Bladder Tumor Model Research Articles

Abstract B167: KRAS gene mutations are associated with tumor resistance toward the LN1222/AD736 p38 inhibitor

Abstract The p38 MAPK pathway, also called stress activated protein kinase pathway, is involved in basic cellular processes of inflammation and acts on cell growth, proliferation, differentiation, migration, and apoptosis. p38 MAP kinase activation occurs by environmental stress and proinflammatory cytokines signaling and is frequently deregulated in cancers. p38 MAP kinase inhibition has been suggested for treatment of the cancer; a number of inhibitors have been developed and some are in an early phase of clinical evaluation. The present study aimed to investigate the antitumor activity and discover potential predictive biomarkers for the novel p38 inhibitor LN1222/AD736 in a large and diverse series of tumor models. Cancer cell inhibition was tested in vitro by means of a propidium-based monolayer assay in a total of 222 human tumor cell lines, covering 29 different types of solid tumors including 70 derived from PDX. To illuminate molecular determinants of drug sensitivity, we conducted a biomarker discovery study using the molecular profiles of cell lines, which included whole exome mutations, gene copy number variations, and gene expression profiles as determined by next-generation sequencing, Affymetrix SNP6.0 and Affymetrix U133 2plus. Throughout the 222 cell lines, the IC50 and IC70 geometric means were 0.33 μM and 1.3 μM, respectively. High antitumor potency (IC70 <500 nΜ) was found in 121 out of 222 cell lines (54%), and the cell line sensitivity toward LN1222/AD736 was well dichotomized into very sensitive (<500 nM) and very resistant (>30 μM) models. Very sensitive cell lines were observed in leukemia and lymphoma as well as a wide variety of solid tumors including sarcoma (soft tissues and osteosarcoma), prostate, bladder, breast, melanoma, colon, NSCLC, and kidney tumor models, irrespective of the cancer type. Molecular analyses showed that tumor models had comparable expression patterns of the four different isoforms of p38 mRNA (MAPK11, 12, 13, and 14) with those of the patient’s tumors (TCGA data set). None of the four isoforms was found significantly predictive for tumor sensitivity to LN1222/AD736 (Lima test and Spearman correlation analyses). Interestingly, the biomarker discovery screening associated KRAS gene mutations (24 of 127 model tested (20%)) as a strong factor for resistance toward LN1222/AD736, only wild type KRAS models were sensitive (Wilcoxon test p<0.0001). In parallel, we identified a subset of 80 differentially expressed genes that discriminates groups of tumors with a high response rate by using unsupervised hierarchical clustering (p<0.0001). The ingenuity pathway analysis indicates that part of these genes are related to inflammation and cell survival. These biomarker data will be evaluated in an independent data set of tumors treated with p38 inhibitors. Our results demonstrate that the p38 inhibitor LN1222/AD736 had antitumor activity in a wide range of tumors and may represent a relevant treatment option for tumors with wild type KRAS. Extending the analysis in vitro and in vivo in tumor types in which activity was seen and testing combinations of LN1222/AD736 and other compounds targeting the MAPK pathway are needed to refine the evaluation. The biomarker findings should be tested and validated in larger cohort. Citation Format: Vincent Vuaroqueaux, Gerhard Kelter, Hans R Hendriks, Stefan Laufer, Heinz-Herbert Fiebig. KRAS gene mutations are associated with tumor resistance toward the LN1222/AD736 p38 inhibitor [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B167.

Mesenchymal Stem Cells Promote Tumor Progression via Inducing Stroma Remodeling on Rabbit VX2 Bladder Tumor Model.

Background and aim: Mesenchymal stem cells (MSCs) are capable of impacting tumor progression but its role in tumor stroma remodeling still remains unclear. This present study was aimed to evaluate the potential function of MSCs on tumor stroma remodeling using rabbits VX2 bladder tumor model.Methods: The VX2 bladder tumor models were established by injecting mixed cell suspensions (106 of VX2 tumor cells and 0/106/107 of autologous MSCs in group A, B, C, respectively) into the bladder mucosa using thirty male New Zealand white rabbits. The tumor volume was measured by ultrasound at the time points of 1st, 2nd, 3rd and 4th week after inoculation. At the end of the fourth week, the tumor tissue expressions of basic fibroblast growth factor (bFGF), transforming growth factor beta 1 (TGFβ-1), hepatocyte growth factor (HGF), matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) were determined using Real-time quantitative PCR and immunohistochemistry. Masson trichrome staining and Cy3-FITC double-labelled immunofluorescence staining were used to determine the MSCs distribution in tumor tissue in another two rabbits implanted with a cell suspension of 106 VX2 tumor cells and 106 autologous MSCs.Results: MSCs were homogeneously distributed in tumor tissues after 7 days of inoculation, which were not consistent with the distribution of tumor stroma. After 21 days of inoculation, MSCs have been integrated into tumor interstitial tissue and mainly distributed in the mesenchyma around the tumor nest. At the 1st, 2nd, 3rd and 4th week time point, tumor volume in group A < group B < group C, and the difference has statistical significance (all p<0.001).The relative mRNA and protein levels of bFGF, TGFβ-1 and HGF were significantly higher in group B and C compared with group A (all p<0.05), as well as the mRNA levels of bFGF, HGF were higher in group C than group B (p<0.05), and the protein levels of bFGF, TGFβ-1 were higher in group C than group B (p<0.05). The mRNA and protein levels of MMP2 were significantly higher in group B, C than group A (p<0.05). MMP9 was increasingly over expressed along with the growing amount of MSCs inoculated within tumor, both at the level of mRNA and protein (all p<0.05).Conclusion: MSCs participate in tumor stroma remodeling via inducing overexpression of some important growth factors and MMPs.

