Mochel, Jonathan P

While most cases of human muscle-invasive bladder cancer (MIBC) are diagnosed as conventional urothelial carcinoma (UC), there is growing recognition of histologic subtypes and divergent differentiation within conventional UC. In this study, 31 dogs with UC (33 slides) were evaluated for histologic subtypes and divergent differentiation, as specified by the recent World Health Organization update on the classification of urinary bladder cancers. Slides were reviewed by a medical uropathologist and 3 board-certified veterinary pathologists and assessed for expression of uroplakin III, vimentin, and E-cadherin. All tumors were classified as UC. Fifteen cases were identified as conventional UC. Among the remainder, 8 displayed glandular differentiation, 4 were classified as sarcomatoid UC, 2 showed squamous differentiation, 1 case was classified as a large nested subtype, and 1 case was classified as a tubular/microcystic subtype. This study found a higher frequency of certain histologic subtypes and divergent differentiation in canine UC, particularly sarcomatoid UC and UC with glandular differentiation, compared to previous reports of both canine UC and human MIBC. The relatively high prevalence of the sarcomatoid UC and UC with glandular differentiation in dogs observed in this study suggests that canine UC may serve as a valuable translational model for evaluating novel therapeutic agents, particularly for these rare and aggressive subtypes in humans.

Abstract The histologic heterogeneity of human Muscle Invasive Bladder Cancer (MIBC) is one of the main contributing factors to poor treatment outcomes. Recent reports on MIBC histological variants have highlighted increased levels of transcription factors (TF) associated with epithelial-mesenchymal transformation (EMT) and epigenetic regulation in the sarcomatoid histology variant of MIBC. Dogs with spontaneously developing MIBC have been shown to display similar histological and molecular features, in addition to closely mimicking the clinical behavior of human MIBC. Here, we add to previously reported data on histological variants in canine MIBC by evaluating 21 tumor biopsies for variant histology and performing bulk RNAseq analyses on 3 organoid cell lines derived from one sarcomatoid subvariant and two conventional urothelial carcinoma (UC). MIBC biopsies from 21 dogs were reviewed for variant histology by a human urologic pathologist. Organoids derived from the urine of canine MIBC patients were cultured, preserved in RNA later, and sequenced for mRNA expression to identify TF associated with sarcomatoid variants versus conventional UC. All canine MIBC biopsies were classified as invasive, high-grade UC. Histologic variants were identified as glandular differentiation in 7/21, sarcomatoid differentiation in 3/21, squamous differentiation in 3/21, micropapillary carcinoma in 1/21 MIBC samples and small nested variants in 1/21 samples; with the rest of the tumors classified as conventional UC. Raw RNAseq analyses revealed no clear clustering of expression profiles between the three organoid cell lines, indicating distinct RNA expression profiles between the sarcomatoid variants and conventional UC of canine MIBC. To evaluate differences in the expression of TF targets between the organoid cell lines, pathway analyses and VIPER algorithms were used. Organoids derived from sarcomatoid variant UC showed increased expression of Snail familiy transcription repressor 1 (SNAI1) along with decreased expression of cadherin 1 (CDH1), indicating a signature of EMT, similar to that previously identified in human MIBC organoids with sarcomatoid variant histology. Canine MIBC organoids derived from conventional UC histology samples showed a TF profile associated with proliferation, metastasis, and progression, such as increased Zinc finger E-box binding homeobox 1 (ZEB1), E2F transcription factor 3 (E2F3), and centromere protein F (CENPF), as previously described in humans with high grade, invasive UC. In conclusion, the frequency of some histologic variants in canine MIBC, such as sarcomatoid UC, appear to be higher than reported in human patients. TF analyses of canine MIBC-derived organoid cell lines showed evidence of EMT, similar to the sarcomatoid variants of MIBC in humans. Organoids derived from canine MIBC could potentially serve as a valuable model for evaluating the efficacy of novel treatment modalities for the rare histologic variants of UC. Citation Format: Karin Allenspach, Mohamed Elbadawy, Hannah Nocholson, Christopher Zdyrski, John Cheville, Eugene Douglass, Elizabeth W. Howerth, Lilian Oliveira, Jonathan P. Mochel. Sarcomatoid Histological Variants of Canine Muscle-Invasive Bladder Cancer: Transcription Factor Activation Highlights Pathways of Epithelial-Mesenchymal Transformation Similar to Humans [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr PR002.

AbstractBackgroundBladder cancer is a significant malignancy in humans and canines, with high death rates and devastating clinical symptoms. Despite significant advances in therapeutic management over the years, only a small fraction of bladder cancer patients respond to immunotherapies as a second line of treatment. Since immunotherapies act on various cellular and molecular targets in the bladder cancer tumour microenvironment (TME), a greater understanding of the various types of immune cells, immune checkpoint molecules and cytokines involved in antitumour immunity will help to improve the success rate of current and novel immunotherapies, therefore enhancing the patients quality of life. Accumulating evidence shows fundamental similarities between human and canine muscle‐invasive bladder cancer (MIBC) in their clinical, histological and molecular features.AimThis review focuses on comparative aspects of MIBC in both species, highlighting the role that canines can play as a model for studying MIBC. Additionally, we discuss the various types of immune cells within bladder cancer TME that can influence the prognosis and response to immunotherapy and chemotherapy in both species.ConclusionIt remains challenging to recapitulate the heterogeneity and complexity of the bladder cancer tumour microenvironment using in vivo and in vitro models, such as zebrafish and 3D organoids models. Optimization of these techniques to create a more representative translational model has been facilitated through in vitro immune‐oncology cocultures, which are considered promising tools to help select the ideal individualized treatment options and predict disease prognosis.

