Bladder cancer outcome and subtype classification by gene expression

New advances in genitourinary cancer: evidence gathered in 2014

This review provides updated information published in 2014 regarding advances and major achievements in genitourinary cancer. Sections include the best in prostate cancer, renal cancer, bladder cancer, and germ cell tumors. In the field of prostate cancer, data related to treatment approach of hormone-sensitive disease, castrate-resistant prostate cancer, mechanisms of resistance, new drugs, and molecular research are presented. In relation to renal cancer, relevant aspects in the treatment of advanced renal cell carcinoma, immunotherapy, and molecular research, including angiogenesis and von Hippel-Lindau gene, molecular biology of non-clear cell histologies, and epigenetics of clear renal cell cancer are described. New strategies in the management of muscle-invasive localized bladder cancer and metastatic disease are reported as well as salient findings of biomolecular research in urothelial cancer. Some approaches intended to improve outcomes in poor prognosis patients with metastatic germ cell cancer are also reported. Results of clinical trials in these areas are discussed.

Comprehensive Transcriptional Analysis of Early-Stage Urothelial Carcinoma

Non-muscle-invasive bladder cancer (NMIBC) is a heterogeneous disease with widely different outcomes. We performed a comprehensive transcriptional analysis of 460 early-stage urothelial carcinomas and showed that NMIBC can be subgrouped into three major classes with basal- and luminal-like characteristics and different clinical outcomes. Large differences in biological processes such as the cell cycle, epithelial-mesenchymal transition, and differentiation were observed. Analysis of transcript variants revealed frequent mutations in genes encoding proteins involved in chromatin organization and cytoskeletal functions. Furthermore, mutations in well-known cancer driver genes (e.g., TP53 and ERBB2) were primarily found in high-risk tumors, together with APOBEC-related mutational signatures. The identification of subclasses in NMIBC may offer better prognostication and treatment selection based on subclass assignment.

Metformin and gefitinib cooperate to inhibit bladder cancer growth via both AMPK and EGFR pathways joining at Akt and Erk

EGFR is a potential therapeutic target for treating bladder cancer, but has not been approved for clinical use yet. Metformin is a widely used antidiabetic drug and has demonstrated interesting anticancer effects on various cancer models, alone or in combination with chemotherapeutic drugs. The efficacy of gefitinib, a well-known EGFR tyrosine kinase inhibitor, combined with metformin was assessed on bladder cancer and underlying mechanisms were explored. This drug combination induced a strong anti-proliferative and anti-colony forming effect and apoptosis in bladder cancer cell lines. Gefitinib suppressed EGFR signaling and inhibited phosphorylation of ERK and Akt. Metformin amplified this inhibitory effect and enhanced gefitinib-induced activation of AMPK signaling pathway. In vivo intravesical treatment of metformin and gefitinib on syngeneic orthotopic mice confirmed the significant inhibitory effect on bladder tumor growth. These two drugs may be an excellent combination for the treatment of bladder cancer through intravesical instillation.

Genetic subtypes of invasive bladder cancer

PURPOSE OF REVIEW

Recently completed cancer genomics projects identified intrinsic subtypes in muscle-invasive bladder cancers. Here we will describe the studies that led to their discovery and review their biological and clinical properties.

RECENT FINDINGS

Whole genome mRNA expression profiling and unsupervised hierarchical cluster analyses identified intrinsic basal and luminal subtypes in muscle-invasive bladder cancers that are similar to the ones found in breast cancer. Tumors within each subtype have distinct responses to conventional cisplatin-based combination chemotherapy, and they contain gene expression signatures and DNA alterations that may render them vulnerable to clinically available targeted therapies.

SUMMARY

Like their breast cancer counterparts, basal bladder cancers are characterized by poor clinical outcomes in the absence of effective systemic therapy, but a large fraction of them do respond to neoadjuvant chemotherapy, suggesting that the tumors should be managed aggressively. On the contrary, tumors that belong to the 'p53-like' subtype tend to be chemoresistant, so patients with these tumors should probably be managed differently. It seems likely that prospective identification of tumor intrinsic subtype membership could complement the use of DNA-based biomarkers to identify the groups of patients who will benefit the most from chemotherapy and targeted agents.

Novel non invasive diagnostic strategies in bladder cancer

Bladder cancer is one of the most commonly diagnosed malignancies worldwide, derived from the urothelium of the urinary bladder and defined by long asymptomatic and atypical clinical picture. Its complex etiopathogenesis is dependent on numerous risk factors that can be divided into three distinct categories: genetic and molecular abnormalities, chemical or environmental exposure and previous genitourinary disorders and family history of different malignancies. Various genetic polymorphisms and microRNA might represent useful diagnostic or prognostic biomarkers. Genetic and molecular abnormalities - risk factors are represented by miRNA or genetic polymorphisms proved to be part of bladder carcinogenesis such as: genetic mutations of oncogenes TP53, Ras, Rb1 or p21 oncoproteins, cyclin D or genetic polymorhisms of XPD,ERCC1, CYP1B1, NQO1C609T, MDM2SNP309, CHEK2, ERCC6, NRF2, NQO1Pro187Ser polymorphism and microRNA (miR-143, −145, −222, −210, −10b, 576-3p). The aim of our article is to highlight the most recent acquisitions via molecular biomarkers (miRNAs and genetic polymorphisms) involved in bladder cancer in order to provide early diagnosis, precise therapy according to the molecular profile of bladder tumors, as well as to improve clinical outcome, survival rates and life quality of oncological patients. These molecular biomarkers play a key role in bladder carcinogenesis, clinical evolution, prognosis and therapeutic response and explain the molecular mechanisms involved in bladder carcinogenesis; they can also be selected as therapeutic targets in developing novel therapeutic strategies in bladder malignancies. Moreover, the purpose in defining these molecular non invasive biomarkers is also to develop non invasive screening programs in bladder malignancies with the result of decreasing bladder cancer incidence in risk population.

Molecular substratification of bladder cancer: moving towards individualized patient management

Despite advances in surgical techniques, perioperative therapies and postoperative management, outcomes for patients with bladder cancer have largely remained unchanged. Current management of bladder cancer still relies on pathologic staging that does not always reflect the risk for an individual patient. Studies assessing molecular alterations in individual tumors are offering insights into the myriad of cellular pathways that are deregulated in bladder tumorigenesis and progression. Alterations in pathways involved in cell-cycle regulation, apoptosis, cell signaling, angiogenesis and tumor-cell invasion have been shown to influence disease behavior. High-throughput assays are now allowing multiplexed assessment of biomarker alterations, thereby enabling characterization of novel molecular subtypes of bladder cancer. Such approaches have also been used for discovery and validation of robust prognostic molecular signatures. The future of bladder cancer management will rely on the use of validated multimarker panels for risk stratification, optimal surgical management, and theranostic strategies to identify and target specific alterations in individual tumors.

