Loss of p53 and acquisition of angiogenic microRNA profile are insufficient to facilitate progression of bladder urothelial carcinoma in situ to invasive carcinoma

Expression and localization of the mechanosensitive/osmosensitive ion channel TMEM63B in the mouse urinary tract

The epithelial cells that line the kidneys and lower urinary tract are exposed to mechanical forces including shear stress and wall tension; however, the mechanosensors that detect and respond to these stimuli remain obscure. Candidates include the OSCA/TMEM63 family of ion channels, which can function as mechanosensors and osmosensors. Using Tmem63bHA-fl/HA-fl reporter mice, we assessed the localization of HA-tagged-TMEM63B within the urinary tract by immunofluorescence coupled with confocal microscopy. In the kidneys, HA-TMEM63B was expressed by proximal tubule epithelial cells, by the intercalated cells of the collecting duct, and by the epithelial cells lining the thick ascending limb of the medulla. In the urinary tract, HA-TMEM63B was expressed by the urothelium lining the renal pelvis, ureters, bladder, and urethra. HA-TMEM63B was also expressed in closely allied organs including the epithelial cells lining the seminal vesicles, vas deferens, and lateral prostate glands of male mice and the vaginal epithelium of female mice. Our studies reveal that TMEM63B is expressed by subsets of kidney and lower urinary tract epithelial cells, which we hypothesize are sites of TMEM63B mechanosensation or osmosensation, or both.

Mouse models to explore the biological and organismic role of DNA polymerase beta

Gene knock-out (KO) mouse models for DNA polymerase beta (Polβ) revealed that loss of Polβ leads to neonatal lethality, highlighting the critical organismic role for this DNA polymerase. While biochemical analysis and gene KO cell lines have confirmed its biochemical role in base excision repair and in TET-mediated demethylation, more long-lived mouse models continue to be developed to further define its organismic role. The Polb-KO mouse was the first of the Cre-mediated tissue-specific KO mouse models. This technology was exploited to investigate roles for Polβ in V(D)J recombination (variable-diversity-joining rearrangement), DNA demethylation, gene complementation, SPO11-induced DNA double-strand break repair, germ cell genome stability, as well as neuronal differentiation, susceptibility to genotoxin-induced DNA damage, and cancer onset. The revolution in knock-in (KI) mouse models was made possible by CRISPR/cas9-mediated gene editing directly in C57BL/6 zygotes. This technology has helped identify phenotypes associated with germline or somatic mutants of Polβ. Such KI mouse models have helped uncover the importance of key Polβ active site residues or specific Polβ enzyme activities, such as the PolbY265C mouse that develops lupus symptoms. More recently, we have used this KI technology to mutate the Polb gene with two codon changes, yielding the PolbL301R/V303R mouse. In this KI mouse model, the expressed Polβ protein cannot bind to its obligate heterodimer partner, Xrcc1. Although the expressed mutant Polβ protein is proteolytically unstable and defective in recruitment to sites of DNA damage, the homozygous PolbL301R/V303R mouse is viable and fertile, yet small in stature. We expect that this and additional targeted mouse models under development are poised to reveal new biological and organismic roles for Polβ.

Advances in the bladder cancer research using 3D culture models

Bladder cancer represents the most common malignancy of the urinary system, posing a significant threat to patients' life. Animal models and two-dimensional (2D) cell cultures, among other traditional models, have been used for years to study various aspects of bladder cancer. However, these methods are subject to various limitations when mimicking the tumor microenvironment in vivo, thus hindering the further improvement of bladder cancer treatments. Recently, three-dimensional (3D) culture models have attracted extensive attention since they overcome the shortcomings of their traditional counterparts. Most importantly, 3D culture models more accurately reproduce the tumor microenvironment in the human body because they can recapitulate the cell-cell and cell-extracellular matrix interactions. 3D culture models can thereby help us gain deeper insight into the bladder cancer. The 3D culture models of tumor cells can extend the culture duration and allow for co-culturing with different cell types. Study of patient-specific bladder cancer mutations and subtypes is made possible by the ability to preserve cells isolated from particular patients in 3D culture models. It will be feasible to develop customized treatments that target relevant signaling pathways or biomarkers. This article reviews the development, application, advantages, and limitations of traditional modeling systems and 3D culture models used in the study of bladder cancer and discusses the potential application of 3D culture models.

Functional roles for PIEZO1 and PIEZO2 in urothelial mechanotransduction and lower urinary tract interoception

The mechanisms that link visceral mechanosensation to the perception of internal organ status (i.e., interoception) remain elusive. In response to bladder filling, the urothelium releases ATP, which is hypothesized to stimulate voiding function by communicating the degree of bladder fullness to subjacent tissues, including afferent nerve fibers. To determine if PIEZO channels function as mechanosensors in these events, we generated conditional urothelial Piezo1-, Piezo2-, and dual Piezo1/2-knockout (KO) mice. While functional PIEZO1 channels were expressed in all urothelial cell layers, Piezo1-KO mice had a limited phenotype. Piezo2 expression was limited to a small subset of superficial umbrella cells, yet male Piezo2-KO mice exhibited incontinence (i.e., leakage) when their voiding behavior was monitored during their active dark phase. Dual Piezo1/2-KO mice had the most affected phenotype, characterized by decreased urothelial responses to mechanical stimulation, diminished ATP release, bladder hypoactivity in anesthetized Piezo1/2-KO females but not males, and urinary incontinence in both male and female Piezo1/2-KO mice during their dark phase but not inactive light one. Our studies reveal that the urothelium functions in a sex- and circadian rhythm–dependent manner to link urothelial PIEZO1/2 channel–driven mechanotransduction to normal voiding function and behavior, and in the absence of these signals, bladder dysfunction ensues.

Elucidating the role of Agl in bladder carcinogenesis by generation and characterization of genetically engineered mice

Amylo-α-1,6-glucosidase,4-α-glucanotransferase (AGL) is an enzyme primarily responsible for glycogen debranching. Germline mutations lead to glycogen storage disease type III (GSDIII). We recently found AGL to be a tumor suppressor in xenograft models of human bladder cancer (BC) and low levels of AGL expression in BC are associated with poor patient prognosis. However, the impact of low AGL expression on the susceptibility of normal bladder to carcinogenesis is unknown. We address this gap by developing a germline Agl knockout (Agl-/-) mouse that recapitulates biochemical and histological features of GSDIII. Agl-/- mice exposed to N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) had a higher BC incidence compared with wild-type mice (Agl+/+). To determine if the increased BC incidence observed was due to decreased Agl expression in the urothelium specifically, we developed a urothelium-specific conditional Agl knockout (Aglcko) mouse using a Uroplakin II-Cre allele. BBN-induced carcinogenesis experiments repeated in Aglcko mice revealed that Aglcko mice had a higher BC incidence than control (Aglfl/fl) mice. RNA sequencing revealed that tumors from Agl-/- mice had 19 differentially expressed genes compared with control mice. An 'Agl Loss' gene signature was developed and found to successfully stratify normal and tumor samples in two BC patient datasets. These results support the role of AGL loss in promoting carcinogenesis and provide a rationale for evaluating Agl expression levels, or Agl Loss gene signature scores, in normal urothelium of populations at risk of BC development such as older male smokers.