The anti-tumor effect of intravesical administration of normal urothelial cells on bladder cancer

Background aimsUrothelial bladder cancer (UBC) is the second most common cancer of the genitourinary tract and for advanced forms of the disease it has a high mortality rate. There are no approved new molecularly targeted agents or chemotherapeutics for advanced UBC beyond cisplatin-based chemotherapy except the recently approved anti-programmed death ligand 1 (anti-PD-1/PD-L1) antibody. With complex genetic and epigenetic alterations in tumors, despite several druggable targets identified, to cure UBC is still a challenging unmet medical need. Like other cancers, UBC to the host body is considered as a wound, aging stem cell disease and immunosuppressive disorder. Therefore, we proposed a novel cellular approach to target the host body by intravesical instilling of normal urothelial cells that could repair the injury and reduce inflammation by activating body-reparative capacity and because non-self cells are transplanted, host body immune responses could be induced in the tumor microenvironment of UBC to restrain and even eliminate tumor cells. MethodsIn this study, we isolated and expanded normal male murine urothelial cells and intravesically administered them into the bladders of female mice of two orthotopic bladder tumor models and one urothelial injury model. ResultsWe showed that the instillation of normal urothelial cells containing stem/progenitor cell population into bladders could have anti-tumor effect in orthotopic tumor models, possibly by activating immune responses and helping injured urothelium tissue recovery in a chemically induced urothelial injury model. ConclusionsOur findings could lead to an innovative and revolutionary cell therapy modality with normal urothelial cells as an effective and safe therapeutic option for UBC.

Abstract 2669: Antitumor activity of the CMP-001 (TLR9 agonist) alone or combined with immune modulators in syngeneic tumor models

Abstract Targeted blockade of checkpoint inhibitors such as CTLA-4 or PD-1 with antagonist monoclonal antibodies (mAbs) has shown impressive and durable clinical responses in patients with advanced cancer. An alternative strategy to boost anti-tumor immunity is to promote T cell activation through co-stimulatory receptors such as OX40 and 4-1BB. OX40 is of particular interest as treatment with an activating anti-OX40 mAb augments T cell differentiation and cytolytic function leading to enhanced anti-tumor immunity. However, each of these agents benefits only a subset of patients, highlighting the critical need for more effective combinatorial therapeutic strategies. Toll-like receptor 9 (TLR9) agonist CpG oligodeoxynucleotides (ODN) are candidates to promote an anti-tumor immune response. CMP-001, a CpG-A ODN formulated within a virus-like particle, is designed to activate TLR9 (the receptor for CpG-A) in tumor-associated plasmacytoid dendritic cells (pDC) within the tumor or tumor-draining lymph nodes. Resting or immature pDC promote tumor growth, but when activated by CpG-A, the resulting mature pDC promote a robust anti-tumor immune response. Activation of pDC causes secretion of very large quantities of type I interferons, increased expression of costimulatory molecules, and recruitment and activation of other DC subsets to enhance tumor antigen presentation to T cells, culminating in the generation of effective anti-tumor T cell responses. The preclinical efficacy of intratumorally administered CMP-001 alone or in combination with an intraperitoneally administered PD-1 antagonist and/or an OX40 agonist was examined and assessed in a variety of syngeneic tumor models: CT-26 colon tumor model, MBT-2 bladder tumor model, RenCa kidney tumor model, 4T1 breast tumor model and LLC-1 lung tumor model. Tumors were implanted into left and right flanks while only one tumor was injected with CMP-001. In addition to body weight and overall survival, tumor volume was monitored on both flanks to assess direct and abscopal/systemic anti-tumor activity. Some discrepancies were observed between evaluated syngeneic tumor models with non-responders (LLC-1, 4T1) and responders (CT-26, MBT-2, RenCa). The most efficacious results were registered in the CT-26 model. Each therapeutic yielded weak activity as a single agent, which improved when combined with another treatment modality. The best therapeutic efficacy was obtained with the combination of all three agents resulting in cures of both treated and untreated CT-26 tumors in 40% of the mice. The median survival time was increased for these animals compared to those treated with only vehicle or one or two immune modulators (50 vs 18 vs 21 or 23-28 days, respectively). Similar results were generated in the MBT-2 model (and to a less extent in RenCa model) though no complete response was recorded. These data support the clinical investigation of these combinations in cancer patients Citation Format: Francis Bichat, Sylvie Maubant, Jean-François Mirjolet, Philippe Slos, Arthur M. Krieg, Aaron Morris. Antitumor activity of the CMP-001 (TLR9 agonist) alone or combined with immune modulators in syngeneic tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2669. doi:10.1158/1538-7445.AM2017-2669