Differentially expressed genes in metastatic advanced Egyptian bladder cancer

BACKGROUND

Bladder cancer is one of the most common cancers worldwide. Gene expression profiling using microarray technologies improves the understanding of cancer biology. The aim of this study was to determine the gene expression profile in Egyptian bladder cancer patients.

MATERIALS AND METHODS

Samples from 29 human bladder cancers and adjacent non-neoplastic tissues were analyzed by cDNA microarray, with hierarchical clustering and multidimensional analysis.

RESULTS

Five hundred and sixteen genes were differentially expressed of which SOS1, HDAC2, PLXNC1, GTSE1, ULK2, IRS2, ABCA12, TOP3A, HES1, and SRP68 genes were involved in 33 different pathways. The most frequently detected genes were: SOS1 in 20 different pathways; HDAC2 in 5 different pathways; IRS2 in 3 different pathways. There were 388 down-regulated genes. PLCB2 was involved in 11 different pathways, MDM2 in 9 pathways, FZD4 in 5 pathways, p15 and FGF12 in 4 pathways, POLE2 in 3 pathways, and MCM4 and POLR2E in 2 pathways. Thirty genes showed significant differences between transitional cell cancer (TCC) and squamous cell cancer (SCC) samples. Unsupervised cluster analysis of DNA microarray data revealed a clear distinction between low and high grade tumors. In addition 26 genes showed significant differences between low and high tumor stages, including fragile histidine triad, Ras and sialyltransferase 8 (alpha) and 16 showed significant differences between low and high tumor grades, like methionine adenosyl transferase II, beta.

CONCLUSIONS

The present study identified some genes, that can be used as molecular biomarkers or target genes in Egyptian bladder cancer patients.

MicroRNA-99a and 100 mediated upregulation of FOXA1 in bladder cancer

Urothelial cell carcinoma of the bladder (UCC) is a common disease often characterized by FGFR3 dysregulation. Whilst upregulation of this oncogene occurs most frequently in low-grade non-invasive tumors, recent data reveal increased FGFR3 expression characterizes a common sub-type of invasive UCC sharing molecular similarities with breast cancer. These similarities include upregulation of the FOXA1 transcription factor and reduced expression of microRNAs-99a/100. We have previously identified direct regulation of FGFR3 by these two microRNAs and now search for further targets. Using a microarray meta-database we find potential FOXA1 regulation by microRNAs-99a/100. We confirm direct targeting of the FOXA1 3′UTR by microRNAs-99a/100 and also potential indirect regulation through microRNA-485-5p/SOX5/JUN-D/FOXL1 and microRNA-486/FOXO1a. In 292 benign and malignant urothelial samples, we find an inverse correlation between the expression of FOXA1 and microRNAs-99a/100 (r=−0.33 to −0.43, p<0.05). As for FGFR3 in UCC, tumors with high FOXA1 expression have lower rates of progression than those with low expression (Log rank p=0.009). Using global gene expression and CpG methylation profiling we find genotypic consequences of FOXA1 upregulation in UCC. Genetic changes are associated with regional hypomethylation, occur near FOXA1 binding sites, and mirror gene expression changes previously reported in FGFR3 mutant-UCC. These include gene silencing through aberrant hypermethylation (e.g. IGFBP3) and affect genes characterizing breast cancer sub-types (e.g. ERBB2). In conclusion, we have identified microRNAs-99a/100 mediate a direct relationship between FGFR3 and FOXA1 and potentially facilitate cross talk between these pathways in UCC.

The multifaceted functions of sirtuins in cancer

The sirtuins (SIRTs; of which there are seven in mammals) are NAD(+)-dependent enzymes that regulate a large number of cellular pathways and forestall the progression of ageing and age-associated diseases. In recent years, the role of sirtuins in cancer biology has become increasingly apparent, and growing evidence demonstrates that sirtuins regulate many processes that go awry in cancer cells, such as cellular metabolism, the regulation of chromatin structure and the maintenance of genomic stability. In this article, we review recent advances in our understanding of how sirtuins affect cancer metabolism, DNA repair and the tumour microenvironment and how activating or inhibiting sirtuins may be important in preventing or treating cancer.

Intracellular Mono-ADP-Ribosylation in Signaling and Disease

A key process in the regulation of protein activities and thus cellular signaling pathways is the modification of proteins by post-translational mechanisms. Knowledge about the enzymes (writers and erasers) that attach and remove post-translational modifications, the targets that are modified and the functional consequences elicited by specific modifications, is crucial for understanding cell biological processes. Moreover detailed knowledge about these mechanisms and pathways helps to elucidate the molecular causes of various diseases and in defining potential targets for therapeutic approaches. Intracellular adenosine diphosphate (ADP)-ribosylation refers to the nicotinamide adenine dinucleotide (NAD⁺)-dependent modification of proteins with ADP-ribose and is catalyzed by enzymes of the ARTD (ADP-ribosyltransferase diphtheria toxin like, also known as PARP) family as well as some members of the Sirtuin family. Poly-ADP-ribosylation is relatively well understood with inhibitors being used as anti-cancer agents. However, the majority of ARTD enzymes and the ADP-ribosylating Sirtuins are restricted to catalyzing mono-ADP-ribosylation. Although writers, readers and erasers of intracellular mono-ADP-ribosylation have been identified only recently, it is becoming more and more evident that this reversible post-translational modification is capable of modulating key intracellular processes and signaling pathways. These include signal transduction mechanisms, stress pathways associated with the endoplasmic reticulum and stress granules, and chromatin-associated processes such as transcription and DNA repair. We hypothesize that mono-ADP-ribosylation controls, through these different pathways, the development of cancer and infectious diseases.

High APRIL expression correlates with unfavourable survival of gastrointestinal stromal tumour

A proliferation inducing ligand (APRIL) is a member of the tumour necrosis factor superfamily. High APRIL expression has been found to correlate with tumour development, suggesting that APRIL participates in oncogenesis. However, little is known about APRIL expression in gastrointestinal stromal tumours (GISTs) or the relationship between APRIL expression and the clinical characteristics of GIST. Therefore, we assessed the expression of APRIL immunohistochemically using a tissue microarray from 178 patients with GIST and evaluated the relationship between APRIL expression and patient prognosis. Strong APRIL expression was observed in 42.7% of GISTs, with APRIL expression significantly associated with tumour diameter, gross classification and tumour grade (p < 0.05 each). Kaplan-Meier analysis suggested that low APRIL expression and tumour size <5 cm were associated with longer overall survival. These findings indicate that APRIL expression is correlated with malignant GIST phenotypes and it may serve as an unfavourable prognostic marker in patients with GIST.