Mouse Cre-LoxP system: general principles to determine tissue-specific roles of target genes

Genetically engineered mouse models are commonly preferred for studying the human disease due to genetic and pathophysiological similarities between mice and humans. In particular, Cre-loxP system is widely used as an integral experimental tool for generating the conditional. This system has enabled researchers to investigate genes of interest in a tissue/cell (spatial control) and/or time (temporal control) specific manner. A various tissue-specific Cre-driver mouse lines have been generated to date, and new Cre lines are still being developed. This review provides a brief overview of Cre-loxP system and a few commonly used promoters for expression of tissue-specific Cre recombinase. Also, we finally introduce some available links to the Web sites that provides detailed information about Cre mouse lines including their characterization.

Pleiotropic functions of miR107 in cancer networks

MicroRNAs are short regulatory RNAs that posttranscriptionally modulate gene expression and thus play crucial roles in controlling cancer-onset, growth, and progression processes. miR107, a highly conserved microRNA that maps to intron 5 of the PANK1 gene, contributes to the regulation of normal and tumor biological processes. Studies have reported that miR107 has oncogenic or tumor-suppressor functions in different human tumors. The pleiotropic functions of miR107 in various cancers are achieved via its targeting different genes that are involved in tumor proliferation, invasiveness, metastasis, angiogenesis, and chemotherapy-response pathways. The carcinogenicity or cancer-suppressor effects of miR107 occur in a tissue- and cell-specific manner, and the expression level of miR107 can be affected by various factors, including epigenetic and genetic factors, treatment exposure, and daily diet. A comprehensive analysis of the current literature suggests that miR107 functions as a central element in the regulation of cancer networks and can be used as a potential diagnostic and prognostic biomarker and drug target for therapeutic intervention.

Identifying a panel of genes/proteins/miRNAs modulated by arsenicals in bladder, prostate, kidney cancers

Arsenic and arsenic-derivative compounds, named as arsenicals, represent a worldwide problem for their effect on the human health and, in particular, for their capability to increase the risk of developing cancer such as kidney, bladder and prostate cancer. The main source of arsenical exposure is drinking water. Nowadays, it is well known that the chronic exposure to arsenicals leads to a series of epigenetic alterations that have a role in arsenic-induced effects on human health including cancer. Based on these observations, the aim of our study was to select by network analysis the genes/proteins/miRNAs implicated in kidney, bladder and prostate cancer development upon arsenical exposure. From this analysis we identified: (i) the nodes linking the three molecular networks specific for kidney, bladder and prostate cancer; (ii) the relative HUB nodes (RXRA, MAP3K7, NR3C1, PABPC1, NDRG1, RELA and CTNNB1) that link the three cancer networks; (iii) the miRNAs able to target these HUB nodes. In conclusion, we highlighted a panel of potential molecules related to the molecular mechanisms of arsenical-induced cancerogenesis and suggest their utility as biomarkers or therapeutic targets.

Modeling human bladder cancer

INTRODUCTION

Bladder cancer is a major public health concern and the treatment options available are unable to significantly prevent disease recurrence and progression. The need for experimental tumor models to efficiently reproduce the pathology of human cancers has prompted researchers to attempt various approaches.

METHODS

A PubMed search combining the MeSH bladder cancer and models was executed in March 2017.

RESULTS

We review the advantages and limitations of currently available in vitro 2D and 3D bladder cancer models as well as in vivo rodent models. To date, despite the description of a variety of animal models (including transplantable, carcinogen-induced and genetically engineered models), the establishment of reliable, simple, practicable and reproducible animal models remains an ongoing challenge. Recently, sophisticated 3D culture systems have been designed to better recapitulate the phenotypic and cellular heterogeneity as well as microenvironmental aspects of in vivo tumor growth, while being more flexible to conduct repeated experiments.

CONCLUSION

Selecting the most appropriate model for a specific application will maximize the conversion of potential therapies from the laboratory to clinical practice and requires an understanding of the various models available.

Urine miRNA as a potential biomarker for bladder cancer detection - a meta-analysis

Introduction

White light cystoscopy (WLC), often supported by urine cytology, is considered the ‘goldstandard’ in the diagnosis and follow-up of bladder cancer (BCa). In recent years, urine microRNA (miRNA) tests have been performed for the detection of bladder cancer.

Material and methods

A systematic review of the PubMed platform was performed by searching for articles in which miRNA in the urine was used for the detection of BCa.

Results

The greatest sensitivity (86.6%) in BCa detection was achieved for multi-miRNA in urine sediment. The greatest specificity (85.3%) was achieved for multi-miRNA from voided urine. There were significant differences (p <0.01) between single-miRNA (OR 8.96; CI 6.37–12.59) and the multi-miRNA group (OR 19.95; CI 13.35–29.81). There were no differences among the specimens (voided urine, supernatant, sediment) used for the test.

Conclusions

Urine miRNAs have the potential to be a valid marker for bladder cancer detection. They can successfully compete with other non-invasive diagnostic tests.

Orthotopic Mouse Models of Urothelial Cancer

Orthotopic mouse models of urothelial cancer are essential for testing novel therapies and molecular manipulations of cell lines in vivo. These models are either established by orthotopic inoculation of human (xenograft models) or murine tumor cells (syngeneic models) in immunocompromised or immune competent mice. Current techniques rely on inoculation by intravesical instillation or direct injection into the bladder wall. Alternative models include the induction of murine bladder tumors by chemical carcinogens (BBN) or genetic engineering (GEM).

