Urothelial Cancer Cell Lines Research Articles

Trichostatin C Synergistically Interacts with DNMT Inhibitor to Induce Antineoplastic Effect via Inhibition of Axl in Bladder and Lung Cancer Cells.

Aberrant epigenetic modifications are fundamental contributors to the pathogenesis of various cancers. Consequently, targeting these aberrations with small molecules, such as histone deacetylase (HDAC) inhibitors and DNA methyltransferase (DNMT) inhibitors, presents a viable strategy for cancer therapy. The objective of this study is to assess the anti-cancer efficacy of trichostatin C (TSC), an analogue of trichostatin A sourced from the fermentation of Streptomyces sp. CPCC 203909. Our investigations reveal that TSC demonstrates potent activity against both human lung cancer and urothelial bladder cancer cell lines, with IC50 values in the low micromolar range. Moreover, TSC induces apoptosis mediated by caspase 3/7 and arrests the cell cycle at the G2/M phase. When combined with the DNMT inhibitor decitabine, TSC exhibits a synergistic anti-cancer effect. Additionally, protein analysis elucidates a significant reduction in the expression of the tyrosine kinase receptor Axl. Notably, elevated concentrations of TSC correlate with the up-regulation of the transcription factor forkhead box class O1 (FoxO1) and increased levels of the proapoptotic proteins Bim and p21. In conclusion, our findings suggest TSC as a promising anti-cancer agent with HDAC inhibitory activity. Furthermore, our results highlight the potential utility of TSC in combination with DNMT inhibitors for cancer treatment.

Enhancing RECK Expression Through miR-21 Inhibition: A Promising Strategy for Bladder Carcinoma Control.

Bladder carcinoma (BC) is the tenth most frequent malignancy worldwide, with high morbidity and mortality rates. Despite recent treatment advances, high-grade BC and muscle-invasive BC present with significant progression and recurrence rates, urging the need for alternative treatments. The microRNA-21 (miR-21) has superexpression in many malignancies and is associated with cellular invasion and progression. One of its mechanisms of action is the regulation of RECK, a tumor suppressor gene responsible for inhibiting metalloproteinases, including MMP9. In a high-grade urothelial cancer cell line, we aimed to assess if miR-21 downregulation would promote RECK expression and decrease MMP9 expression. We also evaluated cellular migration and proliferation potential by inhibition of this pathway. In a T24 cell line, we inhibited miR-21 expression by transfection of a specific microRNA inhibitor (anti-miR-21). There were also control and scramble groups, the last with a negative microRNA transfected. After the procedure, we performed a genetic expression analysis of miR-21, RECK, and MMP9 through qPCR. Migration, proliferation, and protein expression were evaluated via wound healing assay, colony formation assay, flow cytometry, and immunofluorescence.After anti-miR-21 transfection, miR-21 expression decreased with RECK upregulation and MMP9 downregulation. The immunofluorescence assay showed a significant increase in RECK protein expression (p < 0.0001) and a decrease in MMP9 protein expression (p = 0.0101). The anti-miR-21 transfection significantly reduced cellular migration in the wound healing assay (p < 0.0001). Furthermore, in the colony formation assay, the anti-miR-21 group demonstrated reduced cellular proliferation (p = 0.0008), also revealed in the cell cycle analysis by flow cytometry (p = 0.0038). Our results corroborate the hypothesis that miR-21 is associated with BC cellular migration and proliferation, revealing its potential as a new effective treatment for this pathology.

Abstract 5138: Proteomic analyses of the urothelial cancer landscape reveal highly distinct prognostic and predictive subtypes

