Uroplakin gene expression in normal human tissues and locally advanced bladder cancer

Urothelial carcinoma in a mule

Equine bladder neoplasms are rare. This report aimed to describe the clinical signs and treatment of urothelial carcinoma (UC) in a mule. Cystoscopy of a 20-year-old female mule with a one-week history of hematuria and anemia revealed vascular congestion in the mucosa and an intraluminal, pedunculated mass in the dorsal bladder region. Histopathological examination revealed UC. Initial therapy consisted of four weekly cystoscopic guided injections of fluorouracil. At the fourth chemotherapy session, a paler and more friable tumor mass was observed. Consequently, we opted to surgically remove it during cystoscopy. Following mass excision, patient comfort, gross appearance of urine, and the hematocrit returned to normal. Repeat cystoscopy examinations revealed no gross appearance of tumor recurrence 18 months after treatment. Bladder neoplasms clinically resemble urolithiasis and cystitis and should be considered a differential diagnosis in cases of anemia and hematuria.

Gene of the month: the uroplakins

Uroplakins are a family of membrane-spanning proteins highly specific to the urothelium. There are four uroplakin proteins in humans. These are encoded by the following UPK genes: UPK1A, UPK1B, UPK2 and UPK3 Uroplakin proteins span the apical membrane of umbrella cells of the urothelium, where they associate into urothelial plaques. This provides a barrier function to prevent passage of urine across the urothelium in the renal pelvis, ureters, and bladder. Uroplakins are also involved in developmental processes such as nephrogenesis. The specific localisation of uroplakins within the urothelium means that they are often expressed in primary and metastatic urothelial cell carcinoma and may be used as an immunohistochemical marker of urothelial malignancy.

Alterations in gene expression and microbiome composition upon calcium-sensing receptor deletion in the mouse esophagus

The calcium-sensing receptor (CaSR), a G protein-coupled receptor, regulates Ca2+ concentration in plasma by regulating parathyroid hormone secretion. In other tissues, it is reported to play roles in cellular differentiation and migration and in secretion and absorption. We reported previously that CaSR can be conditionally deleted in the mouse esophagus. This conditional knockout (KO) (EsoCaSR-/-) model showed a significant reduction in the levels of adherens and tight junction proteins and had a marked buildup of bacteria on the luminal esophageal surface. To further examine the role of CaSR, we used RNA sequencing to determine gene expression profiles in esophageal epithelia of control and EsoCaSR-/-mice RNA Seq data indicated upregulation of gene sets involved in DNA replication and cell cycle in EsoCaSR-/-. This is accompanied by the downregulation of gene sets involved in the innate immune response and protein homeostasis including peptide elongation and protein trafficking. Ingenuity pathway analysis (IPA) demonstrated that these genes are mapped to important biological networks including calcium and Ras homologus A (RhoA) signaling pathways. To further explore the bacterial buildup in EsoCaSR-/- esophageal tissue, 16S sequencing of the mucosal-associated bacterial microbiome was performed. Three bacterial species, g_Rodentibacter, s_Rodentibacter_unclassified, and s_Lactobacillus_hilgardi were significantly increased in EsoCaSR-/-. Furthermore, metagenomic analysis of 16S sequences indicated that pathways related to oxidative phosphorylation and metabolism were downregulated in EsoCaSR-/- tissues. These data demonstrate that CaSR impacts major pathways of cell proliferation, differentiation, cell cycle, and innate immune response in esophageal epithelium. The disruption of these pathways causes inflammation and significant modifications of the microbiome.NEW & NOTEWORTHY Calcium-sensing receptor (CaSR) plays a significant role in maintaining the barrier function of esophageal epithelium. Using RNA sequencing, we show that conditional deletion of CaSR from mouse esophagus causes upregulation of genes involved in DNA replication and cell cycle and downregulation of genes involved in the innate immune response, protein translation, and cellular protein synthesis. Pathway analysis shows disruption of signaling pathways of calcium and actin cytoskeleton. These changes caused inflammation and esophageal dysbiosis.

UPK1B promoted the invasion and stem cell characteristics of non-small cell lung cancer cells by modulating c-myc/Sox4 axis

Non-small cell lung cancer (NSCLC) is a malignant tumor with extremely high mortality. Uroplakin1B (UPK1B) promotes the occurrence and development of multiple types of cancer by enhancing the expression of c-myc and Sox4. However, whether UPK1B can modulate the development of NSCLC by regulating c-myc/Sox4 axis is unclear. In this study, UPK1B was overexpressed or knocked down in the non-small cell lung cancer cells (NSCLCs) were. Next, the proliferation and invasion of those cells were detected with the EdU staining and transwell assays. Sphere formation assays was performed to examine the stem cell characteristics of those cells. Then, we overexpressed the Sox4 in UPK1B knockdown cells and determined the proliferation and invasion of those cells. Our results showed that UPK1B promoted the proliferation, invasion and stem cell characteristics of NSCLCs. In addition, UPK1B enhanced the expression of c-myc, Sox4 and stem cell associated proteins in those cells. Overexpression of Sox4 rescued the proliferation and invasion of NSCLCs, which were suppressed by the UPK1B knockdown. In summary, our study suggested that UPK1B enhanced the invasiveness and stem cell characteristics of NSCLCs by activating c-myc/UPK1B axis.

Selective inhibition of integrin αvβ6 leads to rapid induction of urinary bladder tumors in cynomolgus macaques

Administration of a novel and selective small molecule integrin αvβ6 inhibitor, MORF-627, to young cynomolgus monkeys for 28 days resulted in the rapid induction of epithelial proliferative changes in the urinary bladder of 2 animals, in the absence of test agent genotoxicity. Microscopic findings included suburothelial infiltration by irregular nests and/or trabeculae of epithelial cells, variable cytologic atypia, and high mitotic rate, without invasion into the tunica muscularis. Morphologic features and patterns of tumor growth were consistent with a diagnosis of early-stage invasive urothelial carcinoma. Ki67 immunohistochemistry demonstrated diffusely increased epithelial proliferation in the urinary bladder of several monkeys, including those with tumors, and αvβ6 was expressed in some epithelial tissues, including urinary bladder, in monkeys and humans. Spontaneous urothelial carcinomas are extremely unusual in young healthy monkeys, suggesting a direct link of the finding to the test agent. Inhibition of integrin αvβ6 is intended to locally and selectively block transforming growth factor beta (TGF-β) signaling, which is implicated in epithelial proliferative disorders. Subsequent in vitro studies using a panel of integrin αvβ6 inhibitors in human bladder epithelial cells replicated the increased urothelial proliferation observed in monkeys and was reversed through exogenous application of TGF-β. Moreover, analysis of in vivo models of liver and lung fibrosis revealed evidence of epithelial hyperplasia and cell cycle dysregulation in mice treated with integrin αvβ6 or TGF-β receptor I inhibitors. The cumulative evidence suggests a direct link between integrin αvβ6 inhibition and decreased TGF-β signaling in the local bladder environment, with implications for epithelial proliferation and carcinogenesis.

Large-scale human tissue analysis identifies Uroplakin 1a as a putative diagnostic marker for urothelial cancer

Uroplakin 1A (Upk1a) protein is relevant for stabilizing and strengthening urothelial cells and helps to prevent them from rupturing during bladder distension. Based on RNA expression data Upk1a is expressed in a limited number of normal tissues and tumors. To comprehensively evaluate the potential diagnostic and prognostic utility of Upk1a immunohistochemistry, a tissue microarray containing 6929 samples from 115 different tumor types and subtypes and 608 samples of 76 different normal tissue types was analyzed. Upk1a positivity was found in 34 (29.6 %) different tumor types including 9 (7.8 %) tumor types with at least one strongly positive case. The highest rates of Upk1a positivity were seen in various subtypes of urothelial neoplasms (42.6-98 %) including Brenner tumors of the ovary (64.9 %) followed by neoplasms of the thyroid (10.4-33.3 %). In urothelial tumors, Upk1a staining predominated at the cell membranes and staining intensity was often moderate to strong. In thyroidal neoplasms the staining was mostly purely cytoplasmic and of low to moderate intensity. Upk1a positivity was also seen in up to 15 % of cases in 25 additional tumor categories but the staining intensity was often cytoplasmic and the intensity was usually judged as weak and only rarely as moderate. Within non-invasive (pTa) tumors, the Upk1a positivity rate decreased from 94 % in pTa G2 (low grade) to 90.1 % in pTa G3 (p = 0.012) and was even lower in muscle-invasive carcinomas (41.5 %; p < 0.0001 vs pTaG3). Within muscle invasive carcinomas, Upk1a expression was unrelated to nodal metastasis (p > 0.05) and patient outcome (p > 0.05). In conclusion, Upk1a immunohistochemistry is a potentially useful and specific diagnostic marker for the distinction of urothelial carcinomas from other neoplasms. However, its sensitivity is less than 50 % in muscle-invasive cancers because Upk1a expression decreases during grade and stage progression.