Effects of naringin on the expression of miR-19b and cell apoptosis in human hepatocellular carcinoma

The effects of naringin on the expression of miR-19b and cell apoptosis were investigated in the human hepatocellular carcinoma cell line HepG2. HepG2 cells were treated with varied concentrations of naringin. The effects of naringin on the proliferation of HepG2 cells were observed by an MTT assay, morphological changes of cells were observed by an inverted microscope, cell apoptosis was detected by DAPI staining, miR-19b mRNA levels were determined with RT-PCR, and the expression of Bax and Bcl-2 proteins was examined by western blot assay. MTT results showed that naringin significantly inhibited the proliferation of HepG2 cells. Apoptotic HepG2 cells showed obvious changes in morphology under inverted microscope. DAPI staining suggested that naringin could induce cell shrinkage and nuclear chromatin condensation. RT-PCR results showed that naringin could upregulate the expression of miR-19b mRNA. Finally, western blot suggested that naringin upregulated the expression of Bax protein, but downregulated the expression of Bcl-2 protein. In conclusion, naringin can upregulate the expression of miR-19b mRNA and induce HepG2 cell apoptosis. In addition, it can also upregulate the expression of Bax protein and downregulate the expression of Bcl-2 protein during the process of apoptosis.

Insights from animal models of bladder cancer: recent advances, challenges, and opportunities

Bladder cancer (urothelial cancer of the bladder) is the most common malignancy affecting the urinary system with increasing incidence and mortality. Treatment of bladder cancer has not advanced in the past 30 years. Therefore, there is a crucial unmet need for novel therapies, especially for high grade/stage disease that can only be achieved by preclinical model systems that faithfully recapitulate the human disease. Animal models are essential elements in bladder cancer research to comprehensively study the multistep cascades of carcinogenesis, progression and metastasis. They allow for the investigation of premalignant phases of the disease that are not clinically encountered. They can be useful for identification of diagnostic and prognostic biomarkers for disease progression and for preclinical identification and validation of therapeutic targets/candidates, advancing translation of basic research to clinic. This review summarizes the latest advances in the currently available bladder cancer animal models, their translational potential, merits and demerits, and the prevalent tumor evaluation modalities. Thereby, findings from these model systems would provide valuable information that can help researchers and clinicians utilize the model that best answers their research questions.

Transgenic Mouse Models of SV40-Induced Cancer

The SV40 viral oncogene has been used since the 1970s as a reliable and reproducible method to generate transgenic mouse models. This seminal discovery has taught us an immense amount about how tumorigenesis occurs, and its success has led to the evolution of many mouse models of cancer. Despite the development of more modern and targeted approaches for developing genetically engineered mouse models of cancer, SV40-induced mouse models still remain frequently used today. This review discusses a number of cancer types in which SV40 mouse models of cancer have been developed and highlights their relevance and importance to preclinical research.

Understanding the biology of urothelial cancer metastasis

Management of unresectable urothelial cancer (UC) has been a clinical challenge for decades. While drug resistance is a key issue, precise understanding of biology of UC metastasis is another challenge for the improvement of treatment outcome of UC patients. Introduction of the cell biology concepts including epithelial-mesenchymal transition (EMT) and cancer stemness seems to explain UC metastasis. Molecular genetics based on gene expression profiling, next generation sequencing, and explosion of non-coding RNA world has opened the door to intrinsic molecular subtyping of UC. Next steps include, based on the recently accumulated understanding, the establishment of novel disease models representing UC metastasis in various experimental platforms, particularly in vivo animal systems. Indeed, novel knowledge molecular genetics has not been fully linked to the modeling of UC metastasis. Further understanding of bladder carcinogenesis is needed particularly with regard to cell of origin related to tumor characteristics including driver gene alterations, pathological differentiations, and metastatic ability. Then we will be able to establish better disease models, which will consequently lead us to further understanding of biology and eventually the development of novel therapeutic strategies for UC metastasis.

Increased oncogenic microRNA-18a expression in the peripheral blood of patients with prostate cancer: A potential novel non-invasive biomarker

MicroRNAs have been demonstrated to be stably detectable in peripheral blood, thus representing important sources of non-invasive biomarkers of various diseases, including cancer. Recently, microRNA-18a (miR-18a) has been revealed to be highly expressed in prostate cancer (PC) tissues, acting as an oncogenic miRNA. The present study evaluated miR-18a expression in the peripheral blood of patients with PC, patients with benign prostatic hyperplasia (BPH), and healthy individuals, to assess the feasibility of using peripheral blood miR-18a as a potential non-invasive biomarker for PC. Total RNA was extracted from peripheral whole blood samples from 24 PC patients, 24 BPH patients and 23 healthy control individuals. The expression of miR-18a was assessed by reverse transcription quantitative polymerase chain reaction. The results revealed that miR-18a expression was significantly higher in PC patients than in BPH patients and healthy controls [fold change (mean ± standard deviation), 5.5±1.4 for PC, 1.5±0.5 for BPH and 1.2±0.6 for controls; P<0.005]. Higher miR-18a expression was strongly associated with PC [odds ratio (OR), 4.602; 95% confidence interval (CI), 2.194-9.654; P=0.001], but was not significantly associated with BPH (OR, 1.2; 95% CI, 0.7-2.02; P=0.332). Despite the small number of patients, which limits the statistical power of the study, higher miR-18a expression was observed to be significantly correlated with certain clinicopathological parameters, including Gleason score >7 and pathological tumor stage 3/4 (P<0.005). A receiver operating characteristic (ROC) analysis revealed that miR-18a discriminated PC patients from BPH patients and healthy controls [area under the curve (AUC), 0.805; 95% CI, 0.704-0.906). Furthermore, use of the ROC curve to discriminate PC from BPH patients yielded an AUC of 0.878 (95% CI, 0.783-0.972). In summary, the present results indicate that miR-18a expression is significantly increased in peripheral blood of patients with PC compared with that of BPH patients and healthy individuals, and that higher miR-18a expression is associated with progression of PC. Peripheral blood oncogenic miR-18a may serve as a potential novel non-invasive biomarker for PC that also facilitates discrimination between PC and BPH.

The role of WNT signalling in urothelial cell carcinoma

Urothelial cell carcinoma (UCC) of the bladder is one of the most common malignancies, causing considerable morbidity and mortality worldwide. It is unique among the epithelial carcinomas as two distinct pathways to tumourigenesis appear to exist: low grade, recurring papillary tumours usually contain oncogenic mutations in FGFR3 or HRAS whereas high grade, muscle invasive tumours with metastatic potential generally have defects in the pathways controlled by the tumour suppressors p53 and retinoblastoma. Over the last two decades, a number of transgenic mouse models of UCC, containing deletions or mutations of key tumour suppressor genes or oncogenes, have helped us understand the mechanisms behind tumour development. In this summary, I present my work investigating the role of the WNT signalling cascade in UCC.