Abstract Introduction: Urothelial cancer (UC) is a challenging disease with a wide tumor-biological spectrum. Most molecular classifications cover only muscle-invasive bladder cancer and are transcriptome-based, relating only indirectly to the therapeutically relevant and more stable protein level. Also, the recent introduction of antibody-drug conjugates (ADCs) requires quantitative data about the tumor specificity of their target proteins. We turned to the proteome to address these questions. Methods: We performed deep proteomic profiling of a comprehensive cohort by optimized tandem mass tag-labelled liquid chromatography-coupled tandem mass spectrometry. Data acquisition was validated internally with immunoblotting and externally by bioinformatic reclassification within existing, filtered transcriptomic data. After bioinformatics, the top cluster defining proteins were quantified immunohistochemically under real-world conditions. Protein profiles were individualized and separately evaluated with drug repurposing libraries. Cell viability assays were performed for a panel of twelve UC cell lines to validate these predictions in vitro. Results: We analyzed 434 samples with 242 tumors and 192 paired normal mucosae, covering all stages of UC. 9542 proteins were quantified and revealed five distinct proteomic subtypes. These were validated internally and externally, showing relevant survival stratification also in the TCGA dataset. The proteomic subtypes were independent from pathological groups with relevant stratification of progression- free and overall survival (low vs. high-risk: median 103 vs. 27 months). Tumor specificity of all proteins was highly heterogeneous across stages and subtypes. As an example, the ADC target NECTIN4 was generally overexpressed mainly in non-muscle-invasive UC. Drug repurposing revealed several new candidate drugs, each specific to different proteomic subtypes. In vitro data showed increased sensitivity by subtype in line with four out of seven representative predictions. Conclusions: Proteomic subtypes add independent prognostic information and carry predictive value for several newly identified adjuvant drug candidates. The actual tumor specificity of biomarkers and ADC targets is highly dependent on stage and subtype and calls for individualized patient-specific predictive testing. Citation Format: Franz Friedrich Dressler, Falk Diedrichs, Deema Sabtan, Sofie Hinrichs, Paulina Mackedanz, Mareile Schlotfeldt, Christoph Krisp, Martin Hennig, Hartmut Schlueter, Ulrich Wetterauer, Roman Zubarev, David Horst, Sven Perner, Philipp Wolf, Ákos Végvári. Proteomic analyses of the urothelial cancer landscape reveal highly distinct prognostic and predictive subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5138.

Sterile Water Versus Glycine in Transurethral Resection of Bladder Tumors—Immunogenic and Clinical Implications

Background and objectiveWe compared the oncologic outcomes of patients with non-muscle invasive bladder cancer (NMIBC) who underwent transurethral resection of bladder tumor (TUBRT) using sterile water vs glycine irrigation. The tumoricidal and immunogenic effects of these solutions on urothelial cancer cell lines were investigated. MethodsThe medical records of 530 consecutive patients who underwent TURBT using sterile water or glycine irrigation for NMIBC were reviewed. Recurrence and progression rates were evaluated using time dependent analyses.Bladder cancer cell lines (RT4, T24 and 5637) were treated with glycine and sterile water. Cell viability was evaluated with the XTT assay. Cell membrane calreticulin levels were evaluated with flow cytometry. Extracellular high mobility group box 1 (HMGB1) and heat shock 70 (HSP70) protein levels were evaluated using western blots. Key findings and limitationsAfter propensity score matching each study arm comprised 161 patients. Median follow-up was 13.6 months (IQR 6.2, 24.5). The 2-year recurrence free survival was significantly lower in the sterile water vs glycine group (43% vs 71%, respectively, p<0.0001). Similarly, the 2-years progression free survival was significantly lower in the sterile water vs glycine group (85% vs 94%, respectively, p<0.014). Sterile water treatment resulted in the lowest number of viable cells. Early and late immunogenic cell death markers were markedly elevated in cells treated with glycine. Conclusions and clinical implicationsSterile water compared to glycine irrigation during TURBT for NMIBC was associated with higher recurrence and progression rates. Possible explanation for these findings is the diminished immune response associated with sterile water reflected in a comparatively lesser expression of immune response inducers. Patient summaryWe compared two irrigation fluids in non–muscle-invasive bladder cancer surgery: glycine and sterile water. Glycine outperformed sterile water in cancer recurrence, possibly boosting immunogenicity over sterile water.

6]-Shogaol Induces Apoptosis of Murine Bladder Cancer Cells.

Bladder cancer is considered one of the most aggressive neoplasms due to its recurrence and progression profile, and even with the improvement in diagnosis and treatment methods, the mortality rate has not shown a declining trend in recent decades. From this perspective, the search and development of more effective and safer therapeutic alternatives are necessary. Phytochemicals are excellent sources of active principles with therapeutic potential. [6]-Shogaol is a phenolic compound extracted from the ginger rhizomes that has shown antitumor effects in a wide variety of cancer models. However, there is no record in the literature of studies reporting these effects in models of bladder cancer. Thus, this study aimed to investigate the in vitro cytotoxic and pro-apoptotic potential of [6]-Shogaol against murine bladder cancer urothelial cells (MB49). The cytotoxic effects of [6]-Shogaol on cell viability (MTT method), cell morphology (light microscopy), alteration of proliferative processes (clonogenic assay), oxidative stress pathway (levels of reactive oxygen species) and the induction of apoptotic events (flow cytometry and high-resolution epifluorescence imaging) were evaluated in murine urothelial bladder cancer cell lines (MB49), relative to non-tumor murine fibroblasts (L929). The results showed that [6]-Shogaol was able to induce concentration-dependent cytotoxic effects, which compromised cell viability, exhibiting an inhibitory concentration of 50% of cells (IC50) of 146.8 µM for MB49 tumor cells and 236.0 µM for L929 non-tumor fibroblasts. In addition to inhibiting and altering the proliferative processes if colony formation, it presented pro-apoptotic activity identified through a quantitative analysis and the observation of apoptotic phenotypes, events apparently mediated by the induction of nuclear fragmentation. The data presented suggest that [6]-Shogaol has a higher concentration-dependent cytotoxic and apoptosis-inducing potential in MB49 cells than in L929 fibroblasts. These results may contribute to the development of therapeutic alternatives for bladder cancer.