An online tool for evaluating diagnostic and prognostic gene expression biomarkers in bladder cancer

BACKGROUND

In the past ~15 years, the identification of diagnostic and prognostic biomarkers from gene expression data has increased our understanding of cancer biology and has led to advances in the personalized treatment of many cancers. A diagnostic biomarker is indicative of tumor status such as tumor stage, while a prognostic biomarker is indicative of disease outcome. Despite these advances, however, there are no clinically approved biomarkers for the treatment of bladder cancer, which is the fourth most common cancer in males in the United States and one of the most expensive cancers to treat. Although gene expression profiles of bladder cancer patients are publicly available, biomarker identification requires bioinformatics expertise that is not available to many research laboratories.

DESCRIPTION

We collected gene expression data from 13 publicly available patient cohorts (N = 1454) and developed BC-BET, an online Bladder Cancer Biomarker Evaluation Tool for evaluating candidate diagnostic and prognostic gene expression biomarkers in bladder cancer. A user simply selects a gene, and BC-BET evaluates the utility of that gene's expression as a diagnostic and prognostic biomarker. Specifically, BC-BET calculates how strongly a gene's expression is associated with tumor presence (distinguishing tumor from normal samples), tumor grade (distinguishing low- from high-grade tumors), tumor stage (distinguishing non-muscle invasive from muscle invasive samples), and patient outcome (e.g., disease-specific survival) across all patients in each cohort. Patients with low-grade, non-muscle invasive tumors and patients with high-grade, muscle invasive tumors are also analyzed separately in order to evaluate whether the biomarker of interest has prognostic value independent of grade and stage.

CONCLUSION

Although bladder cancer gene expression datasets are publicly available, their analysis is computationally intensive and requires bioinformatics expertise. BC-BET is an easy-to-use tool for rapidly evaluating bladder cancer gene expression biomarkers across multiple patient cohorts.

Patient Mutation Directed shRNA Screen Uncovers Novel Bladder Tumor Growth Suppressors

Next-generation sequencing (NGS) of human bladder cancer has revealed many gene alterations compared with normal tissue, with most being predicted to be "loss of function." However, given the high number of alterations, evaluating the functional impact of each is impractical. Here, we develop and use a high-throughput, in vivo strategy to determine which alterations are loss of function in tumor growth suppressors. Genes reported as altered by NGS in bladder cancer patients were bioinformatically processed by MutationTaster and MutationAssessor, with 283 predicted as loss of function. An shRNA lentiviral library targeting these genes was transduced into T24 cells, a nontumorigenic human bladder cancer cell line, followed by injection into mice. Tumors that arose were sequenced and the dominant shRNA constructs were found to target IQGAP1, SAMD9L, PCIF1, MED1, and KATNAL1 genes. In vitro validation experiments revealed that shRNA molecules directed at IQGAP1 showed the most profound increase in anchorage-independent growth of T24 cells. The clinical relevance of IQGAP1 as a tumor growth suppressor is supported by the finding that its expression is lower in bladder cancer compared with benign patient urothelium in multiple independent datasets. Lower IQGAP1 protein expression associated with higher tumor grade and decreased patient survival. Finally, depletion of IQGAP1 leads to increased TGFBR2 with TGFβ signaling, explaining in part how reduced IQGAP1 promotes tumor growth. These findings suggest IQGAP1 is a bladder tumor growth suppressor that works via modulating TGFβ signaling and is a potentially clinically useful biomarker.

IMPLICATIONS

This study used gene mutation information from patient-derived bladder tumor specimens to inform the development of a screen used to identify novel tumor growth suppressors. This included identification of the protein IQGAP1 as a potent bladder cancer growth suppressor.

Molecular markers in bladder cancer: Novel research frontiers

Bladder cancer (BC) is a heterogeneous disease encompassing distinct biologic features that lead to extremely different clinical behaviors. In the last 20 years, great efforts have been made to predict disease outcome and response to treatment by developing risk assessment calculators based on multiple standard clinical-pathological factors, as well as by testing several molecular markers. Unfortunately, risk assessment calculators alone fail to accurately assess a single patient's prognosis and response to different treatment options. Several molecular markers easily assessable by routine immunohistochemical techniques hold promise for becoming widely available and cost-effective tools for a more reliable risk assessment, but none have yet entered routine clinical practice. Current research is therefore moving towards (i) identifying novel molecular markers; (ii) testing old and new markers in homogeneous patients' populations receiving homogeneous treatments; (iii) generating a multimarker panel that could be easily, and thus routinely, used in clinical practice; (iv) developing novel risk assessment tools, possibly combining standard clinical-pathological factors with molecular markers. This review analyses the emerging body of literature concerning novel biomarkers, ranging from genetic changes to altered expression of a huge variety of molecules, potentially involved in BC outcome and response to treatment. Findings suggest that some of these indicators, such as serum circulating tumor cells and tissue mitochondrial DNA, seem to be easily assessable and provide reliable information. Other markers, such as the phosphoinositide-3-kinase (PI3K)/AKT (serine-threonine kinase)/mTOR (mammalian target of rapamycin) pathway and epigenetic changes in DNA methylation seem to not only have prognostic/predictive value but also, most importantly, represent valuable therapeutic targets. Finally, there is increasing evidence that the development of novel risk assessment tools combining standard clinical-pathological factors with molecular markers represents a major quest in managing this poorly predictable disease.

Biological determinants of bladder cancer gene expression subtypes

Molecular stratification of tumors by gene expression profiling has been applied to a large number of human malignancies and holds great promise for personalized treatment. Comprehensive classification schemes for urothelial carcinoma have been proposed by three separate groups but have not previously been evaluated simultaneously in independent data. Here we map the interrelations between the proposed molecular subtypes onto the intrinsic structure of a rich independent dataset and show that subtype stratification within each scheme can be explained in terms of a set of common underlying biological processes. We highlight novel biological and genomic drivers of urothelial carcinoma molecular subtypes and show that tumors carrying genomic aberrations characteristic of distinct molecular pathways converge on a common top level phenotype corresponding to the two major molecular subtypes of non-muscle invasive disease.

A microaliquoting technique for precise histological annotation and optimization of cell content in frozen tissue specimens

Knowledge of the exact cell content of frozen tissue samples is of growing importance in genomic research. We developed a microaliquoting technique to measure and optimize the cell composition of frozen tumor specimens for molecular studies. Frozen samples of 31 mesothelioma cases were cut in alternating thin and thick sections. Thin sections were stained and evaluated visually. Thick sections, i.e., microaliquots, were annotated using bordering stained sections. A range of cellular heterogeneity was observed among and within samples. Precise annotation of samples was obtained by integration and compared to conventional single face and "front and back"’ section estimates of cell content. Front and back estimates were more highly correlated with block annotation by microaliquoting than were single face estimates. Both methods yielded discrepant estimates, however, and for some studies may not adequately account for the heterogeneity of mesothelioma or other malignancies with variable cellular composition. High yield and quality RNA was extracted from precision annotated, tumor-enriched subsamples prepared by combining individual microaliquots with the highest tumor cellularity estimates. Microaliquoting provides accurate cell content annotation and permits genomic analysis of enriched subpopulations of cells without fixation or amplification.