MP44-01 IN VIVO FLUORESCENCE IMAGING OF AN ORTHOTOPIC RAT BLADDER TUMOR MODEL INDICATES DIFFERENTIAL UPTAKE OF INTRAVESICALLY INSTILLED NEAR-INFRARED LABELED 2-DEOXYGLUCOSE ANALOG BY NEOPLASTIC URINARY BLADDER TISSUES

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology I1 Apr 2017MP44-01 IN VIVO FLUORESCENCE IMAGING OF AN ORTHOTOPIC RAT BLADDER TUMOR MODEL INDICATES DIFFERENTIAL UPTAKE OF INTRAVESICALLY INSTILLED NEAR-INFRARED LABELED 2-DEOXYGLUCOSE ANALOG BY NEOPLASTIC URINARY BLADDER TISSUES Joel Slaton, Carole Davis, Robert Hurst, and Daqing Piao Joel SlatonJoel Slaton More articles by this author , Carole DavisCarole Davis More articles by this author , Robert HurstRobert Hurst More articles by this author , and Daqing PiaoDaqing Piao More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1332AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Bladder cancer is one of the most expensive cancers to manage due to frequent recurrences requiring life-long surveillance and treatment. Deoxyglucose radionucleotides have been shown to detect metastatic bladder cancer. This pilot study has explored differential uptake of intravesically administered IRDye800CW-DG, a near-infrared labeled 2-deoxy-d-glucose probe targeting glucose metabolism pathway, to detect surface cancer in an orthotopic rodent bladder tumor model. METHODS Twenty-five female Fischer rats were randomly grouped to four conditions: control (n=3), control and intravesically instilled with IRDye800CW-DG (n=6), treated with GFP-labeled AY-27 rat bladder urothelial cell carcinoma cells and washed with saline (n=5), and treated with AY-27 and intravesically instilled with IRDye800CW-DG (n=11). Near-infrared fluorescence was measured from the opened bladder wall of anesthetized rat at an excitation wavelength of 750nm and an emission wavelength of 776nm, by using an in-house fluorescence imaging system. RESULTS There is no statistically significant difference of the peak fluorescence intensity among the control bladders (n=3), the control bladders instilled with IRDye800CW-DG (n=6), and the GFP-labeled AY-27 treated bladders washed by saline (n=5). When compared to that of the control bladders instilled with IRDye800CW-DG (n=6), the fluorescence intensity of GFP-labeled AY-27 treated bladders instilled with IRDye800CW-DG and with histology confirmed neoplastic bladder tissue (n=11) was remarkably stronger (3.34 folds of the former) that was also statistically significant (p<0.0001). CONCLUSIONS The differential uptake of IRDye800CW-DG by the neoplastic urinary bladder tissues suggests the potential for cystoscopy-adaptation to enhance diagnosis and guiding surgical management of flat urinary bladder cancer. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e563 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Joel Slaton More articles by this author Carole Davis More articles by this author Robert Hurst More articles by this author Daqing Piao More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Enhanced antitumor effects by combining an IL-12/anti-DNA fusion protein with avelumab, an anti-PD-L1 antibody.

The combined therapeutic potential of an immunocytokine designed to deliver IL-12 to the necrotic regions of solid tumors with an anti-PD-L1 antibody that disrupts the immunosuppressive PD-1/PD-L1 axis yielded a combinatorial benefit in multiple murine tumor models. The murine version of the immunocytokine, NHS-muIL12, consists of an antibody (NHS76) recognizing DNA/DNA-histone complexes, fused with two molecules of murine IL-12 (NHS-muIL12). By its recognition of exposed DNA, NHS-muIL12 targets IL-12 to the necrotic portions of tumors; it has a longer plasma half-life and better antitumor efficacy against murine tumors than recombinant murine IL-12. It is shown here that NHS-muIL12, in an IFN-γ‒dependent mechanism, upregulates mPD-L1 expression on mouse tumors, which could be construed as an immunosuppressive action. Yet concurrent therapy with NHS-muIL12 and an anti-PD-L1 antibody resulted in additive/synergistic antitumor effects in PD-L1‒expressing subcutaneously transplanted tumors (MC38, MB49) and in an intravesical bladder tumor model (MB49). Antitumor efficacy correlated with (a) with a higher frequency of tumor antigen-specific splenic CD8+ T cells and (b) enhanced T cell activation over a wide range of NHS-muIL12 concentrations. These findings suggest that combining NHS-muIL12 and an anti-PD-L1 antibody enhances T cell activation and T cell effector functions within the tumor microenvironment, significantly improving overall tumor regression. These results should provide the rationale to examine the combination of these agents in clinical studies.

A Murine Orthotopic Bladder Tumor Model and Tumor Detection System.