MicroRNA-18a regulates invasive meningiomas via hypoxia-inducible factor-1α

The aim of the present study was to investigate the effects of microRNA-18a (miR-18a) on the invasiveness and metastasis of invasive meningiomas and the underlying mechanism. A total of 69 patients with meningiomas (30 patients in the invasive meningioma group and 39 patients in the non-invasive meningioma group) and 48 cases in the control group were enrolled. Samples of meningioma tissues, serum and cerebrospinal fluid were collected. Reverse transcription-quantitative polymerase chain reaction was performed to quantify the expression levels of hypoxia-inducible factor-1α (HIF-1α) mRNA and miR-18a. Western blot analysis was used to determine protein expression levels of HIF-1α. The expression levels of HIF-1α mRNA and protein in all three types of sample from the invasive meningioma group were significantly higher compared with those in the control and non-invasive meningioma groups (P<0.05), and the expression levels of HIF-1α mRNA in the serum and cerebrospinal fluid of the non-invasive meningioma group were significantly higher compared with those in the control group (P<0.05). The expression levels of miR-18a in the invasive meningioma group were significantly reduced compared with those in the control and non-invasive meningioma groups (P<0.05), whereas the levels of miR-18a in the non-invasive meningioma group were significantly lower compared with those in the control group (P<0.05). The expression of HIF-1α is significantly upregulated in patients with invasive meningiomas, possibly due to the downregulation of miR-18a expression. Therefore, miR-18a may regulate invasive meningiomas via HIF-1α.

Primed for cancer: Li Fraumeni Syndrome and the pre-cancerous niche

The complex relationship between tumour and stroma is still being elucidated but it is clear that cancer is a disease of more than just malignant cells. However, the dominant focus of our current understanding of Li Fraumeni Syndrome (LFS) remains on the function of p53 as ‘guardian of the genome’. Recent evidence shows that the TP53 gene is at the nexus of a wider range of functions, including aspects of cellular metabolism, aging and immunity. Incorporating this broader picture of the role of TP53 together with our understanding of the role of the host microenvironment in cancer initiation and progression gives a more nuanced picture of LFS. Furthermore, there is clinical evidence to suggest that the host environment in healthy individuals with LFS already includes some of the features of a ‘pre-cancerous niche’ that makes cancer initiation more likely. It is suggested, finally, that there are pharmacological interventions capable of altering this pre-cancerous niche, thus potentially reducing the cancer risk in individuals with LFS.

MiR-107 down-regulates SIAH1 expression in human breast cancer cells and silencing of miR-107 inhibits tumor growth in a nude mouse model of triple-negative breast cancer

We have reported that SIAH1 is down-regulated and associated with apoptosis and invasion in human breast cancer. However, the molecular mechanisms leading to SIAH1 down-regulation remain to be elucidated. Here, we demonstrated that miR-107 directly down-regulates SIAH1 expression in human breast cancer cells. Over- expression of miR-107 reduced SIAH1 expression, promoted human breast cancer cell proliferation, colony formation, migration and invasion, and inhibited apoptosis. On the contrary, silencing of miR-107 increased SIAH1 expression and inhibited the tumor growth of MDA-MB-231 cells, a kind of triple-negative breast cancer (TNBC) cells, in vitro and in vivo. Our results reveal that miR-107 is an upstream regulator for SIAH1 down-regulation in human breast cancer cells and miR-107 provides a potential effective target for the treatment of TNBC.

Circulating miR-18a in plasma contributes to cancer detection and monitoring in patients with gastric cancer

BACKGROUND

Recently, circulating microRNAs have been reported to be stably detectable in plasma/serum and to function as potent non-invasive biomarkers in various cancers. We hypothesized that miR-18a could contribute to a novel plasma biomarker in patients with gastric cancer (GC).

METHODS

We focused on miR-18a, which is a component of miR-17-92 cluster and has been reported as highly expressed in GC tissues. The study involved three steps: (1) confirmation of the higher miR-18a expression in primary GC tissues and GC cell lines than in normal gastric tissues and a fibroblast cell line; (2) evaluation of the plasma miR-18a assay using quantitative RT-PCR by comparing 104 GC patients and 65 healthy volunteers; (3) evaluation of monitoring tumor dynamics by the plasma miR-18a assay.

RESULTS

(1) The miR-18a expressions were significantly higher in GC tissues than in normal gastric tissues (P = 0.0286) and higher in all examined GC cell lines than in the fibroblast cell line. (2) The plasma miR-18a concentrations were significantly higher in GC patients than in healthy controls (P < 0.0001). The value of the area under the receiver-operating characteristic curve was 0.8059. (3) The plasma miR-18a levels were significantly reduced in postoperative samples compared to in preoperative samples (P = 0.0002). In an miR-18a overexpressing cell line, the miR-18a concentration of cultured medium increased in both cell number and time-course dependent manners, suggesting microRNA might be released from cancer cells into the surrounding environment.

CONCLUSIONS

Circulating miR-18a could be a useful biomarker for screening GC and monitoring tumor dynamics.

Chronic social defeat, but not restraint stress, alters bladder function in mice

BACKGROUND

Voiding disorders in humans, particularly in children are associated with increased incidence of behavioral issues as well as past history of childhood abuse. We hypothesized that creating stress in mice, utilizing either a chronic social defeat model (SD) or restraint stress in shallow water model (RSSW) would engender changes in bladder function, morphology, and behavior, thereby enabling us to study the resultant voiding dysfunction.

METHODS

For SD stress (14 days), C57BL/6 male mice were exposed daily to a larger aggressive CD-1 male for 10 min, followed by sensory exposure in a barrier cage for 24h. Control mice were similarly housed with no exposure. For RSSW (21 days), C57BL/6 mice were put in a perforated conical tube with feet immersed in water daily for 4h, then returned to single housing cages. Control mice were also in single housing. After the stress period, voiding patterns were obtained on filter paper, followed by behavioral tests. At necropsy, blood was taken for corticosterone analysis, and bladder and body weights measured. Bladder cryosections were stained with hematoxylin and eosin (H&E) for morphological assessment. Sequential sections were immunostained with antibodies to Ki-67 as a proliferation marker, CD31 (endothelial cell marker), and uroplakin-II. ImageJ software was used to measure bladder wall thickness on blinded H&E photomicrographs as well as quantitate CD31 staining. Both Ki-67-positive and -negative nuclei were counted with Imaris software to obtain a proliferation index.