Establishment of Mouse Orthotopic Urinary Bladder Tumor Model and Its Analysis by Light and Electron Microscopy.

Mouse tumor models are an important tool in cancer research, and the orthotopic cancer cell transplantation model is the most widely used among them. Methods for establishing tumor models may differ in many ways, including the selection of cancer cell lines and the type of urinary bladder pretreatment. Here, we describe our mouse orthotopic bladder tumor model using a labeled MB49 urothelial cancer cell line and chemical pretreatment with the cationic polypeptide poly-L-lysine to traumatize the bladder epithelium. Double labeling of MB49 cancer cells by their transduction with GFP and internalization of metal nanoparticles allows the study of their implantation process from the first hours to several days after intravesical injection, as well as the analysis of developed tumors after 3weeks. Thus, our model provides a comprehensive analysis of the early and late stages of tumor development in the bladder at the light and electron microscopic level.

Affimer-mediated locking of p21-activated kinase 5 in an intermediate activation state results in kinase inhibition

Kinases are important therapeutic targets, and their inhibitors are classified according to their mechanism of action, which range from blocking ATP binding to covalent inhibition. Here, a mechanism of inhibition is highlighted by capturing p21-activated kinase 5 (PAK5) in an intermediate state of activation using an Affimer reagent that binds in the P+1 pocket. PAK5 was identified from a non-hypothesis-driven high-content imaging RNAi screen in urothelial cancer cells. Silencing of PAK5 resulted in reduced cell number, G1/S arrest, and enlargement of cells, suggesting it to be important in urothelial cancer cell line survival and proliferation. Affimer reagents were isolated to identify mechanisms of inhibition. The Affimer PAK5-Af17 recapitulated the phenotype seen with siRNA. Co-crystallization revealed that PAK5-Af17 bound in the P+1 pocket of PAK5, locking the kinase into a partial activation state. This mechanism of inhibition indicates that another class of kinase inhibitors is possible.

Abstract ND08: Discovery of FX-909, a first-in-class inverse agonist of the peroxisome proliferator-activated receptor gamma (PPARG) lineage transcription factor, to potentially treat patients with the luminal subtype of advanced urothelial cancer (UC)

Abstract Although the treatment landscape of advanced urothelial cancer (UC) has changed dynamically over the last decade, metastatic UC still has amongst the worst 5-year recurrence rate of any cancer type, highlighting the need for new therapeutic options for these patients. Analogous to breast cancer, advanced UC is a heterogeneous disease, with luminal and basal subtypes. For luminal breast cancer, small molecule targeting of the lineage-defining transcription factor estrogen receptor (ER) is a demonstrated and effective therapeutic strategy. Two-thirds of advanced UC is classified as luminal, which is characterized by overexpression of the urothelial lineage-defining transcription factor PPARG. Thus, small molecule targeting of PPARG in luminal UC may serve as a therapeutic strategy analogous to ER in luminal breast cancer. While PPARG agonists have been well studied in the context of metabolic disease, PPARG inhibitors have received far less attention. Previously reported PPARG inhibitors display minimal phenotypic activity in pre-clinical UC models, calling into question the performance of these molecules, or alternatively, the role of PPARG as a survival lineage oncogene in UC. Leveraging reconstituted, multi-component PPARG biochemical systems, we first identified the limitations of previous tool compounds and then discovered a novel, covalent lead series with unique, context-dependent electrophilic properties. These efforts lead to the discovery of FX-909, a first-in-class covalent PPARG inverse agonist with powerful repressive conformational biasing activity. FX-909 is highly potent in cells (IC50=1 nM), demonstrates high specificity for PPARG (&amp;gt;2000-fold selective over PPARA/PPARD), and elicits robust in vitro growth inhibition in UC cell lines with activated PPARG signaling. Tumor regression was observed in UMUC9 (PPARG amplification) and HT1197 (RXRAS427F hotspot mutation) xenograft models of UC with oral dosing at 1 mg/kg. Predictable, on-target and reversible pharmacology was observed at FX-909 doses above 1 mg/kg, mimicking PPARG loss-of-function mutations with notable tissue remodeling in adipose tissue and the normal urothelium. These collective findings corroborate the role of PPARG as a key UC survival oncogene and suggest that FX-909 will be an effective therapy for patients with advanced UC harboring the luminal subtype. Citation Format: Robert Sims, Jennifer A. Mertz, Jonathan E. Wilson, James E. Audia, Kaylyn E. Williamson, Yong Li, Miljan Kuljanin, Will W. Motely, Byron DeLaBarre, Michaela Bowden, Jacob I. Stuckey. Discovery of FX-909, a first-in-class inverse agonist of the peroxisome proliferator-activated receptor gamma (PPARG) lineage transcription factor, to potentially treat patients with the luminal subtype of advanced urothelial cancer (UC) [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 ND08.

