Model Of Human Bladder Cancer Research Articles

Abstract 1845: Mammalian orthoreoviruses R124 and jin-3 demonstrate oncolytic and immune-stimulatory effects in human preclinical bladder cancer models

Abstract Immunotherapy, including the use of immune checkpoint inhibitors, has emerged as an attractive strategy for treatment of various cancers. Unfortunately, less than half of the bladder cancer patients demonstrate clinical benefit from immune checkpoint inhibitors. Novel therapeutic approaches such as oncolytic virotherapy may unleash the full potential of immunotherapy. Oncolytic viruses display tumor-lysing properties, while leaving normal cells unharmed. Besides the direct oncolytic effects, oncolytic viruses are capable of inducing systemic anti-tumor immune responses, thereby representing a promising anti-cancer therapy. In our multi-center oncolytic viro-immunotherapy (OVIT) consortium we evaluate and compare the oncolytic and immunomodulatory properties of several oncolytic viruses (reoviruses, novel non-human primate Adenoviruses, Newcastle disease virus), develop tools to predict oncolytic virus efficacy and design strategies to personalize oncolytic virus therapy. In this study we evaluated and compared the direct oncolytic and indirect immunostimulatory effects of wildtype reovirus R124 and mutant reovirus jin-3 in human bladder cancer. Mutant reovirus jin-3 harbors mutations in the spike protein Sigma-1 and can infect cells independently of junction adhesion molecule A (JAM-A) expression on the tumor cell surface. For this, we exploited multiple preclinical bladder cancer models, including patient-derived tumor models (e.g. 3D cultures) and ex-vivo cultured tumor tissue slices. Both R124 and jin-3 reoviruses could infect, replicate and induce cell death in a panel of 2D and 3D cultured bladder cancer cells lines with a basal, luminal or mixed phenotype. Furthermore, the viruses were capable of infecting the tumor cells and induced cell death in ex-vivo cultured tumor tissue slices. Reovirus mutant jin-3, and to a lesser extent R124, strongly induced immunogenic cell death markers (HMGB1, cell surface expression of calreticulin, HSP90), interferon-stimulated genes, and inflammatory cytokines (IFNβ, CXCL10, TNFα) in human bladder cancer cells. Co-culture of reovirus-infected murine bladder cancer cells MB-49 with murine splenocytes resulted in increased activation markers of dendritic cells and NK cells. In conclusion, reoviruses display oncolytic properties in multiple preclinical models of human bladder cancer. Mutant reovirus jin-3 displays more potent immunomodulatory responses in preclinical bladder cancer models compared with wildtype reovirus R124. Therefore, jin-3 represents an attractive candidate for clinical translation. Citation Format: Arjanneke F. Van De Merbel, Maaike H. van der Mark, Thijs J. Janssen, Lobke C. Hensen, Diana J. van den Wollenberg, Rob C. Hoeben, Rob F. Bevers, Rob C. Pelger, Gabri van der Pluijm, Geertje van der Horst. Mammalian orthoreoviruses R124 and jin-3 demonstrate oncolytic and immune-stimulatory effects in human preclinical bladder cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1845.

Abstract 6032: Establishment of a bladder cancer model using organoids derived from bladder epithelium in genetically engineered mice

Abstract Despite recent advances in molecular profiling of bladder cancer, molecular mechanisms for urothelial carcinogenesis have not fully understood. It is partly because the lack of faithful disease models that accurately recapitulate human bladder cancer. In our previous study, we have analyzed mutation landscape of chemical-induced mouse bladder cancer and human bladder cancer by exome-sequence and found that some components of histone methyltransferase complex like Kmt2c, Kmt2d, Kdm6a were highly prevalent as common mutations and associated with Trp53. Additionally, the downregulation of tumor suppressor gene PTEN is known in human muscle invasive bladder cancer (MIBC). We also investigated cell of origin of chemical-induced mouse bladder cancer using lineage tracing method and found that Krt5 expressing cells with Trp53 alteration efficiently give a rise of high-grade MIBC with squamous differentiation. Based on these results, we have tried to make MIBC mouse model using genetically engineered mouse in which Cas9 and target gene mutation express specifically in Krt5 expressing cells by Cre-LoxP system, combined with CRISPR/Cas9 gene editing technique and 3D organoid culture system. Eight-week-old mice harboring Krt5CreERT2/+; LSL-Cas9; LSL-Trp53+/R172H were used in this study. After introducing gene recombination by administration of tamoxifen, we generated organoids from bladder epithelial cells. For further gene editing, we infected adeno-associated virus with sgPten and sgMll3 to the organoids, which successfully edited the target genes. There seemed to be no significant differences in growth of the organoids in culture between the wild-type and gene-edited organoids. However, gene-edited organoids showed tumorigenesis in vivo when inoculated in subcutaneous space, renal subcapsular space or bladder submucosa of athymic mice, whereas wild-type organoids did not show tumorigenesis in vivo. Histologically, the organoid-derived tumors showed morphological similarity to human urothelial carcinoma with squamous differentiation and intra-tumoral heterogeneity. Furthermore, tumor derived organoid has a potential of tumor development in immune-competent mice. These tumors also maintain squamous phenotype and tumor heterogeneity. These findings suggest that the technique is a promising approach toward the establishment of a useful model of human bladder cancer for the elucidation of bladder carcinogenesis including driver genes. In addition, we think our syngeneic mouse model may be useful tool for further research of tumor immunity and immune checkpoint inhibitor drugs. Citation Format: Akihiro Hamada, Yuki Kita, Hideaki Takada, Kenji Nakamura, Toru Sakatani, Takeshi Sano, Takayuki Goto, Atsuro Sawada, Shusuke Akamatsu, Takashi Kobayashi. Establishment of a bladder cancer model using organoids derived from bladder epithelium in genetically engineered mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6032.

