Bladder Cancer Cell Lines Research Articles

Novel artesunate-metformin conjugate inhibits bladder cancer cell growth associated with Clusterin/SREBP1/FASN signaling pathway.

Bladder cancer remains the 10th most common cancer worldwide. In recent years, metformin has been found to have potential anti-bladder cancer activity while high concentration of IC50 at millimolar level is needed, which could not be reached by regular oral administration route. Thus, higher efficient agent is urgently demanded for clinically treating bladder cancer. Here, by conjugating artesunate to metformin, a novel artesunate-metformin dimer triazine derivative AM2 was designed and synthesized. The inhibitory effect of AM2 on bladder cancer cell line T24 and the mechanism underlying was determined. Anti-tumor activity of AM2 was assessed by MTT, cloning formation and wound healing assays. Decreasing effect of AM2 on lipogenesis was determined by oil red O staining. The protein expressions of Clusterin, SREBP1 and FASN in T24 cells were evaluated by Western blotting. The results show that AM2 significantly inhibited cell proliferation and migration at micromolar level, much higher than parental metformin. AM2 reduced lipogenesis and down-regulated the expressions of Clusterin, SREBP1 and FASN. These results suggest that AM2 inhibits the growth of bladder cancer cells T24 by inhibiting cellular lipogenesis associated with the Clusterin/SREBP1/FASN signaling pathway.

Exposure of Bladder Cancer Cells to Blue Light (λ = 453 nm) in the Presence of Riboflavin Synergistically Enhances the Cytotoxic Efficiency of Gemcitabine.

Non-muscle invasive bladder cancer is a common tumour in men and women. In case of resistance to the standard therapeutic agents, gemcitabine can be used as off-label instillation therapy into the bladder. To reduce potential side effects, continuous efforts are made to optimise the therapeutic potential of drugs, thereby reducing the effective dose and consequently the pharmacological burden of the medication. We recently demonstrated that it is possible to significantly increase the therapeutic efficacy of mitomycin C against a bladder carcinoma cell line by exposure to non-toxic doses of blue light (453 nm). In the present study, we investigated whether the therapeutically supportive effect of blue light can be further enhanced by the additional use of the wavelength-specific photosensitiser riboflavin. We found that the gemcitabine-induced cytotoxicity of bladder cancer cell lines (BFTC-905, SW-1710, RT-112) was significantly enhanced by non-toxic doses of blue light in the presence of riboflavin. Enhanced cytotoxicity correlated with decreased levels of mitochondrial ATP synthesis and increased lipid peroxidation was most likely the result of increased oxidative stress. Due to these properties, blue light in combination with riboflavin could represent an effective therapy option with few side effects and increase the success of local treatment of bladder cancer, whereby the dose of the chemotherapeutic agent used and thus the chemical load could be significantly reduced with similar or improved therapeutic success.

STAT3 Contributes a Favorable Response to Pembrolizumab Through IFN-γ-induced Apoptosis in Urothelial Cancer.

Pembrolizumab, a second-line therapy for platinum-refractory advanced urothelial carcinoma (UC), is needed to improve objective response rate. Hence, it is crucial to identify optimal predictive biomarkers of responses. This study aimed to clarify the predictive value and role of signal transducer and activator of transcription 3 (STAT3) in selecting patients with advanced UC who might benefit clinically from pembrolizumab therapy. We retrospectively analyzed 31 patients who received pembrolizumab therapy for UC. STAT3, phosphorylated STAT3 (p-STAT3), and PD-L1 expression were determined using tissue microarrays constructed from patient-derived specimens, and the association of these expression levels with overall survival was analyzed. We assessed the functional role of STAT3 in bladder cancer cell lines in response to interferon-gamma (IFN-γ). Patients with high STAT3 or p-STAT3 expression, and high platelet-to-lymphocyte ratio (PLR) (n=6) had a significantly shorter OS; in the other patients (n=25), high STAT3 or p-STAT3 expression was significantly associated with improved prognosis. IFN-γ-induced apoptosis was partially dependent on STAT3 in T24 cells but not in JMSU1 cells. In patients with advanced UC, STAT3 plays a key role in mediating the efficacy of pembrolizumab through apoptosis in response to IFN-γ.

Abstract P29: GSTT2 AND THE RESPONSE TO BCG IMMUNOTHERAPY

Abstract Whilst M. bovis Bacillus Calmette-Guérin (BCG) therapy remains the gold-standard for treatment of high-risk non-muscle invasive bladder cancer (BC), 30-40% of patients fail therapy, resulting in disease recurrence and progression. A better understanding of the underlying mechanisms of BCG therapy can aid in revealing key response pathways, which may lead to the discovery of new targets, and in turn new approaches to treat BC. The glutathione-S-transferase theta 2 (GSTT2) gene is a member of the GST family. Loss of GSTT2 expression has been associated with modulation of intracellular ROS and BCG survival in BC cell lines. Retrospective analysis of BC patients revealed that patients with the GSTT2B deletion responded better to fewer instillations of BCG. To understand these responses, wild-type (WT) and GSTT2-knockout (KO) mice were implanted with MB49-PSA BC cells, in subcutaneous and orthotopic settings. Once tumors were established, the mice were treated with four weekly BCG instillations, after which the subcutaneous tumors and bladders were harvested for downstream analysis. Single-cell RNA sequencing of whole-bladders was used to identify specific cell clusters within the bladder, and to analyze differential gene expression. Hmga2, Ahnak and Peak1 were found to be differentially expressed in bladders from WT and GSTT2-KO mice. These genes are known to be involved in pro- and anti-tumorigenic pathways such as epithelial-mesenchymal transition and inflammation. Additionally, quantitative real-time PCR analysis in the subcutaneous and orthotopic tumors revealed differences in the expression of immune-related genes, especially markers of immune exhaustion such as PD-L1 and CTLA-4. Flow cytometry analysis of subcutaneous tumors also revealed differences in T-cell infiltration. Thus, loss of GSTT2 may influence the response to BCG therapy, through modulating downstream signaling pathways and immune responses. Elucidating such pathways can lead to a better understanding of the mechanism of BCG and its role as a therapy for BC. Citation Format: Mugdha Patwardhan, Kane Toh, Edmund Chiong, Ratha Mahendran. GSTT2 AND THE RESPONSE TO BCG IMMUNOTHERAPY [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P29.