Abstract Introduction: Muscle-Invasive Bladder Cancer (MIBC) is associated with a poor overall survival rate. One important factor that contributes to poor treatment outcomes is the histologic heterogeneity of MIBC tumors, which limits the translational value of some rodent models. As opposed to mice, dogs with spontaneously occurring bladder cancer have been shown to present with similar clinical behavior as human MIBC. In addition, canines have an intact immune system, which could provide for an ideal pre-clinical study population to investigate the efficacy of immunotherapy. In this study, we evaluated canine MIBC tumor biopsies for their similarities to human MIBC with regards to histology and immune cell infiltration. Materials & Methods: Nine canine MIBC tumor samples were provided by the ISU pathology service and evaluated by a human uropathologist. Canine MIBC tumors were phenotypically characterized using either immunofluorescence (IF) or RNA in situ hybridization (RNA-ISH), including CD44, KRT7 and FOXA1, as well as specific markers characterizing the immune cell infiltrate, such as CD163 (tumor-associated macrophages), CD8a (cytotoxic T-lymphocytes), PD-L1 (immune-checkpoint protein) and TGFβ2 (cancer-associated fibroblasts). Results: Histologically, all canine MIBCs were classified as invasive, high-grade urothelial carcinomas (UC) with identical morphology to human MIBC. Interestingly, previously described histological variants of human MIBC tumors were also observed within the canine MIBC samples, such as glandular differentiation in 3/9 canine MIBC samples; epithelial-mesenchymal transition with sarcomatoid differentiation 1/9, squamous differentiation in 2/9 and micropapillary carcinoma in 1/9, all of which have been associated with poor clinical outcomes in human patients. IF was strongly positive for KRT7, FOXA1 and CD44, and immune cell markers CD163 and TGFβ2. However, CD8a was only weakly expressed (5/9) or negative, and PD-L1 was only positive in 4/9 canine MIBC biopsies. Conclusions: Canine MIBC tumors showed significant heterogeneity with highly similar histological variant morphologies to those reported in humans with MIBC. Furthermore, phenotypic characterization of immune cell infiltrates and checkpoint proteins suggest that the tumors were typically immunologically “cold”. These data further establish the utility of the spontaneous canine model of MIBC for pre-clinical investigation of novel therapeutic drug candidates, including immunotherapies. Citation Format: Karin Allenspach, John Cheville, Hannah Wickham, Christopher Zdyrski, Vojtech Gabriel, Basant Ahmed, Mei-Jyun Ciou, Fabrice Lucien, Igor Frank, Olufemi Fasina, Pablo Pineyro, Johnathan P. Mochel. Similar variant histology and immune cell infiltration in canine and human muscle-invasive bladder cancer [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 2509.

Lipopolysaccharide (LPS) is associated with chronic intestinal inflammation and promotes intestinal cancer progression in the gut. While the interplay between LPS and intestinal immune cells has been well-characterized, little is known about LPS and the intestinal epithelium interactions. In this study, we explored the differential effects of LPS on proliferation and the transcriptome in 3D enteroids/colonoids obtained from dogs with naturally occurring gastrointestinal (GI) diseases including inflammatory bowel disease (IBD) and intestinal mast cell tumor. The study objective was to analyze the LPS-induced modulation of signaling pathways involving the intestinal epithelia and contributing to colorectal cancer development in the context of an inflammatory (IBD) or a tumor microenvironment. While LPS incubation resulted in a pro-cancer gene expression pattern and stimulated proliferation of IBD enteroids and colonoids, downregulation of several cancer-associated genes such as Gpatch4, SLC7A1, ATP13A2, and TEX45 was also observed in tumor enteroids. Genes participating in porphyrin metabolism (CP), nucleocytoplasmic transport (EEF1A1), arachidonic acid, and glutathione metabolism (GPX1) exhibited a similar pattern of altered expression between IBD enteroids and IBD colonoids following LPS stimulation. In contrast, genes involved in anion transport, transcription and translation, apoptotic processes, and regulation of adaptive immune responses showed the opposite expression patterns between IBD enteroids and colonoids following LPS treatment. In brief, the crosstalk between LPS/TLR4 signal transduction pathway and several metabolic pathways such as primary bile acid biosynthesis and secretion, peroxisome, renin–angiotensin system, glutathione metabolism, and arachidonic acid pathways may be important in driving chronic intestinal inflammation and intestinal carcinogenesis.