MP06-19 ANTI-TUMOR EFFECT IN BLADDER CANCER MODEL OF TUMOR VASCULATURE-TARGETED 10 B DELIVERY MEDIATED BORON NEUTRON CAPTURE THERAPY

You have accessJournal of UrologyCME1 May 2022MP06-19 ANTI-TUMOR EFFECT IN BLADDER CANCER MODEL OF TUMOR VASCULATURE-TARGETED 10B DELIVERY MEDIATED BORON NEUTRON CAPTURE THERAPY Tohru Yoneyama, Shingo Hatakeyama, Mihoko Sutoh Yoneyama, Taku Yoshiya, Tsuyoshi Uemura, Takehiro Ishizu, Minoru Suzuki, Shingo Hachinohe, Shintaro Ishiyama, Motohiro Nonaka, Michiko N. Fukuda, and Chikara Ohyama Tohru YoneyamaTohru Yoneyama More articles by this author , Shingo HatakeyamaShingo Hatakeyama More articles by this author , Mihoko Sutoh YoneyamaMihoko Sutoh Yoneyama More articles by this author , Taku YoshiyaTaku Yoshiya More articles by this author , Tsuyoshi UemuraTsuyoshi Uemura More articles by this author , Takehiro IshizuTakehiro Ishizu More articles by this author , Minoru SuzukiMinoru Suzuki More articles by this author , Shingo HachinoheShingo Hachinohe More articles by this author , Shintaro IshiyamaShintaro Ishiyama More articles by this author , Motohiro NonakaMotohiro Nonaka More articles by this author , Michiko N. FukudaMichiko N. Fukuda More articles by this author , and Chikara OhyamaChikara Ohyama More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002523.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: p-Boronophenylalanine (10BPA) is a powerful 10B drug used in current clinical trials of BNCT. For BNCT to be successful, a high (500 mg/kg) dose of 10BPA must be administered over a few hours. Here, we report BNCT efficacy after rapid, ultralow-dose administration of either tumor vasculature-specific annexin A1-targeting IFLLWQR (IF7)-conjugated 10BPA or borocaptate sodium (10BSH). METHODS: IF7 conjugates of either 10B drugs intravenously injected into MBT2 bladder tumor-bearing mice and biodistribution of 10B in tumors and normal organs analyzed by prompt gamma-ray analysis. Therapeutic effect of IF7-10B drug-mediated BNCT was assessed by either MBT2 bladder tumor bearing C3H/He mice and YTS-1 tumor bearing nude mice. RESULTS: Intravenous injection of IF7C conjugates of either 10B drugs into MBT2 bladder tumor-bearing mice promoted rapid 10B accumulation in tumor tissues and suppressed tumor growth. Moreover, multiple treatments at ultralow (10–20 mg/kg) doses of IF7-10B drug-mediated BNCT significantly suppressed tumor growth in a mouse model of human YTS-1 bladder cancer, with increased Anxa1 expression in tumors and infiltration by CD8-positive lymphocytes. Our findings suggest BNCT treatment induces an immune response by the host against tumor cells, triggering a strong cytotoxic reaction and also inflammatory and immune responses that increase after BNCT upregulate Anxa1 expression in tumor tissues. Moreover, we hypothesize that if the first BNCT treatment upregulates Anxa1 in tumor tissues due to an inflammatory response or induced immunogenicity, more effective 10B accumulation in tumor tissues might occur following the second injection of IF7-10B drugs. Thus, multiple ultralow doses of IF7-10B drug-mediated BNCT likely boost BNCT therapeutic potential. CONCLUSIONS: We conclude that IF7 serves as an efficient 10B delivery vehicle by targeting bladder tumor tissues via the tumor vasculature and could serve as a relevant vehicle for BNCT drugs. Source of Funding: This study was supported by a Center of Innovation program grant for the young scientist collaborative research fund project (no. R02W16) from the Japan Science and Technology Agency and supported by the Japan Society for the Promotion of Science KAKENHI (grants nos. 17K11119, 20K09517, and 19H05556). The study was also supported by the Kobayashi Foundation for Cancer Research and by the Aomori Prefecture Quantum Science Center © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e84 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Tohru Yoneyama More articles by this author Shingo Hatakeyama More articles by this author Mihoko Sutoh Yoneyama More articles by this author Taku Yoshiya More articles by this author Tsuyoshi Uemura More articles by this author Takehiro Ishizu More articles by this author Minoru Suzuki More articles by this author Shingo Hachinohe More articles by this author Shintaro Ishiyama More articles by this author Motohiro Nonaka More articles by this author Michiko N. Fukuda More articles by this author Chikara Ohyama More articles by this author Expand All Advertisement PDF DownloadLoading ...

