Urothelial Carcinoma Of The Bladder Cells Research Articles

Reinvestigating the clinical relevance of the m6A writer METTL3 in urothelial carcinoma of the bladder

METTL3 is the major writer of N6-Methyladenosine (m6A) and has been associated with controversial roles in cancer. This is best illustrated in urothelial carcinoma of the bladder (UCB), where METTL3 was described to have both oncogenic and tumor-suppressive functions. Here, we reinvestigated the role of METTL3 in UCB. METTL3 knockout reduced the oncogenic phenotype and m6A levels of UCB cell lines. However, complete depletion of METTL3/m6A was not achieved due to selection of cells expressing alternative METTL3 isoforms. Systematic vulnerability and inhibitor response analyses suggested that uroepithelial cells depend on METTL3 for viability. Furthermore, expression and survival analyses of clinical data revealed a complex role for METTL3 in UCB, with decreased m6A mRNA levels in UCB tumors. Our results suggest that METTL3 expression may be a suitable diagnostic UCB biomarker, as the enzyme promotes UCB formation. However, the suitability of the enzyme as a therapeutic target should be evaluated carefully.

LncRNA MIR4435-2HG drives cancer progression by modulating cell cycle regulators and mTOR signaling in stroma-enriched subtypes of urothelial carcinoma of the bladder

BackgroundThe risk for recurrence and metastasis after treatment for urothelial carcinoma of the bladder (UCB) is high. Therefore, identifying efficient prognostic markers and novel therapeutic targets is urgently needed. Several long noncoding RNAs (lncRNAs) have been reported to be correlated with UCB progression. In this study, we found that the subtype-specific lncRNA MIR4435-2 host gene (MIR4435-2HG) plays a novel oncogenic role in UCB.MethodsRNA-Seq data of TCGA/BLCA were analyzed. The expression of MIR4435-2HG was measured by qRT-PCR in 16 pairs of bladder cancer tissues and adjacent normal tissues. The clinical relecance of MIR4435-2HG was validated via in situ hybridization performed on an in-house cohort of 116 UCB patient samples. RNA pull-down followed by mass spectrometry was performed to identify MIR4435-2HG-binding proteins. To identify signaling pathways involved in MIR4435-2HG activity, comprehensive in vitro and in vivo studies and RNA-Seq assays were performed using UCB cells in which MIR4435-2HG expression was knocked down or exogenously overexpressed. In addition, we performed RNA immunoprecipitation and Western blot analyses to validate the identified MIR4435-2HG-binding proteins and to determine the molecular mechanisms by which MIR4435-2HG promotes UCB progression.ResultsWe found that MIR4435-2HG was significantly upregulated in the stromal-enriched subtype of UCB. Increased MIR4435-2HG expression was positively correlated with a high histological grade, advanced T stages, larger tumors, lymph node metastasis and a poor prognosis. In vitro experiments revealed that MIR4435-2HG expression silencing suppressed cell proliferation and induced apoptosis. Inhibition of MIR4434-2HG delayed xenograft tumor growth, while MIR4435-2HG overexpression reversed the MIR4435-2HG silencing-induced inhibition of UCB tumor phenotype acquisition. Mechanistically, we found that MIR4435-2HG positively regulated the expression of a variety of cell cycle regulators, including BRCA2 and CCND1. Knocking down MIR4435-2HG increased the sensitivity of tumor cells to the VEGFR inhibitor cediranib. Furthermore, we found that MIR4435-2HG regulated mTOR signaling and epithelial-mesenchymal transition (EMT) signaling pathways by modulating the phosphorylation of mTOR, 70S6K and 4EBP1. Finally, we confirmed that MIR4435-2HG enhances tumor metastasis through regulation of the EMT pathway.ConclusionsOur data indicate that upregulated MIR4435-2HG expression levels are significantly correlated with a poor prognosis of UCB patients. MIR4435-2HG promotes bladder cancer progression, mediates cell cycle (de)regulation and modulates mTOR signaling. MIR4435-2HG is an oncogenic lncRNA in UCB that may serve as a diagnostic and therapeutic target.