Abstract The outcome of patients with Muscle Invasive Bladder Cancer (MIBC) is highly variable with many patients experiencing progressive disease despite multimodal therapy. A key variable that contributes to poor patient outcomes lies in our inability to predict therapeutic response due to the molecular heterogeneity of MIBC tumors. There is, therefore, a significant unmet clinical need to accurately predict effective drug combinations and therapeutic doses in individual patients with MIBC. Patient-derived tumor organoids (PDOs) have the potential to serve as an ex vivo model of urothelial carcinoma (UC) capable of functionally predicting patient-specific treatment responses. However, current culture procedures typically rely on the expansion of UC organoids from resected tumors or biopsy specimens, which is inherently invasive and hence limits clinical application. We hypothesized that culture of MIBC PDOs can be achieved from urine samples, as is the case in dogs with MIBC, since histopathological features, tumor heterogeneity and subtypes, metastatic activity, and gene expression profiles of canine MIBC mimic those of human MIBC. Herein, we successfully cultured MIBC organoids from both human and canine patients using first-catch urine. Briefly, after centrifuging urine samples to pellet cells, the cells were washed with basal culture media containing FBS and Pen/Strep before being cultured in canine or human culture media containing essential growth factors based on their species of origin. Paraffin-embedded samples were used for molecular characterization by RNA in situ hybridization or immunohistochemistry. Organoids from canine MIBC patients were analyzed for expression of the urothelial differentiation marker (FOXA1) associated with high grade bladder cancer, CD44, a non-kinase transmembrane glycoprotein expressed in UC cancer stem cells, and CK7, an epithelial cell marker that is upregulated in neoplastic UC cells. FOXA1 expression was undetectable in canine MIBC, although CD44 expression was enhanced compared to healthy dog bladder organoids. All canine MIBC organoids had significantly enhanced CK7 expression. Similarly, in human-derived UC organoids, GATA binding protein 3 (GATA3), transcription factor paired box 8 (Pax8), and tumor protein p63 were utilized as markers, with a Pax8-/p63+/GATA3+ profile indicating UC origin of the organoids. Functional response to chemotherapy (cisplatin and gemcitabine) was further assessed using cell viability assay in canine and human UC organoids. Our data suggest that organoids cultured from the urine of patients with MIBC can recapitulate organ structures and maintain marker expression profiles of the original tumor tissues. 3D organoids may provide novel insights to predict therapeutic response to chemotherapy and serve as early diagnostic biomarkers of bladder cancer in both canine and human patients. Citation Format: Dipak Kumar Sahoo, Allison P. Mosichuk, Fabrice Lucien, Igor Frank, John C. Cheville, Karin Allenspach, Jonathan P. Mochel. Urine-derived urinary carcinoma organoids: A novel tool for providing new insights into human and canine bladder cancer treatment [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 3092.

Abstract Lipopolysaccharide (LPS) is associated with chronic intestinal inflammation and promotes intestinal cancer progression in the gut. While the interplay between LPS and intestinal immune cells has been well characterized, little is known about LPS and intestinal epithelium interactions. In this study, we explored the differential effect of LPS on proliferation and the transcriptome in 3D enteroids/colonoids obtained from dogs with naturally occurring gastrointestinal (GI) diseases, such as Inflammatory Bowel Disease (IBD) and GI mast cell tumor. The study objective was to analyze LPS-induced modulation of signaling pathways involving the intestinal epithelia and critical to colorectal cancer development in the context of IBD or a tumor microenvironment. While LPS incubation resulted in a pro-cancer gene expression pattern and stimulated proliferation of IBD enteroids and colonoids, down-regulation of several cancer-associated genes like CRYZL1, Gpatch4, SLC7A1, ATP13A2, and ZNF358 was also observed in tumor enteroids. Genes participating in porphyrin metabolism (CP), thiamine and purine metabolism (TAP2, EEF1A1), arachidonic acid, and glutathione metabolism (GPX1) exhibited a similar pattern of altered expression between IBD enteroids and IBD colonoids following LPS stimulation. In contrast, genes involved in anion transport, transcription and translation, apoptotic processes, and regulation of adaptive immune responses showed opposite expression patterns between IBD enteroids and colonoids following LPS treatment. In brief, the cross-talk between LPS/TLR4 signal transduction pathway and several metabolic pathways, such as fatty acid degradation and biosynthesis, and purine, thiamine, arachidonic acid, and glutathione metabolism, may be important in driving chronic intestinal inflammation and intestinal carcinogenesis.

Urinary bladder cancer (UBC) is the most common malignancy of the urinary tract in humans, with an estimated global prevalence of 1.1 million cases over 5 years. Because of its high rates of recurrence and resistance to chemotherapy, UBC is one of the most expensive cancers to treat, resulting in significant health care costs. The development of innovative molecular and cellular tools is necessary to refine patient stratification and help predict response to treatment. Urine is an underused resource of biological components shed from bladder tumors, such as exfoliated cells and extracellular vesicles, that could serve as molecular fingerprints and provide valuable biological insights into tumor phenotype and mechanisms of resistance to chemotherapy. Additionally, characterization of urine-derived extracellular vesicles and cells could be used as reliable biomarkers for prediction of response to neoadjuvant therapy.