Integrative analysis of the bladder cancer from a cell cycle NCAM1 perspective at both single cell and bulk resolution.

Bladder cancer (BLCA) is a prevalent and deadly form of urinary cancer, and there is a need for effective therapies, particularly for muscle-invasive bladder cancer (MIBC). Cell cycle inhibitors show promise in restoring control of the cell cycle in BLCA cells, but their clinical prognosis evaluation is limited. Transcriptome and scRNA-seq data were collected from the Cancer Genome Atlas Program (TCGA)-BLCA and GSE190888 cohort, respectively. R software and the Seurat package were used for data analysis, including cell quality control, dimensionality reduction, and identification of differentially expressed genes. Genes related to the cell cycle were obtained from the genecards website, and a protein-protein interaction network analysis was performed using cytoscape software. Functional enrichment analysis, immune infiltration analysis, drug sensitivity analysis, and molecular docking were conducted using various tools and packages. BLCA cell lines were cultured and transfected for in vitro experimental assays, including RT-qPCR analysis, and CCK-8 cell viability assays. We identified 32 genes as independent risk or protective factors for BLCA prediction. Functional enrichment analysis revealed their involvement in cell cycle regulation, apoptosis, and various signaling pathways. Using these genes, we developed a nomogram for predicting BLCA survival, which displayed high prognosis stratification efficacy in BLCA patients. Four cell cycle associated key genes identified, including NCAM1, HBB, CKD6, and CTLA4. We also identified the main cell types in BLCA patients and investigated the functional differences between epithelial cells based on their expression levels of key genes. Furthermore, we observed a high positive correlative relationship between the infiltration of cancer-associated fibroblasts and the risk score value. Finally, we conducted in vitro experiments to demonstrate the suppressive role of NCAM1 in BLCA cell proliferation. These findings suggest that cell cycle associated genes could serve as potential biomarkers for predicting BLCA prognosis and may represent therapeutic targets for the development of more effective therapies. Hopefully, these findings provide valuable insights into the molecular mechanisms and potential therapeutic targets in BLCA from the perspective of cell cycle. Moreover, NCAM1 was a novel cell proliferation suppressor in the BLCA carcinogenesis.

Abstract LB437: Development of a bladder cancer-on-a-chip assay to assess the invasive potential of bladder cancer cells

Abstract Goals: The primary goal of this study was to develop a 3D functional bioassay to assess the relative invasiveness of bladder cancer cells. This model will support the testing of migrastatic drugs and investigation of the molecular mechanisms which allow for bladder cancer cell invasion to occur. Methods: Our model uses an organ-on-a-chip platform to assess bladder cancer cell invasiveness. This platform supports 3D culture of cells as well as pharmacokinetic studies. Our chips were designed to have a center channel to hold cells supported in Matrigel®, 2 adjacent side channels filled with Matrigel® only, and 2 outer media channels. Total cell and Matrigel® side channel length is 3 cm, channel height is 150 µm, and each channel width is 1 mm. Four bladder cancer cell lines (MB49, T24, J82, RT4) and cells isolated from a mouse bladder were used to develop our model. Cells were mixed with 1:1 media and Matrigel® and a total of 5,000 cells/µl introduced into the center channel. The 2 adjacent side channels were then filled with Matrigel®. The upper media channel was filled with 10% FBS cell culture media while the lower media channel was filled with 1% charcoal stripped cell culture media to thereby create a nutrient and growth factor gradient. Invasion of cells into the Matrigel®-containing side channels was assessed every 24 hours. Using the ImageXpress machine (Molecular Dynamics), we measured the furthest distance travelled by the cells. The chips were then fixed in 4% paraformaldehyde and stained using FITC-phalloidin and DAPI. Results: J82 and T24 cell lines, derived from patients with muscle invasive bladder cancer, and the MB49 cell line, a highly invasive mouse bladder cancer cell line, started invading into the Matrigel® side channels within 24 hours. T24, J82, and MB49 cells moved a maximum of 110, 87, and 170 µm by 48 hours, respectively. In contrast, RT4 cells, derived from a patient with non-invasive bladder cancer, took 48 hours to invade the Matrigel® channels and only invaded a maximum of 3 µm. Cells isolated from a mouse bladder did not invade into the Matrigel® side channels but survived within the chips for over 20 days. Staining of chips with DAPI and FITC-phalloidin allowed for clear visualization of cells and the actin cytoskeleton and demonstrated that immunostaining of cells within chips is possible. Conclusions: Our chip model allows for studying the invasiveness of bladder cancer cells and immunostaining experiments which can be used to assess the molecular mechanisms which drive invasion. It can also support the growth and assessment of primary cells. This model has the potential to improve bladder cancer patient treatments and outcomes by providing a physiologically relevant system to test new and existing drug combinations and to better understand the molecular mechanisms which drive bladder cancer cell invasion. Citation Format: Desiree Ewell, Nita Vue, Sakib Moinuddin, Tanoy Sarkar, Fakhrul Ahsan, Ruth L. Vinall. Development of a bladder cancer-on-a-chip assay to assess the invasive potential of bladder cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB437.