M5C-dependent cross-regulation between nuclear reader ALYREF and writer NSUN2 promotes urothelial bladder cancer malignancy through facilitating RABL6/TK1 mRNAs splicing and stabilization

The significance of 5-methylcytosine (m5C) methylation in human malignancies has become an increasing focus of investigation. Here, we show that m5C regulators including writers, readers and erasers, are predominantly upregulated in urothelial carcinoma of the bladder (UCB) derived from Sun Yat-sen University Cancer Center and The Cancer Genome Atlas cohort. In addition, NOP2/Sun RNA methyltransferase family member 2 (NSUN2) as a methyltransferase and Aly/REF export factor (ALYREF) as a nuclear m5C reader, are frequently coexpressed in UCB. By applying patient-derived organoids model and orthotopic xenograft mice model, we demonstrate that ALYREF enhances proliferation and invasion of UCB cells in an m5C-dependent manner. Integration of tanscriptome-wide RNA bisulphite sequencing (BisSeq), RNA-sequencing (RNA-seq) and RNA Immunoprecipitation (RIP)-seq analysis revealed that ALYREF specifically binds to hypermethylated m5C site in RAB, member RAS oncogene family like 6 (RABL6) and thymidine kinase 1 (TK1) mRNA via its K171 domain. ALYREF controls UCB malignancies through promoting hypermethylated RABL6 and TK1 mRNA for splicing and stabilization. Moreover, ALYREF recognizes hypermethylated m5C site of NSUN2, resulting in NSUN2 upregulation in UCB. Clinically, the patients with high coexpression of ALYREF/RABL6/TK1 axis had the poorest overall survival. Our study unveils an m5C dependent cross-regulation between nuclear reader ALYREF and m5C writer NSUN2 in activation of hypermethylated m5C oncogenic RNA through promoting splicing and maintaining stabilization, consequently leading to tumor progression, which provides profound insights into therapeutic strategy for UCB.

PXDNL activates the motility of urothelial bladder carcinoma cells through the Wnt/β-catenin pathway and has a prognostic value

AimsAlthough aberrant expression of peroxidasin-like (PXDNL) has been associated with carcinogenesis, its potential role in the Urothelial Carcinoma of the Bladder (UCB) remains unknown. The present study aimed to explore the role of PXDNL in UCB carcinogenesis and its potential clinical value. Main methodsBased on The Cancer Genome Atlas (TCGA) data, bioinformatics was used to explore the potential clinical value of PXDNL. Wound healing and Transwell invasion assays were employed for the purpose of assessing the cell motility, while the Western Blotting experiments were utilized for investigating the protein expression pattern of PXDNL in UCB and investigating the Epithelial-to-Mesenchymal Transition (EMT) and Wnt/β-catenin pathways for understanding the probable mechanisms involved. Key findsPXDNL mRNA was overexpressed in UCB tissues and indicated a poor prognosis. High PXDNL mRNA levels were also associated with advanced clinicopathological features and were regarded as independent prognostic factors for UCB. However, PXDNL showed a weak correlation with immune cell infiltration in UCB. In addition, the findings of the study verified that the existing form of the PXDNL protein was 57-kDa and it was upregulated in the UCB cell lines and tissue samples. Furthermore, silencing PXDNL inhibited, while overexpressing PXDNL promoted EMT and motility of UCB cells in vitro. Mechanistic studies showed that PXDNL activated UCB cell motility via the Wnt/β-catenin pathway. SignificanceThe results reveal a novel molecular target that could be further explored for developing preventive, predictive, and individualized treatment strategies for UCB.

Targeted Inhibition of O-Linked β-N-Acetylglucosamine Transferase as a Promising Therapeutic Strategy to Restore Chemosensitivity and Attenuate Aggressive Tumor Traits in Chemoresistant Urothelial Carcinoma of the Bladder.

Acquisition of acquired chemoresistance during treatment cycles in urothelial carcinoma of the bladder (UCB) is the major cause of death through enhancing the risk of cancer progression and metastasis. Elevated glucose flux through the abnormal upregulation of O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) controls key signaling and metabolic pathways regulating diverse cancer cell phenotypes. This study showed that OGT expression levels in two human UCB cell models with acquired resistance to gemcitabine and paclitaxel were significantly upregulated compared with those in parental cells. Reducing hyper-O-GlcNAcylation by OGT knockdown (KD) markedly facilitated chemosensitivity to the corresponding chemotherapeutics in both cells, and combination treatment with OGT-KD showed more severe growth defects in chemoresistant sublines. We subsequently verified the suppressive effects of OGT-KD monotherapy on cell migration/invasion in vitro and xenograft tumor growth in vivo in chemoresistant UCB cells. Transcriptome analysis of these cells revealed 97 upregulated genes, which were enriched in multiple oncogenic pathways. Our final choice of suspected OGT glycosylation substrate was VCAN, S1PR3, PDGFRB, and PRKCG, the knockdown of which induced cell growth defects. These findings demonstrate the vital role of dysregulated OGT activity and hyper-O-GlcNAcylation in modulating treatment failure and tumor aggression in chemoresistant UCB.

