Search Results (7)

Background: Bladder cancer (BCa) is characterized by frequent recurrence and limited durable responses to immunotherapy, in part due to poor T-cell infiltration into tumors. While the chemokine CCL2 and its receptor CCR2 have traditionally been associated with recruitment of immunosuppressive myeloid cells and tumor promotion, we reveal an unexpected anti-tumor role for this pathway in BCa. Methods: Using orthotopic and carcinogen-induced murine BCa models, we demonstrate that genetic deletion or antibody blockade of CCL2 or CCR2 accelerates tumor progression, reduces intratumoral CD4⁺ and CD8⁺ T-cell infiltration, and shortens survival. Results: Mechanistic studies show that CCL2 promotes recruitment of CCR2⁺ effector T cells with enhanced activation and cytotoxicity. Mixed bone marrow chimeras, T-cell-specific CCR2 knockouts, and adoptive transfers confirm that CCR2 signaling within T cells is essential for their trafficking and anti-tumor function. In human BCa, CCL2 expression is reduced in tumors compared to adjacent urothelium, correlating with diminished T-cell infiltration. Importantly, high tumor CCL2 levels are associated with improved recurrence-free survival in patients with BCa. To therapeutically leverage this pathway, we developed a novel intravesical recombinant CCL2 (rCCL2) approach. rCCL2 delivery significantly increased CCR2⁺ T-cell infiltration, reduced tumor burden, and extended survival in both syngeneic MB49 and double-humanized patient-derived xenograft (PDX) BCa models. Conclusions: These findings redefine the CCL2-CCR2 axis as a T-cell-mediated tumor-suppressive pathway in BCa and support rCCL2-based therapy as a strategy to enhance immune infiltration and improve outcomes in treatment-resistant BCa. Full article

More than 90% of bladder cancers are classified as urothelial carcinomas (UC), with approximately 75% of these cases presenting as non-muscle-invasive bladder cancer (NMIBC). Bacillus Calmette–Guérin (BCG) is the current standard immunotherapy for NMIBC, yet it suffers from limited efficacy, frequent tumor recurrence, and substantial toxicity. These limitations underscore the need for safer, more effective, and accessible alternatives. We investigated whether uropathogenic Escherichia coli (UPEC), a natural inducer of immune responses in the bladder, could serve as a novel intravesical immunotherapeutic agent. Using orthotopic bladder cancer models in both mice (MB49-luc) and rats (AY-27), we evaluated the efficacy, specificity, immune dependence, and safety of formaldehyde-inactivated UPEC strains, including mutants with altered type 1 fimbriae expression. Intravesical administration of inactivated UPEC significantly reduced tumor burden and prolonged survival, outperforming BCG in murine models and demonstrating equivalent efficacy with markedly reduced toxicity in rats. The antitumor effect was T cell-dependent and partially mediated by type I fimbriae, which facilitated tumor-specific adhesion. Notably, systemic (subcutaneous) administration of UPEC abrogated efficacy and increased mortality, emphasizing the necessity of localized bladder delivery. In conclusion, we identify inactivated UPEC as a potent, tumor-targeting, and T cell-dependent immunotherapeutic agent with a superior safety profile compared to BCG. This approach might represent a promising and practical alternative for bladder cancer treatment. Full article

Background: Bladder cancer is a common and heterogeneous malignancy of the urinary tract. Traditional chemotherapy using bivalent platinum drugs such as cisplatin(CDDP) is often limited by severe side effects and acquired resistance. To overcome these limitations, we explored a novel Pt(IV) prodrug, DNP, designed to release both cytotoxic cisplatin and the anti-inflammatory cyclooxygenase-2 (COX-2) inhibitor naproxen(NPX). Methods: We evaluated the cytotoxic activity of DNP using both two-dimensional (2D) monolayer and three-dimensional (3D) spheroid models of bladder cancer cells. Transcriptomic analysis via RNA-seq identified apoptosis- and inflammation-related signaling pathways modulated by DNP. RNA-seq-based transcriptomic profiling revealed that DNP regulates signaling pathways associated with apoptosis and inflammation. The anti-inflammatory effects were evaluated using a lipopolysaccharide (LPS)-induced macrophage model, while the in vivo antitumor efficacy was assessed in an orthotopic MB49 bladder cancer model. Results: Compared with CDDP, DNP significantly increased intracellular platinum accumulation and exhibited superior cytotoxicity. It effectively inhibited tumor proliferation, induced apoptosis, and attenuated inflammation both in vitro and in vivo. Conclusions: These findings suggest that DNP exerts dual antitumor effects through enhanced delivery of cytotoxic and anti-inflammatory agents, offering a promising strategy for bladder cancer therapy. Full article