This protocol describes the generation of bladder tumors in female C57BL/6J mice using the murine bladder cancer cell line MB49, which has been modified to secrete human Prostate Specific Antigen (PSA), and the procedure for the confirmation of tumor implantation. In brief, mice are anesthetized using injectable drugs and are made to lay in the dorsal position. Urine is vacated from the bladder and 50 µL of poly-L-lysine (PLL) is slowly instilled at a rate of 10 µL/20 s using a 24 G IV catheter. It is left in the bladder for 20 min by stoppering the catheter. The catheter is removed and PLL is vacated by gentle pressure on the bladder. This is followed by instillation of the murine bladder cancer cell line (1 x 105 cells/50 µL) at a rate of 10 µL/20 s. The catheter is stoppered to prevent premature evacuation. After 1 h, the mice are revived with a reversal drug, and the bladder is vacated. The slow instillation rate is important, as it reduces vesico-ureteral reflux, which can cause tumors to occur in the upper urinary tract and in the kidneys. The cell line should be well re-suspended to reduce clumping of cells, as this can lead to uneven tumor sizes after implantation. This technique induces tumors with high efficiency. Tumor growth is monitored by urinary PSA secretion. PSA marker monitoring is more reliable than ultrasound or fluorescence imaging for the detection of the presence of tumors in the bladder. Tumors in mice generally reach a maximum size that negatively impacts health by about 3 - 4 weeks if left untreated. By monitoring tumor growth, it is possible to differentiate mice that were cured from those that were not successfully implanted with tumors. With only end-point analysis, the latter may be mistakenly assumed to have been cured by therapy.

A Murine Orthotopic Bladder Tumor Model and Tumor Detection System

This protocol describes the generation of bladder tumors in female C57BL/6J mice using the murine bladder cancer cell line MB49, which has been modified to secrete human Prostate Specific Antigen (PSA), and the procedure for the confirmation of tumor implantation. In brief, mice are anesthetized using injectable drugs and are made to lay in the dorsal position. Urine is vacated from the bladder and 50 µL of poly-L-lysine (PLL) is slowly instilled at a rate of 10 µL/20 s using a 24 G IV catheter. It is left in the bladder for 20 min by stoppering the catheter. The catheter is removed and PLL is vacated by gentle pressure on the bladder. This is followed by instillation of the murine bladder cancer cell line (1 x 105 cells/50 µL) at a rate of 10 µL/20 s. The catheter is stoppered to prevent premature evacuation. After 1 h, the mice are revived with a reversal drug, and the bladder is vacated. The slow instillation rate is important, as it reduces vesico-ureteral reflux, which can cause tumors to occur in the upper urinary tract and in the kidneys. The cell line should be well re-suspended to reduce clumping of cells, as this can lead to uneven tumor sizes after implantation. This technique induces tumors with high efficiency. Tumor growth is monitored by urinary PSA secretion. PSA marker monitoring is more reliable than ultrasound or fluorescence imaging for the detection of the presence of tumors in the bladder. Tumors in mice generally reach a maximum size that negatively impacts health by about 3 - 4 weeks if left untreated. By monitoring tumor growth, it is possible to differentiate mice that were cured from those that were not successfully implanted with tumors. With only end-point analysis, the latter may be mistakenly assumed to have been cured by therapy.

Comparison of therapeutic efficacy of lipo-doxorubicin and doxorubicin in treating bladder cancer

ObjectivesDoxorubicin is commonly used in the treatment of superficial bladder cancer, but more side effects and shorter intracellular retention time hamper its clinical application. Since lipo-doxorubicin (Lipodox) has the advantages of longer half-life and lower clearance rate than doxorubicin, it should improve the efficacy of tumor therapy and reduce the normal tissue toxicity of doxorubicin. Materials and MethodsIn this study, we compared the cytotoxicity of Lipodox and doxorubicin in different treatment durations on bladder cancer cells by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Drug distribution was tracked under fluorescence microscopy. The metabolic rate after treatment was measured by serial flow cytometry. Finally, an in vivo orthotopic MBT-2 bladder tumor model was established for comparing the differences of therapeutic efficacy, including tumor weight and survival rate. ResultsThe 50% inhibitory concentration (IC50) of doxorubicin and Lipodox for MBT-2 cells was 0.62 μg/mL and 130 μg/mL, respectively, after 48 hours treatment. Lipo-dox presented higher cytotoxicity than doxorubicin at 6 hours (93% vs 73%) and 12 hours (93% vs 80%) treatment. After drug treatment, Lipodox fluorescence distribution was observed mostly in the cell membrane, lysosomes, and nuclei of tumor cells, while doxorubicin was concentrated in the nuclei. Initial fluorescence intensity of doxorubicin was 27.3 times that of Lipodox (p < 0.001) at time of treatment. The fluorescence intensity of doxorubicin decreased to 12% after 24 hours culture but that of Lipodox remained at 81%. In an orthotopic model, the average tumor weight and survival were: control group: 1.0 ± 0.3 g, 25%; doxorubicin treatment group: 0.7 ± 0.05 g, 43%; and Lipodox treatment group: 0.2 ± 0.1 g, 57%. ConclusionOur study demonstrated that Lipodox can enhance doxorubicin cytotoxicity in bladder cancer cells and inhibit tumor growth in orthotopic bladder cancer with improved survival rate. Therefore, we suggest Lipodox may act as an alternative to doxorubicin in the treatment of local bladder cancer.

