Bladder cancer or bladder cancers? Genetically distinct malignant conditions of the urothelium

Gold nanorod-assisted theranostic solution for nonvisible residual disease in bladder cancer

Residual nonvisible bladder cancer after proper treatment caused by technological and therapeutic limitations is responsible for tumor relapse and progression. This study aimed to demonstrate the feasibility of a solution for simultaneous detection and treatment of bladder cancer lesions smaller than one millimeter. The α5β1 integrin was identified as a specific marker in 81% of human high-grade nonmuscle invasive bladder cancers and used as a target for the delivery of targeted gold nanorods (GNRs). In a preclinical model of orthotopic bladder cancer expressing the α5β1 integrin, the photoacoustic imaging of targeted GNRs visualized lesions smaller than one millimeter, and their irradiation with continuous laser was used to induce GNR-assisted hyperthermia. Necrosis of the tumor mass, improved survival, and computational modeling were applied to demonstrate the efficacy and safety of this solution. Our study highlights the potential of the GNR-assisted theranostic strategy as a complementary solution in clinical practice to reduce the risk of nonvisible residual bladder cancer after current treatment. Further validation through clinical studies will support the findings of the present study.

Preclinical models of bladder cancer: BBN and beyond

Preclinical modelling is a crucial component of advancing the understanding of cancer biology and therapeutic development. Several models exist for understanding the pathobiology of bladder cancer and evaluating therapeutics. N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced bladder cancer is a commonly used model that recapitulates many of the features of human disease. Particularly in mice, BBN is a preferred laboratory model owing to a high level of reproducibility, high genetic fidelity to the human condition, and its relative ease of use. However, important aspects of the model are often overlooked in laboratory studies. Moreover, the advent of new models has yielded a variety of methodologies that complement the use of BBN. Toxicokinetics, histopathology, molecular genetics and sex can differ between available models and are important factors to consider in bladder cancer modelling.

Urothelium-Specific Expression of Mutationally Activated Pik3ca Initiates Early Lesions of Noninvasive Bladder Cancer

Although approximately 70% of bladder cancers are noninvasive and have high recurrence rates, early-stage disease is understudied. The lack of models to validate the contribution of molecular drivers of bladder tumorigenesis is a significant issue. Although mutations in PIK3CA are frequent in human bladder cancer, an in vivo model for understanding their contribution to bladder tumorigenesis is unavailable. Therefore, a Upk2-Cre/Pik3caH1047R mouse model expressing one or two R26-Pik3caH1047R alleles in a urothelium-specific manner was generated. Pik3caH1047R functionality was confirmed by quantifying Akt phosphorylation, and mice were characterized by assessing urothelial thickness, nuclear atypia, and expression of luminal and basal markers at 6 and 12 months of age. While at 6 months, Pik3caH1047R mice developed increased urothelial thickness and nuclear atypia, progressive disease was not observed at 12 months. Immunohistochemistry showed urothelium maintained luminal differentiation characterized by high forkhead box A1 (Foxa1) and peroxisome proliferator-activated receptor γ expression. Surprisingly, Pik3caH1047R mice subjected to low-dose carcinogen exposure [N-butyl-N-(4-hydroxybutyl)nitrosamine] exhibited no significant differences after exposure relative to mice without exposure. Furthermore, single-sample gene set enrichment analysis of invasive human tumors showed those with mutant PIK3CA did not exhibit significantly increased phosphatidylinositol 3-kinase/AKT pathway activity compared with wild-type PIK3CA tumors. Overall, these data suggest that Pik3caH1047R can elicit early tumorigenic changes in the urothelium, but progression to invasion may require additional genetic alterations.

Proteogenomics of different urothelial bladder cancer stages reveals distinct molecular features for papillary cancer and carcinoma in situ

The progression of urothelial bladder cancer (UC) is a complicated multi-step process. We perform a comprehensive multi-omics analysis of 448 samples from 190 UC patients, covering the whole spectrum of disease stages and grades. Proteogenomic integration analysis indicates the mutations of HRAS regulated mTOR signaling to form urothelial papilloma rather than papillary urothelial cancer (PUC). DNA damage is a key signaling pathway in the progression of carcinoma in situ (CIS) and related to APOBEC signature. Glucolipid metabolism increase and lower immune cell infiltration are associated with PUC compared to CIS. Proteomic analysis distinguishes the origins of invasive tumors (PUC-derived and CIS-derived), related to distinct clinical prognosis and molecular features. Additionally, loss of RBPMS, associated with CIS-derived tumors, is validated to increase the activity of AP-1 and promote metastasis. This study reveals the characteristics of two distinct branches (PUC and CIS) of UC progression and may eventually benefit clinical practice.

Accurate Characterization of Bladder Cancer Cells with Intraoperative Flow Cytometry

Simple Summary

Bladder cancer is a malignancy that predominantly affects male patients. Surgical treatment is the first option for clinical management and cancer cell characterization is critical for tumor margin detection and complete tumor removal. We developed a specialized intraoperative flow cytometry (iFC) methodology for bladder cancer cell detection. Our study, including 52 individuals, reveals that iFC is highly specific, sensitive and accurate in detecting cancer cells, based on the quantification of cell proliferation and the presence of tumor aneuploidy. The results of this study advocate further research on the utility of iFC as a next-generation malignancy evaluation technique during transurethral resections.

Abstract

Bladder cancer represents a major health issue. Transurethral resection is the first line treatment and an accurate assessment of tumor margins might warrant complete tumor removal. Genomic instability and proliferative potential are common hallmarks of cancer cells. We have previously demonstrated the utility of intraoperative flow cytometry (iFC), a next-generation margin evaluation methodology for assessment of DNA content, in the detection of several types of malignancy. In the current study we investigated the possible value of iFC in the characterization of bladder cancer during surgery. Samples from a population of 52 people with urothelial cancer were included in the study. The total time for iFC evaluation is 3–5 min per sample and included a two-step analysis, including DNA-index and Tumor-index calculation. First, DNA-index calculation revealed 24 hyperploid and one hypoploid tumor. Second, cell cycle analysis and Tumor-index calculation revealed that tumor samples are distinguished from normal cells based on their significantly higher proliferative potential. The standard for iFC evaluation was pathology assessment and revealed that our protocol exhibits an accuracy of 98% in defining the presence of cancer cells in a given sample. Our results support the further assessment of iFC value towards its use as a novel malignancy evaluation tool in transurethral resections.

New Directions and Challenges in Targeted Therapies of Advanced Bladder Cancer: The Role of FGFR Inhibitors

Bladder neoplasms, including the most common urothelial carcinoma, have been an escalating problem for years, especially in highly developed countries. Recent decades have brought us a steadily growing share of this cancer in terms of both morbidity and mortality statistics. Bladder neoplasms are not only a therapeutic challenge but also an economical one due to the demanding, costly diagnostics and treatment. The treatment of urothelial cancer can be divided depending on the stage and advancement; thus, we can distinguish three main categories: non-muscle invasive bladder cancer, conventionally treated by surgical interventions; muscle invasive bladder cancer, conventionally treated with chemotherapeutics; and advanced bladder cancer with distant metastases, conventionally treated with the intensive chemotherapy in the MVAC scheme (methotrexate, vinblastine, doxorubicin, and cisplatin). Recent years have brought a breakthrough: immunotherapy and targeted therapy were discovered to be beneficial for patients disqualified from chemotherapy or patients who progressed despite treatment. This literature review summarizes the latest research into the use of targeted therapy in the treatment of advanced bladder cancer, its benefits, and its limitations.