The Prognostic Value of Cell Cycle Gene Expression Signatures in Muscle Invasive, High-Grade Bladder Cancer

Background:

Approximately half of patients with muscle invasive bladder cancer succumb to their disease. Previous work identified cell cycle related genes as a prognostic class of gene expression biomarkers in bladder cancer and found a specific 31-gene cell cycle proliferation (CCP) signature predicted outcome across multiple bladder cancer cohorts. However, the prognostic value of the CCP signature specifically in muscle invasive tumors was not evaluated.

Objective:

To determine the prognostic value of cycle related genes in patients with muscle invasive bladder cancers.

Method:

We collected all publicly available gene expression data for patients with high-grade, muscle invasive bladder cancer (8 cohorts, N = 458). We evaluated the CCP signature and two larger cell cycle gene sets: 1826 genes with a Gene Ontology (GO) annotation of “cell cycle” (GO-CCS) and 124 genes belonging to the “cell cycle” pathway in the KEGG pathway database (KEGG-CCS). An independently derived a sex identification gene signature (SIS) was developed as a positive control.

Results:

While SIS distinguished males from females in all cohorts with information about patient sex, the CCP signature was not prognostic in any of the cohorts we analyzed, and the GO-CCS and KEGG-CCS were never prognostic in more than 2 independent cohorts. Furthermore, neither the CCP, GO-CCS, nor KEGG-CCS signatures were consistently enriched in prognostic genes while SIS was enriched with genes associated with sex in all cohorts.

Conclusions:

Our findings suggest that cell cycle related genes have limited prognostic value in patients with high-grade, muscle invasive tumors. Their usefulness in predicting progression of noninvasive disease and patient response to chemotherapy remains to be determined.

Mitochondrial sirtuins and their relationships with metabolic disease and cancer

SIGNIFICANCE

Maintenance of metabolic homeostasis is critical for cellular and organismal health. Proper regulation of mitochondrial functions represents a crucial element of overall metabolic homeostasis. Mitochondrial sirtuins (SIRT3, SIRT4, and SIRT5) play pivotal roles in promoting this homeostasis by regulating numerous aspects of mitochondrial metabolism in response to environmental stressors.

RECENT ADVANCES

New work has illuminated multiple links between mitochondrial sirtuins and cancer. SIRT5 has been shown to regulate the recently described post-translational modifications succinyl-lysine, malonyl-lysine, and glutaryl-lysine. An understanding of these modifications is still in its infancy. Enumeration of SIRT3 and SIRT5 targets via advanced proteomic techniques promises to dramatically enhance insight into functions of these proteins.

CRITICAL ISSUES

In this review, we highlight the roles of mitochondrial sirtuins and their targets in cellular and organismal metabolic homeostasis. Furthermore, we discuss emerging roles for mitochondrial sirtuins in suppressing and/or promoting tumorigenesis, depending on the cellular and molecular context.

FUTURE DIRECTIONS

Currently, hundreds of potential SIRT3 and SIRT5 molecular targets have been identified in proteomic experiments. Future studies will need to validate the major targets of these enzymes, and elucidate how acetylation and/or acylation modulate their functionality. A great deal of interest exists in targeting sirtuins pharmacologically; this endeavor will require development of sirtuin-specific modulators (activators and inhibitors) as potential treatments for cancer and metabolic disease.

To be an ally or an adversary in bladder cancer: the NF-κB story has not unfolded

Signaling and regulation of transcription factor nuclear factor-kappaB (NF-κB) has been an area of extensive research since its first discovery nearly three decades ago. Members of the NF-κB family have been reported to critically mediate a multitude of responses in normal cells. Therefore, it is not surprising that NF-κB function can go awry and result in pathological conditions including cancer. Despite its critical importance, the functional role of NF-κB has not received the same attention in cancers of all tissue types. In the case of cancer of the urinary bladder, which is the second most common urologic cancer, the involvement of NF-κB in the development of superficial or muscle invasive disease and during cancer recurrence is rudimentary at best. Nuclear expression of p65/RelA is seen in bladder cancer patients and has been found to negatively affect survival of patients with superficial and muscle invasive disease. Despite these observations, the exact mechanism of NF-κB upregulation and function remains unknown. Furthermore, the emergence of a tumor suppressive role for NF-κB in recent years suggests that the family may play the role of a double-edged sword in cancer, which remains unexplored in bladder cancer. The challenge now is to delineate the increasing complexity of this pathway in the development and progression of bladder cancer. Here, we review key aspects of the current knowledge of signaling and regulation by the NF-κB family focusing on its controversial role in cancer and highlight the importance of studying NF-κB in bladder cancer in particular.

Increased expression of L-selectin (CD62L) in high-grade urothelial carcinoma: A potential marker for metastatic disease

INTRODUCTION

L-Selectin (CD62L) is a vascular adhesion molecule constitutively expressed on leukocytes with a primary function of directing leukocyte migration and homing of lymphocytes to lymph nodes. In a gene expression microarray study comparing laser-captured microdissected high-grade muscle-invasive bladder cancer (MIBC) without prior treatment and low-grade bladder cancer (LGBC) human samples, we found CD62L to be the highest differentially expressed gene. We sought to examine the differential expression of CD62L in MIBCs and its clinical relevance.

METHODS

Unfixed fresh and formalin-fixed paraffin-embedded human bladder cancer specimens and serum samples were obtained from the University of Connecticut Health Center tumor bank. Tumor cells were isolated from frozen tumor tissue sections by laser-captured microdissected followed by RNA isolation. Quantitative polymerase chain reaction was used to validate the level of CD62L transcripts. Immunohistochemistry and enzyme-linked immunosorbent assay were performed to evaluate the CD62L protein localization and expression level. Flow cytometry was used to identify the relative number of cells expressing CD62L in fresh tumor tissue. In silico studies were performed using the Oncomine database.

RESULTS

Immunostaining showed a uniformly higher expression of CD62L in MIBC specimens vs. LGBCs specimens. Further, CD62L localization was seen in foci of metastatic tumor cells in lymph node specimens from patients with high-grade MIBC and known nodal involvement. Up-regulated expression of CD62L was also observed by flow cytometric analysis of freshly isolated tumor cells from biopsies of high-grade cancers vs. LGBC specimens. Circulating CD62L levels were also found to be higher in serum samples from patients with high-grade metastatic vs. high-grade nonmetastatic MIBC. In addition, in silico analysis of Oncomine Microarray Database showed a significant correlation between CD62L expression and tumor aggressiveness and clinical outcomes.

CONCLUSION

These data confirm the expression of CD62L on urothelial carcinoma cells and suggest that CD62L may serve as biomarker to predict the presence of or risk for developing metastatic disease in patients with bladder cancer.