RESULTS

Only SD mice had a single large void pattern. Bladder-to-body weight ratios increased in SD mice (p≤0.02) but not in RSSW mice. Plasma corticosterone levels were elevated in all stressed mice. SD mice exhibited lower levels of locomotor activity compared with controls; RSSW mice were hyperactive. In SD mice, bladder wall thickness was increased (p ≤ 0.003) but no change was seen in Ki-67 proliferation index, consistent with hypertrophy. No difference with control mice was seen in vascularity as visualized by CD31 staining. Uniform uroplakin-II staining lined the urothelium of both SD and control mice.

CONCLUSIONS

Mice exposed to repeated SD (14 days) respond with altered voiding indicative of urine retention, and exhibit bladder wall changes consistent with hypertrophy while the urothelial barrier is maintained. These changes were not observed with repeated RSSW. SD, in contrast to RSSW, provides a model of psychological stress to further study the interplay of behavior and bladder dysfunction, enabling an improved understanding of voiding dysfunction, and the ability to create innovative and more effective management pathways for children who present with voiding dysfunction.

Expression and function analysis of indoleamine 2 and 3-dioxygenase in bladder urothelial carcinoma

Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for tryptophan metabolism inducing immune tolerance of tumors. The purpose of this study is to investigate IDO expression and its prognostic significance in bladder urothelial carcinoma (BUC). In this study, immunohistochemical staining for IDO expression in BUC tissues (n = 84) and normal bladder tissues (n = 22) was performed. The mRNA expression levels of IDO in BUC and normal bladder were analyzed by quantitative RT-PCR. Survival analysis was performed for the correlation of IDO expression and clinicopathological factors with disease-free survival. Positive expression of IDO was found in 48 of 84 cases in BUC tissues and was significantly correlated with histological classification, histological grade and TNM stage. While IDO expression in normal bladder tissues was expressed in only 4 of 22 (18.2%) cases. Moreover, IDO mRNA levels of BUC were significantly higher than that of normal bladder. We also found that IDO, histological grade and TNM stage were closely associated with DFS. These results indicated that IDO was related to the progression of BUC and might be one of the crucial prognostic factors for BUC.

Animal models for bladder cancer: The model establishment and evaluation (Review)

Bladder cancer is the most common type of tumor in the urogenital system. Approximately 75% of patients with bladder cancer present with non-muscle-invasive cancer, which is generally treated by transurethral resection and intravesical chemotherapy. In spite of different therapeutic options, there remains a very variable risk of recurrence and progression. Novel therapeutic methods of treating bladder cancer are urgently required. The exploration and preclinical evaluation of new treatments requires an animal tumor model that mimics the human counterpart. Animal models are key in bladder cancer research and provide a bridge to the clinic. Various animal bladder cancer models have been described to date, but the tumor take rate is reported to be 30-100%. Establishment of reliable, simple, practicable and reproducible animal models remains an ongoing challenge. The present review summarizes the latest developments with regard to the establishment of animal models and tumor evaluation.

Decreased expression of microRNA-107 predicts poorer prognosis in glioma

The expression level of microRNA-107 (miR-107) has been proved to be decreased in many human malignant cancers. Especially in glioma, accumulating evidence indicates that miR-107 may play important parts in cell proliferation, apoptosis, and invasion in glioma. However, its clinical significance in glioma has not been investigated. This study aims at investigating the relationship between miR-107 expression level and clinical significance and analyzing its value of miR-107 in valuing the prognosis of glioma patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression of miR-107 in 80 glioma and 17 normal brain tissues. The results showed the miR-107 expression level in glioma tissues was significantly lower than those in normal brain tissues (p < 0.001). The decreased expression of miR-107 in glioma was positively associated with high WHO grade (p < 0.001), low Karnofsky performance score (KPS) (p < 0.001), and large tumor size (p < 0.001) and had a significant impact on overall survival (OS) (p < 0.001) and progression-free survival (PFS) (p < 0.001) according to Kaplan-Meier survival with log-rank test. Finally, Cox regression analyses showed that low miR-107 expression (p < 0.001) might be an independent prognostic parameter to predict poor prognosis. In conclusion, it is the first data to prove that expression level of miR-107 may be a novel and valuable prognostic factor in glioma.

Delineating the regulation of energy homeostasis using hypothalamic cell models

Attesting to its intimate peripheral connections, hypothalamic neurons integrate nutritional and hormonal cues to effectively manage energy homeostasis according to the overall status of the system. Extensive progress in the identification of essential transcriptional and post-translational mechanisms regulating the controlled expression and actions of hypothalamic neuropeptides has been identified through the use of animal and cell models. This review will introduce the basic techniques of hypothalamic investigation both in vivo and in vitro and will briefly highlight the key advantages and challenges of their use. Further emphasis will be place on the use of immortalized models of hypothalamic neurons for in vitro study of feeding regulation, with a particular focus on cell lines proving themselves most fruitful in deciphering fundamental basics of NPY/AgRP, Proglucagon, and POMC neuropeptide function.

Modelling bladder cancer in mice: opportunities and challenges

The prognosis and treatment of bladder cancer have improved little in the past 20 years. Bladder cancer remains a debilitating and often fatal disease, and is among the most costly cancers to treat. The generation of informative mouse models has the potential to improve our understanding of bladder cancer progression, as well as to affect its diagnosis and treatment. However, relatively few mouse models of bladder cancer have been described, and in particular, few that develop invasive cancer phenotypes. This Review focuses on opportunities for improving the landscape of mouse models of bladder cancer.

microRNA-18a is a genetic marker for the early diagnosis of cerebral injury induced by type 2 diabetes

The present study aimed to investigate the value of microRNA (miRNA)-18a for the early diagnosis of cerebral injury in patients with type 2 diabetes. Blood samples were collected from patients with type 2 diabetes, admitted to hospital between January and December 2013. The patients were randomly divided into three groups, which included one control and two experimental groups of severely and mildly diabetic patients (33 individuals per group). The levels of biochemical indicators in the serum, including S100 protein, neuron-specific enolase, myelin basic protein and endothelin-1, were determined. The mRNA and protein expression levels of hypoxia-inducible factor (HIF)-1α in the serum were measured by quantitative polymerase chain reaction (qPCR) and western blot analysis, respectively. In addition, the serum expression levels of miRNA-18a were determined by qPCR. The concentrations of the biochemical indicators in the severe diabetes group were significantly higher compared with those from the other two groups. Furthermore, the mRNA and protein expression levels of HIF-1α in the severe diabetes group were significantly upregulated compared with the other groups. However, the levels of miRNA-18a in the severe diabetes group were significantly downregulated compared with the other groups. The present study demonstrated that the elevation of biochemical indicators in the serum and the upregulation of HIF-1α mRNA and protein expression are associated with the downregulation of miRNA-18a. Therefore, miRNA-18a may be a potential genetic marker for the early diagnosis of cerebral injury induced by type 2 diabetes.