A Review of Progress in the Construction and Application of Human-Derived Xenograft Models for Bladder Cancer

The patient-derived xenografts (PDX) model is an animal model established by transplanting primary tumors or fresh tumor tissues of patient origin directly into immunodeficient mice, which preserves the heterogeneity and survival microenvironment of the primary tumor and is widely used in preclinical and precision medicine research of tumors. This article reviews the construction of the PDX model of human bladder cancer and the progress of the application of the PDX model in bladder cancer.

Abstract P245: Synergistic effect of combination of pemigatinib with enfortumab vedotin (EV) in human bladder cancer models

Abstract Bladder cancer is among the most prevalent cancers worldwide, with urothelial carcinoma accounting for approximately 90% of cases. Until recently, poor overall survival after chemotherapy combined with immune checkpoint blockade therapies for patients with advanced urothelial carcinoma highlighted the need for new therapies. Although data supports the use of targeted therapies, such as FGFR inhibitors, recent advances in the treatment of bladder cancer are changing the landscape. Enfortumab vedotin (EV) is an antibody drug conjugate (ADC) consisting of an anti-Nectin-4 antibody conjugated to monomethyl auristatin E, which specifically delivers the auristatin payload to Nectin-4 high-expressing urothelial carcinomas. While activity and durability of response from both monotherapy trials as well as combination with pembrolizumab are favorable, additional treatment options might be required for either patients not responding to treatment or those who might develop resistance. Importantly, FGFR activation through rearrangement or mutation is frequently found in the luminal papillary subtype which also expresses high levels of Nectin-4. Thus, we sought to test the potential of combining pemigatinib and EV in models of human bladder cancer which express both activated FGFR3 and Nectin-4. Our initial analysis show that FGFR3 mutant tumors express high levels of Nectin-4. We further demonstrated that two bladder cancer cell lines RT112/84 (FGFR3-TACC3 fusion) and UM-UC-14 (FGFR3S249C) are sensitive to both pemigatinib and EV in vitro and in vivo. Notably, synergistic anti-tumor effects were observed when pemigatinib was combined with EV in vivo. In addition, combination of pemigatinib with EV significantly improved overall survival when compared to single treatments in these models. Altogether, our data strongly suggest a potential for combination of these therapies in the clinic. Citation Format: Rodrigo A. Hess, Lisa Truong, Antony Chadderton, Michelle Frascella, Leslie Hall, Holly Koblish. Synergistic effect of combination of pemigatinib with enfortumab vedotin (EV) in human bladder cancer models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P245.

Tumor vasculature-targeted 10B delivery by an Annexin A1-binding peptide boosts effects of boron neutron capture therapy

Backgroundp-Boronophenylalanine (10BPA) is a powerful 10B drug used in current clinical trials of BNCT. For BNCT to be successful, a high (500 mg/kg) dose of 10BPA must be administered over a few hours. Here, we report BNCT efficacy after rapid, ultralow-dose administration of either tumor vasculature-specific annexin A1-targeting IFLLWQR (IF7)-conjugated 10BPA or borocaptate sodium (10BSH).Methods(1) IF7 conjugates of either 10B drugs intravenously injected into MBT2 bladder tumor-bearing mice and biodistribution of 10B in tumors and normal organs analyzed by prompt gamma-ray analysis. (2) Therapeutic effect of IF7-10B drug-mediated BNCT was assessed by either MBT2 bladder tumor bearing C3H/He mice and YTS-1 tumor bearing nude mice.ResultsIntravenous injection of IF7C conjugates of either 10B drugs into MBT2 bladder tumor-bearing mice promoted rapid 10B accumulation in tumor and suppressed tumor growth. Moreover, multiple treatments at ultralow (10–20 mg/kg) doses of IF7-10B drug-mediated BNCT significantly suppressed tumor growth in a mouse model of human YTS-1 bladder cancer, with increased Anxa1 expression in tumors and infiltration by CD8-positive lymphocytes.ConclusionsWe conclude that IF7 serves as an efficient 10B delivery vehicle by targeting tumor tissues via the tumor vasculature and could serve as a relevant vehicle for BNCT drugs.