CircUGGT2 facilitates progression and cisplatin resistance of bladder cancer through nonhomologous end-joining pathway

The development of resistance to cisplatin (CDDP) in bladder cancer presents a notable obstacle, with indications pointing to the substantial role of circular RNAs (circRNAs) in this resistance. Nevertheless, the precise mechanisms through which circRNAs govern resistance are not yet fully understood. Our findings demonstrate that circUGGT2 is significantly upregulated in bladder cancer, facilitating cancer cell migration and invasion. Additionally, our analysis of eighty patient outcomes revealed a negative correlation between circUGGT2 expression levels and prognosis. Using circRNA pull-down assays, mass spectrometry analyses, and RNA Immunoprecipitation (RIP), it was shown that circUGGT2 interacts with the KU heterodimer, consisting of KU70 and KU80. Both KU70 and KU80 are critical components of the non-homologous end joining (NHEJ) pathway, which plays a role in CDDP resistance. Flow cytometry was utilized in this study to illustrate the impact of circUGGT2 on the sensitivity of bladder cancer cell lines to CDDP through its interaction with KU70 and KU80. Additionally, a reduction in the levels of DNA repair factors associated with the NHEJ pathway, such as KU70, KU80, DNA-PKcs, and XRCC4, was observed in chromatin of bladder cancer cells following circUGGT2 knockdown post-CDDP treatment, while the levels of DNA repair factors in total cellular proteins remained constant. Thus, the promotion of CDDP resistance by circUGGT2 is attributed to its facilitation of repair factor recruitment to DNA breaks via interaction with the KU heterodimer. Furthermore, our study demonstrated that knockdown of circUGGT2 resulted in reduced levels of γH2AX, a marker of DNA damage response, in CDDP-treated bladder cancer cells, implicating circUGGT2 in the NHEJ pathway for DNA repair.

Silencing the Mitochondrial Gatekeeper VDAC1 as a Potential Treatment for Bladder Cancer.

The strategy for treating bladder cancer (BC) depends on whether there is muscle invasion or not, with the latter mostly treated with intravesical therapy, such as with bacillus Calmette-Guérin (BCG). However, BCG treatment is unsuccessful in 70% of patients, who are then subjected to radical cystectomy. Although immune-checkpoint inhibitors have been approved as a second-line therapy for a subset of BC patients, these have failed to meet primary endpoints in clinical trials. Thus, it is crucial to find a new treatment. The mitochondrial gatekeeper protein, the voltage-dependent anion channel 1 (VDAC1), mediates metabolic crosstalk between the mitochondria and cytosol and is involved in apoptosis. It is overexpressed in many cancer types, as shown here for BC, pointing to its significance in high-energy-demanding cancer cells. The BC cell lines UM-UC3 and HTB-5 express high VDAC1 levels compared to other cancer cell lines. VDAC1 silencing in these cells using siRNA that recognizes both human and mouse VDAC1 (si-m/hVDAC1-B) reduces cell viability, mitochondria membrane potential, and cellular ATP levels. Here, we used two BC mouse models: subcutaneous UM-UC3 cells and chemically induced BC using the carcinogen N-Butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Subcutaneous UM-UC3-derived tumors treated with si-m/hVDAC1 showed inhibited tumor growth and reprogrammed metabolism, as reflected in the reduced expression of metabolism-related proteins, including Glut1, hexokinase, citrate synthase, complex-IV, and ATP synthase, suggesting reduced metabolic activity. Furthermore, si-m/hVDAC1-B reduced the expression levels of cancer-stem-cell-related proteins (cytokeratin-14, ALDH1a), modifying the tumor microenvironment, including decreased angiogenesis, extracellular matrix, tumor-associated macrophages, and inhibited epithelial-mesenchymal transition. The BBN-induced BC mouse model showed a clear carcinoma, with damaged bladder morphology and muscle-invasive tumors. Treatment with si-m/hVDAC1-B encapsulated in PLGA-PEI nanoparticles that were administered intravesically directly to the bladder showed a decreased tumor area and less bladder morphology destruction and muscle invasion. Overall, the obtained results point to the potential of si-m/hVDAC1-B as a possible therapeutic tool for treating bladder cancer.

MANNosylation of Mesoporous Silica Nanoparticles Modifies TLR4 Localization and NF-κB Translocation in T24 Bladder Cancer Cells.