EpCAM tumor specificity and proteoform patterns in urothelial cancer.

The role of the epithelial cell adhesion molecule (EpCAM) in cancer is still unclear. EpCAM cleavage through regulated intramembrane proteolysis results in fragments which interact with both oncogenic and tumor suppressive pathways. Additionally, the EpCAM molecule itself is used as a descriptive therapeutic target in urothelial cancer (UC), while data on its actual tumor specificity remain limited. Samples from diagnostic formalin-fixed paraffin-embedded (FFPE) UC tissue and fresh-frozen UC cells were immunoblotted and used for qualitative characterization of five different EpCAM fragments. These expression patterns were quantified across a cohort of 76 samples with 52 UC and 24 normal urothelial samples. Cell viability effects of the extracellular EpEX fragment were assessed in the UC cell lines T24 and HT1376. The proteolytic EpCAM fragments could be identified in clinical FFPE tissue specimens too. Neither overall nor fragment-specific EpCAM expression showed relevant tumor specificity. EpEX and its deglycosylated variant showed an inverse relationship across healthy and tumor tissue with a decrease of deglycosylated EpEX in tumors. However, extracellular EpEX did not show a relevant effect in vitro. EpCAM should not be regarded as tumor-specific in UC without patient-specific predictive testing. EpCAM fragment patterns indicate cancer-specific changes and could be involved in its complex tumor-biological role.

Abstract 4430: Sacituzumab-Interferon beta mutein fusion protein, ABN202 (anti Trop2-interferon beta mutein), is a potent therapeutics for Trop-2-positive urothelial cancer

Abstract Background: Trop2, trophoblast cell-surface antigen 2, is a type 1 transmembrane glycoprotein overexpressed in many solid tumors such as breast, lung, pancreatic, gastric, colon, urothelial cancer. Overexpression of Trop2 is associated with aggressive disease progression and poor prognosis. Recently, Trop2 targeting antibody-drug conjugate such as sacituzumab-govitecan (Trodelvy®) was approved for the treatment of triple-negative breast cancer and urothelial cancer (UC) patients. Interferon-beta (IFN-beta), a pleiotropic cytokine, can induce direct/in-direct tumor killing and activate anti-tumor immune response in tumor microenvironments. However, it is challenging to develop IFN-beta as an anti-cancer agent due to its low biophysical properties, short half-life, and the systemic toxicity. Previously, we developed IFN-beta mutein (ABN102), which showed improved stability and biophysical properties compared to wild-type IFN-beta. We hypothesis to reduce any toxicity of ABN102 by fusing with tumor targeting antibody. In this study, we generated antibody cytokine fusion protein (ABN202), anti Trop2-interferon-beta mutein, and evaluated the efficacy of ABN202 against Trop2-positive UC cell line models. Method &amp; Result: We aimed to determine the direct anti-cancer efficacy of ABN202 using Trop2-positive UC cell lines and the indirect immune cell mediated effect of ABN202 using Trop2-positive UC cell lines co-cultured with human peripheral blood mononuclear cell (PBMC). The in vivo efficacy of ABN202 was further confirmed in Trop2 positive tumor mouse model. Our results revealed that ABN202 directly inhibited proliferation and activates the apoptosis-related signaling mechanisms via Type 1 IFN signaling, showing better efficacy than either anti Trop2 antibody (sacituzumab) or ABN102 alone. ABN202 induces the activation of PBMC subsets and enhanced immune cell-mediated cancer cell killing when UC cell lines were co-cultured with PBMC. The anti-cancer efficacy of ABN202 were confirmed in Trop2-positive tumor mouse model. Conclusion: We evaluated the direct and indirect anti-cancer efficacy of ABN202 (anti Trop2-interferon-beta mutein) in Trop2-positive urothelial cancer. Our results support that ABN202 is a potent drug candidate in Trop2-positive urothelial cancer by directly inhibiting tumor growth and activating anti-cancer immune responses through type 1 IFN signaling. Citation Format: Jiyang Lee, Myeung-Ryun Seo, Heegeon Park, YeongMun Kim, Saehyung Lee, Na Young Kim, Chan Gyu Lee, Hae Min Jeong, Jun Young Choi, Young kee Shin. Sacituzumab-Interferon beta mutein fusion protein, ABN202 (anti Trop2-interferon beta mutein), is a potent therapeutics for Trop-2-positive urothelial 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 4430.

