa, dysregulation of autophagy intertwines with cell death mechanisms, wherein pro-survival autophagy impedes apoptosis and ferroptosis, while pro-death autophagy diminishes tumor cell survival. The impact of autophagy on BCa progression is multifaceted, influencing metastasis rates and engaging with the epithelial-mesenchymal transition (EMT) mechanism. Pharmacological modulation of autophagy emerges as a viable strategy to impede BCa progression and augment cell death. Notably, the introduction of nanoparticles for targeted autophagy regulation holds promise as an innovative approach in BCa suppression. This review underscores the intricate interplay of autophagy with cell death pathways and its therapeutic implications in the nuanced landscape of bladder cancer.

The Role of Tumor and Host Microbiome on Immunotherapy Response in Urologic Cancers

Introduction & Objective

The role of the microbiome in the development and treatment of genitourinary malignancies is just starting to be appreciated. Accumulating evidence suggests that the microbiome can modulate immunotherapy through signaling in the highly dynamic tumor microenvironment. Nevertheless, much is still unknown about the immuno-oncology-microbiome axis, especially in urologic oncology. The objective of this review is to synthesize our current understanding of the microbiome's role in modulating and predicting immunotherapy response to genitourinary malignancies.

Methods

A literature search for peer-reviewed publications about the microbiome and immunotherapy response in bladder, kidney, and prostate cancer was conducted. All research available in PubMed, Google Scholar, clinicaltrials.gov, and bioRxiv up to September 2023 was analyzed.

Results

Significant differences in urinary microbiota composition have been found in patients with genitourinary cancers compared to healthy controls. Lactic acid-producing bacteria, such as Bifidobacterium and Lactobacillus genera, may have value in augmenting BCG responsiveness to bladder cancer. BCG may also be a dynamic regulator of PD-L1. Thus, the combination of BCG and immune checkpoint inhibitors may be an effective strategy for bladder cancer management. In advanced renal cell carcinoma, studies show that recent antibiotic administration negatively impacts survival outcomes in patients undergoing immunotherapy, while administration of CBM588, a live bacterial product, is associated with improved progression-free survival. Specific bacterial taxa, such as Streptococcus salivarius, have been linked with response to pembrolizumab in metastatic castrate-resistant prostate cancer. Fecal microbiota transplant has been shown to overcome resistance and reduce toxicity to immunotherapy; it is currently being investigated for both kidney and prostate cancers.

Conclusions

Although the exact mechanism is unclear, several studies identify a symbiotic relationship between microbiota-centered interventions and immunotherapy efficacy. It is possible to improve immunotherapy responsiveness in genitourinary malignancies using the microbiome, but further research with more standardized methodology is warranted.

Longitudinal Transcription Profiling of Bladder Cancers Dictate the Response to BCG Treatment and Disease Progression

Although the intravesical instillation of Bacillus Calmette-Guerin (BCG) is widely used as adjuvant treatment for nonmuscle-invasive bladder cancers, the clinical benefit is variable across patients, and the molecular mechanisms underlying the sensitivity to BCG administration and disease progression are poorly understood. To establish the molecular signatures that predict the responsiveness and disease progression of bladder cancers treated with BCG, we performed transcriptome sequencing (RNA-seq) for 13 treatment-naïve and 22 post-treatment specimens obtained from 14 bladder cancer patients. To overcome disease heterogeneity, we used non-negative matrix factorization to identify the latent molecular features associated with drug responsiveness and disease progression. At least 12 molecular features were present, among which the immune-related feature was associated with drug responsiveness, indicating that pre-treatment anti-cancer immunity might dictate BCG responsiveness. We also identified disease progression-associated molecular features indicative of elevated cellular proliferation in post-treatment specimens. The progression-associated molecular features were validated in an extended cohort of BCG-treated bladder cancers. Our study advances understanding of the molecular mechanisms of BCG activity in bladder cancers and provides clinically relevant gene markers for evaluating and monitoring patients.

Targeting MHC-I molecules for cancer: function, mechanism, and therapeutic prospects

The molecules of Major histocompatibility class I (MHC-I) load peptides and present them on the cell surface, which provided the immune system with the signal to detect and eliminate the infected or cancerous cells. In the context of cancer, owing to the crucial immune-regulatory roles played by MHC-I molecules, the abnormal modulation of MHC-I expression and function could be hijacked by tumor cells to escape the immune surveillance and attack, thereby promoting tumoral progression and impairing the efficacy of cancer immunotherapy. Here we reviewed and discussed the recent studies and discoveries related to the MHC-I molecules and their multidirectional functions in the development of cancer, mainly focusing on the interactions between MHC-I and the multiple participators in the tumor microenvironment and highlighting the significance of targeting MHC-I for optimizing the efficacy of cancer immunotherapy and a deeper understanding of the dynamic nature and functioning mechanism of MHC-I in cancer.