D-mannose is widely used as non-antibiotic treatment for bacterial urinary tract infections. This application is based on a well-studied mechanism of binding to the type 1 bacterial pili and, therefore, blocking bacteria adhesion to the uroepithelial cells. To implement D-mannose into carrier systems, the mechanism of action of the sugar in the bladder environment is also relevant and requires investigation. Herein, two different MANNosylation strategies using mesoporous silica nanoparticles (MSNs) are described. The impact of different chemical linkers on bacterial adhesion and bladder cell response is studied via confocal microscopy imaging of the MSN interactions with the respective organisms. Cytotoxicity is assessed and the expression of Toll-like receptor 4 (TLR4) and caveolin-1 (CAV-1), in the presence or absence of simulated infection with bacterial lipopolysaccharide(LPS), is evaluated using the human urinary bladder cancer cell line T24. Further, localisation of the transcription factor NF-κB due to the MANNosylated materials is examined over time. The results show that MANNosylation modifies bacterial adhesion to the nanomaterials and significantly affects TLR4, caveolin-1, and NF-κB in bladder cells. These elements are essential components of the inflammatory cascade/pathogens response during urinary tract infections. These findings demonstrate that MANNosylation is a versatile tool to design hybrid nanocarriers for targeted biomedical applications.

Evaluating a combination treatment of NK cells and reovirus against bladder cancer cells using an in vitro assay to simulate intravesical therapy

Intravesical treatment using either reovirus or natural killer (NK) cells serves as an efficient strategy for the treatment of bladder cancer cells (BCCs); however, corresponding monotherapies have often shown modest cytotoxicity. The potential of a locoregional combination using high-dose reovirus and NK cell therapy in an intravesical approach has not yet been studied. In this study, we evaluated the effectiveness of reoviruses and expanded NK cells (eNK) as potential strategies for the treatment of bladder cancer. The anti-tumor effects of mono-treatment with reovirus type 3 Dearing strain (RC402 and RP116) and in combination with interleukin (IL)-18/-21-pretreated eNK cells were investigated on BCC lines (5637, HT-1376, and 253J-BV) using intravesical therapy to simulate in vitro model. RP116 and IL-18/-21-pretreated eNK cells exhibited effective cytotoxicity against grade 1 carcinoma (5637 cells) when used alone, but not against HT-1376 (grade 2 carcinoma) and 253J-BV cells (derived from a metastatic site). Notably, combining RP116 with IL-18/-21-pretreated eNK cells displayed effective cytotoxicity against both HT-1376 and 253J-BV cells. Our findings underscore the potential of a combination therapy using reoviruses and NK cells as a promising strategy for treating bladder cancer.

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.

CircITGA7 regulates malignant phenotypes in bladder cancer cells via targeting miR-330-3p/KLF10 axis.

Bladder cancer (BCa) is one of the common malignancies. Circular RNAs (circRNAs) play regulatory roles in cancer progression. CircITGA7 is a circRNA generated from several exons of ITGA7. The potential role of circITGA7 in BCa remains unknown and needs to be explored. Quantitative real time polymerase chain reaction (qRT-PCR) was used to assess circITGA7 and miR-330-3p expression in BCa tissues and cell lines. Kaplan-Meier analysis was used to evaluate the overall survival of these BCa patients. The biological function of circITGA7 was examined by overexpression of circITGA7 using CCK-8, EdU, wound-healing, and Transwell assays. Xenograft assay was performed to further validate the in vitro results. To explore the mechanism of circITGA7, luciferase reporter, RNA pull-down, fluorescence in situ hybridization (FISH) assays were employed to examine the binding interaction among circITGA7, miR-330-3p and kruppel-like factor 10 (KLF10). Western blot was used to study the protein levels of KLF10.CircITGA7 was downregulated in BCa tissues and cell lines and indicated longer overall survival. Moreover, circITGA7 restricted cell proliferation, migration and invasion of BCa through negatively regulating miR-330-3p. The in vivo model showed that circITGA7 influenced the tumor growth. Besides, the overexpression of miR-330-3p promoted cell progression by directly targeting KLF10. Mechanistically, circITGA7 inhibited BCa progression by activating KLF10 via targeting miR-330-3p.CircITGA7 alleviates BCa cell progression via circITGA7/hsa-miR-330-3p/KLF10 axis, which may provide novel therapeutic targets for BCa.