Chemotherapy with gemcitabine and cisplatin downregulates tumor expression level of nectin-4 in a syngeneic model of murine MBT2 urothelial cancer cell line and C3H mice.

Chemotherapy with gemcitabine and cisplatin downregulates tumor expression level of nectin-4 in a syngeneic model of murine MBT2 urothelial cancer cell line and C3H mice.

Enhancement of human bladder carcinoma cell chemosensitivity to Mitomycin C through quasi-monochromatic blue light (λ=453±10nm).

Human urothelial bladder carcinoma (uBC) is the second most tumor entity of the urogenital tract. As far as possible, therapy for non-muscle invasive uBC takes place as resection of the tumor tissue, followed by intravesical chemotherapy or immunotherapy. Because of the high recurrence rate of uBC, there is a need for improved efficiency in the treatment. In the present in vitro study we have evaluated a new approach to enhance the cytotoxic efficiency of Mitomycin C (MMC), which is commonly used for intravesical treatment of uBC on the relevant urothelial cancer cell line RT112. For that we used quasi-monochromatic blue light (453±10nm) at its non-toxic dose of 110J/cm2 as an additive stimulus to enhance the therapeutic efficiency of MMC (10μg/ml). We found, that blue light exposure of RT112 cells led to a very strong increase in intracellular production of reactive oxygen species (ROS) and to a significant reduction (p<0.05) of all function parameters of mitochondrial respiration, including basal activity and ATP production. Although not being toxic when used as a single impact, together with MMC blue light strongly enhanced the therapeutic efficiency of MMC in the form of significantly enhanced cytotoxicity via apoptosis and secondary necrosis. Our results clearly show that blue light, most likely due to its ability to increase intracellular ROS production and reduce mitochondrial respiration, increased the cytotoxic efficiency of MMC and therefore might represent an effective, low-side-effect, and success-enhancing therapy option in the local treatment of bladder cancer.

94 (PB084) - Novel inhibitors of the luminal lineage transcription factor peroxisome proliferator-activated receptor gamma (PPARG) durably eradicate tumors in urothelial cancer (UC) animal models