Anti-tumor effects and cell motility inhibition of the DN604-gemcitabine combined treatment in human bladder cancer models

Bladder cancer is one of the major tumors for men in the world, in which therapy the combination of cisplatin and gemcitabine is still fist-line applied to treat with advanced or metastatic bladder cancer. In our early study, we developed a potential Pt(II) agent, DN604, which has anti-tumor effect as potent as cisplatin toward bladder cancers. Herein, we aim at investigating the combinatory application of DN604 with gemcitabine for bladder cancer treatment. In vitro studies proved that the combined treatment of DN604 and gemcitabine could limit cell proliferation by elevating the incidence of DNA damage induced apoptosis. Notably, further researches showed that the DN604-gemcitabine treatment suppressed cell autophagy to inhibit cell motility upon the ROS dependent p38 MAPK signaling pathway, explicating its better anti-tumor activity than single drug treatment or the cisplatin-gemcitabine treatment. In vivo tests confirmed that the DN604-gemcitabine treatment has superior anti-tumor activity with low toxicity to cisplatin or its combination with gemcitabine treatments. DN604 plus gemcitabine, is of great significance for the treatment with human bladder cancer. Our study has provided a potential combination treatment option.

A Non-invasive Imageable GFP-expressing Mouse Model of Orthotopic Human Bladder Cancer.

A more realistic mouse model of bladder cancer is necessary to develop effective drugs for the disease. Tumor models enhanced by bright fluorescent-reporter genes to follow the disease in real-time would enhance the ability to accurately predict the efficacy of various therapeutics on this particularly-malignant human cancer. A highly-fluorescent green fluorescent protein (GFP)-expressing bladder cancer model was orthotopically established in nude mice using the UM-UC-3 human bladder-cancer cell line (UM-UC-3-GFP). Fragments from a subcutaneous tumor of UM-UC-3-GFP were surgically implanted into the nude mouse bladder. Non-invasive and intra-vital fluorescence imaging was obtained with a simple imaging box. The GFP-expressing orthotopic bladder tumor was imaged in real-time non-invasively as well as intra-vitally, with the two methods correlating at r=0.99. This is the first non-invasive-fluorescence-imaging orthotopic model of bladder cancer and can be used for rapidly screening novel effective agents for this recalcitrant disease.

An outcome model for human bladder cancer: A comprehensive study based on weighted gene co-expression network analysis.

The precision evaluation of prognosis is crucial for clinical treatment decision of bladder cancer (BCa). Therefore, establishing an effective prognostic model for BCa has significant clinical implications. We performed WGCNA and DEG screening to initially identify the candidate genes. The candidate genes were applied to construct a LASSO Cox regression analysis model. The effectiveness and accuracy of the prognostic model were tested by internal/external validation and pan‐cancer validation and time‐dependent ROC. Additionally, a nomogram based on the parameter selected from univariate and multivariate cox regression analysis was constructed. Eight genes were eventually screened out as progression‐related differentially expressed candidates in BCa. LASSO Cox regression analysis identified 3 genes to build up the outcome model in E‐MTAB‐4321 and the outcome model had good performance in predicting patient progress free survival of BCa patients in discovery and test set. Subsequently, another three datasets also have a good predictive value for BCa patients' OS and DFS. Time‐dependent ROC indicated an ideal predictive accuracy of the outcome model. Meanwhile, the nomogram showed a good performance and clinical utility. In addition, the prognostic model also exhibits good performance in pan‐cancer patients. Our outcome model was the first prognosis model for human bladder cancer progression prediction via integrative bioinformatics analysis, which may aid in clinical decision‐making.