Abstract 1783: Understanding lipogenesis in bladder cancer

Abstract Cancer cells are known to have different metabolic needs for growth and survival and by understanding these demands of individual cancers, targeted novel therapies may be developed. Lipogenesis and ß-oxidation serve to balance lipid levels in the cell. Lipogenesis is rate limited by a series of reactions that include enzymes fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC1) that facilitate lipid formation; whereas ß-oxidation is rate limited by the transporter carnitine palmitoyltransferase 1 (CPT1) and the enzyme thiolase that catalyzes the final step of the ß-oxidation cycle. Many cancers are dependent on lipogenesis, but the role of these factors in BCa is poorly defined. The Cancer Genome Atlas was used to assess levels of relevant metabolic proteins in normal and cancerous BCa tissue, and showed FASN levels were elevated in BCa tissue and were associated with worse survival. The purpose of this project is to better understand the metabolic demands of bladder cancer (BCa) cell lines, and we hypothesized lipogenesis is a major metabolic pathway for BCa cell growth. T24, HTB-5, and HTB-9 BCa cell lines were used to evaluate the role of metabolism. CPT1 was inhibited with etomoxir, thiolase with trimetazidine, FASN with cerulenin, and ACC1 with 5-(Tetradecyloxy)-2-furoic acid (TOFA). Cell viability was assessed at 48 and 72 hours with an enzymatic activity assay measuring ß-hexosaminidase activity as a surrogate for cell proliferation. The IC50 (concentration of a drug to reduce cell proliferation by 50%) was calculated from this data. At 48 hours, cerulenin-treated cells had an IC50 of 11.80 µM, 13.28 µM, 18.31 µM for HTB-9, T24, and HTB-5 respectively. At 48 hours, TOFA-treated cells had an IC50 of 64.25 µM, 59.29 µM, 32.03 µM for HTB-9, T24, and HTB-5 respectively. Cellular proliferation was not inhibited by CPT1 or trimetazidine at enzymatic IC50 concentrations consistent with their known levels of efficacy. When adding the lipid palmitate (20µM) to TOFA-treated cells, it appeared to mediate a rescue of cell proliferation almost to control, although statistical significance was not achieved. Crystal violet assays were performed to assess long-term cell viability. There was visible reduction in colony formation in a dose-dependent manner at 5 µM and 10 µM cerulenin in T24 cells at 14 days of culture, and there were similar results in HTB-9 cells treated with 20 µM and 40 µM TOFA at 17 days. In both cerulenin and TOFA-treated cells, there was elevated cleaved caspase-3 protein expression, indicating initiation of apoptosis. In conclusion, inhibition of lipogenesis in BCa cell lines reduces cell viability by reducing proliferation and inducing apoptosis whereas inhibitors of ß-oxidation did not produce the same effect at relevant concentrations. These data indicate lipogenesis is a key metabolic pathway for BCa cell growth. Citation Format: Juliann Leak, David Matye, Erika Abbott, Benjamin Woolbright, John A. Taylor. Understanding lipogenesis in bladder cancer [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 1783.

Abstract 3329: Development of HM-001 as a therapeutic drug for non-muscle invasive bladder cancer

Abstract HM-001 is a drug containing sodium chlorite as the active ingredient that is being developed as a drug for non-muscle invasive bladder cancer (NMIBC), and is currently undergoing physician-led clinical trials. It has been discovered that sodium chlorite generates radicals in an acidic environment, and phosphatidylserine on the surface of tumor cells acts as a Lewis acid to generate radicals. HM-001, like other anticancer drugs and BCG, is intended to be injected into the bladder, retained, and then excreted. GLP studies using the same administration method has been completed, and no toxic changes have been observed in human trial doses. The efficacy of HM-001 against NMIBC was evaluated using an orthotopic transplantation model of UM-UC-3, a bladder cancer cell line. In the model, cells were transplanted into the bladder of SCID mouse after epithelial removal with trypsin, 600, 800, 1,600, and 3,200 ppm of HM-001 were administered once a week, and the weight of the excised bladder was calculated. After 4 weeks, the tumor weight was calculated and the tumor weight suppression rate in the control group was evaluated. As a result, the medicinal efficacy was confirmed at concentrations of 800ppm or higher. On the other hand, the UM-UC-3 model is a commonly used model, but it mimics CIS (carcinoma in situ) and can only partially mimic NMIBC. That is, other models are needed to evaluate efficacy for low- and high-grade NMIBC other than CIS. Therefore, we established high-grade and low-grade PDX and evaluated the effectiveness of HM-001 against low- and high-grade PDX through ex vivo testing. First, patient-derived tissue was transplanted into SCID mice, allowed to grow, and then removed. After extraction, they were cut into 2 mm3 pieces, exposed to HM-001 at 800, 1600, and 3200 ppm for 2 hours, and then transplanted into SCID mice. As a result of comparing the tumor size after transplantation with the control group, a dose-dependent tumor regression effect was confirmed in high-grade and low-grade PDX. NMIBC is divided into low-, medium-, and high-risk categories, with different treatment methods and drugs used for each. In particular, low-grade forms are restricted to low- and intermediate-risk groups. The results of this study show that HM-001 is effective not only for high-risk (including CIS) NMIBC but also for low- and intermediate-risk (low-grade) NMIBC. Citation Format: Shinji Mima, Monta Sakaki, Noriaki Kiya, Atsunari Kawashima, Norio Nonomura, Chihaya Kakinuma. Development of HM-001 as a therapeutic drug for non-muscle invasive bladder cancer [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 3329.