The Golgi complex: An organelle that determines urothelial cell biology in health and disease

The Golgi complex undergoes considerable structural remodeling during differentiation of urothelial cells in vivo and in vitro. It is known that in a healthy bladder the differentiation from the basal to the superficial cell layer leads to the formation of the tightest barrier in our body, i.e., the blood–urine barrier. In this process, urothelial cells start expressing tight junctional proteins, apical membrane lipids, surface glycans, and integral membrane proteins, the uroplakins (UPs). The latter are the most abundant membrane proteins in the apical plasma membrane of differentiated superficial urothelial cells (UCs) and, in addition to well-developed tight junctions, contribute to the permeability barrier by their structural organization and by hindering endocytosis from the apical plasma membrane. By studying the transport of UPs, we were able to demonstrate their differentiation-dependent effect on the Golgi architecture. Although fragmentation of the Golgi complex is known to be associated with mitosis and apoptosis, we found that the process of Golgi fragmentation is required for delivery of certain specific urothelial differentiation cargoes to the plasma membrane as well as for cell–cell communication. In this review, we will discuss the currently known contribution of the Golgi complex to the formation of the blood–urine barrier in normal UCs and how it may be involved in the loss of the blood–urine barrier in cancer. Some open questions related to the Golgi complex in the urothelium will be highlighted.

Large-scale human tissue analysis identifies Uroplakin 1b as a putative diagnostic marker in surgical pathology

Uroplakin 1B (Upk1b) stabilizes epithelial cells lining the bladder lumen to prevent rupturing during bladder distension. Little is known about Upk1b expression in other normal and malignant tissues. To comprehensively evaluate the potential diagnostic and prognostic utility of Upk1b expression analysis, a tissue microarray containing 14,061 samples from 127 different tumor types and subtypes and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. Upk1b immunostaining was found in 61 (48%) different tumor types including 50 (39%) with at least one moderately positive and 39 tumor types (31%) with at least one strongly positive tumor. Highest positivity rates were found in urothelial neoplasms (58-95%), Brenner tumors of the ovary (92%), epitheloid mesothelioma (87%), serous carcinoma of the ovary (58%) and the endometrium (53%) as well as in squamous cell carcinoma of the head and neck (18-37%), lung (39%) and esophagus (26%). In urothelial carcinoma, low Upk1b expression was linked to high grade and invasive tumor growth (p<0.0001 each) and nodal metastasis (p=0.0006). Our data suggest diagnostic applications of Upk1b immunohistochemistry in panels for the distinction of malignant mesothelioma from adenocarcinoma of the lung, urothelial carcinoma from prostatic adenocarcinoma in the bladder, or pancreatico-biliary and gastro-esophageal from colorectal adenocarcinoma.

Initial Evaluation of Uroplakins UPIIIa and UPII in Selected Benign Urological Diseases

BACKGROUND

Uroplakins (UPs) are glycoproteins that play a specific role in the structure and function of the urothelium. Disorders which affect the normal expression of UPs are associated with the pathogenesis of infections and neoplasms of the urinary tract, primary vesicoureteral reflux, hydronephrosis and renal dysfunction. The appearance of uroplakins in the urine and/or plasma may be of potential importance in the detection of urinary tract dysfunction. The aim of the present study was to investigate uroplakin IIIa (UPIIIa) and uroplakin II (UPII) expression in patients with selected urological diseases.

METHODS

Plasma and urine from patients with benign prostatic hyperplasia (BPH), urethral stricture (US), urinary tract infection (UTI) and urolithiasis were compared to healthy people without urological disorders. UPs concentrations were measured by the immunoenzymatic method.

RESULTS

In patients with BPH and UTI, concentrations of UPIIIa in urine and plasma, as well as UPII in urine, were statistically significantly higher than in the control groups. In the US group, only the plasma UPIIIa concentration differed significantly from the control.

CONCLUSION

The conducted research shows that benign urological diseases may affect the state of the urothelium, as manifested by increased concentrations of both UPs in patients' urine and plasma, especially in BPH and UTI.

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.

Persistent urothelial differentiation changes in the reconstructed exstrophic bladder: Congenital or acquired dysfunction of the epithelial barrier?

BACKGROUND

We have previously characterised the urothelium from infants with classic bladder exstrophy (CBE) for the expression of urothelial differentiation-associated markers. We found abnormal expression patterns of uroplakin 3a, cytokeratin 13, cytokeratin 20 and claudin 4 in the majority of bladder biopsies taken at the time of primary bladder closure. Abnormal urothelial differentiation results in a compromised urothelial barrier with potential implications on bladder development and the success of reconstructive surgery.

OBJECTIVE

To investigate whether the urothelial differentiation changes observed in the unclosed exstrophic bladder persist after successful primary exstrophy repair.

DESIGN, SETTING AND PARTICIPANTS

From 2005 to 2018 bladder biopsies from 115 children with CBE obtained at the time of primary bladder closure (n = 67, median age: 8.1 weeks) and during secondary procedures aimed at achieving continence (n = 48, median age: 6.8 years) were prospectively collected. Following histological assessment immunohistochemistry was used to investigate the expression of uroplakin 3a, cytokeratin 13 and 20 and claudin 4, well-characterized markers associated with the terminally-differentiated, fully functional urothelial phenotype. The urothelium from 16 children with VUR and with non-refluxing disorders of the urinary tract served as controls.

RESULTS

Tissue specimen from 100 children were included in the analysis. Only 32% of bladder specimens from children having undergone successful primary bladder closure in early infancy displayed a fully differentiated urothelial phenotype with regular expression of all 4 markers. The remaining bladders revealed irregular or absent marker expression suggesting abnormal urothelial differentiation. 86% of the samples had inflammatory, proliferative or metaplastic histological changes.

CONCLUSION

Our results suggest persisting urothelial differentiation changes in two-thirds of exstrophic bladders following successful bladder closure in early infancy. Despite some limitations, the findings provide a platform for translational studies into the role of the urothelium for the developmental potential of the exstrophic bladder and the success of reconstructive surgery.

Expression of uroplakin II and GATA-3 in bladder cancer mimickers: caveats in the use of a limited panel to determine cell of origin in bladder lesions

Antibodies targeting uroplakin II (UPII) are highly specific for urothelial cells and are frequently used to determine if a primary bladder lesion or a metastatic lesion originates from the urothelium. However, to date, no studies have tested the expression of UPII in histological mimickers of bladder cancer that are nonurothelial in origin. Given the potential risk of misdiagnosis, immunohistochemical markers are often used to better characterize these lesions. In the present study, we analyzed the immunohistochemical expression of UPII in a set of urothelial carcinoma mimickers that included conventional nephrogenic adenoma (n = 8), papillary nephrogenic adenoma (n = 6), endometriosis/endosalpingiosis (n = 5), inflammatory myofibroblastic tumor (n = 4), ectopic prostate tissue (n = 2), and malakoplakia (n = 2). We also examined the expression of GATA-3, another commonly used immunohistochemical marker in bladder cancer diagnosis, in the same lesions. Weak immunoreactivity for UPII was identified in 6 of 27 mimickers (22%), and GATA-3 was expressed in 16 of 27 mimickers (59%). Strong immunoreactivity for UPII appeared to be a specific marker for urothelial cell of origin, although weak staining was seen in a significant proportion of mimickers. GATA-3 immunostaining was present in a greater number and broader spectrum of mimickers; however, only one case of papillary nephrogenic adenoma showed dual positivity for UPII and GATA-3. These findings support the immunohistochemical panel-based approach in the diagnosis of bladder lesions, especially if nonurothelial bladder cancer mimickers are in the differential diagnosis. Additional larger studies would be of value to expand on these findings.