LRPPRC regulates redox homeostasis via the circANKHD1/FOXM1 axis to enhance bladder urothelial carcinoma tumorigenesis

Reactive oxygen species (ROS) which are continuously generated mainly by mitochondria, have been proved to play an important role in the stress signaling of cancer cells. Moreover, pentatricopeptide repeat (PPR) proteins have been suggested to take part in mitochondrial metabolism. However, the mechanisms integrating the actions of these distinct networks in urothelial carcinoma of the bladder (UCB) pathogenesis are elusive. In this study, we found that leucine rich pentatricopeptide repeat containing (LRPPRC) was frequently upregulated in UCB and that it was an independent prognostic factor in UCB. We further revealed that LRPPRC promoted UCB tumorigenesis by regulating the intracellular ROS homeostasis. Mechanistically, LRPPRC modulates ROS balance and protects UCB cells from oxidative stress via mt-mRNA metabolism and the circANKHD1/FOXM1 axis. In addition, the SRA stem-loop interacting RNA binding protein (SLIRP) directly interacted with LRPPRC to protect it from ubiquitination and proteasomal degradation. Notably, we showed that LRPPRC modulated the tumorigenesis of UCB cells in a circANKHD1-FOXM1-dependent manner. In conclusion, LRPPRC exerts critical roles in regulating UCB redox homeostasis and tumorigenesis, and is a prognostic factor for UCB; suggesting that LRPPRC may serve as an exploitable therapeutic target in UCB.

ZHX3 promotes the progression of urothelial carcinoma of the bladder via repressing of RGS2 and is a novel substrate of TRIM21.

Clinically, patients with urothelial carcinoma of the bladder (UCB) with tumor metastasis are incurable. To find new therapeutic strategies, the mechanisms underlying UCB invasion and metastasis should be further investigated. In this study, zinc finger and homeobox 3 (ZHX3) was first screened as a critical oncogenic factor associated with poor prognosis in a UCB dataset from The Cancer Genome Atlas (TCGA). These results were also confirmed in a large cohort of clinical UCB clinical samples. Next, we found that ZHX3 could promote the migration and invasion capacities of UCB cells both in vitro and in vivo. Mechanistically, coimmunoprecipitation (coIP) and mass spectrometry (MS) analysis indicated that ZHX3 was a target of tripartite motif 21 (TRIM21), which mediates its ubiquitination, and subsequent degradation. Notably, RNA‐seq analysis showed that ZHX3 repressed the expression of regulator of G protein signaling 2 (RGS2). Generally, our results suggest that ZHX3 plays an oncogenic role in UCB pathogenesis and might serve as a novel therapeutic target for UCB.

Overexpression of lncRNA TINCR is associated with high-grade, invasive, and recurring tumors, and facilitates proliferation in vitro and in vivo of urothelial carcinoma of the bladder

ObjectivesThe aberrant expression of long noncoding RNAs (lncRNAs) plays roles in cancer development. In this work, we measured the expression of lncRNA terminal differentiation-induced non-coding RNA (TINCR) in urothelial carcinoma of the bladder (UCB), determined its impact on the proliferation of UCB in vitro and in vivo and identified its possible targets. MethodsThe expression levels of genes were measured by Real-Time quantitative Polymerase Chain Reaction (qPCR). Cell proliferation, cell motility, and cell apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, wound healing assay, and ELISA, respectively. Tumor growth in vivo was determined by xenograft formation assay in nude mice. The predicted binding site between TINCR and hsa-miR-125b was confirmed by dual luciferase reporter assay. ResultsThe expression levels of TINCR were higher in cancerous tissues than that in paired noncancerous tissues of UCB. Higher expression levels of TINCR were positively associated with high-grade, invasive, and recurring tumors. Depletion of TINCR retarded proliferation, decreased motility, increased apoptosis in UCB cells, and markedly reduced tumor growth in xenograft nude mice. The predicted binding site between TINCR and hsa-miR-125b was functional. TINCR downregulated hsa-miR-125b in UCB cells. Hsa-miR-125b mimic reversed the proliferation caused by TINCR up-expression in UCB cells. ConclusionsUp-regulation of TINCR may act as an unfavorable indicator for the diseasing status of UCB. TINCR facilitates bladder cancer proliferation in vitro and in vivo. Hsa-miR-125b is a target for TINCR in UCB.

Disabled Homolog 2 (DAB2) Protein in Tumor Microenvironment Correlates with Aggressive Phenotype in Human Urothelial Carcinoma of the Bladder.