An Outcome Model for Human Bladder Cancer: A Comprehensive Study Based on Weighted Gene Co-Expression Network Analysis

Background: The evaluation of prognosis is crucial for clinical treatment decision of bladder cancer (BCa) patients. We aim to establishing an effective and reliable model to predict the prognosis of BCa patients. Methods: We performed WGCNA and DEG screening to initially identify the candidate genes. The candidate genes were applied to construct a LASSO Cox regression analysis model. The effectiveness and accuracy of the prognostic model were tested by internal/external validation and pan-cancer validation and time-dependent ROC. Additionally, a nomogram based on the parameter selected from univariate and multivariate cox regression analysis was constructed. Findings: Eight genes were eventually screened out as progression-related differentially expressed candidates in BCa. LASSO Cox regression analysis identified 3 genes to build up the outcome model in E-MTAB-4321 and the outcome model had good performance in predicting patient progress free survival of BCa patients in discovery and test set. Subsequently, another three datasets also have a good predictive value for BCa patients' OS and DFS. Time-dependent ROC indicated an ideal predictive accuracy of the outcome model. Meanwhile, the nomogram showed a good performance and clinical utility. In addition, the prognostic model also exhibits good performance in pan-cancer patients. Interpretation: Our outcome model has proven to be an effective prognostic model for predicting the risk of prognosis in BCa as well as some other cancers. Funding Statement: This work was supported by the Health commission of Hubei Province scientific research project (WJ2019H023 and WJ2019H013) and the Fundamental Research Funds for the Central Universities (2042019kf0150 and 2042019kf0176). Declaration of Interests: The authors declare that there is no conflict of interests. Ethics Approval Statement: Informed consent was obtained from all subjects. The Ethics Committee at Zhongnan Hospital of Wuhan University approved the experiments using human bladder tissue samples for RNA isolation and immunofluorescence staining analysis (approval number: 2015029). All methods used for human bladder tissue samples were performed in accordance with the approved guidelines and regulations.

Abstract 3972: Investigation of tumor intrinsic PD1/PD-L1 in canine urothelial carcinomas as a spontaneous translational model for human invasive bladder cancer

Abstract Urothelial carcinoma (UC) is the fourth most common malignancy in human and the most common form of urinary bladder cancer in dogs. This neoplasia tends to be invasive at advanced stages hence novel therapeutic approaches are urgently needed. As urothelial carcinomas share many similarities between the dog and human in the immunological responses, dogs are a perfect model for studying immunotherapeutic approaches. Recently immuno-checkpoint blockade using anti-PD1/PD-L1 antibodies have shown a promising effect and durable responses in the treatment of UC. Although until recently the PD1/PD-L1 axis was considered to be mostly affecting immune cells, recent reports identified, that PD-1/PD-L1 interaction is also capable of pro-tumorigenic signaling in melanoma and other cancers. Yet, little is known regarding this phenomenon in UC. In our study, we aim at identification of the expression level of PD-1 in canine UC and subsequently characterize the effect of overexpression and CRISPR-based knock-out of PD-1 and PD-L1. Using flow cytometry and immunocytochemistry, we identified that PD-1 is expressed on the surface of canine UC cell line. Interestingly, incubation with high concentration of PD-1 antibody decreased the proliferation rate of the tumor. After transfection with a PD-1 overexpression vector, we notice a significant morphological change and decrease in proliferation and colony formation. Our result provides the first report on PD-1 intrinsic signaling play as an important role in tumor growth of canine UC and thus may also be responsive to immune checkpoint blockade. The effect identified further strengthens the dog as a potential translational model for UC immunotherapy. Citation Format: Yu Jia Wang, Katarzyna Pietrzak, Mikolaj Kocikowski, David Argyle, Ted Hupp, Maciej Parys. Investigation of tumor intrinsic PD1/PD-L1 in canine urothelial carcinomas as a spontaneous translational model for human invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3972.

CD47-Targeted Near-Infrared Photoimmunotherapy for Human Bladder Cancer.

Near-infrared photoimmunotherapy (NIR-PIT) is a localized molecular cancer therapy combining a photosensitizer-conjugated mAb and light energy. CD47 is an innate immune checkpoint widely expressed on bladder cancer cells, but absent from luminal normal urothelium. Targeting CD47 for NIR-PIT has the potential to selectively induce cancer cell death and minimize damage to normal urothelium. The cytotoxic effect of NIR-PIT with anti-CD47-IR700 was investigated in human bladder cancer cell lines and primary human bladder cancer cells derived from fresh surgical samples. Phagocytosis assays were performed to evaluate macrophage activity after NIR-PIT. Anti-CD47-IR700 was administered to murine xenograft tumor models of human bladder cancer for in vivo molecular imaging and NIR-PIT. Cytotoxicity in cell lines and primary bladder cancer cells significantly increased in a light-dose-dependent manner with CD47-targeted NIR-PIT. Phagocytosis of cancer cells significantly increased with NIR-PIT compared with antibody alone (P = 0.0002). In vivo fluorescence intensity of anti-CD47-IR700 in tumors reached a peak 24-hour postinjection and was detectable for at least 14 days. After a single round of CD47-targeted NIR-PIT, treated animals showed significantly slower tumor growth compared with controls (P < 0.0001). Repeated CD47-targeted NIR-PIT treatment further slowed tumor growth (P = 0.0104) and improved survival compared with controls. CD47-targeted NIR-PIT increased direct cancer cell death and phagocytosis resulting in inhibited tumor growth and improved survival in a murine xenograft model of human bladder cancer.