Animal Models in Bladder Cancer

BACKGROUND

Bladder cancer (urothelial cancer of the bladder) is the most common malignancy affecting the urinary system with an increasing incidence and mortality. Mouse models of bladder cancer should possess a high value of reproducibility, predictability, and translatability to allow mechanistic, chemo-preventive, and therapeutic studies that can be furthered into human clinical trials.

OBJECTIVES

To provide an overview and resources on the origin, molecular and pathological characteristics of commonly used animal models in bladder cancer.

METHODS

A PubMed and Web of Science search was performed for relevant articles published between 1980 and 2021 using words such as: "bladder" and/or "urothelial carcinoma" and animal models. Animal models of bladder cancer can be categorized as autochthonous (spontaneous) and non-autochthonous (transplantable). The first are either chemically induced models or genetically engineered models. The transplantable models can be further subclassified as syngeneic (murine bladder cancer cells implanted into immunocompetent or transgenic mice) and xenografts (human bladder cancer cells implanted into immune-deficient mice). These models can be further divided-based on the site of the tumor-as orthotopic (tumor growth occurs within the bladder) and heterotopic (tumor growth occurs outside of the bladder).

Comparative Cancer Cell Signaling in Muscle-Invasive Urothelial Carcinoma of the Bladder in Dogs and Humans

Muscle-invasive urothelial carcinoma (MIUC) is the most common type of bladder malignancy in humans, but also in dogs that represent a naturally occurring model for this disease. Dogs are immunocompetent animals that share risk factors, pathophysiological features, clinical signs and response to chemotherapeutics with human cancer patients. This review summarizes the fundamental pathways for canine MIUC initiation, progression, and metastasis, emerging therapeutic targets and mechanisms of drug resistance, and proposes new opportunities for potential prognostic and diagnostic biomarkers and therapeutics. Identifying similarities and differences between cancer signaling in dogs and humans is of utmost importance for the efficient translation of in vitro research to successful clinical trials for both species.

Gain of TPPP as a predictor of progression in patients with bladder cancer

The present study investigated the role of tubulin polymerization promoting protein (TPPP) in the regulation of bladder cancer (BC) cell proliferation and migration, in addition to the association between TPPP gene copy number amplification and clinicopathological characteristics of BC. TPPP gene amplification was measured in human BC epithelial cells and samples obtained from 52 patients with BC via fluorescence in situ hybridization. TPPP gain was defined as mean TPPP copy number >2.2 per nucleus (cutoff). The neutrophil-to-lymphocyte ratio (NLR) was also obtained from the preoperative data of the patients. For in vitro assays, BC cell lines were transfected with either TPPP small interfering RNAs or scrambled control, following which cell proliferation and migration were determined using Cell Counting Kit-8 and Transwell migration assays, respectively. The percentage of cells with TPPP copy number amplification in the four BC epithelial cell lines (MGH-U1, -U1R, -U3, -U4) examined (86.0-100.0%) was found to be higher compared with that in the normal human uroepithelial cell lines (3.0 and 9.0%). Patients were divided into one- (1.9%), two- (55.8%), three- (7.7%), four- (26.9%) and five-copy (7.7%) types. Results calculated using Fisher's exact test indicated that the gain of TPPP in patients with BC associated significantly with age (P<0.05), advanced histological grade (P<0.001), tumor stage (P<0.05), histological type (P<0.001) and NLR (P<0.05). In MGH-U1R and MGH-U4 cells, cell proliferation and migration were revealed to be significantly lower following TPPP knockdown compared with those in cells transfected with the scrambled control. In conclusion, findings from the present study suggest that TPPP is important for cell proliferation, cell migration and BC progression, such that TPPP copy number assessment would be advised for preoperative urine cytology for urothelial neoplasia diagnosis.

Diagnostic roles of proliferative markers in pathological Grade of T1 Urothelial Bladder Cancer

The stage T1 urothelial bladder cancer (T1 UBC) tumor grade classification is important for prognosis and clinical management. However, the reproducibility of this two-grade classification system is limited in regards to pathological diagnosis, and there is lack of ideal, objective and easily detected markers for pathological diagnosis. In our study, bladder urothelial lesions from a total of 124 patients diagnosed pathologically after transurethral resection of the bladder tumor (TURBT) were collected, including non-cancerous lesions from 33 patients and lesions from 91 T1 UBC patients. A series of previous studies have suggested some common and valuable factors in the diagnosis and prognosis of UBC, but there are still some controversial factors, such as the mitotic figure (MF) of tumor cell, cell proliferation index Ki-67, graded differentiation marker CK20, P53, P504S and carcinogenesis associated telomerase reverse transcriptase (TERT) promoter mutations. The purpose of this study was to evaluate the value of these factors in the pathological grading diagnosis of T1 UBC. The results showed that gender, lesion size, mitotic index (MI), CK20, P53, Ki-67, P504S and TERT promoter hot spot mutations (C228T and C250T) were correlated with T1 UBC diagnosis (P<0.05). The MI, Ki-67 and P504S were correlated with the pathological grade of T1 UBC (P<0.05). Logistic regression analysis showed that the MI and Ki-67 were independent risk factors for high-grade (HG) of T1 UBC (P<0.05). The combined detection of the MI, Ki-67 and P504S in a multivariate diagnostic model improved the diagnostic accuracy of assigning the T1 UBC pathological grade (AUC=0.904, 95%CI: 0.824~0.956, P<0.05). In conclusion, MI and Ki-67, as important markers of histopathology and cell proliferation, can be easily measured and have good reproducibility. These markers may be meaningful parameters for assigning the pathological grade of UBC.

Tissue Profile of CDK4 and STAT3 as Possible Innovative Therapeutic Targets in Urinary Bladder Cancer

Bladder cancer represents a global health problem. It ranks ninth in worldwide cancer incidence. In Egypt, carcinoma of the bladder is the most prevalent cancer, Bladder cancer has the highest recurrence rate of any malignancy. Certainly, suitable molecular diagnostic markers are required to improve the early detection of bladder cancer and then to prolong survival of patients. The present study was aimed to explore the expression of CDk4 and STAT3 in bladder cancer tissues as prospective for target therapy. Our studied groups showed higher values of CDK4 and STAT3 expression in malignant tissues (SCC andUC collectively) compared to cystitis, however, significantly higher values of CDK4 and STAT3 expression were detected in UC group compared to SCC group. Urothelial carcinomas with papillary patterns showed lower parameters of CDK4 and STAT3 expression compared to the non-papillary variant, with significant differences. Higher grades of UC showed significantly higher parameters of CDK4 and STAT3 expression compared to low grade ones. Muscle invasion increases the level of CDK4 and STAT3 expression parameters, compared to non-muscle invasive UC.

The analysis of a ceRNA network and the correlation between lncRNA, miRNA, and mRNA in bladder cancer

Background

To explore the correlation between the lncRNA-miRNA-mRNA and ceRNA network through the differential expression analysis of lncRNAs, miRNAs and mRNAs in bladder cancer based on The Cancer Genome Atlas (TCGA) database combined with Gene Ontology (GO) and Kyoto Encyclopedia of Genes Genomes (KEGG) enrichment analysis.