Background: Small molecule targeting of cell lineage-defining transcription factors is a demonstrated and effective therapeutic strategy in oncology, exemplified by estrogen receptor (ER) agents in luminal breast cancer. Two-thirds of advanced UC is classified as luminal and overexpression of PPARG is characteristic of this molecular subtype. Currently, there is a poor understanding of how recurrent missense mutations in PPARG and its obligate heterodimer retinoid X receptor alpha (RXRA) impact PPARG function; previous tool compounds designed to inhibit PPARG have minimal phenotypic activity in UC cell lines. Material and Methods: The PPARG inhibitor FTX-6746 was evaluated in UC cell lines including UMUC9 (PPARG amplification) and HT1197 (RXRA-S427F hotspot mutation), which activate PPARG by different genetic mechanisms. In vitro analyses included clonogenic growth assays and assessment of target gene modulation after treatment. in vivo studies were performed in NCG or Balb/C nude mice with oral administration of FTX-6746 at doses indicated below. Results: Our biochemical studies indicate that patient-derived missense mutations in PPARG and RXRA bias an active conformation of PPARG, mimicking an agonist-bound state. Addressing the limitations of previous tool compounds, we discovered novel inhibitors that drive a powerful repressive conformation of PPARG with high specificity (>100X selective over PPARA/ PPARD). This results in robust PPARG target gene silencing in cells (IC50 = 5 nM), and in vitro growth inhibition preferentially observed in cell lines with activated PPARG signaling. Tumor growth inhibition or regression was observed in two xenograft models of UC at well-tolerated oral doses with no tumor regrowth upon cessation of treatment. Treatment of UMUC9 xenograft tumors with 3, 10, 30 and 60 mg/kg twice daily of FTX-6746 resulted in up to 80% target gene suppression in tumor tissue at day 2 and up to >100% tumor growth inhibition at day 21. Similar efficacy was observed in HT1197 xenograft studies treated with 30 and 60 mg/kg twice daily of FTX-6746, with >45% target gene suppression at day 2 and 85–112% tumor growth inhibition at day 42.Tabled 1ModelDose (mg/kg)Schedule%Tumor Growth Inhibition%Target Gene Suppression (D2)UMUC93BID*205916UMUC910BID*2070NDUMUC930BID*208373UMUC930BID*2110580UMUC960BID*21108NDHT119730BID*428546HT119760BID*4211259 Open table in a new tab Conclusions: These collective results suggest that PPARG is a lineage-defining transcription factor in UC and small molecule PPARG inhibition will be an effective therapy for patients with advanced urothelial cancer harboring the luminal subtype. Conflict of interest: Ownership: All authors are shareholders in Flare Therapeutics.

Novel parameter for cancer chemosensitivity to fibroblast growth factor receptor inhibitors.

Fibroblast growth factor receptor inhibitors (FGFRi) were introduced into clinical trials on several cancer types and found to be particularly efficacious on urothelial cancer and cholangiocarcinoma. Although many enrolled patients responded well in clinical trials, there were some patients who did not respond to FGFRi even though their tumors carried the genomic changes that met the enrollment criteria. As already established, fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR) share the downstream signaling pathway of MAPK activation. Accordingly, it is conceivable that targeted inhibition of FGFR alone could leave the MAPK signaling unaffected when the signaling through EGFR is relatively strong. To test this hypothesis, we calculated here the FGFR to EGFR mRNA ratio (F/E for short) of biliary tract and urothelial cancer cell lines utilized in preclinical studies. In six biliary tract cancer cell lines, two responsive lines had an F/E of 9.5 and 9.0, whereas the F/E of four nonresponsive lines was 0.1-1.8. In 22 urothelial cancer cell lines, four of the five responsive lines showed an F/E of 2.8-4.9 (median, 3.6), whereas the F/E range of 17 nonresponsive lines was 0.01-2.7 (median, 0.6) (p=0.004). We further investigated our 47 patient-derived colorectal cancer-stem cell spheroid lines. The 18 responsive lines showed relatively high F/E (median, 16.4), whereas 29 nonresponsive lines had low F/E (median, 9.2) (p=0.0006). These results suggest that F/E is another strong predictor of responses to FGFRi that is as useful as the current genomic criteria based solely on the FGFR genomic changes.

HUS1 as a Potential Therapeutic Target in Urothelial Cancer.

Platinum-based chemotherapy is the standard of care with concern to first-line systemic therapy for metastatic disease in urothelial cancer (UC). Resistance to chemotherapy despite an initial response is linked with the ability to remove platinum-based DNA adducts and to repair chemotherapy-induced DNA lesions by various DNA repair proteins. The Rad9-Rad1-HUS1 complex that is loaded onto DNA at sites of damage is involved in checkpoint activation as well as DNA repair. Here, we addressed for the first time the potential influence of HUS1 expression in urothelial carcinogenesis (using two human basal urothelial cancer cell lines UM-UC-3 and HT1197) and its role as a potential therapeutic target for predicting responses to platinum-based chemotherapy. Specific inhibition of HUS1 expression in both cell lines was achieved by specific siRNA and validated by Western blot. In order to define the possible importance of HUS1 in the regulation of cellular proliferation, parental and resistant cells were treated with increasing concentrations of either control or HUS1 siRNA. HUS1 protein expression was observed in both human basal urothelial cancer cell lines UM-UC-3 and HT1197. In cisplatin-sensitive cells, knock-down of HUS1 inhibited cellular proliferation in the presence of cisplatin. On the contrary, knock-down of HUS1 in resistant cells did not result in a re-sensitization to cisplatin. Finally, RNAseq data from the Cancer Genome Atlas provided evidence that HUS1 expression is a significant prognostic factor for poor survival in UC patients. In summary, HUS1 may acts as an oncogene in UC and might be a key determinant of the cellular response to cisplatin-based chemotherapy.