Abstract 4696: ERBB2 signaling and inhibition in bladder cancer

Abstract The role of human epidermal growth factor receptor-2 (HER2) protein and the inhibition of its oncogenic signaling pathway, ERBB2, is well defined and found to be beneficial in combination with standard chemotherapies in breast and certain gastro-intestinal cancers. Targeting the ERBB2 pathway has had unclear or inconsistent results in early trials in bladder cancer (BLCA) and the efficacy of its combination with cisplatin, a standard BLCA chemotherapy, is not known. In this study, we identify the transcriptomic oncogenic signatures that correlate with ERBB2 signaling in BLCA, explore how HER2 expression in BLCA cell lines correlates with treatment response in vitro, and evaluate the potential of ERBB2 inhibition in combination with cisplatin for BLCA. We analyzed the tumor transcriptome from the Cancer Genome Atlas (TCGA) study of BLCA with single sample Gene Set Enrichment Analyses (ssGSEA) for Hallmark and Oncogenic gene sets. We performed multiple Pearson correlation analyses of HER2 protein levels and ERBB2 signaling with other signaling pathways in the TCGA BLCA tumors and adjusted the significance for multiple comparisons using the Benjamini-Hochberg method. Immunoblotting was used to assess HER2 protein levels across a panel of bladder cancer cell lines. We then assessed cell viability and colony formation upon exposure to the specific ERBB2 inhibitor, tucatinib. Synergy between cisplatin and tucatinib in BLCA cell lines was evaluated using the Chou-Talalay method. In the TCGA BLCA dataset, HER2 protein positively correlates with ERBB2 signaling with a Pearson correlation coefficient of 0.45 and an adjusted p-value of 1.73E-17. ERBB2 signaling has multiple significant positive and negative correlations. ERBB2 signaling negatively correlates with the DNA repair gene set with a Pearson coefficient of -0.5 and an adjusted p-value of 1.40E-22. HER2 protein expression varies greatly between bladder cancer cell lines: HT-1197 and UMUC3 have lower HER2 expression, with HT-1376, T24, RT4, 5637, and SW780 showing higher HER2 expression. HT-1197 and RT4 had the lowest IC50s for tucatinib and showed a strong response to low doses of tucatinib in the colony formation assay. Cisplatin and tucatinib have synergetic growth inhibition (combination index <1) at low concentration levels in the HT-1197 and SW780 cell lines. Multiple oncogenic pathways coexist with ERBB2 signaling in BLCA. The varied response to specific ERBB2 inhibition and the lack of correlation of the response with HER2 protein level in cell lines alludes to alternative oncogenic pathways. A strong negative correlation of ERBB2 signaling with the DNA response pathway in the TCGA BLCA dataset, combined with preclinical evidence of synergy between tucatinib and cisplatin, indicates a potential for development of the combination as a clinical treatment strategy and warrants further study. Citation Format: Constance Caparas-Spaugy, Chris Stubben, Ken Boucher, Bingjian Feng, Aaron Atkinson, David Nix, Bradley Cairns, Sumati Gupta. ERBB2 signaling and inhibition in bladder cancer [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 4696.

Abstract 6405: Identification of molecular targets in bladder cancer variants using single-cell analysis

Abstract Introduction and objectives: Variant subtypes in bladder cancer, also known as histologic variants, are clinically aggressive tumors associated with poor prognosis. The rarity of these tumors has made molecular characterization elusive using bulk transcriptional profiling. The aim of this study was to use single cell RNA sequencing to identify molecular features associated with variant subtypes that could be potential targets for therapy. Methods: Fresh tissue from bladder cancer patients undergoing surgery at our institution was sequenced using a bead-based single-cell RNA sequencing platform (Seq-Well) to generate an atlas of 9 tumors containing variants (micropapillary, nested, squamous differentiation, pleomorphic giant-cell like, plasmacytoid, small cell) and 3 tumors with pure urothelial carcinoma (UC) histology. Pathologic diagnoses were independently confirmed. Analysis was performed using the Seurat package in R Studio. Immunostaining validation was performed on a separately banked cohort. Bulk RNA sequencing data and clinical data were extracted and analyzed from The Cancer Genome Atlas (TCGA) database. Chimeric Antigen Receptor (CAR) T cells targeting TM4SF1 were generated by lentiviral transduction of primary human T cells and tested against publicly available bladder cancer cell lines. Results: Variant tumors were enriched in TM4SF1, a surface molecule that we demonstrate to be susceptible to CAR T therapy in vitro. Variants also share a cell state characterized by highly specific expression of MUC16 (CA125), which is enriched in metastatic sites, harbors transcriptional hallmarks of epithelial-mesenchymal transition and luminal-basal plasticity, and is associated with poor survival and resistance to chemotherapy. Finally, we find evidence of transcriptional mimicry between variants and similar appearing non-urothelial cells (e.g. plasmacytoid:plasma cell), suggesting common pathways between distinct cell types that could be exploited. Conclusion: We have identified several targetable molecular features within variant bladder cancer subtypes. These findings set a critical starting point for future therapeutic investigation. Funding: California Urology Foundation (HY)Conflicts of interest: noneKeywords: Single cell analysis, bladder cancer, variants, genomics, biomarkers Citation Format: Heiko Yang, Hanbing Song, Paul Allegakoen, Kevin Lu, Elizabeth Yip, Keliana Hui, Kevin Chang, Corynn Kasap, Janae Gayle, Bradley Stohr, Arun Wiita, Chien-Kuang C. Ding, Maxwell V. Meng, Jonathan Chou, Sima P. Porten, Franklin W. Huang. Identification of molecular targets in bladder cancer variants using single-cell analysis [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 6405.

Abstract 4086: ABN202 (anti-Trop-2-interferon-beta mutein): A potent antibody-cytokine fusion protein for the treatment of Trop-2 positive solid tumors