Methods

Firstly, the expression profile data and corresponding clinical data of RNAs in bladder cancer were searched and downloaded from TCGA database, and aberrantly expressed long non-coding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) were screened and found by using TCGA database. The relationship between lncRNA-miRNA-mRNA was established by comparing these lncRNAs, miRNAs, and mRNAs, while the ceRNA network was constructed. Combined with the analysis of the GO annotation and KEGG pathway, the effects of lncRNA-miRNA-mRNA interaction on the development of bladder cancer were explored.

Results

A total of 1,742 differentially expressed lncRNA, 511 differentially expressed miRNAs, and 4,373 differentially expressed mRNAs were identified, and 328 lncRNAs, 73 miRNAs, and 677 mRNAs were screened by survival analysis. With the lncRNA-miRNA-mRNA correlation analysis, a ceRNA network consisting of 45 lncRNAs, 14 miRNAs, and 29 mRNAs was successfully constructed. The GO annotation and functional enrichment of target gene mRNAs in the network are mainly concentrated in the signal pathways and include fatty acid biosynthesis, gap junction, insulin signaling pathway, and the MAPK signaling pathway biological processes such as positive regulation of cellular process and system development.

Conclusions

We successfully identified the target gene correlating lncRNA, miRNA, and mRNA, and constructed a ceRNA network. Our findings can provide a potential target for the study of the occurrence, development, diagnosis, treatment, and prognosis of bladder cancer.

Advances in urinary biomarker discovery in urological research

A disease-specific biomarker (or biomarkers) is a characteristic reflecting a pathological condition in human body, which can be used as a diagnostic or prognostic tool for the clinical management. A urine-based biomarker(s) may provide a clinical value as attractive tools for clinicians to utilize in the clinical setting in particular to bladder diseases including bladder cancer and other bladder benign dysfunctions. Urine can be easily obtained by patients with no preparation or painful procedures required from patients' side. Currently advanced omics technologies and computational power identified potential omics-based novel biomarkers. An unbiased profiling based on transcriptomics, proteomics, epigenetics, metabolomics approaches et al. found that expression at RNA, protein, and metabolite levels are linked with specific bladder diseases and outcomes. In this review, we will discuss about the urine-based biomarkers reported by many investigators including us and how these biomarkers can be applied as a diagnostic and prognostic tool in clinical trials and patient care to promote bladder health. Furthermore, we will discuss how these promising biomarkers can be developed into a smart medical device and what we should be cautious about toward being used in real clinical setting.

Gelsolin-like actin-capping protein has prognostic value and promotes tumorigenesis and epithelial-mesenchymal transition via the Hippo signaling pathway in human bladder cancer

Background:

Transitional cell carcinoma (TCC) of the bladder, the major histologic subtype of bladder cancer, is increasing in incidence and mortality, which requires the identification of effective biomarkers. Actin-regulating proteins have recently been proposed as important antitumor druggable targets. As a gelsolin-family actin-modulating protein, CAPG (gelsolin-like actin-capping protein) generated great interest due to its crucial effects in various biological and physiological processes; however, the role and mechanism of CAPG in TCCs remain unknown.

Materials and methods:

Bioinformatic analysis and immunohistochemistry of clinical specimens were performed to detect the expression level of CAPG. Both in vitro and in vivo assays were used to determine the oncogenic effect of CAPG in TCCs. Male 4–5-week-old BALB/c nude mice were used for in vivo tumorigenesis assays, while SCID mice were used for in vivo metastatic assays. Affymetrix microarray was used to identify the underlying molecular mechanism. Western blot and immunofluorescence were used to validate the expression and localization of proteins.

Results:

CAPG was frequently upregulated in TCCs and associated with clinical aggressiveness and worse prognosis. Functional assays demonstrated that CAPG could contribute to the tumorigenesis, metastasis and epithelial-mesenchymal transition (EMT) of TCCs both in vitro and in vivo. A novel mechanism that CAPG promoted TCC development via inactivating the Hippo pathway, leading to a nucleus translocation of Yes-associated protein was suggested.

Conclusions:

The current study identified CAPG as a novel and critical oncogene in TCCs, supporting the pursuit of CAPG as a potential target for TCC intervention.

Low-risk non-muscle-invasive bladder cancer: Further prognostic stratification into the "very-low-risk" group based on tumor size

OBJECTIVE

To validate the significance of the entity of "very-low-risk" bladder cancer by analyzing the clinical outcomes of low-risk bladder cancer when further stratified by tumor size.

METHODS

We accessed our prospectively maintained, single-institution, electronic bladder cancer registry to extract the clinicopathological data of patients who were diagnosed with primary, solitary, Ta, low-grade tumors that were <3 cm. Patients were divided into two prognostic groups based on tumor size (≤1.0 cm vs >1.0 cm). The survival data of the two groups were compared for recurrence, progression and mortality.

RESULTS

A total of 165 patients were followed up for a median period of 79 months (interquartile range 47-118 months). A total of 45% (75/165) of the study cohort had tumors that were ≤1.0 cm. Recurrences were found in 40% (66/165) of the study cohort. On Kaplan-Meier analysis, patients with tumor size ≤1.0 cm had significantly longer time to recurrence (P < 0.001, log-rank test). Using multivariate Cox modeling, only tumor size >1.0 cm was significantly associated with shorter time to recurrence (HR 2.54, 95% CI 1.35-4.77, P = 0.004). Tumor size was not significantly associated with any differences in time to overall progression, muscle-invasive progression or overall mortality (P = 0.108, P = 0.362 and P = 0.225, respectively, log-rank test).

CONCLUSIONS

Low-risk bladder cancer can be further stratified based on tumor size. Larger tumors (>1.0 cm) are significantly associated with shorter time to recurrence compared with smaller tumors (≤1.0 cm). However, there were no significant differences in the probability of developing disease progression or overall mortality between larger and smaller tumors.

Canine Cancer Genomics: Lessons for Canine and Human Health

Dogs are second only to humans in medical surveillance and preventative health care, leading to a recent perception of increased cancer incidence. Scientific priorities in veterinary oncology have thus shifted, with a demand for cancer genetic screens, better diagnostics, and more effective therapies. Most dog breeds came into existence within the last 300 years, and many are derived from small numbers of founders. Each has undergone strong artificial selection, in which dog fanciers selected for many traits, including body size, fur type, color, skull shape, and behavior, to create novel breeds. The adoption of the breed barrier rule-no dog may become a registered member of a breed unless both its dam and its sire are registered members-ensures a relatively closed genetic pool within each breed. As a result, there is strong phenotypic homogeneity within breeds but extraordinary phenotypic variation between breeds. One consequence of this is the high level of breed-associated genetic disease. We and others have taken advantage of this to identify genes for a large number of canine maladies for which mouse models do not exist, particularly with regard to cancer.