Mining The Cancer Genome Atlas gene expression data for lineage markers in distinguishing bladder urothelial carcinoma and prostate adenocarcinoma

Distinguishing bladder urothelial carcinomas from prostate adenocarcinomas for poorly differentiated carcinomas derived from the bladder neck entails the use of a panel of lineage markers to help make this distinction. Publicly available The Cancer Genome Atlas (TCGA) gene expression data provides an avenue to examine utilities of these markers. This study aimed to verify expressions of urothelial and prostate lineage markers in the respective carcinomas and to seek the relative importance of these markers in making this distinction. Gene expressions of these markers were downloaded from TCGA Pan-Cancer database for bladder and prostate carcinomas. Differential gene expressions of these markers were analyzed. Standard linear discriminant analyses were applied to establish the relative importance of these markers in lineage determination and to construct the model best in making the distinction. This study shows that all urothelial lineage genes except for the gene for uroplakin III were significantly expressed in bladder urothelial carcinomas (p < 0.001). In descending order of importance to distinguish from prostate adenocarcinomas, genes for uroplakin II, S100P, GATA3 and thrombomodulin had high discriminant loadings (> 0.3). All prostate lineage genes were significantly expressed in prostate adenocarcinomas(p < 0.001). In descending order of importance to distinguish from bladder urothelial carcinomas, genes for NKX3.1, prostate specific antigen (PSA), prostate-specific acid phosphatase, prostein, and prostate-specific membrane antigen had high discriminant loadings (> 0.3). Combination of gene expressions for uroplakin II, S100P, NKX3.1 and PSA approached 100% accuracy in tumor classification both in the training and validation sets. Mining gene expression data, a combination of four lineage markers helps distinguish between bladder urothelial carcinomas and prostate adenocarcinomas.

Reciprocal regulation of HIF-1α and Uroplakin 1A promotes glycolysis and proliferation in Hepatocellular Carcinoma

Uroplakin 1A (UPK1A) has recently been found dysregulation in many cancers. However, the functions of UPK1A and its underlying mechanisms in hepatocellular carcinoma (HCC) remain poorly understand. In the present study, we found that UPK1A was highly expressed in HCC tumor tissues compared with adjacent non-tumor tissues. Datasets from the Cancer Genome Atlas project (TCGA) and Gene expression Omnibus confirmed that UPK1A was highly expressed in HCC. High expression of UPK1A predicted poor overall survival (OS) in patients with HCC. Univariate and multivariate analysis showed that UPK1A was a significant and independent prognostic predictor for OS of patients with HCC. Functionally, silencing UPK1A suppressed HCC cell glycolysis and proliferation. Mechanistically, hypoxia-inducible factor 1α (HIF-1α) directly bound to the hypoxia response elements (HRE) of UPK1A promoter region, which led to the up-regulation of UPK1A under hypoxia. Furthermore, downregulation of UPK1A reduced key enzyme of glycolysis via regulating HIF-1α. Taken together, these data indicates the existence of a positive feedback loop between HIF-1α and UPK1A that modulates glycolysis and proliferation under hypoxia in HCC cells.

Proteomic Analysis of Exosomes for Discovery of Protein Biomarkers for Prostate and Bladder Cancer

Extracellular vesicles (EVs) are released by nearly all cell types as part of normal cell physiology, transporting biological cargo, including nucleic acids and proteins, across the cell membrane. In pathological states such as cancer, EV-derived cargo may mirror the altered state of the cell of origin. Exosomes are the smaller, 50–150 nanometer-sized EVs released from fusion of multivesicular endosomes with the plasma membrane. Exosomes play important roles in cell-cell communication and participate in multiple cancer processes, including invasion and metastasis. Therefore, proteomic analysis of exosomes is a promising approach to discover potential cancer biomarkers, even though it is still at an early stage. Herein, we critically review the advances in exosome isolation methods and their compatibility with mass spectrometry (MS)-based proteomic analysis, as well as studies of exosomes in pathogenesis and progression of prostate and bladder cancer, two common urologic cancers whose incidence rates continue to rise annually. As urological tumors, both urine and blood samples are feasible for noninvasive or minimally invasive analysis. A better understanding of the biological cargo and functions of exosomes via high-throughput proteomics will help provide new insights into complex alterations in cancer and provide potential therapeutic targets and personalized treatment for patients.

Comprehensive analysis reveals CTHRC1, SERPINE1, VCAN and UPK1B as the novel prognostic markers in gastric cancer

Background

Gastric cancer (GC) is one of the most common malignant diseases worldwide, the incidence and mortality for GC is still high, thus it is urgently important to identify the effective and reliable biomarkers to evaluate GC and the underlying molecular events.

Methods

The study integrated four Gene Expression Omnibus (GEO) profile datasets and The Cancer Genome Atlas (TCGA) dataset to screen differentially expressed genes (DEGs), screened key genes by performing the Kaplan-Meier analysis, univariate and multivariate-cox analysis. Further analysis were performed to evaluate and validate the prognostic value of the key genes based on TCGA database and online websites. In addition, mechanism analysis of the key genes was performed thought biological processes and KEGG pathway analysis.

Results

In the study, 192 DEGs (92 up-regulated and 100 down-regulated) were identified from the GEO and TCGA datasets. Next, gene ontology (GO) for DEGs focused primarily on cell adhesion, extracellular region and extracellular matrix structural constituent. Then four significant key genes were screened by performed the Kaplan-Meier analysis, univariate and multivariate-cox analysis. By using Kaplan-Meier plotter and OncoLnc, the expression level was associated with a worse prognosis. In addition, the area under curve (AUC) for time-dependent receiver operating characteristic (ROC) indicated a moderate diagnostic value. Furthermore, the expression of collagen triple helix repeat containing 1 (CTHRC1), serpin family E member 1 (SERPINE1), Versican (VCAN) was associated with tumor size, Uroplakin 1B (UPK1B) expression was associated with distant metastasis. Finally, multiple biological processes and signaling pathway associated with key genes revealed the underlying mechanism in GC.

Conclusions

Taken together, CTHRC1, SERPINE1, VCAN, UPK1B were novel potential prognostic molecular markers for GC, which acted as oncogene to promote the development of GC.

Unravelling the proteomic landscape of extracellular vesicles in prostate cancer by density-based fractionation of urine

Extracellular vesicles (EV) are increasingly being recognized as important vehicles of intercellular communication and promising diagnostic and prognostic biomarkers in cancer. Despite this enormous clinical potential, the plethora of methods to separate EV from biofluids, providing material of highly variable purity, and lacking knowledge regarding methodological repeatability pose a barrier to clinical translation. Urine is considered an ideal proximal fluid for the study of EV in urological cancers due to its direct contact with the urogenital system. We demonstrate that density-based fractionation of urine by bottom-up Optiprep density gradient centrifugation separates EV and soluble proteins with high specificity and repeatability. Mass spectrometry-based proteomic analysis of urinary EV (uEV) in men with benign and malignant prostate disease allowed us to significantly expand the known human uEV proteome with high specificity and identifies a unique biological profile in prostate cancer not uncovered by the analysis of soluble proteins. In addition, profiling the proteome of EV separated from prostate tumour conditioned medium and matched uEV confirms the specificity of the identified uEV proteome for prostate cancer. Finally, a comparative proteomic analysis with uEV from patients with bladder and renal cancer provided additional evidence of the selective enrichment of protein signatures in uEV reflecting their respective cancer tissues of origin. In conclusion, this study identifies hundreds of previously undetected proteins in uEV of prostate cancer patients and provides a powerful toolbox to map uEV content and contaminants ultimately allowing biomarker discovery in urological cancers.

Characterizing smoking-induced transcriptional heterogeneity in the human bronchial epithelium at single-cell resolution

The human bronchial epithelium is composed of multiple distinct cell types that cooperate to defend against environmental insults. While studies have shown that smoking alters bronchial epithelial function and morphology, its precise effects on specific cell types and overall tissue composition are unclear. We used single-cell RNA sequencing to profile bronchial epithelial cells from six never and six current smokers. Unsupervised analyses led to the characterization of a set of toxin metabolism genes that localized to smoker ciliated cells, tissue remodeling associated with a loss of club cells and extensive goblet cell hyperplasia, and a previously unidentified peri-goblet epithelial subpopulation in smokers who expressed a marker of bronchial premalignant lesions. Our data demonstrate that smoke exposure drives a complex landscape of cellular alterations that may prime the human bronchial epithelium for disease.