Subcutaneous and orthotopic xenograft models of human bladder carcinoma in nude mice for epidermal growth factor receptor-targeted treatment

Introduction.Approaches based on the principles of a targeted therapy are considered a promising strategy that is capable to improve the effectiveness of treatment for bladder cancer (BC) patients.The purposeof the study was to establish an orthotopic xenograft model of human BC in mice and to prove its suitability for experimental examination of drugs targeting the epidermal growth factor receptor (EGFR).Materials and methods.The objects of the study were ectopic subcutaneous and orthotopic human BC xenografts established using EJ and 5637 human BC cell lines. The growth of orthotopic xenografts in vivo was assessed by magnetic resonance imaging. Tumor tissues were investigated using histological and immunohistochemical techniques.Results.It was shown that EJ and 5637 xenografts exhibit a good reproducibility, a sufficient blood supply of the tumor tissues, a high level of EGFR expression, and different pattern of a subcellular receptor localization. Implantation and subsequent proliferation of human EJ or 5637 cells in the murine bladder mucosa presumably results in muscle-non-invasive tumor formation.Conclusions.The EJ and 5637 xenograft models can be useful for investigation of the efficacy of EGFR-targeted biotherapeutic treatments.

Tumor-Specific Zr-89 Immuno-PET Imaging in a Human Bladder Cancer Model

PurposeTumor-specific molecular imaging is an important tool for assessing disease burden and treatment response. CA19.9 is an important tumor-specific marker in several malignancies, including urothelial carcinoma. [89Zr]DFO-HuMab-5B1 (MVT-2163) is a CA19.9-specific antibody-based construct that has been validated in preclinical animal models of lung, colorectal, and pancreatic malignancies for positron emission tomography (PET) imaging and is currently in a phase I trial for pancreatic cancer (NCT02687230). Here, we examine whether [89Zr]DFO-HuMab-5B1 may be useful in defining urothelial malignancies.ProceduresSurface expression of CA19.9 was confirmed in the human bladder cancer line HT 1197. The radioimmunoconjugate [89Zr]DFO-HuMab-5B1 was injected into mice bearing HT 1197 xenografts, and followed by PET imaging, ex vivo experiments including biodistribution, histology and autoradiography, and analysis of blood samples for shed antigen levels were performed.Results[89Zr]DFO-HuMab-5B1 specifically accumulates in HT 1197 engrafted tumors when imaged with PET. Ex vivo biodistribution of organs and autoradiography of engrafted tumors confirm our construct’s specific tumor binding. The target antigen CA19.9 was not found to be shed in vitro or in vivo.Conclusions[89Zr]DFO-HuMab-5B1 can be used to delineate urothelial carcinomas by PET imaging and may provide tumor-specific information prior to, during, and after systemic therapies.

Effect of contrast media on urinary cytopathology specimens.

Urological dogma dictates that washings collected from the urinary tract for cytological assessment must be performed without interference from contrast agents that may alter cellular integrity and diagnostic interpretation. In practice, the initial contrast used to outline the upper tracts is commonly discarded with subsequent saline washings sent for cytology. We hypothesize that contrast washings do not affect the morphology of urothelial carcinoma cells or the integrity of cytology interpretation. Samples obtained from (1) human bladder cell lines; (2) urine from a human xenograft bladder cancer model using UC-3 cells; and (3) patients with urothelial carcinoma were subjected to various experimental solutions (water, saline, urine, and dilutions of contrast media) for different exposure times. After exposure to various different solutions, samples underwent cytological analysis to assess morphologic and degenerative changes. No cytological differences were seen when cells were exposed to ionic, hyperosmolar, or non-ionic low-osmolar contrast agents for any exposures up to five minutes. Cells exposed to mixtures of contrast agents and urine also demonstrated no evidence of degenerative change. Cells exposed to water for greater than one minute demonstrated significant hydropic degeneration impacting cytological interpretation. At 40 minutes or later, all reagents caused severe degeneration when evaluating urine samples from the mouse bladder cancer model and from patients undergoing urothelial carcinoma. Commonly used contrast agents have no effect on urinary cytology up to five minutes. Contrast washings of the urinary tract should not be discarded and can be sent for cytological diagnosis if fixed within this time period.