Current animal models of bladder cancer: Awareness of translatability (Review)

Experimental animal models are crucial in the study of biological behavior and pathological development of cancer, and evaluation of the efficacy of novel therapeutic or preventive agents. A variety of animal models that recapitulate human urothelial cell carcinoma have thus far been established and described, while models generated by novel techniques are emerging. At present a number of reviews on animal models of bladder cancer comprise the introduction of one type of method, as opposed to commenting on and comparing all classifications, with the merits of a certain method being explicit but the shortcomings not fully clarified. Thus the aim of the present study was to provide a summary of the currently available animal models of bladder cancer including transplantable (which could be divided into xenogeneic or syngeneic, heterotopic or orthotopic), carcinogen-induced and genetically engineered models in order to introduce their materials and methods and compare their merits as well as focus on the weaknesses, difficulties in operation, associated problems and translational potential of the respective models. Findings of these models would provide information for authors and clinicians to select an appropriate model or to judge relevant preclinical study findings. Pertinent detection methods are therefore briefly introduced and compared.

Specific activation of K-RasG12D allele in the bladder urothelium results in lung alveolar and vascular defects

K-ras is essential for embryogenesis and its mutations are involved in human developmental syndromes and cancer. To determine the consequences of K-ras activation in urothelium, we used uroplakin-II (UPK II) promoter driven Cre recombinase mice and generated mice with mutated KrasG12D allele in the urothelium (UPK II-Cre;LSL-K-rasG12D). The UPK II-Cre;LSL-K-rasG12D mice died neonatally due to lung morphogenesis defects consisting of simplification with enlargement of terminal air spaces and dysmorphic pulmonary vasculature. A significant alteration in epithelial and vascular basement membranes, together with fragmentation of laminin, points to extracellular matrix degradation as the causative mechanism of alveolar and vascular defects. Our data also suggest that altered protease activity in amniotic fluid might be associated with matrix defects in lung of UPK II-Cre;LSL-K-rasG12. These defects resemble those observed in early stage human neonatal bronchopulmonary dysplasia (BPD), although the relevance of this new mouse model for BPD study needs further investigation.

Role of miR-107 and its signaling pathways in diseases

MicroRNAs exert their biologic effects by targeting specific mRNAs for degradation or translational inhibition. MicroRNA-mediated regulation is complex, potentially affecting expression of the host gene, related enzymes within the same pathway or apparently distinct targets. miR-107 is found to be implicated in the pathogenesis of some diseases. This review was performed to sum up the role of miR-107 and its signaling pathways in renal diseases.

miR-107 orchestrates ER stress induction and lipid accumulation by post-transcriptional regulation of fatty acid synthase in hepatocytes

MicroRNAs, a class of small non-coding RNAs, are believed to regulate several biological pathways and processes and are implicated in several diseases. They mostly regulate the levels of their target genes at the post transcriptional stage by primarily binding to the 3' UTR. Elevated hepatic levels of miR-107 are a consistent feature associated with several obese and diabetic models. Here, we show that miR-107 post-transcriptionally regulates fatty acid synthase (FASN) by binding to its 3' UTR and reduces its protein levels and the 3'UTR luciferase reporter activity, which are blunted by the miR-107 inhibitor and mutation in the miR-107 binding site in the 3' UTR. Knock-down of endogenous miR-107 levels increased FASN levels in a dose-dependent manner. Overexpression of miR-107 led to significant accumulation of malonyl CoA, accompanied by ER stress induction. All these events were prevented in the presence of the miR-107 inhibitor. While overexpression of FASN could attenuate miR-107 mediated ER stress markers' induction; the ER stress inhibitor, 4-phenyl-butyric acid did not rescue miR-107 induced FASN inhibition. This was followed by increased triglyceride formation and lipid accumulation in the presence of miR-107. These indicate that miR-107 inhibits FASN levels by binding to its 3' UTR and this interaction promotes ER stress induction and malonyl CoA and lipid accumulation in HepG2 cells and primary hepatocytes. Our results suggest that increased levels of miR-107 are critical in promoting lipid accumulation in hepatocytes and this might form the basis of diverse etiologies encountered in a fatty liver.

Upregulation of microRNA-107 induces proliferation in human gastric cancer cells by targeting the transcription factor FOXO1

MicroRNA-107 (miR-107) has been demonstrated to regulate proliferation and apoptosis in many types of cancers. Nevertheless, its biological function in gastric cancer remains largely unexplored. Here, we found that the expression level of miR-107 was increased in gastric cancer in comparison with the adjacent normal tissues. The enforced expression of miR-107 was able to promote cell proliferation in NCI-N87 and AGS cells, while miR-107 antisense oligonucleotides (antisense miR-107) blocked cell proliferation. At the molecular level, our results further revealed that expression of FOXO1 was negatively regulated by miR-107. Therefore, the data reported here demonstrate that miR-107 is an important regulator in gastric cancer, which will contribute to a better understanding of the important mis-regulated miRNAs in gastric cancer.

Deciphering microRNA code in pain and inflammation: lessons from bladder pain syndrome

MicroRNAs (miRNAs), a novel class of molecules regulating gene expression, have been hailed as modulators of many biological processes and disease states. Recent studies demonstrated an important role of miRNAs in the processes of inflammation and cancer, however, there are little data implicating miRNAs in peripheral pain. Bladder pain syndrome/interstitial cystitis (BPS/IC) is a clinical syndrome of pelvic pain and urinary urgency/frequency in the absence of a specific cause. BPS is a chronic inflammatory condition that might share some of the pathogenetic mechanisms with its common co-morbidities inflammatory bowel disease (IBD), asthma and autoimmune diseases. Using miRNA profiling in BPS and the information about validated miRNA targets, we delineated the signaling pathways activated in this and other inflammatory pain disorders. This review projects the miRNA profiling and functional data originating from the research in bladder cancer and immune-mediated diseases on the BPS-specific miRNAs with the aim to gain new insight into the pathogenesis of this enigmatic disorder, and highlighting the common regulatory mechanisms of pain and inflammation.