Uroplakin expression in the male reproductive tract of rat

Uroplakins (UPKs) play an important role in the normal and pathophysiology of the urothelium. They protect the urothelium and play a crucial role during urothelial infections by Uropathogenic E. coli. However, their functions beyond this organ system remain unexplored. A wide variety of proteins secreted in the male reproductive tract tissues contribute to spermatogenesis, sperm maturation, fertilization and innate immunity. However, the presence of UPKs and their possible contribution to the male reproductive tract physiology is not yet reported. Hence, in this study, we characterized UPKs in the male reproductive tract of rats. To the best of our knowledge, for the first time, we report the expression of UPKs in the male reproductive system. Upk1a, Upk1b, Upk2 and Upk3b mRNA and their corresponding proteins were abundantly expressed in the caput, cauda, testis, seminal vesicles and the prostate. Their expression was not developmentally regulated. UPK protein expression was also localized on the spermatozoa, suggesting a role for these proteins in sperm function. To study the role of UPKs in innate immunity, Upk mRNA expression in response to endotoxin challenge was evaluated in vitro and in vivo. In the rat testicular and epididymal cell lines, Upk mRNA levels increased in response to lipopolysaccharide challenge. However, in the caput, cauda, testes, seminal vesicle and prostate obtained from LPS treated rats, Upk mRNA expression was significantly reduced. Results of this study indicate a role for UPKs in male reproductive physiology and innate immune responses.

Uroplakins play conserved roles in egg fertilization and acquired additional urothelial functions during mammalian divergence

Uroplakin (UP) tetraspanins and their associated proteins are major mammalian urothelial differentiation products that form unique two-dimensional crystals of 16-nm particles (“urothelial plaques”) covering the apical urothelial surface. Although uroplakins are highly expressed only in mammalian urothelium and are often referred to as being urothelium specific, they are also expressed in several mouse nonurothelial cell types in stomach, kidney, prostate, epididymis, testis/sperms, and ovary/oocytes. In oocytes, uroplakins colocalize with CD9 on cell-surface and multivesicular body-derived exosomes, and the cytoplasmic tail of UPIIIa undergoes a conserved fertilization-dependent, Fyn-mediated tyrosine phosphorylation that also occurs in Xenopus laevis eggs. Uroplakin knockout and antibody blocking reduce mouse eggs’ fertilization rate in in vitro fertilization assays, and UPII/IIIa double-knockout mice have a smaller litter size. Phylogenetic analyses showed that uroplakin sequences underwent significant mammal-specific changes. These results suggest that, by mediating signal transduction and modulating membrane stability that do not require two-dimensional-crystal formation, uroplakins can perform conserved and more ancestral fertilization functions in mouse and frog eggs. Uroplakins acquired the ability to form two-dimensional-crystalline plaques during mammalian divergence, enabling them to perform additional functions, including umbrella cell enlargement and the formation of permeability and mechanical barriers, to protect/modify the apical surface of the modern-day mammalian urothelium.

Differential transcription factor expression by human epithelial cells of buccal and urothelial derivation

Identification of transcription factors expressed by differentiated cells is informative not only of tissue-specific pathways, but to help identify master regulators for cellular reprogramming. If applied, such an approach could generate healthy autologous tissue-specific cells for clinical use where cells from the homologous tissue are unavailable due to disease. Normal human epithelial cells of buccal and urothelial derivation maintained in identical culture conditions that lacked significant instructive or permissive signaling cues were found to display inherent similarities and differences of phenotype. Investigation of transcription factors implicated in driving urothelial-type differentiation revealed buccal epithelial cells to have minimal or absent expression of PPARG, GATA3 and FOXA1 genes. Retroviral overexpression of protein coding sequences for GATA3 or PPARy1 in buccal epithelial cells resulted in nuclear immunolocalisation of the respective proteins, with both transductions also inducing expression of the urothelial differentiation-associated claudin 3 tight junction protein. PPARG1 overexpression alone entrained expression of nuclear FOXA1 and GATA3 proteins, providing objective evidence of its upstream positioning in a transcription factor network and identifying it as a candidate factor for urothelial-type transdifferentiation or reprogramming.

Uroplakin traffic through the Golgi apparatus induces its fragmentation: new insights from novel in vitro models

Uroplakins (UPs) play an essential role in maintaining an effective urothelial permeability barrier at the level of superficial urothelial cell (UC) layer. Although the organization of UPs in the apical plasma membrane (PM) of UCs is well known, their transport in UCs is only partially understood. Here, we dissected trafficking of UPs and its differentiation-dependent impact on Golgi apparatus (GA) architecture. We demonstrated that individual subunits UPIb and UPIIIa are capable of trafficking from the endoplasmic reticulum to the GA in UCs. Moreover, UPIb, UPIIIa or UPIb/UPIIIa expressing UCs revealed fragmentation and peripheral redistribution of Golgi-units. Notably, expression of UPIb or UPIb/UPIIIa triggered similar GA fragmentation in MDCK and HeLa cells that do not express UPs endogenously. The colocalization analysis of UPIb/UPIIIa-EGFP and COPI, COPII or clathrin suggested that UPs follow constitutively the post-Golgi route to the apical PM. Depolymerisation of microtubules leads to complete blockade of the UPIb/UPIIIa-EGFP post-Golgi transport, while disassembly of actin filaments shows significantly reduced delivery of UPIb/UPIIIa-EGFP to the PM. Our findings show the significant effect of the UPs expression on the GA fragmentation, which enables secretory Golgi-outpost to be distributed as close as possible to the sites of cargo delivery at the PM.

Temporal upregulation of host surface receptors provides a window of opportunity for bacterial adhesion and disease

Host surface receptors provide bacteria with a foothold from which to attach, colonize and, in some cases, invade tissue and elicit human disease. In this review, we discuss several key host receptors and cognate adhesins that function in bacterial pathogenesis. In particular, we examine the elevated expression of host surface receptors such as CEACAM-1, CEACAM-6, ICAM-1 and PAFR in response to specific stimuli. We explore how upregulated receptors, in turn, expose the host to a range of bacterial infections in the respiratory tract. It is apparent that exploitation of receptor induction for bacterial adherence is not unique to one body system, but is also observed in the central nervous, gastrointestinal and urogenital systems. Prokaryotic pathogens which utilize this mechanism for their infectivity include Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Escherichia coli. A number of approaches have been used, in both in vitro and in vivo experimental models, to inhibit bacterial attachment to temporally expressed host receptors. Some of these novel strategies may advance future targeted interventions for the prevention and treatment of bacterial disease.

Heterarchy of transcription factors driving basal and luminal cell phenotypes in human urothelium

Cell differentiation is affected by complex networks of transcription factors that co-ordinate re-organisation of the chromatin landscape. The hierarchies of these relationships can be difficult to dissect. During in vitro differentiation of normal human uro-epithelial cells, formaldehyde-assisted isolation of regulatory elements (FAIRE-seq) and RNA-seq was used to identify alterations in chromatin accessibility and gene expression changes following activation of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) as a differentiation-initiating event. Regions of chromatin identified by FAIRE-seq, as having altered accessibility during differentiation, were found to be enriched with sequence-specific binding motifs for transcription factors predicted to be involved in driving basal and differentiated urothelial cell phenotypes, including forkhead box A1 (FOXA1), P63, GRHL2, CTCF and GATA-binding protein 3 (GATA3). In addition, co-occurrence of GATA3 motifs was observed within subsets of differentiation-specific peaks containing P63 or FOXA1. Changes in abundance of GRHL2, GATA3 and P63 were observed in immunoblots of chromatin-enriched extracts. Transient siRNA knockdown of P63 revealed that P63 favoured a basal-like phenotype by inhibiting differentiation and promoting expression of basal marker genes. GATA3 siRNA prevented differentiation-associated downregulation of P63 protein and transcript, and demonstrated positive feedback of GATA3 on PPARG transcript, but showed no effect on FOXA1 transcript or protein expression. This approach indicates that as a transcriptionally regulated programme, urothelial differentiation operates as a heterarchy, wherein GATA3 is able to co-operate with FOXA1 to drive expression of luminal marker genes, but that P63 has potential to transrepress expression of the same genes.