Microchips for detection of exfoliated tumor cells in urine for identification of bladder cancer

Bladder cancer (BC) is a common malignancy, and it accounts for one of the highest management costs among urogenital cancers. As a non-invasive method, urine cytology plays an important role in the detection of exfoliated tumor cells (ETCs) for early diagnosis of BC. However, urine cytology suffers from its low sensitivity and reliance on microscopic examination. To address this issue, an integrated filtration device was developed with a pore size of 5 μm that isolated and enriched ETCs from discarded urine samples, and then quantified ETCs using a microchip ELISA method. The results revealed that the number of urinary ETCs from BC patients (n = 35) was obviously higher than the number of ETCs from healthy donors (n = 20). The ROC curve showed that the integrated filtration microfluidic device had a sensitivity of 77.1% when the specificity was set at 90% in identifying BC patients. Thus, the integrated filtration device holds great potential for the screening of BC or the follow-up analysis of treatment efficacy in point-of-care (POC) settings.

Next-generation sequencing (NGS) of cell-free circulating tumor DNA and tumor tissue in patients with advanced urothelial cancer: a pilot assessment of concordance

Background

Advances in cancer genome sequencing have led to the development of various next-generation sequencing (NGS) platforms. There is paucity of data regarding concordance of different NGS tests carried out in the same patient.

Methods

Here, we report a pilot analysis of 22 patients with metastatic urinary tract cancer and available NGS data from paired tumor tissue [FoundationOne (F1)] and cell-free circulating tumor DNA (ctDNA) [Guardant360 (G360)].

Results

The median time between the diagnosis of stage IV disease and the first genomic test was 23.5 days (0-767), after a median number of 0 (0-3) prior systemic lines of treatment of advanced disease. Most frequent genomic alterations (GA) were found in the genes TP53 (50.0%), TERT promoter (36.3%); ARID1 (29.5%); FGFR2/3 (20.5%), PIK3CA (20.5%) and ERBB2 (18.2%). While we identified GA in both tests, the overall concordance between the two platforms was only 16.4% (0%-50%), and 17.1% (0%-50%) for those patients (n = 6) with both tests conducted around the same time (median difference = 36 days). On the contrary, in the subgroup of patients (n = 5) with repeated NGS in ctDNA after a median of 1 systemic therapy between the two tests, average concordance was 55.5% (12.1%-100.0%). Tumor tissue mutational burden was significantly associated with number of GA in G360 report (P < 0.001), number of known GA (P = 0.009) and number of variants of unknown significance (VUS) in F1 report (P < 0.001), and with total number of GA (non-VUS and VUS) in F1 report (P < 0.001).

Conclusions

This study suggests a significant discordance between clinically available NGS panels in advanced urothelial cancer, even when collected around the same time. There is a need for better understanding of these two possibly complementary NGS platforms for better integration into clinical practice.

The evolution of bladder cancer genomics: What have we learned and how can we use it?

BACKGROUND

With advancements in molecular biology techniques, great progress has been made in the understanding of urothelial carcinoma pathogenesis.

OBJECTIVE

To examine the historic description of molecular alterations in bladder cancer and their evolution towards our current comprehension of the biology of the disease.

RESULTS

Historically, a two-pathway model was described from histological and cytogenetic studies: low-grade papillary non-muscle invasive bladder cancers (NMIBC) were described to arise from epithelial hyperplasia with loss of chromosome 9 as an early event, whereas muscle-invasive bladder cancers (MIBC) were considered to develop from dysplasia, associated with genetic instability. Although there could be connections between the 2 pathways, NMIBC and MIBC were largely believed to develop secondary to different molecular alterations. Next-generation sequencing has allowed important insights into cancer biology and a better understanding of the pathways involved in bladder cancer pathogenesis and heterogeneity. Urothelial carcinoma has been found to have a high frequency of somatic mutations compared to other solid tumors, including several mutations in multiple signaling pathways, such as cell cycle regulators (TP53, RB1), RTK/RAS/RAF pathway, PI3K/AKT/mTOR pathway and TERT gene promoter. Epigenetic changes and mutations in chromatin remodeling genes are especially frequent in bladder cancer. Mutations in FGFR3 and KDM6A are more common in NMIBC than in MIBC, whereas mutations in TP53 and KMT2D are more common in MIBC, suggesting the previously hypothesized 2 different pathways, with a subset of tumors progressing from NMIBC to MIBC. Using comprehensive RNA expression profiling studies, at least 5 subtypes of bladder cancer have been identified, the most fundamental division being Basal/Squamous-like and Luminal. These subtypes have different prognoses, natural histories and responses to systemic treatments: Luminal subtypes are enriched with papillary histology and have a better prognosis, while Basal/Squamous-like subtypes are enriched with squamous features, are associated with advanced stage at presentation, and portend a worse prognosis.

CONCLUSION

This new understanding of bladder cancer will optimistically translate into better understanding of this heterogeneous disease and lead to improvement in patient outcome and quality of life through better tailored treatments.

Identification of differentially expressed genes and biological pathways in bladder cancer

The purpose of the present study was to identify key genes and investigate the related molecular mechanisms of bladder cancer (BC) progression. From the Gene Expression Omnibus database, the gene expression dataset GSE7476 was downloaded, which contained 43 BC samples and 12 normal bladder tissues. GSE7476 was analyzed to screen the differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for the DEGs using the DAVID database, and a protein-protein interaction (PPI) network was then constructed using Cytoscape software. The results of the GO analysis showed that the upregulated DEGs were significantly enriched in cell division, nucleoplasm and protein binding, while the downregulated DEGs were significantly enriched in ‘extracellular matrix organization’, ‘proteinaceous extracellular matrix’ and ‘heparin binding’. The results of the KEGG pathway analysis showed that the upregulated DEGs were significantly enriched in the ‘cell cycle’, whereas the downregulated DEGs were significantly enriched in ‘complement and coagulation cascades’. JUN, cyclin-dependent kinase 1, FOS, PCNA, TOP2A, CCND1 and CDH1 were found to be hub genes in the PPI network. Sub-networks revealed that these gene were enriched in significant pathways, including the ‘cell cycle’ signaling pathway and ‘PI3K-Akt signaling pathway’. In summary, the present study identified DEGs and key target genes in the progression of BC, providing potential molecular targets and diagnostic biomarkers for the treatment of BC.

The Cancer Genome Atlas Project in Bladder Cancer

Bladder cancer (BC) remains an aggressive disease with a poor prognosis, especially for patients with metastatic disease who have a limited median overall survival of 14 months. Urothelial carcinomas harbor frequent molecular dysregulations including recurrent mutations and copy number alteration, some of which could be potential therapeutic targets. However, no molecularly targeted agents have been approved to date for the treatment of advanced BC. Gaining new insights into the molecular landscape of BC will be critical to tailor future targeted agents for the treatment of advanced disease. The Cancer Genome Atlas (TCGA) project is cataloguing the genetic and epigenetic alterations responsible for cancer through the application of high-throughput genome analysis techniques. After the landmark paper profiling 131 patients was published in 2014, additional patients have been added with an updated TCGA analysis now including 412 patients. This chapter will review the previously described genomic alterations reported in the first manuscript and the new major highlights found in the expanded analyses recently published. The aim will be to review how this comprehensive integrated genomic analysis can inform the design of precision medicine targeted therapy for the treatment of advanced disease.