Disabled homolog-2 (DAB2) has been reported to be a tumor suppressor gene. However, a number of contrary studies suggested that DAB2 promotes tumor invasion in urothelial carcinoma of the bladder (UCB). Here, we investigated the clinical role and biological function of DAB2 in human UCB. Immunohistochemical staining analysis for DAB2 was carried out on UCB tissue specimens. DAB2 expression levels were compared with clinicopathological factors. DAB2 was knocked-down by small interfering RNA (siRNA) transfection, and then its effects on cell proliferation, invasion, and migration, and changes to epithelial-mesenchymal transition (EMT)-related proteins were evaluated. In our in vivo assays, tumor-bearing athymic nude mice subcutaneously inoculated with human UCB cells (MGH-U-3 or UM-UC-3) were treated by DAB2-targeting siRNA. Higher expression of DAB2 was associated with higher clinical T category, high tumor grade, and poor oncological outcome. The knock-down of DAB2 decreased both invasion and migration ability and expression of EMT-related proteins. Significant inhibitory effects on tumor growth and invasion were observed in xenograft tumors of UM-UC-3 treated by DAB2-targeting siRNA. Our findings suggested that DAB2 expression was associated with poor prognosis through increased oncogenic properties including tumor proliferation, migration, invasion, and enhancement of EMT in human UCB.

Transcription factor Nrf2 induces the up-regulation of lncRNA TUG1 to promote progression and adriamycin resistance in urothelial carcinoma of the bladder.

BackgroundTaurine-upregulated gene 1 (TUG1) has been documented to be implicated in carcinogenesis and chemoresistance in solid tumors. Here, we explored the biological role and regulatory mechanism of TUG1 in progression and chemoresistance of urothelial carcinoma of the bladder (UCB).MethodsNuclear factor-erythroid 2 (NF-E2)-related factor 2 (Nrf2) mRNA and TUG1 expression was determined by quantitative reverse transcription polymerase chain reaction. Western blot was performed to determine the protein levels of Nrf2, p-glycoprotein (p-gp), Ki-67 (Ki67), matrix metalloproteinase (MMP)-2 and MMP-9 and cleaved caspase-3. The effects of either Nrf2 or TUG1 knockdown on the proliferation, invasion, apoptosis and adriamycin (ADM) resistance of UCB cells were evaluated by CCK-8 assay, transwell invasion assay and flow cytometry analysis. Xenograft tumor assay was carried out to confirm the role of Nrf2 and TUG1 in ADM resistance of UCB cells in vivo.ResultsNrf2 and TUG1 were upregulated in UCB tissues and cell lines. A positive correlation between Nrf2 and TUG1 expression was discovered in UCB tissues. Moreover, Nrf2 and TUG1 expression levels were higher in ADM-resistant cells compared with those in parental cells. Furthermore, Nrf2 positively regulated the expression of TUG1 in UCB cells. Knockdown of either Nrf2 or TUG1 led to the inhibition of cell proliferation and invasion and promotion of cell apoptosis, accompanying with down-regulation of Ki67, MMP-2 and MMP-9 and up-regulation of cleaved caspase-3. Knockdown of either Nrf2 or TUG1 enhanced the sensitivity of BIU-87/ADM and T24/ADM cells to ADM, as indicated by decreased expression of p-gp. Besides, knockdown of either Nrf2 or TUG1 inhibited tumor growth in the absence or presence of ADM in vivo.ConclusionsNrf2 induces the up-regulation of TUG1 to promote progression and ADM resistance in UCB.

Abstract 2219: Evaluation of PD-L1 expression on circulating tumor cells (CTCs) in patients with advanced urothelial carcinoma of the bladder