Constitutive β-catenin activation induces male-specific tumorigenesis in the bladder urothelium

The incidence for bladder urothelial carcinoma, a common malignancy of the urinary tract, is about three times higher in men than in women. Although this gender difference has been primarily attributed to differential exposures, it is likely that underlying biologic causes contribute to the gender inequality. In this study, we report a transgenic mouse bladder tumor model upon induction of constitutively activated β-catenin signaling in the adult urothelium. We showed that the histopathology of the tumors observed in our model closely resembled that of the human low-grade urothelial carcinoma. In addition, we provided evidence supporting the KRT5-positive;KRT7-negative (KRT5(+); KRT7(-)) basal cells as the putative cells-of-origin for β-catenin-induced luminal tumor. Intriguingly, the tumorigenesis in this model showed a marked difference between opposite sexes; 40% of males developed macroscopically detectable luminal tumors in 12 weeks, whereas only 3% of females developed tumors. We investigated the mechanisms underlying this sexual dimorphism in pathogenesis and showed that nuclear translocation of the androgen receptor (AR) in the urothelial cells is a critical mechanism contributing to tumor development in male mice. Finally, we carried out global gene profiling experiments and defined the molecular signature for the β-catenin-induced tumorigenesis in males. Altogether, we have established a model for investigating sexual dimorphism in urothelial carcinoma development, and implicated synergy between β-catenin signaling and androgen/AR signaling in carcinogenesis of the basal urothelial cells.

Alterations of DNA methylome in human bladder cancer

Bladder cancer is the fourth most common cancer in men in the United States, and its recurrence rate is highest among all malignancies. The unmet need for improved strategies for early detection, treatment, and monitoring of the progression of this disease continues to translate into high mortality and morbidity. The quest for advanced diagnostic, therapeutic, and prognostic approaches for bladder cancer is a high priority, which can be achieved by understanding the molecular mechanisms of the initiation and progression of this malignancy. Aberrant DNA methylation in single or multiple cancer-related genes/loci has been found in human bladder tumors and cancer cell lines, and urine sediments, and correlated with many clinicopathological features of this disease, including tumor relapse, muscle-invasiveness, and survival. The present review summarizes the published research on aberrant DNA methylation in connection with human bladder cancer. Representative studies are highlighted to set forth the current state of knowledge, gaps in the knowledgebase, and future directions in this prime epigenetic field of research. Identifying the potentially reversible and 'drugable' aberrant DNA methylation events that initiate and promote bladder cancer development can highlight biological markers for early diagnosis, effective therapy and accurate prognosis of this malignancy.

Low-expression of microRNA-107 inhibits cell apoptosis in glioma by upregulation of SALL4

Glioma is the most common highly malignant primary brain tumor. The molecular pathways that result in the pathogenesis of glioma remain elusive. In this study, we found microRNA-107 (miR-107) was downregulated in glioma tissues and cell lines. Our results revealed miR-107 overexpression suppressed cell proliferation in glioma cells, whereas miR-107 knockdown promoted cell growth in MO59K. miR-107 expression induced apoptosis in glioma cells possibly through the increase in Fas (TNFRSF6)-associated via death domain (FADD) expression and activation of caspases-8 and -3/7. Moreover, the activity of caspase-8 in miR-107-overexpressing SHG44 cells was suppressed with FADD knockdown. The tumor growth in nude mice bearing miR-107-overexpressing SHG44 cells was blocked through apoptosis induction. Sal-like 4 (Drosophila) (SALL4) level was reduced upon miR-107 overexpression in glioma cells, and the inverse was observed upon miR-107 knockdown in MO59K. Using a luciferase reporter system, SALL4 3'-UTR-dependent luciferase activity was reduced by miR-107 mimics or increased by an inhibitor of miR-107. In SHG44, SALL4 downregulation triggered growth inhibition and activated FADD-mediated cell apoptosis pathway. The caspase-8 activity in miR-107-overexpressing SHG44 cells was suppressed with SALL4 upregulation. Furthermore, primary glioma tumors with low miR-107 expression show elevated SALL4 level. An obvious inverse correlation was observed between miR-107 expression and SALL4 level in clinical glioma samples. Therefore, our results demonstrate upregulation of miR-107 suppressed glioma cell growth through direct targeting of SALL4, leading to the activation of FADD/caspase-8/caspase-3/7 signaling pathway of cell apoptosis. These data suggest miR-107 is a potential therapeutic target against glioma.

Clinical impact of circulating miR-18a in plasma of patients with oesophageal squamous cell carcinoma

Background:

Several recent studies demonstrated that microRNAs are stably detectable in plasma/serum. We tested whether miR-18a, which is located in the miR-17-92 cluster and reported to be highly expressed in tissues of oesophageal squamous cell carcinoma (ESCC), served as a plasma biomarker in patients with ESCC.

Methods:

This study was divided into three steps: (1) confirmation of higher miR-18a levels in primary ESCC tissues and cell lines than normal ESCC tissues and a human fibroblast cell line. (2) Evaluation of the plasma miR-18a assay using quantitative RT–PCR by comparing results from 106 consecutive patients with ESCC and 54 healthy volunteers. (3) Evaluation of the assay for monitoring tumour dynamics in patients with ESCC.

Results:

(1) Expression of miR-18a was significantly higher in ESCC tissues (P=0.0020) and ESCC cell lines (P=0.0121) than normal tissues and fibroblasts. (2) Plasma concentrations of miR-18a were significantly higher in ESCC patients than healthy volunteers (P<0.0001; ESCC patients vs healthy volunteers (mean±s.d.): 11.77±13.45 vs 0.73±0.54 amol μl⁻¹). The value of the area under the receiver-operating characteristic (ROC) curve (AUC) was 0.9449. Furthermore, the ROC curves to detect early ESCC such as pTis-1 and pStage0-I showed AUCs of 0.9479 and 0.9642, respectively. (3) Plasma levels of miR-18a were significantly lower in postoperative samples than preoperative samples (P=0.0076).

Conclusion:

Plasma miR-18a may be a very useful biomarker for cancer detection and the monitoring of tumour dynamics in patients with ESCC.