On a FOX hunt: functions of FOX transcriptional regulators in bladder cancer

Genomic and transcriptional studies have identified discrete molecular subtypes of bladder cancer. These observations could be the starting point to identify new treatments. Several members of the forkhead box (FOX) superfamily of transcription factors have been found to be differentially expressed in the different bladder cancer subtypes. In addition, the FOXA protein family are key regulators of embryonic bladder development and patterning. Both experimental and clinical data support a role for FOXA1 and FOXA2 in urothelial carcinoma. FOXA1 is expressed in embryonic and adult urothelium and its expression is altered in urothelial carcinomas and across disparate molecular bladder cancer subtypes. FOXA2 is normally absent from the adult urothelium, but developmental studies identified FOXA2 as a marker of a transient urothelial progenitor cell population during bladder development. Studies also implicate FOXA2 in bladder cancer and several other FOX proteins might be involved in development and/or progression of this disease; for example, FOXA1 and FOXO3A have been associated with clinical patient outcomes. Future studies should investigate to what extent and by which mechanisms FOX proteins might be directly involved in bladder cancer pathogenesis and treatment responses.

Novel Gene Expression Signature Predictive of Clinical Recurrence After Radical Prostatectomy in Early Stage Prostate Cancer Patients

BACKGROUND

Current clinical tools have limited accuracy in differentiating patients with localized prostate cancer who are at risk of recurrence from patients with indolent disease. We aimed to identify a gene expression signature that jointly with clinical variables could improve upon the prediction of clinical recurrence after RP for patients with stage T2 PCa.

METHODS

The study population includes consented patients who underwent a radical retropubic prostatectomy (RP) and bilateral pelvic lymph node dissection at the University of Southern California in the PSA-era (1988-2008). We used a nested case-control study of 187 organ-confined patients (pT2N0M0): 154 with no recurrence ("controls") and 33 with clinical recurrence ("cases"). RNA was obtained from laser capture microdissected malignant glands representative of the overall Gleason score of each patient. Whole genome gene expression profiles (29,000 transcripts) were obtained using the Whole Genome DASL HT platform (Illumina, Inc). A gene expression signature of PCa clinical recurrence was identified using stability selection with elastic net regularized logistic regression. Three existing datasets generated with the Affymetrix Human Exon 1.0ST array were used for validation: Mayo Clinic (MC, n = 545), Memorial Sloan Kettering Cancer Center (SKCC, n = 150), and Erasmus Medical Center (EMC, n = 48). The areas under the ROC curve (AUCs) were obtained using repeated fivefold cross-validation.

RESULTS

A 28-gene expression signature was identified that jointly with key clinical variables (age, Gleason score, pre-operative PSA level, and operation year) was predictive of clinical recurrence (AUC of clinical variables only was 0.67, AUC of clinical variables, and 28-gene signature was 0.99). The AUC of this gene signature fitted in each of the external datasets jointly with clinical variables was 0.75 (0.72-0.77) (MC), 0.90 (0.86-0.94) (MSKCC), and 0.82 (0.74-0.91) (EMC), whereas the AUC for clinical variables only in each dataset was 0.72 (0.70-0.74), 0.86 (0.82-0.91), and 0.76 (0.67-0.85), respectively.

CONCLUSIONS

We report a novel gene-expression based classifier identified using agnostic approaches from whole genome expression profiles that can improve upon the accuracy of clinical indicators to stratify early stage localized patients at risk of clinical recurrence after RP. Prostate 76:1239-1256, 2016. © 2016 Wiley Periodicals, Inc.

Atypical presentation of infantile-onset farber disease with novel ASAH1 mutations

Farber disease is a very rare autosomal recessive disease caused by mutation of ASAH1 that results in the accumulation of ceramide in various tissues. Clinical symptoms of classic Farber disease comprise painful joint deformity, hoarseness of voice, and subcutaneous nodules. Here, we describe a patient with Farber disease with atypical presentation of early onset hypotonia, sacral mass, congenital heart disease, and dysmorphic face since birth. Severe cognitive disability, failure to gain motor skills, failure to thrive, and joint contractures developed. Using whole-exome sequencing, we identified the compound heterozygote missense mutations of ASAH1 (p.R333C and p.G235R). Because of the diagnostic delay, she underwent sacral mass excision, which revealed enlarged lysosomes and zebra bodies. We report an atypical presentation of Farber disease with her pathology and associated genetic defect. This case expands the phenotypic spectrum of Farber disease to include novel mutations of ASAH1, which pose a diagnostic challenge. We also discuss the clinical utility of whole-exome sequencing for diagnosis of ultra-rare diseases. © 2016 Wiley Periodicals, Inc.

Comprehensively evaluating cis-regulatory variation in the human prostate transcriptome by using gene-level allele-specific expression

The identification of cis-acting regulatory variation in primary tissues has the potential to elucidate the genetic basis of complex traits and further our understanding of transcriptomic diversity across cell types. Expression quantitative trait locus (eQTL) association analysis using RNA sequencing (RNA-seq) data can improve upon the detection of cis-acting regulatory variation by leveraging allele-specific expression (ASE) patterns in association analysis. Here, we present a comprehensive evaluation of cis-acting eQTLs by analyzing RNA-seq gene-expression data and genome-wide high-density genotypes from 471 samples of normal primary prostate tissue. Using statistical models that integrate ASE information, we identified extensive cis-eQTLs across the prostate transcriptome and found that approximately 70% of expressed genes corresponded to a significant eQTL at a gene-level false-discovery rate of 0.05. Overall, cis-eQTLs were heavily concentrated near the transcription start and stop sites of affected genes, and effects were negatively correlated with distance. We identified multiple instances of cis-acting co-regulation by using phased genotype data and discovered 233 SNPs as the most strongly associated eQTLs for more than one gene. We also noted significant enrichment (25/50, p = 2E-5) of previously reported prostate cancer risk SNPs in prostate eQTLs. Our results illustrate the benefit of assessing ASE data in cis-eQTL analyses by showing better reproducibility of prior eQTL findings than of eQTL mapping based on total expression alone. Altogether, our analysis provides extensive functional context of thousands of SNPs in prostate tissue, and these results will be of critical value in guiding studies examining disease of the human prostate.

Transcriptional profiling of ectoderm specification to keratinocyte fate in human embryonic stem cells

In recent years, several studies have shed light into the processes that regulate epidermal specification and homeostasis. We previously showed that a broad-spectrum γ-secretase inhibitor DAPT promoted early keratinocyte specification in human embryonic stem cells triggered to undergo ectoderm specification. Here, we show that DAPT accelerates human embryonic stem cell differentiation and induces expression of the ectoderm protein AP2. Furthermore, we utilize RNA sequencing to identify several candidate regulators of ectoderm specification including those involved in epithelial and epidermal development in human embryonic stem cells. Genes associated with transcriptional regulation and growth factor activity are significantly enriched upon DAPT treatment during specification of human embryonic stem cells to the ectoderm lineage. The human ectoderm cell signature identified in this study contains several genes expressed in ectodermal and epithelial tissues. Importantly, these genes are also associated with skin disorders and ectodermal defects, providing a platform for understanding the biology of human epidermal keratinocyte development under diseased and homeostatic conditions.

Downregulation of UPK1A suppresses proliferation and enhances apoptosis of bladder transitional cell carcinoma cells

Uroplakin 1A (UPK1A) is a specific marker of mammalian urothelium and one of major proteins contained in urothelial plaques. Many recent studies reported that UPK1A could be useful marker for diagnosis, detection and prognostic prediction of transitional cell carcinoma. However, relatively little is known about its exact roles in bladder transitional cell carcinoma (BTCC). We tried to explore the roles UPK1A plays in BTCC via the transfection of its antisense nucleotides (AS) into T24 cells to observe their changes of proliferation and apoptosis. After AS was successfully transfected into T24 cells, the percentages of proliferating T24 cells at 24 and 48 h after the treatment were 57.2 ± 6.8 and 44.7 ± 5.2%, significantly lower than that of control group, as shown by MTT (p < 0.05 and 0.01). At 24 h after transfection of AS, the percentage of apoptotic T24 cells was 26.87% measured by flow cytometry, significantly higher than that of control group (p < 0.01). Similarly, Hoechst 33258 staining showed that the percentage of apoptotic nuclei of T24 cells after 24 h treated by AS was 28.9%, significantly higher than that of control (p < 0.05). The most common and typical morphological changes of apoptosis, including shrink, pyknosis and karyorrhexis of T24 cells nuclei and DNA fragmentation were seen from Hoechst 33258 staining and DNA agarose gel electrophoresis. Taken together, inhibition of UPK1A can suppress proliferation and enhance apoptosis of BTCC T24 cells, suggesting it a potential target to treat this disease.