Antitumor effect of WEE1 blockade as monotherapy or in combination with cisplatin in urothelial cancer

Overcoming cisplatin (CDDP) resistance is a major issue in urothelial cancer (UC), in which CDDP‐based chemotherapy is the first‐line treatment. WEE1, a G2/M checkpoint kinase, confers chemoresistance in response to genotoxic agents. However, the efficacy of WEE1 blockade in UC has not been reported. MK‐1775, a WEE1 inhibitor also known as AZD‐1775, blocked proliferation of UC cell lines in a dose‐dependent manner irrespective of TP53 status. MK‐1775 synergized with CDDP to block proliferation, inducing apoptosis and mitotic catastrophe in TP53‐mutant UC cells but not in TP53‐WT cells. Knocking down TP53 in TP53‐WT cells induced synergism of MK‐1775 and CDDP. In UMUC3 cell xenografts and two patient‐derived xenograft lines with MDM2 overexpression, in which the p53/cell cycle pathway was inactivated, AZD‐1775 combined with CDDP suppressed tumor growth inducing both M‐phase entry and apoptosis, whereas AZD‐1775 alone was as effective as the combination in RT4 cell xenografts. Drug susceptibility assay using an ex vivo cancer tissue‐originated spheroid system showed correlations with the in vivo efficacy of AZD‐1775 alone or combined with CDDP. We determined the feasibility of the drug susceptibility assay using spheroids established from UC surgical specimens obtained by transurethral resection. In conclusion, WEE1 is a promising therapeutic target in the treatment of UC, and a highly specific small molecule inhibitor is currently in early phase clinical trials for cancer. Differential antitumor efficacy of WEE1 blockade alone or combined with CDDP could exist according to p53/cell cycle pathway activity, which might be predictable using an ex vivo 3D primary culture system.

Single-cell RNAseq and longitudinal proteomic analysis of a novel semi-spontaneous urothelial cancer model reveals tumor cell heterogeneity and pretumoral urine protein alterations.

Bladder cancer, one of the most prevalent malignancies worldwide, remains hard to classify due to a staggering molecular complexity. Despite a plethora of diagnostic tools and therapies, it is hard to outline the key steps leading up to the transition from high-risk non–muscle-invasive bladder cancer (NMIBC) to muscle-invasive bladder cancer (MIBC). Carcinogen-induced murine models can recapitulate urothelial carcinogenesis and natural anti-tumor immunity. Herein, we have developed and profiled a novel model of progressive NMIBC based on 10 weeks of OH-BBN exposure in hepatocyte growth factor/cyclin dependent kinase 4 (R24C) (Hgf-Cdk4R24C) mice. The profiling of the model was performed by histology grading, single cell transcriptomic and proteomic analysis, while the derivation of a tumorigenic cell line was validated and used to assess in vivo anti-tumor effects in response to immunotherapy. Established NMIBC was present in females at 10 weeks post OH-BBN exposure while neoplasia was not as advanced in male mice, however all mice progressed to MIBC. Single cell RNA sequencing analysis revealed an intratumoral heterogeneity also described in the human disease trajectory. Moreover, although immune activation biomarkers were elevated in urine during carcinogen exposure, anti-programmed cell death protein 1 (anti-PD1) monotherapy did not prevent tumor progression. Furthermore, anti-PD1 immunotherapy did not control the growth of subcutaneous tumors formed by the newly derived urothelial cancer cell line. However, treatment with CpG-oligodeoxynucleotides (ODN) significantly decreased tumor volume, but only in females. In conclusion, the molecular map of this novel preclinical model of bladder cancer provides an opportunity to further investigate pharmacological therapies ahead with regards to both targeted drugs and immunotherapies to improve the strategies of how we should tackle the heterogeneous tumor microenvironment in urothelial bladder cancer to improve responses rates in the clinic.