Interleukin-17-positive mast cells influence outcomes from BCG for patients with CIS: Data from a comprehensive characterisation of the immune microenvironment of urothelial bladder cancer

The tumour immune microenvironment is considered to influence cancer behaviour and outcome. Using a panel of markers for innate and adaptive immune cells we set out to characterise and understand the bladder tumour microenvironment of 114 patients from a prospective multicentre cohort of newly-diagnosed bladder cancer patients, followed-up for 4.33±1.71 years. We found IL-17-positive cells were significantly increased in primary and concomitant carcinoma in situ (CIS), p<0.0001, a highly malignant lesion which is the most significant single risk factor for disease progression. Further characterisation of the tumour immunophenotype identified IL-17+ cells as predominantly mast cells rather than T-cells, in contrast to most other tumour types. Expression of the IL-17-receptor in bladder tumours, and functional effects and gene expression changes induced by IL-17 in bladder tumour cells in vitro suggest a role in tumour behaviour. Finally, we assessed the effects of IL-17 in the context of patient outcome, following intravesical BCG immunotherapy which is the standard of care; higher numbers of IL-17+ cells were associated with improved event-free survival (p = 0.0449, HR 0.2918, 95% CI 0.08762–0.9721) in patients with primary and concomitant CIS (n = 41), we propose a model of IL-17+ Mast cells mechanism of action. Thus, in the context of bladder CIS, IL-17+ mast cells predict favourable outcome following BCG immunotherapy indicative of a novel mechanism of BCG immunotherapy in UBC and could form the basis of a stratified approach to treatment.

Fluorescence in situ hybridization as prognostic predictor of tumor recurrence during treatment with Bacillus Calmette-Guérin therapy for intermediate- and high-risk non-muscle-invasive bladder cancer

A significant number of patients with intermediate- or high-risk bladder cancer treated with intravesical Bacillus Calmette-Guérin (BCG) immunotherapy are non-responders to this treatment. Since we cannot predict in which patients BCG therapy will fail, markers for responders are needed. UroVysion® is a multitarget fluorescence in situ hybridization (FISH) test for bladder cancer detection. The aim of this study was to evaluate whether FISH can be used to early identify recurrence during treatment with BCG. In a multicenter, prospective study, three bladder washouts at different time points during treatment (t 0 = week 0, pre-BCG, t 1 = 6 weeks following TURB, t 2 = 3 months following TURB) were collected for FISH from patients with bladder cancer treated with BCG between 2008 and 2013. Data on bladder cancer recurrence and duration of BCG maintenance therapy were recorded. Thirty-six (31.6%) out of 114 patients developed a recurrence after a median of 6 months (range 2-32). No significant association was found between a positive FISH test at t 0 or t 1 and risk of recurrence (p = 0.79 and p = 0.29). A positive t 2 FISH test was associated with a higher risk of recurrence (p = 0.001). Patients with a positive FISH test 3 months following TURB had a 4.0-4.6 times greater risk of developing a recurrence compared to patients with a negative FISH. Patients with a positive FISH test 3 months following TURB and induction BCG therapy have a higher risk of developing tumor recurrence. FISH can therefore be a useful additional tool for physicians when determining a treatment strategy.

Precursor Lesions of Urologic Malignancies

CONTEXT

- Precursor lesions of urologic malignancies are established histopathologic entities, which are important not only to recognize for clinical purposes, but also to further investigate at the molecular level in order to gain a better understanding of the pathogenesis of these malignancies.

OBJECTIVE

- To provide a brief overview of precursor lesions to the most common malignancies that develop within the genitourinary tract with a focus on their clinical implications, histologic features, and molecular characteristics.

DATA SOURCES

- Literature review from PubMed, urologic pathology textbooks, and the 4th edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs. All photomicrographs were taken from cases seen at Weill Cornell Medicine or from the authors' personal slide collections.

CONCLUSIONS

- The clinical importance and histologic criteria are well established for the known precursor lesions of the most common malignancies throughout the genitourinary tract, but further investigation is warranted at the molecular level to better understand the pathogenesis of these lesions. Such investigation may lead to better risk stratification of patients and potentially novel treatments.

Immunohistochemiocal subtyping using CK20 and CK5 can identify urothelial carcinomas of the upper urinary tract with a poor prognosis

PURPOSE

Genome-wide analyses revealed basal and luminal subtypes of urothelial carcinomas of the bladder. It is unknown if this subtyping can also be applied to upper tract urothelial carcinomas.

MATERIALS AND METHODS

Tumor samples from 222 patients with upper tract urothelial carcinomas who were treated with radical nephroureterectomy were analyzed for the expression of seven basal/luminal immunohistochemical markers (CK5, EGFR, CD44, CK20, p63, GATA3, FOXA1).

RESULTS

Hierarchical clustering revealed a basal-like subtype (enrichment of CK5, EGFR and CD44) in 23.9% and a luminal-like subtype (enrichment of CK20, GATA3, p63 and FOXA1) in 13.1% of the patients. In 60.8%, little to no markers were expressed, whereas markers of both subtypes were expressed in 2.2%. By using CK5 and CK20 as surrogate markers for the basal and luminal subtypes, we defined four subtypes of upper tract urothelial carcinomas: (i) exclusively CK20 positive and CK5 negative (CK20+/CK5-), (ii) exclusively CK5 positive and CK20 negative (CK20-/ CK5+), (iii) both markers positive (CK20+/CK5+) and (iv) both markers negative (CK20-/CK5-). A receiver-operator analysis provided the optimal cut-off values for this discrimination. An immunoreactive score >1 for CK5 and >6 for CK20 were defined as positive. In multivariate Cox's regression analysis, the CK20+/CK5- subtype was an independent negative prognostic marker with a 3.83-fold increased risk of cancer-specific death (p = 0.02) compared to the other three subtypes.

CONCLUSIONS

Immunohistochemical subgrouping of upper tract urothelial carcinomas by analyzing CK5 and CK20 expression can be performed in a routine setting and can identify tumors with a significantly worse cancer-specific survival prognosis.

Next-generation sequencing of urine specimens: A novel platform for genomic analysis in patients with non-muscle-invasive urothelial carcinoma treated with bacille Calmette-Guérin

BACKGROUND

Biopsies from patients with high-risk (HR) non-muscle-invasive urothelial carcinoma (NMIUC), especially flat urothelial carcinoma in situ, frequently contain scant diagnostic material or denuded mucosa only, and this precludes further extensive genomic analysis. This study evaluated the use of next-generation sequencing (NGS) analysis of urine cytology material from patients with HR NMIUC in an attempt to identify genetic alterations that might correlate with clinical features and responses to bacille Calmette-Guérin (BCG) treatment.

METHODS

Forty-one cytology slides from patients with HR NMIUC treated with intravesical BCG were selected for this study. Histological confirmation was available for all cases. The specimens were subjected to NGS analysis with a customized targeted exome capture assay composed of 341 genes.

RESULTS

In this cohort, genomic alterations were successfully identified in all cytology samples. Mutations were detected down to a 2% allele frequency and chromosomal rearrangements including copy number alterations and gene fusions were identified. The most frequently altered genes included telomerase reverse transcriptase (TERT), tumor protein 53 (TP53), Erb-B2 receptor tyrosine kinase 2 (ERBB2), and chromatin remodeling genes such as lysine demethylase 6A (KDM6A) and AT-rich interaction domain 1A (ARID1A). For patients with matched tumor tissue, cytology specimens revealed all mutations detected in tissue as well as additional mutations, and this suggested that urine might more effectively capture the full genetic heterogeneity of disease than an individual cystectomy. Alterations in multiple genes correlated with clinical and histopathological features, including responses to BCG treatment, flat architecture versus papillary architecture, and smoking history.