Targeted therapies in bladder cancer: signaling pathways, applications, and challenges

Bladder cancer (BC) is one of the most prevalent malignancies in men. Understanding molecular characteristics via studying signaling pathways has made tremendous breakthroughs in BC therapies. Thus, targeted therapies including immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and tyrosine kinase inhibitor (TKI) have markedly improved advanced BC outcomes over the last few years. However, the considerable patients still progress after a period of treatment with current therapeutic regimens. Therefore, it is crucial to guide future drug development to improve BC survival, based on the molecular characteristics of BC and clinical outcomes of existing drugs. In this perspective, we summarize the applications and benefits of these targeted drugs and highlight our understanding of mechanisms of low response rates and immune escape of ICIs, ADCs toxicity, and TKI resistance. We also discuss potential solutions to these problems. In addition, we underscore the future drug development of targeting metabolic reprogramming and cancer stem cells (CSCs) with a deep understanding of their signaling pathways features. We expect that finding biomarkers, developing novo drugs and designing clinical trials with precisely selected patients and rationalized drugs will dramatically improve the quality of life and survival of patients with advanced BC.

From mucosal infection to successful cancer immunotherapy

The clinical management of advanced malignancies of the upper and lower urinary tract has been revolutionized with the advent of immune checkpoint blockers (ICBs). ICBs reinstate or bolster pre-existing immune responses while creating new T cell specificities. Immunogenic cancers, which tend to benefit more from immunotherapy than cold tumours, harbour tumour-specific neoantigens, often associated with a high tumour mutational burden, as well as CD8+ T cell infiltrates and ectopic lymphoid structures. The identification of beneficial non-self tumour antigens and natural adjuvants is the focus of current investigation. Moreover, growing evidence suggests that urinary or intestinal commensals, BCG and uropathogenic Escherichia coli influence long-term responses in patients with kidney or bladder cancer treated with ICBs. Bacteria infecting urothelium could be a prominent target for T follicular helper cells and B cells, linking innate and cognate CD8+ memory responses. In the urinary tract, commensal flora differ between healthy and tumoural mucosae. Although antibiotics can affect the prognosis of urinary tract malignancies, bacteria can have a major influence on cancer immunosurveillance. Beyond their role as biomarkers, immune responses against uropathogenic commensals could be harnessed for the design of future immunoadjuvants that can be advantageously combined with ICBs.

A Phase II Study of Durvalumab for Bacillus Calmette-Guerin (BCG) Unresponsive Urothelial Carcinoma In Situ of the Bladder

PURPOSE

Immune checkpoint blockade holds promise for treating bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). In this phase II study, we investigated the safety and efficacy of durvalumab, a human IgG1 monoclonal antibody, against BCG-unresponsive carcinoma in situ (CIS).

PATIENTS AND METHODS

Patients with BCG-unresponsive CIS-containing NMIBC received durvalumab IV at 1,500 mg every 4 weeks for up to 12 months. The primary endpoint was complete response (CR) rate at month 6, defined by negative cystoscopy, urine cytology, and absence of high-grade recurrence on bladder mapping biopsy. The null hypothesis specified a CR rate of 18% and alternative hypothesis of 40%. According to the Simon two-stage design, if ≤3/13 patients achieved CR during stage 1, the trial is stopped due to futility.

RESULTS

Between March 8, 2017, and January 24, 2020, 17 patients were accrued whereas 4 withdrew from study treatment after bladder biopsy at month 3 was positive for CIS. Two of 17 (12%) achieved a CR at month 6, with duration of response of 10 and 18 months, respectively. A single grade 3 lipase elevation was attributed to durvalumab, and immune-related adverse events were observed in 7/17 (41%) patients. Only 1/17 patients had high programmed death-ligand 1 expression pretreatment. On RNA sequencing, complement activation genes were elevated posttreatment, along with enrichment of tumor-associated macrophage signature.

CONCLUSIONS

Durvalumab monotherapy conferred minimal efficacy in treating BCG-unresponsive CIS of the bladder, with 6-month CR of 12%. Complement activation is a potential mechanism behind treatment resistance.