Abstract 3068: Anti-tumor effect of DHP107, a mucoadhesive lipid formulae of oral paclitaxel, in bladder cancer model

Abstract Purpose: Paclitaxel is an effective anti-neoplastic agent in many solid tumors including bladder cancer. With the development of new drug delivery strategies, novel formulations of Cremophor EL-free paclitaxel have been developed. Here, we investigated the in vitro and in vivo anti-tumor effect of a mucoadhesive oral formulation of paclitaxel (DHP107) in comparison with iv paclitaxel in a human bladder cancer model. Methods: Four human bladder cancer cell lines (RT4, T24, J82, HT1376) and one murine bladder cancer cell line (MBT-2) were used in this study. In vitro antitumor activity and underlying mechanisms were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cell-cycle analysis and apoptosis assay. In the in vivo study, RT4 cell line was implanted subcutaneously in the flank of nu/nu mice, and treated with iv paclitaxel and 2 doses of DHP107. The effects were assessed by the tumor growth, body weight and Ki-67 staining in tumor tissues. Results: The IC50 values of DHP107 ranged from 4.15 to 34.72 μg/ml with MTT assay. In RT4 cell line, both drugs induced similar G2-M arrest and apoptosis. The xenograft experiments showed that both DHP107 (per os, 50 mg/kg, equivalent of paclitaxel 10 mg/kg) and iv paclitaxel (intraperitoneal, 10 mg/kg) attenuated the growth of RT4 tumors in mice, equivalently. The higher dose (per os, 100 mg/kg) of DHP107 resulted in increased efficacy compared with the lower dose (50 mg/kg) without weight loss in mice. However, significant weight loss was observed in iv paclitaxel (-20% at Day 11) treated group. We observed significantly decreased proliferation with Ki-67 staining in DHP107 (100 mg/kg) treated group than in DHP107 (50 mg/kg) or iv paclitaxel (10 mg/kg) treated groups. Conclusion: Our findings provide the evidence that DHP107 showed comparable antitumor effect with iv paclitaxel and is a promising anti-tumor agent in bladder cancer. Clinical studies in patients with bladder cancer warrant further investigation. Citation Format: Se Hyun Kim, Jung Min Kim, Tae Soo Kim, Won Suk Lee, Woo Sun Kwon, Seung Tak Lim, Joong Bae Ahn, Se-Kyu Kim, Yeong Woo Jo, Sun Young Rha. Anti-tumor effect of DHP107, a mucoadhesive lipid formulae of oral paclitaxel, in bladder cancer model. [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 3068.

Treatment of urinary bladder cancers by growth hormone-releasing hormone antagonists: A preclinical report.

433 Background: Urinary bladder cancer is the fifth most frequent cancer diagnosed and among the most expensive cancers to treat in the United States. The management of muscle-invasive tumors presents a clinical challenge because of the toxicity and limitations in efficacy and durability of current therapeutic modalities. Novel therapeutic strategies for this disease are of paramount importance. Growth hormone-releasing hormone (GHRH) receptors and its splice variant were detected in a series of urothelial malignancies and GHRH has been shown to influence the growth of these tumors. Herein we evaluated the effect of GHRH antagonists on the growth of various experimental human urinary bladder cancers in vitro and in vivo in nude mice. Methods: We investigated the effects of several GHRH antagonists MIA 602, MIA 606 and MIA 690 on growth of urothelial HT-1376, J82, and RT-4 tumors xenografted into nude mice. The presence of GHRH receptors was validated by Western blotting. Results: The receptors for GHRH and their main splice variant, SV1, were detected in tumor samples of all 3 human bladder cancer models. In the HT-1376 tumors, the GHRH antagonists caused a 30-60% reduction in volume and 52-70% decrease in tumor weights (p &lt; 0.05). All three antagonists strongly inhibited growth of J82 cancers as shown by a 62-75% reduction in tumor volume and 54-66% decrease in tumor weights (p &lt; 0.05). Treatment with MIA-602 and MIA-606 resulted in a similar marked inhibition of growth of RT-4 cancers; tumor volume and weights were reduced by about 51-71% in the treated groups (p &lt; 0.05). The mice tolerated this therapy well; body and organ weights were not significantly changed by the treatments. No toxicity from the GHRH antagonists was noted. Conclusions: We demonstrated the efficacy of potent GHRH antagonists and their lack of toxicity in inhibiting the growth of experimental models of bladder cancer in vivo. The expression of GHRH receptors was detected in all 3 models of human primary urothelial bladder carcinomas. Our findings warrant further development of GHRH antagonists for clinical therapy of bladder cancer alone or in combination with current chemotherapeutic agents and Exploration of their mechanism of action.

Intravesical administration of exogenous microRNA-145 as a therapy for mouse orthotopic human bladder cancer xenograft.