CONCLUSIONS

Urine specimens can replace tissue as a substrate for NGS analysis of HR NMIUC. Several genomic alterations identified in urine specimens might be associated with histological features and clinical characteristics. Cancer Cytopathol 2017;125:416-26. © 2017 American Cancer Society.

High expression of insulin receptor on tumour-associated blood vessels in invasive bladder cancer predicts poor overall and progression-free survival

Bladder cancer is a frequently recurring disease with a very poor prognosis once progressed to invasive stages, and tumour-associated blood vessels play a crucial role in this process. In order to identify novel biomarkers associated with progression, we isolated blood vascular endothelial cells (BECs) from human invasive bladder cancers and matched normal bladder tissue, and found that tumour-associated BECs greatly up-regulated the expression of insulin receptor (INSR). High expression of INSR on BECs of invasive bladder cancers was significantly associated with shorter progression-free and overall survival. Furthermore, increased expression of the INSR ligand IGF-2 in invasive bladder cancers was associated with reduced overall survival. INSR may therefore represent a novel biomarker to predict cancer progression. Mechanistically, we observed pronounced hypoxia in human bladder cancer tissue, and found a positive correlation between the expression of the hypoxia marker gene GLUT1 and vascular INSR expression, indicating that hypoxia drives INSR expression in tumour-associated blood vessels. In line with this, exposure of cultured BECs and human bladder cancer cell lines to hypoxia led to increased expression of INSR and IGF-2, respectively, and IGF-2 increased BEC migration through the activation of INSR in vitro. Taken together, we identified vascular INSR expression as a potential biomarker for progression in bladder cancer. Furthermore, our data suggest that IGF-2/INSR mediated paracrine crosstalk between bladder cancer cells and endothelial cells is functionally involved in tumour angiogenesis and may thus represent a new therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

CDK4/6 Inhibitors in Cancer Therapy: A Novel Treatement Strategy for Bladder Cancer

Patients with metastatic bladder cancer (mBC) treated with cisplatin-based chemotherapy have a limited median survival of only around 14 months [1]. Despite over 30 years of basic and clinical research, until recently no therapeutic options beyond cisplatin-based therapy had entered clinical routine and, at least in the US, none of the tested agents had been approved for second-line treatment. This has changed with the advent of immune checkpoint blockade, including especially PD-1/PD-L1 inhibitors. The high response rates of 24% over a 14.4 month follow up led to the first US Food and Drug Administration (FDA) approval for a second line therapy for these patients, and it is likely that this marks the beginning of a new era in the systemic treatment of muscle-invasive bladder cancer [2–4].

The strong clinical need to improve the medical management of this disease for those patients, not responding to current therapy has led to an increased molecular understanding of bladder cancer and has forstered the development of many potential molecular manipulations and targeted strategies beyond the new immune-oncologic approaches. Among the molecular alterations indentified in bladder cancer, cell cycle deregulation appears to be a key driver of disease progression. Target-directed therapy against CDK4/6 is an emerging strategy to regain control of cell cycle deregulation. Here, we provide an overview of the current status of CDK4/6 inhibitors in cancer therapy, their potential use in mBC and the challenges for their clinical use.

An integrated double-filtration microfluidic device for isolation, enrichment and quantification of urinary extracellular vesicles for detection of bladder cancer

Extracellular vesicles (EVs), including exosomes and microvesicles, are present in a variety of bodily fluids, and the concentration of these sub-cellular vesicles and their associated biomarkers (proteins, nucleic acids, and lipids) can be used to aid clinical diagnosis. Although ultracentrifugation is commonly used for isolation of EVs, it is highly time-consuming, labor-intensive and instrument-dependent for both research laboratories and clinical settings. Here, we developed an integrated double-filtration microfluidic device that isolated and enriched EVs with a size range of 30–200 nm from urine, and subsequently quantified the EVs via a microchip ELISA. Our results showed that the concentration of urinary EVs was significantly elevated in bladder cancer patients (n = 16) compared to healthy controls (n = 8). Receiver operating characteristic (ROC) analysis demonstrated that this integrated EV double-filtration device had a sensitivity of 81.3% at a specificity of 90% (16 bladder cancer patients and 8 healthy controls). Thus, this integrated device has great potential to be used in conjunction with urine cytology and cystoscopy to improve clinical diagnosis of bladder cancer in clinics and at point-of-care (POC) settings.

Residual tumor micro-foci and overwhelming regulatory T lymphocyte infiltration are the causes of bladder cancer recurrence

Bladder cancer has an unexplained, high recurrence rate. Causes of recurrence might include the presence of sporadic tumor micro-foci in the residual urothelial tissue after surgery associated with an inverted ratio between intratumoral effector and regulatory T cell subsets. Hence, surgical specimens of both tumors and autologous, macroscopically/histologically free-of-tumor tissues were collected from 28 and 20 patients affected by bladder or renal cancer, respectively. The frequencies of effector (IFNγ+ and IL17+ T cells) and regulatory (CD4+CD25hiCD127lo and CD8+CD28-CD127loCD39+ Treg) T cell subpopulations among tumor infiltrating lymphocytes were analyzed by immunofluorescence, while the gene expression of MAGE-A1 and MAGE-A2 tumor-associated antigens was studied by RT-PCR. The results show that both the T cell infiltrate and the frequency of MAGE-A1/A2 gene expression were comparable in tumors and in autologous free-of-tumor tissues in bladder cancer, while the autologous free-of-tumor renal tissues showed reduced T cell infiltrate and frequency of MAGE gene expression as compared to the autologous tumors. Importantly, the intra-tumor T effector/Treg cell ratio was consistently <1 in bladder cancer patients (n. 7) who relapsed within two years, while it was always >1 in patients (n. 6) without recurrence (regardless of tumor stage) (P = 0.0006, Odds ratio = 195). These unprecedented findings clarify the pathogenic mechanism of bladder cancer recurrence and suggest that microscopically undetectable micro-foci of tumor may predispose to recurrence when associated with an inverted intratumoral T effector/Treg cell ratio.

Invasive Bladder Cancer: Genomic Insights and Therapeutic Promise

Invasive bladder cancer, for which there have been few therapeutic advances in the past 20 years, is a significant medical problem associated with metastatic disease and frequent mortality. Although previous studies had identified many genetic alterations in invasive bladder cancer, recent genome-wide studies have provided a more comprehensive view. Here, we review those recent findings and suggest therapeutic strategies. Bladder cancer has a high mutation rate, exceeded only by lung cancer and melanoma. About 65% of all mutations are due to APOBEC-mediated mutagenesis. There is a high frequency of mutations and/or genomic amplification or deletion events that affect many of the canonical signaling pathways involved in cancer development: cell cycle, receptor tyrosine kinase, RAS, and PI-3-kinase/mTOR. In addition, mutations in chromatin-modifying genes are unusually frequent in comparison with other cancers, and mutation or amplification of transcription factors is also common. Expression clustering analyses organize bladder cancers into four principal groups, which can be characterized as luminal, immune undifferentiated, luminal immune, and basal. The four groups show markedly different expression patterns for urothelial differentiation (keratins and uroplakins) and immunity genes (CD274 and CTLA4), among others. These observations suggest numerous therapeutic opportunities, including kinase inhibitors and antibody therapies for genes in the canonical signaling pathways, histone deacetylase inhibitors and novel molecules for chromatin gene mutations, and immune therapies, which should be targeted to specific patients based on genomic profiling of their cancers.