Abstract Trop-2, trophoblast cell-surface antigen 2, is a type 1 transmembrane glycoprotein overexpressed in many solid cancers, including breast, lung, pancreatic, bile duct and bladder cancer. Overexpression of Trop-2 in cancer patients is associated with disease progression and poor prognosis. The antibody-drug conjugate (ADC) targeting Trop-2, Sacituzumab-govitecan (Trodelvy®), is approved for patients with triple-negative breast cancer (TNBC) and bladder cancer. However, Trop-2 targeting ADCs exhibit a high frequency of grade 3/4 adverse events and a short duration of response. Therefore, there is an unmet medical need for new treatment strategies beyond ADCs. In a previous study, we designed ABN202 (αTrop-2) to comprise a Trop-2 targeting antibody (Sacituzumab) and IFN-β mutein (ABN102) for the Trop2-positive tumor-specific delivery of ABN102. We confirmed anti-cancer activities of ABN202 against Trop-2 positive bladder cancer. In this study, we evaluated in vitro and in vivo anti-cancer efficacy of ABN202 (αTrop-2) in Trop-2 positive TNBC, bile duct cancer and bladder cancer cell lines. To identify response biomarkers for ABN202 (αTrop-2), we analyzed cell lines exhibiting both response and non-response to ABN202 (αTrop-2). In conclusion, ABN202 (αTrop-2) demonstrated potent anti-cancer efficacy compared to Trodelvy®. Our results support ABN202 (αTrop-2) as a promising drug candidate against Trop2-positive solid tumors. Citation Format: Hee Geon Park, Hyun Kyung Lee, Myeung Ryun Seo, Daa Eun Kim, Sang Beom Bang, Ji Yang Lee, Sung Youl Hong, Kyoung Song, Chan Gyu Lee, Hae Min Jeong, Sae Hyung Lee, Na Young Kim, Jun Young Choi, Young Kee Shin. ABN202 (anti-Trop-2-interferon-beta mutein): A potent antibody-cytokine fusion protein for the treatment of Trop-2 positive solid tumors [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 4086.

Abstract 5272: APL-1202 enhances anti-tumor immune response through induction of cellular stress signaling and immunogenic cell death pathway in cancer cells

Abstract Introduction: Treatment approach combining cancer cell targeted therapy and immunotherapy is an effective strategy to trigger robust tumor-specific immune responses. The aim of this study is to determine the impact of APL-1202, a clinical-stage drug candidate (NCT04813107), on cellular stress-driven immunogenic outcomes in bladder cancer cells. Methods: RNA-seq analysis was performed using bladder cancer and endothelial cell lines (A56, J82, T24, HUVEC) treated with APL-1202. Key determinants of immunogenic cell death pathway were measured by cell-surface translocation of calreticulin (flow cytometry), extracellular ATP release assay (bioluminescence) and HMGB1 secretion (ELISA) in the supernatants of cancer cells after APL-1202 treatment. Effects on the innate immune effector function was measured by flow cytometry-based phagocytosis assay consisting of Far-Red dye-stained, pre-treated bladder cancer cell lines (UMUC3, T24) in coculture with THP1-derived macrophages/immature dendritic cells or human monocyte-derived dendritic cells. In vivo, tumor end-point immune cell analysis, tumor weight and mouse survival were compared in chemically induced (BBN: N-butyl-N-(4-hydroxybutyl)-nitrosamine) orthotopic bladder cancer mice treated with APL-1202 and anti-PD1 antibody. Results: Pathway analysis of RNA-seq data from APL-1202 treated cells suggested upregulation of cellular stress-related gene signatures (oxidative stress, autophagy, P53) and pro-inflammatory responses (IL-6, IL-8, HMGB1 signaling). Conversely, downregulation of cell cycle (E2F targets, G2-M checkpoint) and IL-10 signaling suggested increased genomic stress and inflammatory switching in the treated cancer cells. Acute exposure to APL-1202 increased cell-surface translocation of calreticulin as well as extracellular release of ATP and HMGB1 in the treated T24 and UMUC3 cells. Higher percentages of phagocytic activities were detected in both THP-1-derived macrophages/immature dendritic cells and human monocyte-derived dendritic cells after coculture with APL-1202 treated T24 and UMUC3 cells compared to coculture with DMSO treated control cells. Immune phenotyping in tumors derived from BBN bladder cancer mouse model revealed increased infiltration of NK cells and CD8+ T cells. Furthermore, APL-1202 enhanced the anti-tumor effects of a therapeutic anti-PD1 antibody in mice as reflected by significantly decreased tumor weights and increased survival in a combination group with APL-1202 treatment compared to the anti-PD-1 antibody alone treatment group. Conclusion: APL-1202 may improve the efficacy of immune-checkpoint blockade therapies in bladder cancer patients by enhancing cancer cell immunogenicity and subsequent anti-tumor effector immune cell processes, particularly in tumors with deficits in antigen-specific immunity. Citation Format: Rakesh BAM, Jingmin Guan, Neetha Nanoth Vellichirammal, Murli Manohar, David Mulholland, John Sfakianos, Qiaoling Sun, Zuoan Yi, Alice Chen. APL-1202 enhances anti-tumor immune response through induction of cellular stress signaling and immunogenic cell death pathway in cancer cells [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 5272.