Molecular biomarkers for predicting outcomes in urothelial carcinoma of the bladder

Molecular biomarkers are used routinely in the clinical management of several tumours such as prostate, colon, ovarian and pancreatic cancer but management decisions in bladder cancer remain dependent on clinical and pathological criteria, which are limited in their ability to predict outcomes. Molecular markers are urgently needed in detection, surveillance and prognostication of bladder cancer as well as to predict treatment response to intravesical and systemic therapies. Advances in cancer genomics and platforms for biomarker profiling have led to a plethora of biomarkers, which must now be rigorously validated in the clinical setting. Pre-clinical and clinical studies exploring the role of emerging targeted therapies to risk stratify and reduce cancer progression are also needed.

Molecular biology of bladder cancer: new insights into pathogenesis and clinical diversity

Urothelial carcinoma of the bladder comprises two long-recognized disease entities with distinct molecular features and clinical outcome. Low-grade non-muscle-invasive tumours recur frequently but rarely progress to muscle invasion, whereas muscle-invasive tumours are usually diagnosed de novo and frequently metastasize. Recent genome-wide expression and sequencing studies identify genes and pathways that are key drivers of urothelial cancer and reveal a more complex picture with multiple molecular subclasses that traverse conventional grade and stage groupings. This improved understanding of molecular features, disease pathogenesis and heterogeneity provides new opportunities for prognostic application, disease monitoring and personalized therapy.

Discovery and validation of novel expression signature for postcystectomy recurrence in high-risk bladder cancer

Background

Nearly half of muscle-invasive bladder cancer patients succumb to their disease following cystectomy. Selecting candidates for adjuvant therapy is currently based on clinical parameters with limited predictive power. This study aimed to develop and validate genomic-based signatures that can better identify patients at risk for recurrence than clinical models alone.

Methods

Transcriptome-wide expression profiles were generated using 1.4 million feature-arrays on archival tumors from 225 patients who underwent radical cystectomy and had muscle-invasive and/or node-positive bladder cancer. Genomic (GC) and clinical (CC) classifiers for predicting recurrence were developed on a discovery set (n = 133). Performances of GC, CC, an independent clinical nomogram (IBCNC), and genomic-clinicopathologic classifiers (G-CC, G-IBCNC) were assessed in the discovery and independent validation (n = 66) sets. GC was further validated on four external datasets (n = 341). Discrimination and prognostic abilities of classifiers were compared using area under receiver-operating characteristic curves (AUCs). All statistical tests were two-sided.

Results

A 15-feature GC was developed on the discovery set with area under curve (AUC) of 0.77 in the validation set. This was higher than individual clinical variables, IBCNC (AUC = 0.73), and comparable to CC (AUC = 0.78). Performance was improved upon combining GC with clinical nomograms (G-IBCNC, AUC = 0.82; G-CC, AUC = 0.86). G-CC high-risk patients had elevated recurrence probabilities (P < .001), with GC being the best predictor by multivariable analysis (P = .005). Genomic-clinicopathologic classifiers outperformed clinical nomograms by decision curve and reclassification analyses. GC performed the best in validation compared with seven prior signatures. GC markers remained prognostic across four independent datasets.

Conclusions

The validated genomic-based classifiers outperform clinical models for predicting postcystectomy bladder cancer recurrence. This may be used to better identify patients who need more aggressive management.

High expression of GEM and EDNRA is associated with metastasis and poor outcome in patients with advanced bladder cancer

Background

The standard treatment for non-metastatic muscle-invasive bladder cancer (stages T2–T4a) is radical cystectomy with lymphadenectomy. However, patients undergoing cystectomy show metastatic spread in 25% of cases and these patients will have limited benefit from surgery. Identification of patients with high risk of lymph node metastasis will help select patients that may benefit from neoadjuvant and/or adjuvant chemotherapy.

Methods

RNA was procured by laser micro dissection of primary bladder tumors and corresponding lymph node metastases for Affymetrix U133 Plus 2.0 Gene Chip expression profiling. A publically available dataset was used for identification of the best candidate markers, and these were validated using immunohistochemistry in an independent patient cohort of 368 patients.

Results

Gene Set Enrichment Analysis showed significant enrichment for e.g. metastatic signatures in the metastasizing tumors, and a set of 12 genes significantly associated with lymph node metastasis was identified. Tumors did not cluster according to their metastatic ability when analyzing gene expression profiles using hierarchical cluster analysis. However, half (6/12) of the primary tumor clustered together with matching lymph node metastases, indicating a large degree of intra-patient similarity in these patients. Immunohistochemical analysis of 368 tumors from cystectomized patients showed high expression of GEM (P = 0.033; HR = 1.46) and EDNRA (P = 0.046; HR = 1.60) was significantly associated with decreased cancer-specific survival.

Conclusions

GEM and EDNRA were identified as promising prognostic markers for patients with advanced bladder cancer. The clinical relevance of GEM and EDNRA should be evaluated in independent prospective studies.

The role of EGFR family inhibitors in muscle invasive bladder cancer: a review of clinical data and molecular evidence

PURPOSE

Conventional platinum based chemotherapy for advanced urothelial carcinoma is plagued by common resistance to this regimen. Several studies implicate the EGFR family of RTKs in urothelial carcinoma progression and chemoresistance. Many groups have investigated the effects of inhibitors of this family in patients with urothelial carcinoma. This review focuses on the underlying molecular pathways that lead to urothelial carcinoma resistance to EGFR family inhibitors.

MATERIALS AND METHODS

We performed a PubMed® search for peer reviewed literature on bladder cancer development, EGFR family expression, clinical trials of EGFR family inhibitors and molecular bypass pathways. Research articles deemed to be relevant were examined and a summary of original data was created. Meta-analysis of expression profiles was also performed for each EGFR family member based on data sets accessible via Oncomine®.

RESULTS

Many clinical trials using inhibitors of EGFR family RTKs have been done or are under way. Those that have concluded with results published to date do not show an added benefit over standard of care chemotherapy in an adjuvant or second line setting. However, a neoadjuvant study using erlotinib before radical cystectomy demonstrated promising results.

CONCLUSIONS

Clinical and preclinical studies show that for reasons not currently clear prior treatment with chemotherapeutic agents rendered patients with urothelial carcinoma with muscle invasive bladder cancer resistant to EGFR family inhibitors as well. However, EGFR family inhibitors may be of use in patients with no prior chemotherapy in whom EGFR or ERBB2 is over expressed.