The sustaining of fluorescence in photodynamic diagnosis after the administration of 5-aminolevulinic acid in carcinogen-induced bladder cancer orthotopic rat model and urothelial cancer cell lines

BackgroundThe administration of 5-aminolevulic acid hydrochloride (5-ALA·HCl) 3 h (range: 2–4 h) before photodynamic diagnosis (PDD) is recommended for detecting bladder tumors. However, there is insufficient evidence on the time duration for the fluorescence of PDD after oral administration of 5-ALA. We investigated the sustainability of the photodynamic effect and protoporphyrinⅨ (PpⅨ) after 5-ALA administration in a carcinogen-induced bladder tumor rat model and bladder cancer cell lines. MethodsThe carcinogen-induced bladder tumor orthotopic rat model was established by the administration of N-butyl-N-(4-hydroxybutyl) nitrosamine. ResultsRed fluorescence was visible 2–8 h after the oral administration of 5-ALA in the carcinogen-induced bladder tumor rat model. Plasma and intratissue PpⅨ (nM) progressed to a higher level at 2 h and remained almost constant 2–8 h after oral administration of 5-ALA. The peak fluorescence intensity of PpⅨ was observed 3–4 h after the administration of 5-ALA in bladder cancer cell lines. The accumulated PpⅨ remained for 4 h after the removal of 5-ALA in UMUC3 cells. It was not clearly visible 3 h after the removal of 5-ALA in MGHU3 and T24 cells. The expression level of ferrochelatase was significantly lower in UMUC3 cells than in other cells. Our findings suggest that 5-ALA-assisted PDD (ALA-PDD) can aid in detecting non-muscle-invasive bladder cancer 2–8 h after 5-ALA administration. ConclusionUrologists might not be required to make excess effort to start ALA-PDD-assisted transurethral resection of bladder tumor after the administration of 5-ALA.

Expression patterns of the immune checkpoint ligand CD276 in urothelial carcinoma

BackgroundCD276 is an immune checkpoint molecule. Elevated CD276 expression by urothelial carcinoma is associated with poor prognosis, but little is known about its expression across different tumor stages. We therefore investigated CD276 expression in bladder cancer (BC) cells and in tissue samples of BC stages from pT2 to pT4.MethodsCD276 expression was explored in 4 urothelial cancer cell lines and 4 primary normal urothelial cell populations by quantitative RT-PCR, Western blot and flow cytometry. CD276 was investigated in bladder tumors from 98 patients by immunohistochemistry using a score (0–300) incorporating both, staining intensity and area of CD276 staining. Normal appearing urothelium in the bladder of the same patients served as controls.ResultsThe urothelial carcinoma cell lines expressed significantly higher levels of CD276 on transcript (p < 0.006), total protein levels (p < 0.005), and on the cell surface (p < 0.02) when compared to normal urothelial cells. In pT2–T4 tumor tissue samples, CD276 was overexpressed (median score 185) when compared to corresponding healthy tissues from the same patients (median score 50; p < 0.001). No significant differences in CD276 expression were recorded in late, locally advanced ≥ pT3a tumors (median score 185) versus organ-confined < pT3a tumors (median score 190), but it was significantly lower in the normal urothelial tissue associated with ≥ pT3a tumors (median score 40) versus < pT3a tumors (median score 80; p < 0.05).ConclusionCD276 expression is significantly elevated in urothelial carcinoma cells in all stages but varies between individuals considerably. Reduced CD276 expression in normal urothelial cells may imply that these cells would be protected from CD276-mediated immuno therapies.

MMP-7 Serum and Tissue Levels Are Associated with Poor Survival in Platinum-Treated Bladder Cancer Patients.

Chemotherapy resistance is a main cause of therapeutic failure and death in bladder cancer. With the approval of immune checkpoint inhibitors, prediction of platinum treatment became of great clinical importance. Matrix metalloproteinase-7 (MMP-7) was shown to be involved in cisplatin resistance. Therefore, tissue and circulating MMP-7 levels were evaluated in 124 bladder cancer patients who received postoperative platinum-based chemotherapy. Tissue MMP-7 levels were analyzed by immunohistochemistry in 72 formalin-fixed, paraffin-embedded chemo-naïve tumor samples, while MMP-7 serum concentrations were determined in 132 serum samples of an independent cohort of 52 patients. MMP-7 tissue and serum levels were correlated with clinicopathological and follow-up data. MMP-7 gene expression was determined by RT-qPCR in 20 urothelial cancer cell lines and two non-malignant urothelial cell lines. MMP-7 was overexpressed in RT-112 and T-24 cells by stable transfection, to assess its functional involvement in platinum sensitivity. High MMP-7 tissue expression and pretreatment serum concentrations were independently associated with poor overall survival (tissue HR = 2.296, 95%CI = 1.235–4.268 and p = 0.009; serum HR = 2.743, 95%CI = 1.258–5.984 and p = 0.011). Therefore, MMP-7 tissue and serum analysis may help to optimize therapeutic decisions. Stable overexpression in RT-112 and T-24 cells did not affect platinum sensitivity.