Abstract A16: Expression of PD-L1 and BCG immunotherapy in non-muscle invasive bladder cancer

Abstract Background: Immunotherapy based on BCG has been a standard therapy to prevent recurrence and progression in bladder cancer. Activation of immune checkpoints by binding PD-1 to its ligands, PD-L1, is vital for physiologic regulation of immune system. Tumor cells can co-opt the PD-1 pathway to escape from immunosurveillance mechanism. We investigated expression of immune checkpoints and their effects on T cells in bladder cancer. Methods: A panel of transitional cell carcinoma cell lines (UC-3,T24,KU1919 and 253J) and normal human bladder urothelial cells (SVHUC1) were used to evaluate expression of immune checkpoints. Western blot analysis was used for protein expressions from cell lines and qPCR for RNA expression from human bladder tissues. Human bladder cancer/normal paired tissues were obtained at two time points; surgical resection and then after BCG immunotherapy. Immunohistochemical staining was performed to assess infiltration and distribution of CD4+ and CD8+ T cells in bladder tumor tissues and normal bladder tissues. Immune cells were isolated and T cells were isolated by FACS sorting after immune cell isolation from tumor/normal tissues. Results: PD-L1 proteins were highly expressed in bladder cancer cell lines compared to normal bladder epithelial cell line (SVHUC1). In paired human samples (cancer and normal tissues), PD-L1 were also highly expressed in bladder cancer tissues compared with paired normal tissues. Real time RT-PCR confirmed the high expression of PD-L1 in bladder cancer tissues. Interestingly, normal epithelial tissues regenerated after surgical resection of the tumor and BCG immunotherapy had low PD- after surgical resection and BCG immunotherapy while recurred tumor showed high expression of PD-L1. Isolation of TIL and immunohistochemical staining with CD4/CD8 showed that T cells were more infiltrated in bladder cancer tissues compared to paired normal tissues. Mouse bladder tumor model expressing PD-L1 showed increased CD3+CD4+ T cells and Treg cells. Conclusion: PD-L1 are highly expressed in bladder cancer. CD3+CD4+ T cells and Treg cells are highly infiltrated in human and mouse bladder cancer tissues. Our data suggest that PD-L1 might be involved in tumor recurrence after BCG immunotherapy and might be a novel targets in bladder cancer. Citation Format: Jun Hyeok Heo, Hyun A. Jin, You Hyun Kang, Ki Hong Kim, Sung Joon Hong, Kyung Seok Han. Expression of PD-L1 and BCG immunotherapy in non-muscle invasive bladder cancer. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr A16.

Abstract 4243: ChAcNLS-A14-B105, a novel fluorescence imaging agent for enhanced detection of muscle invasive bladder cancer

Abstract Fluorescence imaging (FI) provides increased sensitivity for the detection of bladder tumors compared to white light cystoscopy. However, most advanced dyes used in FI suffer from nonspecific cellular accumulation resulting in increased false-positives. In addition, these dyes have not made significant progress in detecting the most aggressive bladder tumors such as muscle invasive bladder cancer (MIBC). Our objective is to develop an antibody-conjugate (AC) PDI agent against interleukin-5 receptor α-subunit (IL-5Rα)-positive MIBC cells. IL-5Rα is overexpressed on MIBC cells relative to superficial bladder cancer or healthy bladder cells. We selected a class of fluorescent dyes termed BODIPY for its availability, facile coupling to proteins, and easy chemical modifications to accommodate required absorption and fluorescence properties. BODIPY was attached to an AC composed of the antibody A14 functionalized with a moiety termed ChAcNLS, which we have shown enables it to escape endosome entrapment and redirect its trafficking to the nucleus. This novel approach results in increased intracellular accumulation of attached molecular payloads in MIBC cells. We aim to determine if ChAcNLS-A14 will increase intracellular accumulation of BODIPY to enhance fluorescence detection of MIBC by probe-based confocal laser endomicroscopy (pCLE). In addition, we aim to develop in an improved orthotopic rat bladder tumor model of human MIBC for testing. Methods We have prepared a carboxyl BODIPY derivative (B105) that allows for facile coupling to A14-ChAcNLS using routine procedures and reagents. The number of B105 and ChAcNLS per A14 was determined by fluorescence spectroscopy and SDS-PAGE, respectively. Intracellular accumulation of B105 was determined by treating HT1376 MIBC cells with A14-B105 and ChAcNLS-A14-B105. Cells were then imaged by fluorescence confocal microscopy. For the in vivo model of MIBC, RNU rats were anesthetized and their bladder washed in mild acid to disrupt the endothelium. HT1376 cells marked with the fluorescent marker DiL and instilled in the rat bladder. Intravesical pCLE was performed 2 weeks later. Results ChAcNLS-A14-B105 conjugate contained 7 molecules of B105 and 3 ChAcNLS peptides per A14. Confocal microscopy revealed the level of B105 intracellular accumulation in IL-5Rα-positive MIBC cells was increase ≥10-fold with ChAcNLS-A14-B105 relative to A14-B105. pCLE revealed HT1376 cells survived and colonized the rat bladder urothelium. Conclusion ChAcNLS-A14-B105 was successfully constructed and shown to significantly enhance B105 intracellular accumulation in target IL-5Rα-positive MIBC cells. A novel orthotopic rat bladder tumor model of human MIBC was also generated. Future testing of ChAcNLS-A14-B105 administered intravesically in RNU rat bladders bearing orthotopic tumors of human MIBC will be performed to determine the potential clinical translation of this new FI agent. Citation Format: Laurent Fafard-Couture, Simon Beaudoin, Samira Osati, Véronique Dumoulon-Perreault, Réjean Lebel, Brigitte Guérin, Johan E. van Lier, Jeffrey Leyton. ChAcNLS-A14-B105, a novel fluorescence imaging agent for enhanced detection of muscle invasive bladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4243.