Amygdalin blocks bladder cancer cell growth in vitro by diminishing cyclin A and cdk2

Amygdalin, a natural compound, has been used by many cancer patients as an alternative approach to treat their illness. However, whether or not this substance truly exerts an anti-tumor effect has never been settled. An in vitro study was initiated to investigate the influence of amygdalin (1.25–10 mg/ml) on the growth of a panel of bladder cancer cell lines (UMUC-3, RT112 and TCCSUP). Tumor growth, proliferation, clonal growth and cell cycle progression were investigated. The cell cycle regulating proteins cdk1, cdk2, cdk4, cyclin A, cyclin B, cyclin D1, p19, p27 as well as the mammalian target of rapamycin (mTOR) related signals phosphoAkt, phosphoRaptor and phosphoRictor were examined. Amygdalin dose-dependently reduced growth and proliferation in all three bladder cancer cell lines, reflected in a significant delay in cell cycle progression and G0/G1 arrest. Molecular evaluation revealed diminished phosphoAkt, phosphoRictor and loss of Cdk and cyclin components. Since the most outstanding effects of amygdalin were observed on the cdk2-cyclin A axis, siRNA knock down studies were carried out, revealing a positive correlation between cdk2/cyclin A expression level and tumor growth. Amygdalin, therefore, may block tumor growth by down-modulating cdk2 and cyclin A. In vivo investigation must follow to assess amygdalin's practical value as an anti-tumor drug.

Más-o-menos: a simple sign averaging method for discrimination in genomic data analysis

MOTIVATION

The successful translation of genomic signatures into clinical settings relies on good discrimination between patient subgroups. Many sophisticated algorithms have been proposed in the statistics and machine learning literature, but in practice simpler algorithms are often used. However, few simple algorithms have been formally described or systematically investigated.

RESULTS

We give a precise definition of a popular simple method we refer to as más-o-menos, which calculates prognostic scores for discrimination by summing standardized predictors, weighted by the signs of their marginal associations with the outcome. We study its behavior theoretically, in simulations and in an extensive analysis of 27 independent gene expression studies of bladder, breast and ovarian cancer, altogether totaling 3833 patients with survival outcomes. We find that despite its simplicity, más-o-menos can achieve good discrimination performance. It performs no worse, and sometimes better, than popular and much more CPU-intensive methods for discrimination, including lasso and ridge regression.

AVAILABILITY AND IMPLEMENTATION

Más-o-menos is implemented for survival analysis as an option in the survHD package, available from http://www.bitbucket.org/lwaldron/survhd and submitted to Bioconductor.

Intrinsic basal and luminal subtypes of muscle-invasive bladder cancer

Whole-genome analyses have revealed that muscle-invasive bladder cancers (MIBCs) are heterogeneous and can be grouped into basal and luminal subtypes that are highly reminiscent of those found in breast cancer. Basal MIBCs are enriched with squamous and sarcomatoid features and are associated with advanced stage and metastatic disease at presentation. Like basal breast cancers, basal bladder tumours contain a claudin-low subtype that is enriched with biomarkers characteristic of epithelial-to-mesenchymal transition. The stem cell transcription factor ΔNp63α controls basal MIBC gene expression, just as it does in basal breast cancers. Luminal MIBCs are enriched with activating FGFR3 and ERBB3 mutations and ERBB2 amplifications, and their gene expression profiles are controlled by peroxisome proliferator activator receptor γ (PPARγ) and possibly also by oestrogen receptor activation. Luminal bladder cancers can be further subdivided into two subtypes, p53-like and luminal, which can be distinguished from one another by different levels of biomarkers that are characteristic of stromal infiltration, cell cycle progression, and proliferation. Importantly, basal bladder cancers are intrinsically aggressive, but are highly sensitive to cisplatin-based combination chemotherapy. Although the luminal subtypes are not as intrinsically aggressive as basal cancers, p53-like tumours are resistant to chemotherapy and might, therefore, represent a problem for treated patients.

Role in tumor growth of a glycogen debranching enzyme lost in glycogen storage disease

BACKGROUND

Bladder cancer is the most common malignancy of the urinary system, yet our molecular understanding of this disease is incomplete, hampering therapeutic advances.

METHODS

Here we used a genome-wide functional short-hairpin RNA (shRNA) screen to identify suppressors of in vivo bladder tumor xenograft growth (n = 50) using bladder cancer UMUC3 cells. Next-generation sequencing was used to identify the most frequently occurring shRNAs in tumors. Genes so identified were studied in 561 patients with bladder cancer for their association with stratification of clinical outcome by Kaplan-Meier analysis. The best prognostic marker was studied to determine its mechanism in tumor suppression using anchorage-dependent and -independent growth, xenograft (n = 20), and metabolomic assays. Statistical significance was determined using two-sided Student t test and repeated-measures statistical analysis.

RESULTS

We identified the glycogen debranching enzyme AGL as a prognostic indicator of patient survival (P = .04) and as a novel regulator of bladder cancer anchorage-dependent (P < .001), anchorage-independent (mean ± standard deviation, 180 ± 23.1 colonies vs 20±9.5 in control, P < .001), and xenograft growth (P < .001). Rescue experiments using catalytically dead AGL variants revealed that this effect is independent of AGL enzymatic functions. We demonstrated that reduced AGL enhances tumor growth by increasing glycine synthesis through increased expression of serine hydroxymethyltransferase 2.

CONCLUSIONS

Using an in vivo RNA interference screen, we discovered that AGL, a glycogen debranching enzyme, has a biologically and statistically significant role in suppressing human cancer growth.

Toll-like receptor 6 and connective tissue growth factor are significantly upregulated in mitomycin-C-treated urothelial carcinoma cells under hydrostatic pressure stimulation

BACKGROUND

Urothelial carcinoma (UC) is the most common histologic subtype of bladder cancer. The administration of mitomycin C (MMC) into the bladder after transurethral resection of the bladder tumor (TURBT) is a common treatment strategy for preventing recurrence after surgery. We previously applied hydrostatic pressure combined with MMC in UC cells and found that hydrostatic pressure synergistically enhanced MMC-induced UC cell apoptosis through the Fas/FasL pathways. To understand the alteration of gene expressions in UC cells caused by hydrostatic pressure and MMC, oligonucleotide microarray was used to explore all the differentially expressed genes.

RESULTS

After bioinformatics analysis and gene annotation, Toll-like receptor 6 (TLR6) and connective tissue growth factor (CTGF) showed significant upregulation among altered genes, and their gene and protein expressions with each treatment of UC cells were validated by quantitative real-time PCR and immunoblotting.

CONCLUSION

Under treatment with MMC and hydrostatic pressure, UC cells showed increasing apoptosis using extrinsic pathways through upregulation of TLR6 and CTGF.

[Squamous cell lesions of the urinary bladder]

BACKGROUND

Squamous cell carcinoma (SCC) and transitional carcinoma with squamous differentiation (SCC/TCC) are rare in western countries. Chronic inflammation and irritation of the urothelium are common risk factors for the development of SCC and TCC/SCC. Tumour biology of squamous cell cancer and precancerous squamous lesions is different from transitional cell cancer (TCC). Recent advances in molecular analysis of benign and malignant squamous cell lesions indicate that they are closely associated and might lead to improved bladder cancer subclassification in the future.