Metformin represses bladder cancer progression by inhibiting stem cell repopulation via COX2/PGE2/STAT3 axis

Cancer stem cells (CSCs) are a sub-population of tumor cells playing essential roles in initiation, differentiation, recurrence, metastasis and development of drug resistance of various cancers, including bladder cancer. Although multiple lines of evidence suggest that metformin is capable of repressing CSC repopulation in different cancers, the effect of metformin on bladder cancer CSCs remains largely unknown. Using the N-methyl-N-nitrosourea (MNU)-induced rat orthotropic bladder cancer model, we demonstrated that metformin is capable of repressing bladder cancer progression from both mild to moderate/severe dysplasia lesions and from carcinoma in situ (CIS) to invasive lesions. Metformin also can arrest bladder cancer cells in G1/S phases, which subsequently leads to apoptosis. And also metformin represses bladder cancer CSC repopulation evidenced by reducing cytokeratin 14 (CK14+) and octamer-binding transcription factor 3/4 (OCT3/4+) cells in both animal and cellular models. More importantly, we found that metformin exerts these anticancer effects by inhibiting COX2, subsequently PGE2 as well as the activation of STAT3. In conclusion, we are the first to systemically demonstrate in both animal and cell models that metformin inhibits bladder cancer progression by inhibiting stem cell repopulation through the COX2/PGE2/STAT3 axis.

Claudin-low bladder tumors are immune infiltrated and actively immune suppressed

We report the discovery of a claudin-low molecular subtype of high-grade bladder cancer that shares characteristics with the homonymous subtype of breast cancer. Claudin-low bladder tumors were enriched for multiple genetic features including increased rates of RB1, EP300, and NCOR1 mutations; increased frequency of EGFR amplification; decreased rates of FGFR3, ELF3, and KDM6A mutations; and decreased frequency of PPARG amplification. While claudin-low tumors showed the highest expression of immune gene signatures, they also demonstrated gene expression patterns consistent with those observed in active immunosuppression. This did not appear to be due to differences in predicted neoantigen burden, but rather was associated with broad upregulation of cytokine and chemokine levels from low PPARG activity, allowing unopposed NFKB activity. Taken together, these results define a molecular subtype of bladder cancer with distinct molecular features and an immunologic profile that would, in theory, be primed for immunotherapeutic response.

The miR-130 family promotes cell migration and invasion in bladder cancer through FAK and Akt phosphorylation by regulating PTEN

Bladder cancer causes an estimated 150,000 deaths per year worldwide. Although 15% of the recurrent bladder cancer becomes an invasive type, currently used targeted therapy for malignant bladder cancer is still not efficient. We focused on the miR-130 family (miR-130b, miR-301a, and miR-301b) that was significantly upregulated in bladder cancer specimens than that of the normal urothelial specimens. We analyzed the functional significance of miR-130 family using a 5637 bladder cancer cell line and revealed that miR-130 family of inhibitors suppressed cell migration and invasion by downregulating focal adhesion kinase (FAK) and Akt phosphorylation. Mechanistic analyses indicate that the miR-130 family directly targets phosphatase and tensin homolog deleted from chromosome 10 (PTEN), resulting in the upregulation of FAK and Akt phosphorylation. In clinical bladder cancer specimens, downregulation of PTEN was found to be closely correlated with miR-130 family expression levels. Overall, the miR-130 family has a crucial role in malignant progression of bladder cancer and thus the miR-130 family could be a promising therapeutic target for invasive bladder cancer.

Deletion/duplication mutation screening of TP53 gene in patients with transitional cell carcinoma of urinary bladder using multiplex ligation-dependent probe amplification

Bladder cancer is a molecular disease driven by the accumulation of genetic, epigenetic, and environmental factors. The aim of this study was to detect the deletions/duplication mutations in TP53 gene exons using multiplex ligation-dependent probe amplification (MLPA) method in the patients with transitional cell carcinoma (TCC). The achieved formalin-fixed paraffin-embedded tissues from 60 patients with TCC of bladder were screened for exonal deletions or duplications of every 12 TP53 gene exons using MLPA. The pathological sections were examined by three pathologists and categorized according to the WHO scoring guideline as 18 (30%) grade I, 22 (37%) grade II, 13 (22%) grade III, and 7 (11%) grade IV cases of TCC. None mutation changes of TP53 gene were detected in 24 (40%) of the patients. Furthermore, mutation changes including, 15 (25%) deletion, 17 (28%) duplication, and 4 (7%) both deletion and duplication cases were observed among 60 samples. From 12 exons of TP53 gene, exon 1 was more subjected to exonal deletion. Deletion of exon 1 of TP53 gene has occurred in 11 (35.4%) patients with TCC. In general, most mutations of TP53, either deletion or duplication, were found in exon 1, which was statistically significant. In addition, no relation between the TCC tumor grade and any type of mutation were observed in this research. MLPA is a simple and efficient method to analyze genomic deletions and duplications of all 12 exons of TP53 gene. The finding of this report that most of the mutations of TP53 occur in exon 1 is in contrast to that of the other reports suggesting that exons 5-8 are the most (frequently) mutated exons of TP53 gene. The mutations of exon 1 of TP53 gene may play an important role in the tumorogenesis of TCC.

Gene expression test for the non-invasive diagnosis of bladder cancer: A prospective, blinded, international and multicenter validation study

OBJECTIVE

This study aimed to validate, in a prospective, blinded, international and multicenter cohort, our previously reported four non-invasive tests for bladder cancer (BC) diagnosis based on the gene expression patterns of urine.

METHODS

Consecutive voided urine samples from BC patients and controls were prospectively collected in five European centres (n=789). Finally, 525 samples were successfully analysed. Gene expression values were quantified using TaqMan Arrays and previously reported diagnostic algorithms were applied to gene expression data. Results from the most accurate gene signature for BC diagnosis were associated with clinical parameters using analysis of variance test.

RESULTS

High diagnostic accuracy for the four gene signatures was found in the independent validation set (area under curve [AUC]=0.903-0.918), with the signature composed of two genes (GS_D2) having the best performance (sensitivity: 81.48%; specificity: 91.26%; AUC: 0.918). The diagnostic accuracy of GS_D2 was not affected by the number of tumours (p=0.58) but was statistically associated with tumour size (p=0.008). Also, GS_D2 diagnostic accuracy increases with increasing BC tumour risk. We found no differences in the performance of the GS_D2 test among the populations and centres in detecting tumours (p=0.7) and controls (p=0.2).

CONCLUSIONS

Our GS_D2 test is non-invasive, non-observer dependent and non-labour-intensive, and has demonstrated diagnostic accuracy in an independent, international and multicenter study, equal or superior to the current gold standard (cystoscopy combined with cytology). Additionally, it has higher sensitivity than cytology while maintaining its specificity. Consequently, it meets the requirements for consideration as a molecular test applicable to clinical practice in the management of BC.