Bladder cancer was the twelfth most common cancer worldwide in 2020. Although bladder cancer has been diagnosed using macroscopic techniques, such as white-light cystoscopy and fluorescence blue-light cystoscopy, there is a need to explore more effective noninvasive optical imaging techniques for accurate bladder cancer diagnosis. This study demonstrates the high effectiveness of the near-infrared fluorescence (NIRF) probe ASP5354, which has been developed for ureteral identification during in vivo diagnosis of bladder cancer in an MB49 bladder cancer orthotopic mouse model. After the intravesical injection of 2.4 μM ASP5354 followed by bladder rinsing with saline at 5 min post injection or intravenous administration of ASP5354 at 240 nmol/kg mouse body weight, followed by a waiting period of 5–24 h in mice, ASP5354 was absorbed specifically by cancerous tissue and not by normal tissues in the bladder. NIRF of ASP5354 in cancer tissues was detected using the NIRF imaging camera system. The NIRF clearly showed a boundary between cancerous and normal tissues. Therefore, ASP5354 provides noninvasive and specific optical in vivo imaging of MB49 bladder cancer using intravesical or intravenous injection of ASP5354. ASP5354 may allow for new diagnostic applications for bladder cancer in humans. Full article

Bacillus Calmette-Guérin (BCG) instillations for the treatment of non-muscle-invasive bladder cancer patients can result in significant side effects and treatment failure. Immune checkpoint blockade and/or decreasing tumor-infiltrating myeloid suppressor cells may be alternative or complementary treatments. Here, we have characterized immune cell infiltration and chemoattractant molecules in mouse orthotopic MB49 bladder tumors. Our data show a 100-fold increase in CD45⁺ immune cells from day 5 to day 9 tumors including T cells and mainly myeloid cells. Both monocytic myeloid-derived suppressor-cells (M-MDSC) and polymorphonuclear (PMN)-MDSC were strongly increased in day 9 tumors, with PMN-MDSC representing ca. 70% of the myeloid cells in day 12 tumors, while tumor associated macrophages (TAM) were only modestly increased. The kinetic of PD-L1 tumor expression correlated with published data from patients with PD-L1 expressing bladder tumors and with efficacy of anti-PD-1 treatment, further validating the orthotopic MB49 bladder-tumor model as suitable for designing novel therapeutic strategies. Comparison of chemoattractants expression during MB49 bladder tumors grow highlighted CCL8 and CCL12 (CCR2-ligands), CCL9 and CCL6 (CCR-1-ligands), CXCL2 and CXCL5 (CXCR2-ligands), CXCL12 (CXCR4-ligand) and antagonist of C5/C5a as potential targets to decrease myeloid suppressive cells. Data obtained with a single CCR2 inhibitor however showed that the complex chemokine crosstalk would require targeting multiple chemokines for anti-tumor efficacy. Full article

Non-muscle-invasive bladder cancer is the most common form of bladder cancer. The main problem in managing bladder tumors is the high recurrence after the transurethral resection of bladder tumors (TURBT). Our study aimed to examine the fate of intravesically applied cancer cells as the implantation of cancer cells after TURBT is thought to be a cause of tumor recurrence. We established an orthotopic mouse bladder tumor model with MB49-GFP cancer cells and traced them during the first three days to define their location and contacts with normal urothelial cells. Data were obtained by Western blot, immunolabeling, and light and electron microscopy. We showed that within the first two hours, applied cancer cells adhered to the traumatized epithelium by cell projections containing α3β1 integrin on their tips. Cancer cells then migrated through the epithelium and on day 3, they reached the basal lamina or even penetrated it. In established bladder tumors, E-cadherin and desmoplakin 1/2 were shown as feasible immunohistochemical markers of tumor margins based on the immunolabeling of various junctional proteins. Altogether, these results for the first time illustrate cancer cell implantation in vivo mimicking cellular events of tumor recurrence in bladder cancer patients. Full article

Bladder cancer is the second most common urological malignancy in the world. In 70% of cases it is initially diagnosed as non-muscle-invasive bladder cancer (NMIBC) and it is amenable to local treatments, with intravesical (IVES) Bacillus-Calmette-Guerin (BCG) immunotherapy being routinely used after transurethral resection of the lesion. However, this treatment is associated with significant side-effects and treatment failures, highlighting the necessity of novel strategies. One potent approach is the suicide-gene mediated therapy/prodrug combination, provided tumor-specificity can be ensured and anti-tumor immune responses induced. Using the mouse syngeneic orthotopic MB49-bladder tumor model, here we show that IVES human papillomavirus non-replicative pseudovirions (PsV) can pseudoinfect tumors with a ten-fold higher efficacy than normal bladders. In addition, PsV carrying the suicide-gene herpes-simplex virus thymidine kinase (PsV-TK) combined to Ganciclovir (GCV) led to immunogenic cell-death of tumor cells in vitro and to MB49-specific CD8 T-cells in vivo. This was associated with reduction in bladder-tumor growth and increased mice survival. Altogether, our data show that IVES PsV-TK/GCV may be a promising alternative or combinatory treatment for NMIBC. Full article