Abstract Introduction: Immune checkpoint therapies with PD-1/PD-L1 inhibitors show durable responses in a subset of patients with metastatic urothelial carcinoma of the bladder (UCB). However, PD-L1 expression in tumor biopsies does not correlate with response to PD-1/PD-L1 inhibitors in all patients. In addition, determination of PD-L1 expression in tumor tissue has not been harmonized to date and biopsies from metastatic sites are often hardly accessible. Thus, a reliable predictive biomarker is still urgently needed. In this study, we perform detection of PD-L1 on circulating tumor cells (CTCs) in blood samples of patients with advanced UCB. Experimental procedures: Blood samples of 93 non-metastatic (M0) and 33 metastatic (M1) UCB patients were analyzed using the CellSearch® system. Following EpCAM-based enrichment, CK+/DAPI+/CD45- cells were identified as CTCs using the CTC-Kit. For PD-L1 detection, the CellSearch® CXC-Kit (optional fluorescence channel: PE) proved more suitable than the CellSearch® CTC-Kit (optional fluorescence channel: FITC). After enumeration of CTCs by the CTC-Kit, for nine CTC-positive patients (M1) a second blood sample was further analyzed for PD-L1 protein expression using the CXC-Kit. Specificity of the PE-labelled anti-PD-L1-antibody (clone E1L3N) was validated by Western blot analysis, IF and FACS. Results: Enumeration of CTCs by the CellSearch® CTC-Kit revealed significantly higher CTC-positivity in M1 than in M0 patients (51.5% vs. 22.6%, p=0.004 for ≥1 CTCs/7.5 mL blood; 30.3% vs. 3.2%, p<0.001 for ≥5 CTCs/7.5 mL blood). Also mean absolute CTC numbers were significantly higher in M1 than M0 patients (p<0.001). PD-L1 detection in the CellSearch® system was established using five UCB cell lines with different PD-L1 expression, according to Western blot analysis and FACS, which were spiked into whole blood of healthy donors. Using the CXC-Kit, ≥1 PD-L1+ CTCs were detected in 77.8% (7/9) of CTC-positive M1 patients. Thus, PD-L1 expression levels presented with intra- and inter-patient heterogeneity. The follow-up analysis of one patient who received anti-PD-L1 therapy showed substantial increases in CTC numbers as well as in the ratio and intensity of PD-L1+ CTCs in conjunction with disease progression under immunotherapy. The patient died within one month after the follow-up blood draw. Conclusion: This is the first study demonstrating the feasibility to detect and monitor PD-L1 expression on CTCs of advanced UCB patients in the CellSearch® system. The established assay is readily available for clinical application and should be implemented in future clinical trials to evaluate its relevance for predicting response to immune checkpoint inhibitors. Citation Format: Sonja Bergmann, Anja Coym, Gunhild von Amsberg, Melanie Janning, Armin Soave, Michael Rink, Klaus Pantel, Sabine Riethdorf. Evaluation of PD-L1 expression on circulating tumor cells (CTCs) in patients with advanced urothelial carcinoma of the bladder [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2219.

Overexpression of CEP72 Promotes Bladder Urothelial Carcinoma Cell Aggressiveness via Epigenetic CREB-Mediated Induction of SERPINE1

A vital constituent of the centrosome involved in regulating the activity of the organelle during the cell cycle is centrosomal protein (CEP)-72, whose function in the case of human cancer yet lacks clarity. The expression dynamics of CEP72 and its clinical impact were examined in a large cohort of bladder tissues. Several experiments at both the invitro and invivo levels on urothelial carcinoma of the bladder (UCB) cells were conducted to understand the role of this molecule along with the mechanisms. Overexpression of CEP72 in UCB was linked with the acquisition of an aggressive phenotype, which was associated with poor prognosis. In UCB cell lines, knockdown of CEP72 using shRNA was sufficient to inhibit cell invasiveness/metastasis, whereas ectopic overexpression of CEP72 promoted cell invasiveness and/or metastasis both invitro and invivo. CEP72 was demonstrated to induce UCB cell aggressiveness via up-regulation of an important target downstream, the serpin family member 1 gene (SERPINE1) (alias plasminogen activator inhibitor, PAI1), ultimately leading to increased cancer cell invasiveness. Particularly, overexpression of CEP72 was associated with a sizable increase in cAMP response element-binding protein binding at the SERPINE1 promoter, leading to increased SERPINE1 transcription. Such observations are suggestive of the potential use of CEP72 as a therapeutic tool for UCB.

LGALS4 as a Prognostic Factor in Urothelial Carcinoma of Bladder Affects Cell Functions.

Background:To identify the hub genes related to urothelial carcinoma of the bladder prognosis and to understand their underlying mechanism.Methods:The expression profiles of 18 pairs of urothelial carcinoma of the bladder patient tissue and paired adjacent tissue obtained from the Cancer Genome Atlas were performed. Weighted gene coexpression network analysis was employed to screen gene modules and hub genes with significant differential expressions in urothelial carcinoma of the bladder. The hub genes expression in urothelial carcinoma of the bladder tissues was validated by reverse transcription-quantitative polymerase chain reaction. The overall survival curve and disease-free survival curve of prognostic factor (LGALS4) were plotted using the Kaplan-Meier method. Furthermore, LGALS4 messenger RNA and protein expression were also assessed in 2 urothelial carcinoma of the bladder cell lines (T24 and 5637) by quantitative reverse transcription–polymerase chain reaction and Western blot. The functions of urothelial carcinoma of the bladder cells with transfected pcDNA3.1-LGALS4 were identified through MTT assay, plate clone formation assay, flow cytometry, and cell migration experiments.Results:LGALS4 was the hub gene of pink module and it was related to prognosis. Higher LGALS4 expression predicted higher probabilities of overall survival and disease-free survival. Overexpression of LGALS4 in urothelial carcinoma of the bladder cells suppressed cell viability and migration but induced apoptosis.Conclusion:LGALS4 played a critical role in the progression of urothelial carcinoma of the bladder and held a promise to be the biomarker for diagnosis and treatment of urothelial carcinoma of the bladder. It predicted good prognosis of urothelial carcinoma of the bladder and restrained the growth and migration of urothelial carcinoma of the bladder cells.