Uroplakin II is a more sensitive immunohistochemical marker than uroplakin III in urothelial carcinoma and its variants

OBJECTIVES

Uroplakin (UP) II and UPIII are highly specific immunohistochemical markers for urothelial differentiation. Here we studied the sensitivity of UPII and UPIII in conventional and variant urothelial carcinomas (UCs).

METHODS

Immunohistochemical staining for UPII and UPIII was performed on tissue microarray slides, including 105 conventional bladder UCs (BUCs), 90 upper urinary tract UCs (UUTUCs), and 47 micropapillary, 16 plasmacytoid, 22 small cell carcinoma, and 41 sarcomatoid UC variants.

RESULTS

UPII expression was significantly higher than UPIII expression in conventional BUC (44% vs 17%, P < .001) and UUTUC (67% vs 46%, P = .045). UPIII expression was significantly higher in UUTUC than in BUC (P < .001). In UC variants, UPII expression was significantly higher than UPIII expression in micropapillary (91% vs 25%, P < .001), plasmacytoid (63% vs 6%, P < .001), and sarcomatoid (29% vs 5%, P = .032) variants. Only rare cases of the small cell carcinoma variant had focal UPII and UPIII expression. Compared with conventional UC, the sarcomatoid variant had significantly lower UPII expression, whereas the micropapillary variant had significantly higher UPII expression (P < .001).

CONCLUSIONS

UPII demonstrates a significantly higher sensitivity than UPIII in conventional and variant UCs. Thus, UPII is a more valuable marker than UPIII in immunohistochemical analyses for confirming the urothelial origin of carcinomas.

Glycosylation of uroplakins. Implications for bladder physiopathology

Urothelium, a specialized epithelium, covers the urinary tract and act not only as a barrier separating its light from the surrounding tissues, but fulfills an important role in maintaining the homeostasis of the urothelial tract and well-being of the whole organism. Proper function of urothelium is dependent on the precise assemble of highly specialized glycoproteins called uroplakins, the end products and differentiation markers of the urothelial cells. Glycosylation changes in uroplakins correlate with and might reflect progressive stages of pathological conditions of the urothelium such as cancer, urinary tract infections, interstitial cystitis and others. In this review we focus on sugar components of uroplakins, their emerging role in urothelial biology and disease implications. The advances in our understanding of uroplakins changes in glycan moieties composition, structure, assembly and expression of their glycovariants could potentially lead to the development of targeted therapies and discoveries of novel urine and plasma markers for the benefit of patients with urinary tract diseases.

A newly developed uroplakin II antibody with increased sensitivity in urothelial carcinoma of the bladder

CONTEXT

Uroplakin II is a 15-kDa protein component of the urothelial plaques that enhance the permeability barrier and strength of the urothelium. Studies have shown uroplakin II messenger RNA to be expressed in bladder cancer tissues and peripheral blood of patients with urothelial carcinoma. Little is known about the protein expression of uroplakin II in urothelial carcinoma, possibly because of the absence of a commercially available uroplakin II antibody. Pathologists have used the uroplakin III antibody (AU1) to identify tumors of urothelial origin; however, the use of AU1 is limited because of its poor sensitivity.

OBJECTIVES

To evaluate a newly developed mouse monoclonal uroplakin II antibody (BC21) in urothelial carcinoma and to compare it with previously developed mouse monoclonal uroplakin III (BC17 and AU1).

DESIGN

Uroplakin II and III antibodies were optimized for staining using a horseradish peroxidase-polymer detection system and were visualized with 3,3'-diaminobenzidine.

RESULTS

BC21, BC17, and AU1 demonstrated sensitivities in urothelial carcinoma of the bladder of 79% (44 of 56), 55% (31 of 56) (P = .002), and 34% (19 of 56) (P < .001), respectively. Subsequently, the increased staining sensitivity and intensity of BC21, compared with BC17, was validated in a larger study (134 of 174; 77% and 94 of 174; 54%, respectively) (P < .001). BC21 was found to be highly specific when evaluated in various normal and neoplastic tissues, including prostatic and renal carcinomas.

CONCLUSIONS

The mouse monoclonal uroplakin II antibody (BC21) demonstrated superior sensitivity and specificity in urothelial carcinoma, compared with uroplakin III (BC17 and AU1), suggesting its advantages in the differential diagnosis of urothelial carcinoma and in the detection of tumors of unknown origin.

Animal model of naturally occurring bladder cancer: characterization of four new canine transitional cell carcinoma cell lines

Background

Development and further characterization of animal models for human cancers is important for the improvement of cancer detection and therapy. Canine bladder cancer closely resembles human bladder cancer in many aspects. In this study, we isolated and characterized four primary transitional cell carcinoma (K9TCC) cell lines to be used for future in vitro validation of novel therapeutic agents for bladder cancer.

Methods

Four K9TCC cell lines were established from naturally-occurring canine bladder cancers obtained from four dogs. Cell proliferation rates of K9TCC cells in vitro were characterized by doubling time. The expression profile of cell-cycle proteins, cytokeratin, E-cadherin, COX-2, PDGFR, VEGFR, and EGFR were evaluated by immunocytochemistry (ICC) and Western blotting (WB) analysis and compared with established human bladder TCC cell lines, T24 and UMUC-3. All tested K9TCC cell lines were assessed for tumorigenic behavior using athymic mice in vivo.

Results

Four established K9TCC cell lines: K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly were confirmed to have an epithelial-cell origin by morphology analysis, cytokeratin, and E-cadherin expressions. The tested K9TCC cells expressed UPIa (a specific marker of the urothelial cells), COX-2, PDGFR, and EGFR; however they lacked the expression of VEGFR. All tested K9TCC cell lines confirmed a tumorigenic behavior in athymic mice with 100% tumor incidence.

Conclusions

The established K9TCC cell lines (K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly) can be further utilized to assist in development of new target-specific imaging and therapeutic agents for canine and human bladder cancer.

Biomimetic urothelial tissue models for the in vitro evaluation of barrier physiology and bladder drug efficacy

The bladder is an important tissue in which to evaluate xenobiotic drug interactions and toxicities due to the concentration of parent drug and hepatic/enteric-derived metabolites in the urine as a result of renal excretion. Breaching of the barrier provided by the bladder epithelial lining (the urothelium) can expose the underlying tissues to urine and cause harmful effects (e.g., cystitis or cancer). Human urothelium is most commonly represented in vitro as immortalized or established cancer-derived cell lines, but the compromised ability of such cells to undergo differentiation and barrier formation means that nonimmortalized, normal human urothelial (NHU) cells provide a more relevant cell culture system. The impressive capacity for urothelial self-renewal in vivo can be harnessed in vitro to generate experimentally-useful quantities of NHU cells, which can subsequently be differentiated to form a functional or "biomimetic" urothelium. When seeded onto permeable membranes, these barrier-forming human urothelial tissue models enable the modeling of serum and luminal (intravesical) exposure to drugs and metabolites, thus supporting efficacy/toxicity assessments. Biomimetic human urothelial constructs provide a potential step along the preclinical trail and may support the extrapolation from rodent in vivo data to determine human relevance. Early evidence is beginning to demonstrate that human urothelium in vitro can provide information that supersedes conventional rodent studies, but further validation is needed to support widespread adoption.