We previously reported that the level of microRNA (miR)-145 is attenuated in human bladder cancer cells. In this current study, we investigated whether intravesical administration of miR-145 could be a potential therapeutic strategy for controlling bladder cancer by using an orthotopic human bladder cancer xenograft model. Following transfection of 253J B-V cells with miR-145, the effects of the ectopic expression of miR-145 were examined by performing MTT, Western blotting analysis, Hoechst33342 staining, and wound healing assay in vitro. Also, a mouse orthotopic human bladder cancer model was established by inoculating 253J B-V cells into the bladder wall of mice. The anti-cancer effects of intravesical injections of miR-145 into these mice were then assessed. Transfection of 253J B-V cells with miR-145 induced apoptosis and suppression of cell migration in vitro. Western blotting showed that the levels of c-Myc, socs7, FSCN1, E-cadherin, β-catenin, and catenin δ-1 were decreased and that the PI3K/Akt and Erk1/2 signaling pathways were increased in compensatory fashion. In vivo, mice treated with miR-145 showed 76% inhibition of tumor growth, with a significant prolongation of animal survival (p = 0.0183 vs. control). Western blotting showed that both apoptosis and cell motility-related genes were significantly decreased as seen in vitro. Furthermore, PI3k/Akt and Erk1/2 signaling pathways, which were activated in a compensatory manner in vitro, were decreased in vivo. Intravesical administration of exogenous miR-145 was thus concluded to be a valid therapy for bladder cancer in this human bladder cancer xenograft model.

In vivo disruption of an Rb-E2F-Ezh2 signaling loop causes bladder cancer.

Bladder cancer is a highly prevalent human disease in which retinoblastoma (Rb) pathway inactivation and epigenetic alterations are common events. However, the connection between these two processes is still poorly understood. Here, we show that the in vivo inactivation of all Rb family genes in the mouse urothelium is sufficient to initiate bladder cancer development. The characterization of the mouse tumors revealed multiple molecular features of human bladder cancer, including the activation of E2F transcription factor and subsequent Ezh2 expression and the activation of several signaling pathways previously identified as highly relevant in urothelial tumors. These mice represent a genetically defined model for human high-grade superficial bladder cancer. Whole transcriptional characterizations of mouse and human bladder tumors revealed a significant overlap and confirmed the predominant role for Ezh2 in the downregulation of gene expression programs. Importantly, the increased tumor recurrence and progression in human patients with superficial bladder cancer is associated with increased E2F and Ezh2 expression and Ezh2-mediated gene expression repression. Collectively, our studies provide a genetically defined model for human high-grade superficial bladder cancer and demonstrate the existence of an Rb-E2F-Ezh2 axis in bladder whose disruption can promote tumor development.

Abstract 2821: Dual-label microdosing approach to identify chemoresistance to carboplatin and gemcitabine combination chemotherapy

Abstract Gemcitabine is commonly given in combination with cisplatin or carboplatin (GC therapy) as the first-line chemotherapy regimen for several malignancies, including bladder cancer. Unfortunately, less than half of patients respond to the therapy, generating a critical need for a test that predicts tumor response to GC therapy. The goal of this project is to measure drug-DNA adducts after administration of a single non-toxic microdose of gemcitabine in combination with carboplatin and correlating the degree of modification to chemotherapy sensitivity. We have previously shown that resistance to carboplatin may be identified by using a [14C]carboplatin microdose (1% of therapeutic dose), and subsequent measurement of the [14C]-DNA adducts via accelerator mass spectrometry (AMS), an ultrasensitive method used for detecting rare isotopes. We postulate that adduct levels induced in tumors by GC microdoses are proportional to those formed during full dose chemotherapy. Furthermore, we hypothesize that there exists a threshold level of adducts above which tumors respond to GC therapy. We used bladder cancer cell lines and the nod scid gamma severe combined immunodeficient (NSG) mice containing patient-derived tumor xenografts (PDX) from bladder cancer patients to determine GC-DNA adduct levels using AMS. The NSG mouse is uniquely capable of accepting and propagating tumor tissue engrafted directly from patient biopsy samples. The resulting groups of mice each have identical tumors, but can be treated in a variety of ways with replicate experiments; characteristics that are impossible to achieve in normal clinical studies. We will report progress on developing protocols and preliminary GC microdosing data using the NSG-PDX mouse model of human bladder cancer. Citation Format: Maike Zimmermann, Tiffany M. Scharadin, Hongyong Zhang, Tzu-yin Lin, Ralph W. deVere White, Chong-xian Pan, Paul T. Henderson. Dual-label microdosing approach to identify chemoresistance to carboplatin and gemcitabine combination chemotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2821. doi:10.1158/1538-7445.AM2014-2821