Abstract 5726: The potential anti-cancer activity of dual TTK/PLK1 inhibitor, BAL0891, in bladder cancer

Abstract Background: BAL0891 is a novel dual inhibitor of threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1) which affects mitotic spindle assembly checkpoint integrity resulting in aberrant mitotic progression of cancer cells. Since unlike other organs, bladder urothelium is highly regenerative in certain circumstances, there are high chances of cell cycle inhibitors to have anti-cancer activity over bladder cancer. In this study, we investigated the therapeutic potential of BAL0891 in bladder cancer compared to single TTK or PLK1 inhibitor and discovered the best therapeutic combination partner for BAL0891. Methods: We performed meta-analysis of the mRNA expression levels of bladder cancer using Gene Expression Profiling Interactive Analysis 2 (GEPIA2). Representative bladder cancer cell lines (253J, 253J-BV, J82, RT4, T24, J82, HT1197, and HT1376) were treated with the dual protein kinase inhibitors, BAL0891, in comparison with TTK inhibitor (BAY1217389) or PLK1 inhibitor (onvansertib). BAL0891 was combined with CDK4/6 inhibitor, another cell cycle inhibitor working at different point from BAL0891. Cell viability was assessed using CCK-8 assay during 72 hours after treatment. Expression levels of TTK and PLK1 were measured by immunoblotting. Cell cycle analysis and cell apoptosis detection were performed on T24 cell. Results: The mRNA expression levels of both TTK (16.7 times) and PLK1 (10.0 times) were significantly upregulated only in bladder cancers compared to normal bladder tissues (P<0.05). Compared to TTK or PLK1 inhibitor, BAL0891 was sensitive in 75% of bladder cancer cell lines (IC50 <0.1 uM) and significantly reduced proliferation of bladder cancer cell lines depending on the dosage. TTK and PLK1 expression levels of cancer cells were associated with the sensitivity to BAL0891. BAL0891 significantly induced necrosis and increased in polyploidy and G2/M arrest in T24 cell. The anti-cancer activity of BAL0891 was further enhanced in certain cell lines (RT4, and J82) by combination of CDK4/6 inhibitor. Conclusion: This is the first study to suggest the potent anti-cancer activity of BAL0891 in bladder cancer. BAL0891 effectively worked on bladder cancer by two tracks which not only induced G2/M arrest but also increased in polyploidy. Furthermore, BAL0891 in combination with CDK4/6 inhibitor promoted anti-cancer effects. Lastly, this study suggests the use of TTK and PLK1 as the predictive biomarker for BAL0891. These data support further investigation of BAL0891 for the treatment of bladder cancer patients. Citation Format: Jee Soo Park, Ji-eun Lee, Myung Eun Lee, Jongchan Kim, Won Sik Jang, Jae Jung Lee, Jun Seung Lee, Minkyung Kang, Won Sik Ham. The potential anti-cancer activity of dual TTK/PLK1 inhibitor, BAL0891, in bladder cancer [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 5726.

Abstract 1644: Exploring the role of a TERT intronic tandem repeat in regulating cell proliferative responses to environmental factors and cancer risk

Abstract The chr 5p15.33 genomic locus encoding telomerase reverse transcriptase (TERT) is structurally complex, with several highly polymorphic intronic variable number tandem repeats (VNTRs). A germline VNTR located in TERT intron 6 (VNTR6-1, 38 bp repeat unit) has previously been associated with TERT alternative splicing but its potential role in regulating cellular functions and disease risk is unclear. To functionally characterize VNTR6-1, we deleted this region (1-2 kb) using CRISPR/Cas9 in UMUC3 (bladder cancer cell line). Cell count growth tracking of parental and VNTR6-1 knockout (VNTR6-1 KO) cells via automated live-cell monitoring revealed different relative growth rates under serum starvation vs. normal conditions, suggesting that VNTR6-1 might be sensitive to growth factors present in culture media. Evaluation of growth in media with full vs. charcoal-stripped (CS) serum, showed significant differences, with higher cell counts in parental vs. VNTR6-1 KO in CS-serum (P=4.1e-3), parental vs. parental in full (P=1.57e-4) or CS-serum (P=4.76e-2), but not in parental vs. VNTR6-1 KO in full serum (P=0.378). After 5-6 days of growth, cells in CS-serum also rapidly began outgrowing cells in full serum. We observed that VNTR6-1 KO dampened the outgrowth response in cells lacking growth factors in CS-serum. Proliferation-specific growth assays tracking the dilution of an incorporated dye in cells by flow cytometry further showed that VNTR6-1 KO leads to more pronounced proliferation differences due to the presence or absence of serum-supplied factors. Overall, cell growth patterns appear to be sensitive to serum in interaction with VNTR6-1, suggesting a potential VNTR6-1-dependent response to extracellular signaling. In human populations, we have identified two VNTR6-1 groups: Short (24-27 copies) and Long (40.5-66.5 copies). In the PLCO dataset (n=100,445 cancer cases and controls), logistic regression showed that VNTR6-1-Long group was associated with a decreased risk in male-prevalent cancers such as bladder and prostate, but an increased risk in female-prevalent cancers such as breast, endometrial and ovarian. These results support a link between the TERT region, and potentially VNTR6-1, with hormone signaling and cancer risk. Motif analysis within VNTR6-1 predicted binding sites for several transcription factors, including those associated with development and cell growth. Together, these results suggest that VNTR6-1 may be involved in regulating cell growth, potentially by facilitating responses to extracellular signaling pathways. Additionally, given the location of VNTR6-1 within a multi-cancer GWAS region, our findings provide functional context for the role of this polymorphic repeat in differential risk and outcomes in certain cancers. Citation Format: Michelle Ho, Oscar Florez-Vargas, Maxwell Hogshead, Brenen Papenberg, Chia Han Lee, Chi Zhang, Kaitlin Forsythe, Wusheng Yan, Raj Chari, Ludmila Prokunina-Olsson. Exploring the role of a TERT intronic tandem repeat in regulating cell proliferative responses to environmental factors and cancer risk [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 1644.