PRMT5 Circular RNA Promotes Metastasis of Urothelial Carcinoma of the Bladder through Sponging miR-30c to Induce Epithelial-Mesenchymal Transition.

Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells epithelial-mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells' EMT and explored their regulatory mechanisms and clinical significance in UCBs. We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells' EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes, SNAIL1 and E-cadherin, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA). We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cell's EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis. CircPRMT5 exerts critical roles in promoting UCB cells' EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.

CSTF2-Induced Shortening of the RAC1 3'UTR Promotes the Pathogenesis of Urothelial Carcinoma of the Bladder.

Shortening of the 3' untranslated regions (3'UTR) of mRNA is an important mechanism for oncogene activation. However, 3'UTR alteration events, their pathologic functions, and underlying mechanisms in human urothelial carcinoma of the bladder (UCB) are not clear. Here, we combine RNA sequencing, bioinformatics, and clinical studies in two independent cohorts of patients with UCB to identify a novel RAC1 shorter 3'UTR isoform that is frequently expressed in UCB and is critical in the tumorigenesis and acquisition of a poor prognostic phenotype in patients. Short 3'UTR isoform of RAC1 substantially upregulated RAC1 expression by escaping from miRNA-targeted repression and played an essential oncogenic role in UCB pathogenesis. An important cleavage/polyadenylation factor, cleavage stimulation factor 2 (CSTF2), induced 3'UTR shortening of RAC1 in UCB by mediating slow transcriptional elongation at RAC1 Cotranscriptional recruitment of CSTF2 on the GUAAU motif at proximal polyadenylation site of RAC1 attenuated the recruitment of two transcription factors AFF1 and AFF4, causing the defects in elongation. CSTF2 regulated the tumorigenic functions of the shorter RAC1 isoform in UCB cells, enhancing cell proliferation, migration, and invasion. The combination of high expression of CSTF2 and high usage of RAC1 short-3'UTR isoform may be used as a powerful biomarker to predict poor prognosis in UCB. Our findings also suggest a CSTF2-regulated RAC1-3'UTR shortening program as an exploitable therapeutic strategy for patients with UCB.Significance: These findings demonstrate that the short isoform of RAC1 is critical in UCB tumorigenesis and may have implications for developing new therapeutic strategies to treat this disease. Cancer Res; 78(20); 5848-62. ©2018 AACR.

TRIM65 supports bladder urothelial carcinoma cell aggressiveness by promoting ANXA2 ubiquitination and degradation

Clinically, most of human urothelial carcinoma of the bladder (UCB)-related deaths result from tumor metastasis, but the underlying molecular mechanisms are largely unknown. Recently, a growing number of tripartite motif (TRIM) family members have been suggested to be important regulators for tumorigenesis. However, the impact of most TRIM members on UCB pathogenesis is unclear. In this study, TRIM65 was first screened as an important oncogenic factor of UCB from the Cancer Genome Atlas (TCGA) database and was validated by a large cohort of clinical UCB tissues. By in vitro and in vivo experiments, we demonstrated that TRIM65 promotes UCB cell invasive and metastatic capacities. Notably, we showed that TRIM65 modulates cytoskeleton rearrangement and induces UCB cells epithelial-mesenchymal transition by the ubiquitination of ANXA2, ultimately leading to an enhanced invasiveness of UCB cells. Importantly, UCBs with high expression of TRIM65 and low expression of ANXA2 showed the poorest outcome. Collectively, our results suggest that the overexpression of TRIM65 has an essential oncogenic role via ubiquitination of ANXA2 in UCB pathogenesis, and that such could be used as a novel prognostic marker and/or therapeutic target for UCB.