AIM

At present, the clinical management and therapy of SCC remains challenging, as scientific evidence based on prospective clinical trials is not available. We performed an analysis of available literature on natural history, treatment, and prognosis of SCC, SCC/TCC and metaplastic lesions. Furthermore, recent findings in molecular cancer biology are discussed with a focus on their relevance for SCC carcinogenesis.

Intrinsic subtypes of high-grade bladder cancer reflect the hallmarks of breast cancer biology

We sought to define whether there are intrinsic molecular subtypes of high-grade bladder cancer. Consensus clustering performed on gene expression data from a meta-dataset of high-grade, muscle-invasive bladder tumors identified two intrinsic, molecular subsets of high-grade bladder cancer, termed "luminal" and "basal-like," which have characteristics of different stages of urothelial differentiation, reflect the luminal and basal-like molecular subtypes of breast cancer, and have clinically meaningful differences in outcome. A gene set predictor, bladder cancer analysis of subtypes by gene expression (BASE47) was defined by prediction analysis of microarrays (PAM) and accurately classifies the subtypes. Our data demonstrate that there are at least two molecularly and clinically distinct subtypes of high-grade bladder cancer and validate the BASE47 as a subtype predictor. Future studies exploring the predictive value of the BASE47 subtypes for standard of care bladder cancer therapies, as well as novel subtype-specific therapies, will be of interest.

Identification of distinct basal and luminal subtypes of muscle-invasive bladder cancer with different sensitivities to frontline chemotherapy

Muscle-invasive bladder cancers (MIBCs) are biologically heterogeneous and have widely variable clinical outcomes and responses to conventional chemotherapy. We discovered three molecular subtypes of MIBC that resembled established molecular subtypes of breast cancer. Basal MIBCs shared biomarkers with basal breast cancers and were characterized by p63 activation, squamous differentiation, and more aggressive disease at presentation. Luminal MIBCs contained features of active PPARγ and estrogen receptor transcription and were enriched with activating FGFR3 mutations and potential FGFR inhibitor sensitivity. p53-like MIBCs were consistently resistant to neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy, and all chemoresistant tumors adopted a p53-like phenotype after therapy. Our observations have important implications for prognostication, the future clinical development of targeted agents, and disease management with conventional chemotherapy.

Robust prognostic gene expression signatures in bladder cancer and lung adenocarcinoma depend on cell cycle related genes

Few prognostic biomarkers are approved for clinical use primarily because their initial performance cannot be repeated in independent datasets. We posited that robust biomarkers could be obtained by identifying deregulated biological processes shared among tumor types having a common etiology. We performed a gene set enrichment analysis in 20 publicly available gene expression datasets comprising 1968 patients having one of the three most common tobacco-related cancers (lung, bladder, head and neck) and identified cell cycle related genes as the most consistently prognostic class of biomarkers in bladder (BL) and lung adenocarcinoma (LUAD). We also found the prognostic value of 13 of 14 published BL and LUAD signatures were dependent on cell cycle related genes, supporting the importance of cell cycle related biomarkers for prognosis. Interestingly, no prognostic gene classes were identified in squamous cell lung carcinoma or head and neck squamous cell carcinoma. Next, a specific 31 gene cell cycle proliferation (CCP) signature, previously derived in prostate tumors was evaluated and found predictive of outcome in BL and LUAD cohorts in univariate and multivariate analyses. Specifically, CCP score significantly enhanced the predictive ability of multivariate models based on standard clinical variables for progression in BL patients and survival in LUAD patients in multiple cohorts. We then generated random CCP signatures of various sizes and found sets of 10–15 genes had robust performance in these BL and LUAD cohorts, a finding that was confirmed in an independent cohort. Our work characterizes the importance of cell cycle related genes in prognostic signatures for BL and LUAD patients and identifies a specific signature likely to survive additional validation.

Epithelial mesenchymal transition status is associated with anti-cancer responses towards receptor tyrosine-kinase inhibition by dovitinib in human bladder cancer cells

Background

Dovitinib (TKI-258) is a receptor tyrosine kinase (RTK) inhibitor targeting fibroblast growth factor receptor (FGFR) and further related RTKs. TKI-258 is under investigation as anticancer drug for the treatment of various cancers including bladder cancer with aberrant RTK signaling. Here, we analyzed the responses of ten human bladder cancer cell lines towards TKI-258 treatment in relation to the epithelial mesenchymal transition (EMT) status of the cells.

Methods

Expression of epithelial marker E-cadherin as well as mesenchymal markers N-cadherin and vimentin was determined by quantitative RT-PCR and Western-blot in RNA and protein extracts from the cultured cell lines. The cell responses were analyzed upon addition of TKI-258 by viability/proliferation (XTT assay) and colony formation assay for measurement of cell contact independent growth.

Results

The investigated bladder cancer cell lines turned out to display quite different EMT patterns as indicated by the abundance of E-cadherin or N-cadherin and vimentin. Protein and mRNA levels of the respective components strongly correlated. Based on E-cadherin and N-cadherin mRNA levels that were expressed approximately mutual exclusively, an EMT-score was calculated for each cell line. A high EMT-score indicated mesenchymal-like cells and a low EMT-score epithelial-like cells. Then, we determined the IC₅₀ values for TKI-258 by dose response curves (0-12 μM TKI-258) in XTT assays for each cell line. Also, we measured the clonogenic survival fraction after adding TKI-258 (1 μM) by colony formation assay. We observed significant correlations between EMT-score and IC₅₀ values (r = 0.637, p = 0.0474) and between EMT-score and clonogenic survival fraction (r = 0.635, p = 0.0483) as analyzed by linear regression analyses.

Conclusions

In sum, we demonstrated that the EMT status based on E-cadherin and N-cadherin mRNA levels may be useful to predict responses towards TKI-258 treatment in bladder cancer.

Repression of cathepsin E expression increases the risk of mammary carcinogenesis and links to poor prognosis in breast cancer

Despite advances in detection and treatment for breast cancer (BC), recurrence and death rates remain unacceptably high. Therefore, more convenient diagnostic and prognostic methods still required to optimize treatments among the patients. Here, we report the clinical significance of the serum cathepsin E (CatE) activity as a novel prognostic marker for BC. Correlation analysis between the serum levels of CatE expression and clinicopathological parameters revealed that the activity levels, but not the protein levels, were negatively associated with the stages and progression of BC. Univariate and multivariate analyses demonstrated that the serum CatE activity was significantly correlated with favorable prognostic outcomes of the patients. The functional link of CatE expression to BC progression was further corroborated by in vivo and in vitro studies with mice exhibiting different levels of CatE expression. Multiparous CatE (-) (/) (-) mice spontaneously developed mammary tumors concomitant with morphological transformation and altered growth characteristics of the mammary glands. These alterations were associated in part with the induction of epithelial-mesenchymal transition and the activation of β-catenin-dependent pathway in mammary cells. Loss of CatE strongly induced the translocation and accumulation of Wnt5a in the nuclei, thereby leading to the aberrant trafficking, maturation and secretion of Wnt5a and the impaired signaling. The interaction of CatE and Wnt5a was verified by proximity ligation assay and by knockdown or restoration of CatE expression in the mammary cells. Consequently, our data demonstrate that CatE contributes to normal growth and development of mammary glands through proper trafficking and secretion of Wnt5a.