Cell adhesion and urothelial bladder cancer: the role of cadherin switching and related phenomena

Cadherins are mediators of cell-cell adhesion in epithelial tissues. E-cadherin is a known tumour suppressor and plays a central role in suppressing the invasive phenotype of cancer cells. However, the abnormal expression of N- and P-cadherin ('cadherin switching', CS) has been shown to promote a more invasive and m̀alignant phenotype of cancer, with P-cadherin possibly acting as a key mediator of invasion and metastasis in bladder cancer. Cadherins are also implicated in numerous signalling events related to embryonic development, tissue morphogenesis and homeostasis. It is these wide ranging effects and the serious implications of CS that make the cadherin cell adhesion molecules and their related pathways strong candidate targets for the inhibition of cancer progression, including bladder cancer. This review focuses on CS in the context of bladder cancer and in particular the switch to P-cadherin expression, and discusses other related molecules and phenomena, including EpCAM and the development of the cancer stem cell phenotype.

17-DMAG induces heat shock protein 90 functional impairment in human bladder cancer cells: knocking down the hallmark traits of malignancy

Heat shock protein 90 (Hsp90) is a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in multiple oncogenic signaling pathways. Hsp90 holds a prominent role in tumorigenesis, as numerous members of its broad clientele are involved in the generation of the hallmark traits of cancer. 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) specifically targets Hsp90 and interferes with its function as a molecular chaperone, impairing its intrinsic ATPase activity and undermining proper folding of multiple protein clients. In this study, we have examined the effects of 17-DMAG on the regulation of Hsp90-dependent tumorigenic signaling pathways directly implicated in cell cycle progression, survival, and motility of human urinary bladder cancer cell lines. We have used MTT-based assays, FACS analysis, Western blotting, semiquantitative PCR (sqPCR), immunofluorescence, and scratch-wound assays in RT4 (p53(wt)), RT112 (p53(wt)), T24 (p53(mt)), and TCCSUP (p53(mt)) human urinary bladder cancer cell lines. We have demonstrated that, upon exposure to 17-DMAG, bladder cancer cells display prominent cell cycle arrest and commitment to apoptotic and autophagic cell death, in a dose-dependent manner. Furthermore, 17-DMAG administration induced pronounced downregulation of multiple Hsp90 protein clients and other downstream oncogenic effectors, therefore causing inhibition of cell proliferation and decline of cell motility due to the molecular "freezing" of critical cytoskeletal components. In toto, we have clearly demonstrated the dose-dependent and cell type-specific effects of 17-DMAG on the hallmark traits of cancer, appointing Hsp90 as a key molecular component in bladder cancer targeted therapy.

Proteomics identification of PGAM1 as a potential therapeutic target for urothelial bladder cancer

Urothelial bladder cancer (UBC) is a major global health problem. There have been no major advances for the treatment of UBC in the last 30 years. In this study, we attempted to discover novel candidate therapeutic biomarkers for UBC. We utilized a two-dimensional polyacrylamide gel electrophoresis (2-DE) and ESI-Q-TOF MS/MS-based proteomic method to compare and identify differentially expressed proteins in UBC and adjacent normal tissues. Thirty five differentially expressed proteins (over 2-fold, p<0.05) were identified. Further cluster analysis revealed these proteins were mainly involved in metabolism, apoptosis regulation, calcium ion binding and so on. Among them, phosphoglycerate mutase 1 (PGAM1), significantly up-regulated in UBC, was selected for detailed analysis. Immunohistochemical data showed that increased expression of PGAM1 was correlated with the severity of histological grade. Knockdown of PGAM1 expression by RNAi contributed to a marked antitumor activity in vivo. Moreover, we found, upon attenuation of PGAM1, its substrate 3-PG (3-phosphoglycerate) was up-regulated and product 2-PG (2-phosphoglycerate) was down-regulated, which consequently inhibited aerobic glycolysis and oxidative pentose phosphate pathway (PPP) that are essential to cancer cell proliferation. Our finding showed that PGAM1 might serve as a promising therapeutic target for UBC.

Identification of a hypoxia-regulated miRNA signature in bladder cancer and a role for miR-145 in hypoxia-dependent apoptosis

BACKGROUND

Hypoxia leads to the stabilisation of the hypoxia-inducible factor (HIF) transcription factor that drives the expression of target genes including microRNAs (miRNAs). MicroRNAs are known to regulate many genes involved in tumourigenesis. The aim of this study was to identify hypoxia-regulated miRNAs (HRMs) in bladder cancer and investigate their functional significance.

METHODS

Bladder cancer cell lines were exposed to normoxic and hypoxic conditions and interrogated for the expression of 384 miRNAs by qPCR. Functional studies were carried out using siRNA-mediated gene knockdown and chromatin immunoprecipitations. Apoptosis was quantified by annexin V staining and flow cytometry.

RESULTS

The HRM signature for NMI bladder cancer lines includes miR-210, miR-193b, miR-145, miR-125-3p, miR-708 and miR-517a. The most hypoxia-upregulated miRNA was miR-145. The miR-145 was a direct target of HIF-1α and two hypoxia response elements were identified within the promoter region of the gene. Finally, the hypoxic upregulation of miR-145 contributed to increased apoptosis in RT4 cells.

CONCLUSIONS

We have demonstrated the hypoxic regulation of a number of miRNAs in bladder cancer. We have shown that miR-145 is a novel, robust and direct HIF target gene that in turn leads to increased cell death in NMI bladder cancer cell lines.

Correlating bladder cancer risk genes with their targeting microRNAs using MMiRNA-Tar

The Cancer Genome Atlas (TCGA) (http://cancergenome.nih.gov) is a valuable data resource focused on an increasing number of well-characterized cancer genomes. In part, TCGA provides detailed information about cancer-dependent gene expression changes, including changes in the expression of transcription-regulating microRNAs. We developed a web interface tool MMiRNA-Tar (http://bioinf1.indstate.edu/MMiRNA-Tar) that can calculate and plot the correlation of expression for mRNA-microRNA pairs across samples or over a time course for a list of pairs under different prediction confidence cutoff criteria. Prediction confidence was established by requiring that the proposed mRNA-microRNA pair appears in at least one of three target prediction databases: TargetProfiler, TargetScan, or miRanda. We have tested our MMiRNA-Tar tool through analyzing 53 tumor and 11 normal samples of bladder urothelial carcinoma (BLCA) datasets obtained from TCGA and identified 204 microRNAs. These microRNAs were correlated with the mRNAs of five previously-reported bladder cancer risk genes and these selected pairs exhibited correlations in opposite direction between the tumor and normal samples based on the customized cutoff criterion of prediction. Furthermore, we have identified additional 496 genes (830 pairs) potentially targeted by 79 significant microRNAs out of 204 using three cutoff criteria, i.e., false discovery rate (FDR)<0.1, opposite correlation coefficient between the tumor and normal samples, and predicted by at least one of three target prediction databases. Therefore, MMiRNA-Tar provides researchers a convenient tool to visualize the co-relationship between microRNAs and mRNAs and to predict their targeting relationship. We believe that correlating expression profiles for microRNAs and mRNAs offers a complementary approach for elucidating their interactions.