Flavagline analog FL3 induces cell cycle arrest in urothelial carcinoma cell of the bladder by inhibiting the Akt/PHB interaction to activate the GADD45α pathway

BackgroundProhibitin 1 (PHB) is a potential target for the treatment of urothelial carcinoma of the bladder (UCB). FL3 is a newly synthesized agent that inhibits cancer cell proliferation by targeting the PHB protein; however, the effect of FL3 in UCB cells remains unexplored.MethodsFL3 was identified to be a potent inhibitor of UCB cell viability using CCK-8 (cell counting kit-8) assay. Then a series of in vitro and in vivo experiments were conducted to further demonstrate the inhibitory effect of FL3 on UCB cell proliferation and to determine the underlying mechanisms.ResultsFL3 inhibited UCB cell proliferation and growth both in vitro and in vivo. By targeting the PHB protein, FL3 inhibited the interaction of Akt and PHB as well as Akt-mediated PHB phosphorylation, which consequently decreases the localization of PHB in the mitochondria. In addition, FL3 treatment resulted in cell cycle arrest in the G2/M phase, and this inhibitory effect of FL3 could be mimicked by knockdown of PHB.Through the microarray analysis of mRNA expression after FL3 treatment and knockdown of PHB, we found that the mRNA expression of the growth arrest and DNA damage-inducible alpha (GADD45α) gene were significantly upregulated. When knocked down the expression of GADD45α, the inhibitory effect of FL3 on cell cycle was rescued, suggesting that FL3-induced cell cycle inhibition is GADD45α dependent.ConclusionOur data provide that FL3 inhibits the interaction of Akt and PHB, which in turn activates the GADD45α-dependent cell cycle inhibition in the G2/M phase.

Decreased Invasion of Urothelial Carcinoma of the Bladder by Inhibition of Matrix-Metalloproteinase 7.

Objectives:To measure and to modulate the invasive potential of urothelial carcinoma of the bladder (UCB) cells in a standardized preclinical setting using broad-spectrum matrix-metalloproteinase (MMPs) inhibitors and specific targeting of MMP7.Materials and Methods:MMP expression levels in UCB cells were determined by quantitative real-time PCR (qRT-PCR) and gel zymographies of cell supernatants (MMP9, MMP2 and MMP1) and cell lysates (MMP7). The invasiveness of human UCB cells (HT1197 and T24/83) and human benign urothelial cells (UROtsa) was modulated by a broad-spectrum MMP inhibitor (4-Aminobenzoyl-Gly-Pro-D-Leu-D-Ala hydroxamic acid; AHA) and by MMP7 specific siRNAs. MMP7 knockdown efficiency was assessed by qRT-PCR and western blot. Invasive potential of UCB cells was measured by a standardized trans-epithelial electrical resistance (TEER) assay.Results:Different MMP secretion profiles were measured in UCB cells. The active form of MMP7 was exclusively detected in HT1197 cells. Characteristic TEER breakdown patterns were observed in UCB cells when compared to benign cells. Invasive potentials were significantly higher in HT1197 cells than in T24/83 and in UROtsa cells [14.8±5.75 vs. 1.5±0.56 and 1.2±0.15, respectively; p < 0.01]. AHA treatment reduced the invasive potential of HT1197 cells. Also the specific downregulation of MMP7 by siRNA lowered the HT1197 cell invasiveness [20±1.0 vs. 16±2.8; p < 0.05]. Neither AHA nor MMP-7 siRNA transfection altered the invasive potential of T24/83 cells.Conclusions:Invasion of UCB is partially dependent on MMPs. Specific targeting of MMP7 by siRNA reduces the invasive potential in a subgroup of UCB cells. Therefore, MMP7 represents a potential therapeutic target which warrants further investigation.

MP98-03 T-DM1, A NOVEL HER2 ANTIBODY-CYTOTOXIC DRUG CONJUGATE, HAS ANTI-METASTATIC POTENTIAL AND IS EFFECTIVE IN BLADDER CANCER WITH HER2 IHC SCORE 2+/3+