Elucidating the Associated Biological Function and Clinical Significance of RHOJ Expression in Urothelial Carcinoma

Urothelial cancer, a common urinary system malignancy, often presents treatment challenges due to metastasis and chemotherapy side effects. Angiogenesis, crucial for tumor growth, has become a target for drug development. This study explores the expression, prognostic value, and clinical correlation of RHOJ in the TCGA BLCA, GSE31684, and GSE32894 datasets. We identify common differentially expressed genes across these databases and utilize g:Profiler and Cytoscape ClueGO for functional assessment. Further, we perform a gene set enrichment analysis (GSEA) using Hallmark gene sets and use the imsig package for immune cell infiltration analysis. Our analysis indicates that RHOJ expression levels significantly impact survival rates, tumor progression, and immune response in urothelial tumors. High RHOJ expression correlated with poor prognosis, advanced disease stages, and an increase in monocyte population within the tumor microenvironment. This aligns with current literature indicating a key role of immune infiltration in bladder cancer progression and treatment response. Moreover, the GSEA and imsig results further suggest a potential mechanistic link between RHOJ expression and immune-related pathways. Considering the increasing emphasis on immunotherapeutic strategies in bladder cancer management, our findings on RHOJ's potential as a diagnostic biomarker and its association with immune response open new avenues for therapeutic interventions.

Neo-Adjuvant immunotherapies: Bladder cancer as a platform for drug development targeting mucosal immunity

Bacillus Calmette-Guerin (BCG) is a live attenuated Mycobacterium bovis strain, originally developed as a vaccine against tuberculosis. It is also the only bacterial cancer therapy approved by the US Food & Drug Administration for clinical use. BCG is delivered in the bladder, shortly after tumour resection, for patients with high-risk non-muscle invasive bladder cancer (NMIBC). Modulating mucosal immunity by exposing the urothelium to intravesical BCG has been the main therapeutic strategy for high-risk NMIBC over the last three decades. Thus, BCG provides a benchmark for the clinical development of bacteria-or other live attenuated pathogens-as cancer therapy. Currently, a myriad of immuno-oncology compounds is under clinical evaluation in BCG-unresponsive and BCG-naïve patients as an alternative therapy in the context of worldwide BCG shortages. For patients with non-metastatic muscle-invasive bladder cancer (MIBC), studies investigating neoadjuvant immunotherapy with either anti-PD-1/PD-L1 monoclonal antibodies in monotherapy or in combination with anti-CTLA-4 monoclonal antibodies have shown overall efficacy and acceptable safety profiles prior to radical cystectomy. Emerging clinical investigations are testing synergistic approaches by combining intravesical delivery of drugs with systemic immune checkpoint blockades in the neoadjuvant setting for patients with MIBC. Such novel strategy aims to prime a local anti-tumour immunity and reduce distant metastatic relapses by enhancing a systemic adaptive anti-tumour immune response. Here, we present and discuss some of the most promising clinical trials developing such novel therapeutic approaches.

Autophagy-dependent regulation of MHC-I molecule presentation

The major histocompatibility complex (MHC) class I molecules present peptide antigens to MHC class I-restricted CD8+ T lymphocytes to elicit an effective immune response. The conventional antigen-processing pathway for MHC-I presentation depends on proteasome-mediated peptide generation and peptide loading in the endoplasmic reticulum by members of the peptide loading complex. Recent discoveries in this field highlight the role of alternative MHC-I peptide loading and presentation pathways, one of them being autophagy. Autophagy is a cell-intrinsic degradative pathway that ensures cellular homoeostasis and plays critical roles in cellular immunity. In this review article, we discuss the role of autophagy in MHC class I-restricted antigen presentation, elucidating new findings on the crosstalk of autophagy and ER-mediated MHC-I peptide presentation, dendritic cell-mediated cross-presentation and also mechanisms governing immune evasion. A detailed molecular understanding of the key drivers of autophagy-mediated MHC-I modulation holds promising targets to devise effective measures to improve T cell immunotherapies.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease’s origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a “double-edged sword” in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

Bodywide ecological interventions on cancer

Historically, cancer research and therapy have focused on malignant cells and their tumor microenvironment. However, the vascular, lymphatic and nervous systems establish long-range communication between the tumor and the host. This communication is mediated by metabolites generated by the host or the gut microbiota, as well by systemic neuroendocrine, pro-inflammatory and immune circuitries-all of which dictate the trajectory of malignant disease through molecularly defined biological mechanisms. Moreover, aging, co-morbidities and co-medications have a major impact on the development, progression and therapeutic response of patients with cancer. In this Perspective, we advocate for a whole-body 'ecological' exploration of malignant disease. We surmise that accumulating knowledge on the intricate relationship between the host and the tumor will shape rational strategies for systemic, bodywide interventions that will eventually improve tumor control, as well as quality of life, in patients with cancer.