Anti-tumor effect of Radix Paeoniae Rubra extract on mice bladder tumors using intravesical therapy.

Radix Paeoniae Rubra (RPR) is the dried root of Paeonia lactiflora Pallas and Paeonia veitchii Lynch, and is a herbal medicine that is widely used in traditional Chinese medicine for the treatment of blood-heat and blood-stasis syndrome, similarly to Cortex Moutan. The present study identified the same three components in RPR and Cortex Moutan extracts. In addition, it has been reported that RPR has an anti-cancer effect. Bladder cancer is the seventh most common type of cancer worldwide. Due to the high recurrence rate, identifying novel drugs for bladder cancer therapy is essential. In the present study, RPR extract was evaluated as a bladder cancer therapy in vitro and in vivo. The present results revealed that RPR extract reduced the cell viability of bladder cancer cells with a half maximal inhibitory concentration of 1–3 mg/ml, and had an extremely low cytotoxic effect on normal urothelial cells. Additionally, RPR decreased certain cell cycle populations, predominantly cells in the G1 phase, and caused a clear sub-G increase. In a mouse orthotopic bladder tumor model, intravesical application of RPR extract decreased the bladder tumor size without altering the blood biochemical parameters of the mice. In summary, the present results demonstrate the anti-proliferative properties of RPR extract on bladder cancer cells, and its anti-bladder tumor effect in vivo. Compared to Cortex Moutan extract, RPR extract may provide a more effective alternative therapeutic strategy for the intravesical therapy of superficial bladder cancer.

Systemic Immunotherapy of Non-Muscle Invasive Mouse Bladder Cancer with Avelumab, an Anti-PD-L1 Immune Checkpoint Inhibitor.

Bacillus Calmette-Guerin (BCG) is the standard of care for intravesical therapy for carcinoma in situ and non-muscle invasive, nonmetastatic human urothelial carcinoma. Although the responsiveness to this immunotherapeutic is believed to be linked with (i) a high number of somatic mutations and (ii) a large number of tumor-infiltrating lymphocytes, recent findings of the roles that inhibitory immune receptors and their ligands play in tumor evasion may provide insights into the limitations of the effectiveness of BCG and offer new targets for immune-based therapy. In this study, an aggressive, bioluminescent orthotopic bladder cancer model, MB49 tumor cells transfected with luciferase (MB49(luc)), was used to study the antitumor effects of avelumab, an antibody to PD-L1. MB49(luc) murine tumor cells form multifocal tumors on the mucosal wall of the bladder reminiscent of non-muscle invasive, nonmetastatic urothelial carcinomas. MB49(luc) bladder tumors are highly positive for the expression of PD-L1, and avelumab administration induced significant (P < 0.05) antitumor effects. These antitumor effects were more dependent on the presence of CD4 than CD8 T cells, as determined by in vivo immune cell depletions. The findings suggest that in this bladder tumor model, interruption of the immune-suppressive PD-1/PD-L1 complex releases a local adaptive immune response that, in turn, reduces tumor growth. This bladder tumor model can be used to further identify host antitumor immune mechanisms and evaluate combinations of immune-based therapies for carcinoma in situ and non-muscle invasive, nonmetastatic urothelial carcinoma, to provide the rationale for subsequent clinical studies. Cancer Immunol Res; 4(5); 452-62. ©2016 AACR.

Systemic immunotherapy of superficial mouse bladder cancer with Avelumab (MSB0010718C), an anti-PD-L1 immune checkpoint inhibitor

Bladder cancer is considered a malignancy that is responsive to immunotherapy because of the presence of a (a) high number of somatic mutations, (b) large number of tumor-infiltrating lymphocytes and (c) clinical response to the immune stimulant, Bacillus Calmette-Guerin (BCG). Recent findings of the roles that inhibitory immune receptors and their ligands play in tumor evasion provide some possible explanation as to the limitations of BCG and may offer new therapeutic approaches to some patients with bladder cancer. In this study, an aggressive, bioluminescent orthotopic bladder cancer model, MB49 tumor cells transfected with luciferase (MB49luc), was used to study the antitumor effects of an anti-PD-L1 antibody. MB49luc murine tumor cells form multifocal, superficial tumors on the mucosal wall of the bladder reminiscent of superficial human transitional cell bladder carcinomas. MB49luc bladder tumors were shown to constitutively express high PD-L1 levels and the administration of Avelumab, an anti-PD-L1 antibody, induced significant tumor reduction. Antitumor effects subsequently improved overall survival, and both were abrogated by selective in vivo depletion of CD4 or CD8 T cells, but not with NK cell depletion. These findings suggest that in this murine bladder tumor model, interruption of the immune suppressive PD-1/PD-L1 complex releases a local adaptive immune response that, in turn, significantly reduces tumor growth. This experimental bladder tumor model can be used to (a) identify host immune mechanisms responsible for tumor resistance or destruction and (b) evaluate combinations of immune-based therapy for bladder cancer which could provide rationale for future clinical studies.