Microarray gene expression profiling and analysis of bladder cancer supports the sub-classification of T1 tumours into T1a and T1b stages

OBJECTIVE

To try and identify a molecular signature for pathological staging and/or grading. through microarray analysis.

PATIENTS AND METHODS

We performed a prospective multicentre study between September 2007 and May 2008 that included 108 bladder tumours (45 pTa, 35 pT1 and 28>pT1). Microarray analysis was performed using Agilent Technologies Human Whole Genome 4 × 44K oligonucleotide microarrays (Agilent, Santa Clara, CA, USA). A 'dual colour' method was used vs a reference pool of tumours. From the lists of genes provided by the Biometric Research Branch class comparison analyses, we validated the microarray results of 38 selected differentially expressed genes using reverse transcriptase quantitative PCR in another bladder tumour cohort (n = 95).

RESULTS

The cluster 'superficial vs invasive stage' correctly classified 92.9% of invasive stages and 66.3% of superficial stages. Among the superficial tumours, the cluster analysis showed that pT1b tumours were closer to invasive stages than pT1a tumours. We also found molecular differences between low and high grade superficial tumours, but these differences were less well defined than the difference observed for staging.

CONCLUSIONS

We confirmed that the histopathological classification into subgroups pTa, pT1a and pT1b can be translated into a molecular signature with a continuous progression of deregulation (overexpression or repression of these genes) from superficial (pTa) to more invasive (pT1a then b) stages.

Suppression of ERβ signaling via ERβ knockout or antagonist protects against bladder cancer development

Epidemiological studies showed that women have a lower bladder cancer (BCa) incidence, yet higher muscle-invasive rates than men, suggesting that estrogen and the estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), may play critical roles in BCa progression. Using in vitro cell lines and an in vivo carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced mouse BCa model, we found that ERβ plays a positive role in promoting BCa progression. Knockdown of ERβ with ERβ-shRNA in ERβ-positive human BCa J82, 647v and T24 cell lines led to suppressed cell growth and invasion. Mice lacking ERβ have less cancer incidence with reduced expression of the proliferation marker Ki67 in BBN-induced BCa. Consistently, our results show that non-malignant urothelial cells with ERβ knockdown are more resistant to carcinogen-induced malignant transformation. Mechanism dissection found that targeting ERβ suppressed the expression of minichromosome maintenance complex component 5 (MCM5), a DNA replication licensing factor that is involved in tumor cell growth. Restoring MCM5 expression can partially reverse ERβ knockdown-mediated growth reduction. Supportively, treating cells with the ERβ-specific antagonist, 4-[2-Phenyl-5,7-bis(trifluoromethyl) pyrazolo[1,5-a]pyrimidin-3-yl]phenol (PHTPP), reduced BCa cell growth and invasion, as well as MCM5 expression. Furthermore, we provide the first evidence that BCa burden and mortality can be controlled by PHTPP treatment in the carcinogen-induced BCa model. Together, these results demonstrate that ERβ could play positive roles in promoting BCa progression via MCM5 regulation. Targeting ERβ through ERβ-shRNA, PHTPP or via downstream targets, such as MCM5, could serve as potential therapeutic approaches to battle BCa.

Gene profiling suggests a common evolution of bladder cancer subtypes

Background

Bladder cancer exists as several distinct subtypes, including urothelial carcinoma (UCa), squamous cell carcinoma (SCCa), adenocarcinoma and small cell carcinoma. These entities, despite showing distinct morphology and clinical behavior, arise from the urothelial lining and are often accompanied by similar precursor/in situ findings. The relationship between these subtypes has not been explored in detail.

Methods

We compared gene expression analysis of the two most common subtypes of bladder cancer, UCa (n = 10) and SCCa (n = 9), with an additional comparison to normal urothelium from non-cancer patients (n = 8) using Affymetrix GeneChip Human genome arrays (Affymetrix, Santa Clara, CA). The results were stratified by supervised and unsupervised clustering analysis, as well as by overall fold change in gene expression.

Results

When compared to normal urothelium, UCa showed differential expression of 155 genes using a 5-fold cut-off. Examples of differentially regulated genes included topoisomerases, cancer-related transcription factors and cell cycle mediators. A second comparison of normal urothelium to SCCa showed differential expression of 503 genes, many of which were related to squamous-specific morphology (desmosomal complex, intermediate filaments present within squamous epithelium, squamous cornifying proteins, and molecules upregulated in squamous carcinomas from other anatomic sites). When compared, 137 genes were commonly dysregulated in both UCa and SCCa as compared to normal urothelium. All dysregulated genes in UCa were shared in common with SCCa, with the exception of only 18 genes. Supervised clustering analysis yielded correct classification of lesions in 26/27 (96%) of cases and unsupervised clustering analysis yielded correct classification in 25/27 (92.6%) of cases.

Conclusions

The results from this analysis suggest that bladder SCCa shares a significant number of gene expression changes with conventional UCa, but also demonstrates an additional set of alterations that is unique to this entity that defines the squamous phenotype. The similarity in deregulated gene products suggests that SCCa may be a much more closely related entity at the molecular level to conventional UCa than previously hypothesized.

Urinary biomarkers of bladder cancer: an update and future perspectives

Bladder cancer is one of the most prevalent cancers worldwide. Early detection of bladder tumors is critical for improved patient outcomes. The standard method for detection and surveillance of bladder tumors is cystoscopy with urinary cytology. Limitations of cystoscopy and urinary cytology have brought to light the need for more robust diagnostic assays. Ideally, such assays would be applicable to noninvasively obtained, voided urine, and be designed not only for diagnosis, but also for monitoring disease recurrence and response to therapy. Consequently, the development of a noninvasive urine-based assay would be of tremendous benefit to both patients and healthcare systems. This article reports some of the more prominent urine-based biomarkers reported in the literature. In addition, some new technologies that have been used to identify novel urinary biomarkers are highlighted.

Bladder cancer detection and monitoring: assessment of urine- and blood-based marker tests

Bladder cancer is one of the most prevalent cancers worldwide, but the treatment and management of this disease can be very successful if the disease is detected early. The development of molecular assays that could diagnose bladder cancer accurately, and at an early stage, would be a significant advance. Ideally, such molecular assays would be applicable to non-invasively obtained body fluids, and be designed not only for diagnosis but also for monitoring disease recurrence and response to treatment. In this article, we assess the performance of current diagnostic assays for bladder cancer and discuss some of the emerging biomarkers that could be developed to augment current bladder cancer detection strategies.