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology V1 Apr 2017MP98-03 T-DM1, A NOVEL HER2 ANTIBODY-CYTOTOXIC DRUG CONJUGATE, HAS ANTI-METASTATIC POTENTIAL AND IS EFFECTIVE IN BLADDER CANCER WITH HER2 IHC SCORE 2+/3+ Tetsutaro Hayashi, Htoo Zarni Oo, Wolfgang Jäger, Kohei Kobatake, Akihiro Goriki, Roland Seiler, Tilman Todenhöfer, Na Li, Ladan Fazli, Akio Matsubara, and Peter Black Tetsutaro HayashiTetsutaro Hayashi More articles by this author , Htoo Zarni OoHtoo Zarni Oo More articles by this author , Wolfgang JägerWolfgang Jäger More articles by this author , Kohei KobatakeKohei Kobatake More articles by this author , Akihiro GorikiAkihiro Goriki More articles by this author , Roland SeilerRoland Seiler More articles by this author , Tilman TodenhöferTilman Todenhöfer More articles by this author , Na LiNa Li More articles by this author , Ladan FazliLadan Fazli More articles by this author , Akio MatsubaraAkio Matsubara More articles by this author , and Peter BlackPeter Black More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.3068AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although prior clinical trials testing trastuzumab in urothelial carcinoma of the bladder (UCB) have failed, recent genomic studies suggest that UCB could potentially respond to HER2-targeted therapy if patients are selected optimally. T-DM1 is an antibody-drug conjugate consisting of trastuzumab linked to the cytotoxic agent DM1. It showed a significant survival advantage in breast cancer patients refractory to trastuzumab. Our previous study demonstrated that T-DM1 has significant anti-tumor effects in pre-clinical models of HER2-overexpressing UCB. These effects were superior to trastuzumab and depended on level of HER2 expression. Here, we studied the potential anti-metastatic function and optimal patients of T-DM1 in UCB. METHODS HER2 expression in bladder cancer treated by radical cystectomy was examined by the same immunohistochemistry (IHC) criteria as for breast cancer. HER2 expression level in UCB cell lines was examined by western blotting (WB), qRT-PCR, FISH and FACS in adherent (AD) and anchorage independent (AI) culture conditions. RESULTS HER2 over-expression (score 2+ or 3+) in IHC was detected in 59 of 159 (37%) bladder cancer patients. HER2 expression was higher in lymph node metastases than in primary tumors. Higher HER2 expression was detected in all cell lines cultured in AI conditions, compared to those in AD conditions. Furthermore, T-DM1 significantly inhibited colony formation in soft agar compared to control IgG or trastuzumab. Since anoikis is a pre-requisite for metastasis, these results suggest that HER2 expression contributes to the establishment of metastasis and T-DM1 could have anti-metastatic potential. The bladder cancer cell line with the highest HER2 expression (BOY) was equivocal HER2 amplification by FISH (HER2/CEP17 ratio: 1.8, HER2 copy number: 4.7), which is known to correspond to HER2 IHC score 2+ in patient tissue. BOY responded most sensitively to T-DM1, and low concentration (10nM) T-DM1 induced apoptosis only in BOY. This suggests T-DM1 could be effective in patients with HER2 over-expression (IHC score 2+/3+). CONCLUSIONS Our pre-clinical results suggest that T-DM1 could have anti-metastatic potential and be a promising targeted therapy for patients with HER2 score 2+/3+ UCB. T-DM1 warrants clinical evaluation in these patients. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1312-e1313 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Tetsutaro Hayashi More articles by this author Htoo Zarni Oo More articles by this author Wolfgang Jäger More articles by this author Kohei Kobatake More articles by this author Akihiro Goriki More articles by this author Roland Seiler More articles by this author Tilman Todenhöfer More articles by this author Na Li More articles by this author Ladan Fazli More articles by this author Akio Matsubara More articles by this author Peter Black More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Downregulation of miR‐133b predict progression and poor prognosis in patients with urothelial carcinoma of bladder

We found microRNA‐133b (miR‐133b) was downregulated in urothelial carcinoma of the bladder (UCB) tissues, and it could inhibit the proliferation and induce apoptosis in UCB cells. Consequently, we intend to explore the clinical significance of miR‐133b in UCB patients. Expression of miR‐133b in 146 UCB specimens and matched adjacent non‐neoplastic bladder tissues were measured by quantitative real‐time polymerase chain reaction. The overall survival (OS) curve and progression‐free survival (PFS) curve were plotted using the Kaplan–Meier method. Prognostic factors for OS and PFS were identified by univariate and multivariate analyses using the Cox proportional hazards regression model. The expression of miR‐133b was significantly downregulated in UCB tissues compared with those in adjacent non‐neoplastic bladder tissues (P < 0.001). Among UCB patients, low expression of miR‐133b significantly correlated with aggressive clinicopathological features. Multivariate analysis indicated that the expression of miR‐133b was the independent prognostic factors for predicting PFS (RR: 2.97; 95% CI: 1.78–6.44; P = 0.009) and OS (RR: 4.23; 95% CI: 1.51–11.8; P = 0.011) in patients with UCB. Our study demonstrated that downregulation of miR‐133b associated with aggressive clinicopathological features and predicted unfavorable prognosis in patients with UCB, might serve as feasible biomarker for clinical outcome of UCB patients after surgery and potential therapeutic target in the future.