Nicotine Induces Tumor Growth and Chemoresistance through Activation of the PI3K/Akt/mTOR Pathway in Bladder Cancer.

Continued smoking is highly associated with not only a higher incidence but also greater risk of tumor recurrence, progression, and acquired chemoresistance of urothelial carcinoma. We investigated whether nicotine affects urothelial carcinoma, and the detailed mechanism by which nicotine could induce tumor growth and any associated chemoresistance. Cell viability was evaluated in the human bladder cancer cell line T24 exposed to nicotine with or without cisplatin (CDDP) and NVP-BEZ235 as a PI3K/mTOR dual inhibitor by the WST-1 assay. Protein expression of the PI3K/Akt/mTOR pathway was investigated by Western blotting or immunohistochemical analysis. The influence of nicotine on tumor growth was also evaluated with or without CDDP and/or NVP-BEZ235 in a subcutaneous bladder tumor model. The result demonstrated that cell proliferation was increased in T24 cells after exposure to nicotine. Phospho-specific Akt (pAkt) and phospho-specific p70 S6 kinase (pS6) were significantly upregulated by nicotine exposure. Tumor growth in vivo was significantly induced by nicotine exposure in accordance with increased pS6 expression. Nicotine attenuated inhibition of T24 cell growth by CDDP and further upregulated pS6 expression in vitro and in vivo. NVP-BZE235 inhibited T24 cell proliferation and pAkt and pS6 expression induced after exposure to nicotine and/or CDDP. In conclusion, nicotine increases tumor growth and induces acquired chemoresistance through activation of the PI3K/Akt/mTOR pathway in bladder cancer.

Metformin can block precancerous progression to invasive tumors of bladder through inhibiting STAT3-mediated signaling pathways.

BackgroundMetformin is the first line of oral antidiabetic drug in the biguanide class for treatment of type 2 diabetes. Increasing evidence has suggested that it is a potential anti-tumor drug. However, the mechanisms underlying inhibiting tumor development remain elusive, especially in bladder tumors.MethodsT24 and J82 cell lines were used as an in vitro model, and 24 female SD rats were used to build an N-methyl-N-nitrosourea (MNU)-induced orthotopic rat bladder cancer model. Transfection of lentivirus-based shRNA was used to construct the STAT3-KNOCKDOWN T24 cell line. After metformin treatment, the viability of bladde cancer cells was determined by CCK8. Cell cycle distribution and apoptosis were assessed by flow cytometry. The migration and invasion abilities of cells were evaluated by wound healing and transwell asssays. The inactivation of stat3 pahtway was examined by qRTPCR, western blot and Immunofluorescence.ResultsMetformin can effectively inhibit precancerous progression to invasive cancer in an MNU-induced rat orthotopic bladder tumor model, although it could not completely suppress normal cells transforming into tumor cells. While the MNU could induce 50 % rats (4/8) to develop invasive bladder cancers, the rats co-administrated with metformin failed to develop invasive tumors but retained at precancerous or non-invasive stages, exhibiting as dysplasia, papillary tumor and/or carcinoma in situ (CIS). Accordingly, phosphorylation of signal transducer and activator of transcription 3 (STAT3), which is a well known oncogene, was significantly inhibited in the tumors of rats treated with metformin. In vitro experiments revealed that the metformin could efficiently inhibit STAT3 activation, which was associated with the cell cycle arrest, reduction of cell proliferation, migration and invasiveness, and increase in apoptotic cell death of bladder cancer cell lines.ConclusionsThese findings provide for the first time the evidence that metformin can block precancerous lesions progressing to invasive tumors through inhibiting the activation of STAT3 pathway, and may be used for treatment of the non-invasive bladder cancers to prevent them from progression to invasive tumors.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-015-0183-0) contains supplementary material, which is available to authorized users.

Effect of salinomycin on metastasis and invasion of bladder cancer cell line T24.

To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelial-mesenchymal transition (EMT), and to provide experimental basis for the treatment of urological tumors. The bladder cancer cell line T24 was cultured invitro. The rat bladder tumor model was established invivo. The rats were randomized into two groups, among which the rats in the experiment group were given intraperitoneal injection of salinomycin, while the rats in the control group were given intraperitoneal injection of normal saline. The change of tumor cells in the two groups was observed. Transwell was used to detect the cell migration and invasion abilities, Real-time PCR was used to detect the expression of mRNA, while Western-blot was utilized for the determination of the expressions of E-cadherin and vimentin proteins. The metastasis and invasion abilities of serum bladder cancer cell line T24 after salinomycin treatment in the experiment group were significantly reduced when compared with those in the control group, and the tumor metastasis lesions were decreased from an average of 1.59 to 0.6 (P<0.05). T24 cell proliferation in the experiment group was gradually decreasing. T24 cell proliferation at 48h was significantly lower than that at 12h and 24h (P<0.05). T24 cell proliferation at 24h was significantly lower than that at 12h (P<0.05). T24 cell proliferation at each timing point in the experiment group was significantly lower than that in the control group (P<0.05). The serum mRNA level and E-cadherin expression in the tumor tissues in the experiment group were significantly higher than those in the control group, while vimentin expression level was significantly lower than that in the control group (P<0.05). Salinomycin can suppress the metastasis and invasion of bladder cancer cells, of which the mechanism is probably associated with the inhibition of EMT of tumor cells.