Mutation Spectra of Kras and Tp53 in Urethral and Lung Neoplasms in B6C3F1 Mice Treated with 3,3′,4,4′-Tetrachloroazobenzene

3,3′,4,4′-tetrachloroazobenzene (TCAB) is a contaminant formed during manufacture of various herbicide compounds. A recent National Toxicology Program study showed B6C3F1 mice exposed to TCAB developed a treatment-related increase in lung carcinomas in the high-dose group, and urethral carcinomas, an extremely rare lesion in rodents, in all dose groups. As the potential for environmental exposure to TCAB is widespread, and the mechanisms of urethral carcinogenesis are unknown, TCAB-induced urethral and pulmonary tumors were evaluated for alterations in critical human cancer genes, Kras and Tp53. Uroplakin III, CK20, and CK7 immunohistochemistry was performed to confirm the urothelial origin of urethral tumors. TCAB-induced urethral carcinomas harbored transforming point mutations in K-ras (38%) and Tp53 (63%), and 71% displayed nuclear TP53 expression, consistent with formation of mutant protein. Transition mutations accounted for 88% of Tp53 mutations in urethral carcinomas, suggesting that TCAB or its metabolites target guanine or cytosine bases and that these mutations are involved in urethral carcinogenesis. Pulmonary carcinomas in TCAB-exposed animals harbored similar rates of Tp53 (55%) and Kras (36%) mutations as urethral carcinomas, suggesting that TCAB may induce mutations at multiple sites by a common mechanism. In conclusion, TCAB is carcinogenic at multiple sites in male and female B6C3F1 mice through mechanisms involving Tp53 and Kras mutation.

Deregulation of the histone demethylase JMJD2A is involved in human carcinogenesis through regulation of the G(1)/S transition

Although a number of JmjC-containing histone demethylases have been identified and biochemically characterized, pathological roles of their dysfunction in human disease such as cancer have not been well elucidated. Here, we report the Jumonji domain containing 2A (JMJD2A) is integral to proliferation of cancer cells. Quantitative real-time PCR analysis revealed higher expression of JMJD2A in clinical bladder cancer tissues than in corresponding non-neoplastic tissues (P<0.0001). Immunohistochemical analysis also showed positive staining for JMJD2A in 288 out of 403 lung cancer cases, whereas no staining was observed in lung normal tissues. Suppression of JMJD2A expression in lung and bladder cancer cells overexpressing this gene, using specific siRNAs, inhibited incorporation of BrdU and resulted in significant suppression of cell growth. Furthermore, JMJD2A appears to directly transactivate the expression of some tumor associated proteins including ADAM12 through the regulation of histone H3K9 methylation. As expression levels of JMJD2A are low in normal tissues, it may be feasible to develop specific inhibitors targeting the enzyme as anti-tumor agents which should have a minimal risk of adverse reaction.

The histone methyltransferase Wolf-Hirschhorn syndrome candidate 1-like 1 (WHSC1L1) is involved in human carcinogenesis

Histone lysine methylation plays a fundamental role in chromatin organization. Although a set of histone methyltransferases have been identified and biochemically characterized, the pathological roles of their dysfunction in human cancers are still not well understood. In this study, we demonstrate important roles of WHSC1L1 in human carcinogenesis. Expression levels of WHSC1L1 transcript were significantly elevated in various human cancers including bladder carcinoma. Immunohistochemical analysis of bladder, lung, and liver cancers confirmed overexpression of WHSC1L1. WHSC1L1-specific small interfering RNAs significantly knocked down its expression and resulted in suppression of proliferation of bladder and lung cancer cell lines. WHSC1L1 knockdown induced cell cycle arrest at the G(2)/M phase followed by multinucleation of cancer cells. Expression profile analysis using Affymetrix GeneChip(®) showed that WHSC1L1 affected the expression of a number of genes including CCNG1 and NEK7, which are known to play crucial roles in the cell cycle progression at mitosis. As WHSC1L1 expression is significantly low in various normal tissues including vital organs, WHSC1L1 could be a good candidate molecule for development of novel treatment for various types of cancer.

Differentiation-associated reprogramming of the transforming growth factor β receptor pathway establishes the circuitry for epithelial autocrine/paracrine repair

Transforming growth factor (TGF) β has diverse and sometimes paradoxical effects on cell proliferation and differentiation, presumably reflecting a fundamental but incompletely-understood role in regulating tissue homeostasis. It is generally considered that downstream activity is modulated at the ligand:receptor axis, but microarray analysis of proliferative versus differentiating normal human bladder epithelial cell cultures identified unexpected transcriptional changes in key components of the canonical TGFβ R/activin signalling pathway associated with cytodifferentiation. Changes included upregulation of the transcriptional modulator SMAD3 and downregulation of inhibitory modulators SMURF2 and SMAD7. Functional analysis of the signalling pathway revealed that non-differentiated normal human urothelial cells responded in paracrine mode to TGFβ by growth inhibition, and that exogenous TGFβ inhibited rather than promoted differentiation. By contrast, in differentiated cell cultures, SMAD3 was activated upon scratch-wounding and was involved in promoting tissue repair. Exogenous TGFβ enhanced the repair and resulted in hyperplastic scarring, indicating a feedback loop implicit in an autocrine pathway. Thus, the machinery for autocrine activation of the SMAD3-mediated TGFβR pathway is established during urothelial differentiation, but signalling occurs only in response to a trigger, such as wounding. Our study demonstrates that the circuitry of the TGFβR pathway is defined transcriptionally within a tissue-specific differentiation programme. The findings provide evidence for re-evaluating the role of TGFβR signalling in epithelial homeostasis as an autocrine-regulated pathway that suppresses differentiation and promotes tissue repair. This provides a new paradigm to help unravel the apparently diverse and paradoxical effect of TGFβ signalling on cell proliferation and differentiation.

Transcriptional profiling of the bladder in urogenital schistosomiasis reveals pathways of inflammatory fibrosis and urothelial compromise

Urogenital schistosomiasis, chronic infection by Schistosoma haematobium, affects 112 million people worldwide. S. haematobium worm oviposition in the bladder wall leads to granulomatous inflammation, fibrosis, and egg expulsion into the urine. Despite the global impact of urogenital schistosomiasis, basic understanding of the associated pathologic mechanisms has been incomplete due to the lack of suitable animal models. We leveraged our recently developed mouse model of urogenital schistosomiasis to perform the first-ever profiling of the early molecular events that occur in the bladder in response to the introduction of S. haematobium eggs. Microarray analysis of bladders revealed rapid, differential transcription of large numbers of genes, peaking three weeks post-egg administration. Many differentially transcribed genes were related to the canonical Type 2 anti-schistosomal immune response, as reflected by the development of egg-based bladder granulomata. Numerous collagen and metalloproteinase genes were differentially transcribed over time, revealing complex remodeling and fibrosis of the bladder that was confirmed by Masson's Trichrome staining. Multiple genes implicated in carcinogenesis pathways, including vascular endothelial growth factor-, oncogene-, and mammary tumor-related genes, were differentially transcribed in egg-injected bladders. Surprisingly, junctional adhesion molecule, claudin and uroplakin genes, key components for maintaining the urothelial barrier, were globally suppressed after bladder exposure to eggs. This occurred in the setting of urothelial hyperplasia and egg shedding in urine. Thus, S. haematobium egg expulsion is associated with intricate modulation of the urothelial barrier on the cellular and molecular level. Taken together, our findings have important implications for understanding host-parasite interactions and carcinogenesis in urogenital schistosomiasis, and may provide clues for novel therapeutic strategies.

The JmjC domain-containing histone demethylase KDM3A is a positive regulator of the G1/S transition in cancer cells via transcriptional regulation of the HOXA1 gene

A number of histone demethylases have been identified and biochemically characterized, yet their biological functions largely remain uncharacterized, particularly in the context of human diseases such as cancer. In this study, we describe important roles for the histone demethylase KDM3A, also known as JMJD1A, in human carcinogenesis. Expression levels of KDM3A were significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (p < 0.0001), when assessed by real-time PCR. We confirmed that some other cancers including lung cancer also overexpressed KDM3A, using cDNA microarray analysis. Treatment of cancer cell lines with small interfering RNA targeting KDM3A significantly knocked down its expression and resulted in the suppression of proliferation. Importantly, we found that KDM3A activates transcription of the HOXA1 gene through demethylating histone H3 at lysine 9 di-methylation by binding to its promoter region. Indeed, expression levels of KDM3A and HOXA1 in several types of cancer cell lines and bladder cancer samples were statistically correlated. We observed the down-regulation of HOXA1 as well as CCND1 after treatment with KDM3A siRNA, indicating G(1) arrest of cancer cells. Together, our results suggest that elevated expression of KDM3A plays a critical role in the growth of cancer cells, and further studies may reveal a cancer therapeutic potential in KDM3A inhibition.