Studies of the photosensitizer disulfonated meso-tetraphenyl chlorin in an orthotopic rat bladder tumor model

Photochemical internalization (PCI) is a novel technology for the release of a therapeutic molecule from endocytic vesicles into the cytosol of a cell. The release of molecules occurs after activation of an endocytic membrane-embedded photosensitizer by light. In this study uptake and localization of the photosensitizer disulfonated tetraphenyl chlorin (TPCS2a) were explored to optimize a PCI protocol in an orthotopic rat bladder tumor model. Female Fischer F344 rats were intravesically instilled with 0.4×10(6) AY-27 transitional carcinoma cells before allowing tumor growth for 14 days. The photosensitizer TPCS2a was intravesically instilled at different concentrations, and bladders were excised after different time intervals. The retention, penetration, and localization of intratumoral TPCS2a were explored ex vivo using fluorescence spectroscopy and fluorescence microscopy to determine an optimal PCI protocol. These results were compared to histological analysis of necrotic areas after activation of intratumoral TPCS2a by red light (652nm, 0.5J/cm(2)). A superficial distribution pattern of the photosensitizer TPCS2a was seen in bladder tumor tissue, and TPCS2a was almost cleared from the tumors after 72h. The highest retention of TPCS2a was found at 24h after instillation when using a concentration of 3mg/ml. An optimal PCI protocol was defined for the tumor model, including a 24-h TPCS2a-to-light interval and a dose of 3mg/ml TPCS2a. This protocol will be utilized for the study of PCI-enhanced therapeutic effects on non-muscle invasive bladder cancer, using a potent chemotherapeutic under an optimal light dose.

P70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression in orthotopic mouse non-muscle invasive bladder tumor model.

We investigated how the dual inhibition of the molecular mechanism of the mammalian target of the rapamycin (mTOR) downstreams, P70S6 kinase (P70S6K) and eukaryotic initiation factor 4E (eIF4E), can lead to a suppression of the proliferation and progression of urothelial carcinoma (UC) in an orthotopic mouse non-muscle invasive bladder tumor (NMIBT) model. A KU-7-luc cell intravesically instilled orthotopic mouse NMIBC model was monitored using bioluminescence imaging (BLI) in vivo by interfering with different molecular components using rapamycin and siRNA technology. We then analyzed the effects on molecular activation status, cell growth, proliferation, and progression. A high concentration of rapamycin (10 µM) blocked both P70S6K and elF4E phosphorylation and inhibited cell proliferation in the KU-7-luc cells. It also reduced cell viability and proliferation more than the transfection of siRNA against p70S6K or elF4E. The groups with dual p70S6K and elF4E siRNA, and rapamycin reduced tumor volume and lamina propria invasion more than the groups with p70S6K or elF4E siRNA instillation, although all groups reduced photon density compared to the control. These findings suggest that both the mTOR pathway downstream of eIF4E and p70S6K can be successfully inhibited by high dose rapamycin only, and p70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression.

Pre-clinical development of the human CD40 agonistic antibody ADC-1013

Activation of CD40 on dendritic cells increases cross-presentation of tumor antigens and as a result the number of activated tumor directed T effector cells. CD40 agonists have been shown to generate powerful systemic anti-tumor responses when administered in situ. The pre-clinical proof of concept data has been generated mainly using an hCD40 transgenic mouse (hCD40tg) strain. Anti-tumor effects has been demonstrated in multiple syngeneic tumor models including bladder tumor (MB49), melanoma (B16) and lymphoma (A20) models. The anti-tumor effects has been shown to induce long term, T cell dependent, tumor immunity. As expected, the anti-tumor effects depends on the immune status of the tumors as evaluated by immunohistochemistry and flow cytometry. Since CD40 agonistic antibodies mainly exert their effects upstream of the checkpoint inhibitors they have the potential to be ideal candidates for combination regimens including e.g. PD-1 antagonists and OX40 antibodies. Combining ADC-1013 with antibodies against these targets has been shown to improve the anti-tumor effects in B16.F10 melanoma. Toxicology studies were performed in cynomolgus monkeys using subcutaneous or intravenous administration. Doses of 1 to 10 mg/kg were evaluated in both studies. ADC-1013 was well tolerated at all dose levels and no major safety concerns were identified. Receptor saturation of approximately 95% was achieved and pharmacodynamic activity, notably B-cell depletion, was observed at all dose levels. In cynomolgus monkey, serum concentrations of ADC-1013 declined in a multi-phasic manner following a single intravenous dose. The mean terminal half-life was approximately 30 hours. Following subcutaneous administration the mean elimination half-life was found to be between 0.6 and 3.2 days. The clearance (CL_F) decreased and the half-life increased with increasing dose indicating target-mediated clearance. Alligator Bioscience has recently started dosing of the first patients in a clinical trial of the CD40 agonistic antibody ADC-1013. The study is a first-in-human, multicenter, open-label, multiple ascending dose Phase I study in patients with advanced solid tumors to determine the safety, pharmacokinetics and pharmacodynamics of intratumorally administered ADC-1013.