Histone lysine methyltransferase SETD8 promotes carcinogenesis by deregulating PCNA expression

Although the physiologic significance of lysine methylation of histones is well known, whether lysine methylation plays a role in the regulation of nonhistone proteins has not yet been examined. The histone lysine methyltransferase SETD8 is overexpressed in various types of cancer and seems to play a crucial role in S-phase progression. Here, we show that SETD8 regulates the function of proliferating cell nuclear antigen (PCNA) protein through lysine methylation. We found that SETD8 methylated PCNA on lysine 248, and either depletion of SETD8 or substitution of lysine 248 destabilized PCNA expression. Mechanistically, lysine methylation significantly enhanced the interaction between PCNA and the flap endonuclease FEN1. Loss of PCNA methylation retarded the maturation of Okazaki fragments, slowed DNA replication, and induced DNA damage, and cells expressing a methylation-inactive PCNA mutant were more susceptible to DNA damage. An increase of methylated PCNA was found in cancer cells, and the expression levels of SETD8 and PCNA were correlated in cancer tissue samples. Together, our findings reveal a function for lysine methylation on a nonhistone protein and suggest that aberrant lysine methylation of PCNA may play a role in human carcinogenesis.

Deregulation of Rab and Rab effector genes in bladder cancer

Growing evidence indicates that Rab GTPases, key regulators of intracellular transport in eukaryotic cells, play an important role in cancer. We analysed the deregulation at the transcriptional level of the genes encoding Rab proteins and Rab-interacting proteins in bladder cancer pathogenesis, distinguishing between the two main progression pathways so far identified in bladder cancer: the Ta pathway characterized by a high frequency of FGFR3 mutation and the carcinoma in situ pathway where no or infrequent FGFR3 mutations have been identified. A systematic literature search identified 61 genes encoding Rab proteins and 223 genes encoding Rab-interacting proteins. Transcriptomic data were obtained for normal urothelium samples and for two independent bladder cancer data sets corresponding to 152 and 75 tumors. Gene deregulation was analysed with the SAM (significant analysis of microarray) test or the binomial test. Overall, 30 genes were down-regulated, and 13 were up-regulated in the tumor samples. Five of these deregulated genes (LEPRE1, MICAL2, RAB23, STXBP1, SYTL1) were specifically deregulated in FGFR3-non-mutated muscle-invasive tumors. No gene encoding a Rab or Rab-interacting protein was found to be specifically deregulated in FGFR3-mutated tumors. Cluster analysis showed that the RAB27 gene cluster (comprising the genes encoding RAB27 and its interacting partners) was deregulated and that this deregulation was associated with both pathways of bladder cancer pathogenesis. Finally, we found that the expression of KIF20A and ZWINT was associated with that of proliferation markers and that the expression of MLPH, MYO5B, RAB11A, RAB11FIP1, RAB20 and SYTL2 was associated with that of urothelial cell differentiation markers. This systematic analysis of Rab and Rab effector gene deregulation in bladder cancer, taking relevant tumor subgroups into account, provides insight into the possible roles of Rab proteins and their effectors in bladder cancer pathogenesis. This approach is applicable to other group of genes and types of cancer.

RB1 methylation by SMYD2 enhances cell cycle progression through an increase of RB1 phosphorylation

It is well known that RB functions are regulated by posttranslational modifications such as phosphorylation and acetylation, but the significance of lysine methylation on RB has not been fully elucidated. Our expression analysis of SMYD2 by quantitative real-time polymerase chain reaction showed that expression levels of SMYD2 are significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (P < .0001), and its expression levels in tumor tissues were much higher than those of any other normal tissues. SMYD2 knockdown resulted in the suppression of cancer cell growth, and cell cycle analysis indicated that SMYD2 might play a crucial role in the G(1)/S transition. According to an in vitro methyltransferase assay, we found that SMYD2 methylates RB1 protein, and liquid chromatography-tandem mass spectrometry analysis revealed lysine 810 of RB1 to be methylated by SMYD2. Importantly, this methylation enhanced Ser 807/811 phosphorylation of RB1 both in vitro and in vivo. Furthermore, we demonstrated that methylated RB1 accelerates E2F transcriptional activity and promotes cell cycle progression. SMYD2 is an important oncoprotein in various types of cancer, and SMYD2-dependent RB1 methylation at lysine 810 promotes cell cycle progression of cancer cells. Further study may explore SMYD2-dependent RB1 methylation as a potential therapeutic target in human cancer.

Loss of the urothelial differentiation marker FOXA1 is associated with high grade, late stage bladder cancer and increased tumor proliferation

Approximately 50% of patients with muscle-invasive bladder cancer (MIBC) develop metastatic disease, which is almost invariably lethal. However, our understanding of pathways that drive aggressive behavior of MIBC is incomplete. Members of the FOXA subfamily of transcription factors are implicated in normal urogenital development and urologic malignancies. FOXA proteins are implicated in normal urothelial differentiation, but their role in bladder cancer is unknown. We examined FOXA expression in commonly used in vitro models of bladder cancer and in human bladder cancer specimens, and used a novel in vivo tissue recombination system to determine the functional significance of FOXA1 expression in bladder cancer. Logistic regression analysis showed decreased FOXA1 expression is associated with increasing tumor stage (p<0.001), and loss of FOXA1 is associated with high histologic grade (p<0.001). Also, we found that bladder urothelium that has undergone keratinizing squamous metaplasia, a precursor to the development of squamous cell carcinoma (SCC) exhibited loss of FOXA1 expression. Furthermore, 81% of cases of SCC of the bladder were negative for FOXA1 staining compared to only 40% of urothelial cell carcinomas. In addition, we showed that a subpopulation of FOXA1 negative urothelial tumor cells are highly proliferative. Knockdown of FOXA1 in RT4 bladder cancer cells resulted in increased expression of UPK1B, UPK2, UPK3A, and UPK3B, decreased E-cadherin expression and significantly increased cell proliferation, while overexpression of FOXA1 in T24 cells increased E-cadherin expression and significantly decreased cell growth and invasion. In vivo recombination of bladder cancer cells engineered to exhibit reduced FOXA1 expression with embryonic rat bladder mesenchyme and subsequent renal capsule engraftment resulted in enhanced tumor proliferation. These findings provide the first evidence linking loss of FOXA1 expression with histological subtypes of MIBC and urothelial cell proliferation, and suggest an important role for FOXA1 in the malignant phenotype of MIBC.

Expression and potential clinical significance of urothelial cytodifferentiation markers in the exstrophic bladder

PURPOSE

We characterize the urothelium from patients with classic bladder exstrophy-epispadias complex for the expression of proteins associated with urothelial differentiation, and discuss a potential impact of urothelial phenotype on the structural and functional properties of the bladder template following bladder closure.

MATERIALS AND METHODS

From 2005 to 2010 bladder biopsies from 32 infants with bladder exstrophy-epispadias complex obtained at primary bladder closure were collected. After histological assessment immunochemistry was used to investigate the expression of uroplakin IIIa, cytokeratin differentiation restricted antigens CK13 and CK20, and tight junction protein claudin 4.

RESULTS

Overall tissue morphology showed gross alterations with inflammatory, proliferative and metaplastic changes in most specimens. Sections of intact epithelium were present in 78% of biopsies. With respect to urothelial phenotype, CK13 was expressed in all specimens, whereas UPIIIa and CK20 were absent in 76% of the tissues examined. Of the biopsies 52% revealed an irregular expression pattern of tight junction protein Cl-4.

CONCLUSIONS

This is the first study to our knowledge to characterize the urothelium from infants with bladder exstrophy-epispadias complex for the expression of urothelial differentiation associated antigens. Our findings suggest urothelial differentiation changes in a majority of exstrophic bladders, at least at primary bladder closure. Although the underlying etiology remains to be established, abnormal urothelial differentiation may result in a dysfunctional urothelial barrier with implications for the structural and functional properties of the bladder template. Despite the study limitations, our preliminary findings provide a platform for further investigation of the significance of the urothelium for the exstrophic bladder.