Loss of β1-integrin from urothelium results in overactive bladder and incontinence in mice: a mechanosensory rather than structural phenotype

Bladder urothelium senses and communicates information about bladder fullness. However, the mechanoreceptors that respond to tissue stretch are poorly defined. Integrins are mechanotransducers in other tissues. Therefore, we eliminated β1-integrin selectively in urothelium of mice using Cre-LoxP targeted gene deletion. β1-Integrin localized to basal/intermediate urothelial cells by confocal microscopy. β1-Integrin conditional-knockout (β1-cKO) mice lacking urothelial β1-integrin exhibited down-regulation and mislocalization of α3- and α5-integrins by immunohistochemistry but, surprisingly, had normal morphology, permeability, and transepithelial resistance when compared with Cre-negative littermate controls. β1-cKO mice were incontinent, as judged by random urine leakage on filter paper (4-fold higher spotting, P<0.01; 2.5-fold higher urine area percentage, P<0.05). Urodynamic function assessed by cystometry revealed bladder overfilling with 80% longer intercontractile intervals (P<0.05) and detrusor hyperactivity (3-fold more prevoid contractions, P<0.05), but smooth muscle contractility remained intact. ATP secretion into the lumen was elevated (49 vs. 22 nM, P<0.05), indicating abnormal filling-induced purinergic signaling, and short-circuit currents (measured in Ussing chambers) revealed 2-fold higher stretch-activated ion channel conductances in response to hydrostatic pressure of 1 cmH2O (P<0.05). We conclude that loss of integrin signaling from urothelium results in incontinence and overactive bladder due to abnormal mechanotransduction; more broadly, our findings indicate that urothelium itself directly modulates voiding.

Vascular endothelial growth factor-dependent spinogenesis underlies antidepressant-like effects of enriched environment

Current antidepressant treatments remain limited by poor efficacy and a slow onset of action. Increasing evidence demonstrates that enriched environment (EE) treatment can promote structural and behavioral plasticity in the brain and dampen stress-induced alterations of neuroplasticity. Here, we have examined whether short term exposure to EE is able to produce antidepressant-like effects. Our results show that housing adult mice in an EE cage for 7 days led to antidepressant-like behavioral profiles and a significant increase in the number of dendritic spines in hippocampal CA1 pyramidal neurons. These EE-induced antidepressant-like effects are primarily attributed to increased vascular endothelial growth factor (VEGF) expression through a hypoxia-inducible factor-1α (HIF-1α)-mediated transcriptional mechanism. Blockade of HIF-1α synthesis by lentiviral infection with HIF-1α small hairpin RNAs completely blocked the increase in expression of VEGF and the antidepressant-like effects induced by EE. Moreover, no significant antidepressant-like effects were observed with EE treatment in VEGF receptor 2 (Flk-1) knock-out mice. The increase in HIF-1α expression in the hippocampus induced by EE was associated with a decrease in endogenous levels of microRNA-107 (miR-107). Overexpression of miR-107 in the hippocampus completely blocked EE-induced HIF-1α expression and the antidepressant-like effects. These results support a model in which the down-regulation of miR-107, acting through HIF-1α, mediates VEGF-dependent spinogenesis to underlie the EE-induced antidepressant-like effects.

Exploring molecular genetics of bladder cancer: lessons learned from mouse models

Urothelial cell carcinoma (UCC) of the bladder is one of the most common malignancies worldwide, causing considerable morbidity and mortality. It is unusual among the epithelial carcinomas because tumorigenesis can occur by two distinct pathways: low-grade, recurring papillary tumours usually contain oncogenic mutations in FGFR3 or HRAS, whereas high-grade, muscle-invasive tumours with metastatic potential generally have defects in the pathways controlled by the tumour suppressors p53 and retinoblastoma (RB). Over the past 20 years, a plethora of genetically engineered mouse (GEM) models of UCC have been developed, containing deletions or mutations of key tumour suppressor genes or oncogenes. In this review, we provide an up-to-date summary of these GEM models, analyse their flaws and weaknesses, discuss how they have advanced our understanding of UCC at the molecular level, and comment on their translational potential. We also highlight recent studies supporting a role for dysregulated Wnt signalling in UCC and the development of mouse models that recapitulate this dysregulation.

Targeted pituitary overexpression of pituitary adenylate-cyclase activating polypeptide alters postnatal sexual maturation in male mice

The neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) is present in high concentrations within the hypothalamus, suggesting that it may be a hypophysiotropic factor, whereas pituitary expression suggests a paracrine function. PACAP stimulates gonadotropin secretion and enhances GnRH responsiveness. PACAP increases gonadotropin α-subunit (αGSU), lengthens LHβ, but reduces FSHβ mRNA levels in adult pituitary cell cultures in part by increasing follistatin. PACAP stimulates LH secretion in rats; however, acceptance of PACAP as a regulator of reproduction has been limited by a paucity of in vivo studies. We created a transgenic mouse model of pituitary PACAP overexpression using the αGSU subunit promoter. Real-time PCR was used to evaluate PACAP, follistatin, GnRH receptor, and the gonadotropin subunit mRNA in male transgenic and wild-type mice of various ages. Transgenic mice had greater than 1000-fold higher levels of pituitary PACAP mRNA; and immunocytochemistry, Western blot, and ELISA analyses confirmed high peptide levels. FSH, LH, and testosterone levels were significantly suppressed, and the timing of puberty was substantially delayed in PACAP transgenic mice in which gonadotropin subunit and GnRH receptor mRNA levels were reduced and pituitary follistatin expression was increased. Microarray analyses revealed 1229 of 45102 probes were significantly (P < 0.01) different in pituitaries from PACAP transgenic mice, of which 83 genes were at least 2-fold different. Genes involved in small molecule biochemistry, cancer, and reproductive system diseases were the top associated networks. The GnRH signaling pathway was the top canonical pathway affected by pituitary PACAP excess. These experiments provide the first evidence that PACAP affects gonadotropin expression and sexual maturation in vivo.

microRNA-107 functions as a candidate tumor-suppressor gene in head and neck squamous cell carcinoma by downregulation of protein kinase Cɛ

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed each year. Understanding the molecular pathways that lead to HNSCC is crucial to identify new targets for anti-cancer drug development. Protein kinase Cε (PKCε) is elevated in HNSCC and regulates the activation of Akt, Stat3, and Rho GTPases. To date, the molecular mechanism of PKCε dysregulation in HNSCC remains to be elucidated. In silico analysis identified three putative microRNA-107 (miR-107) binding sites in the 3'-untranslated region (UTR) of PKCε. An inverse relationship was revealed between miR-107 and PKCε in HNSCC cell lines. Delivery of miR-107 reduced PKCε levels in SCC15, SCC25, and CAL27, three HNSCC cell lines with high PKCε and low miR-107. The activity of a luciferase reporter construct containing the 3'-UTR of PKCε was down-regulated by miR-107 and mutations in the three cognate miR-107 binding sites completely ablated the regulation by miR-107. Treatment with miR-107 significantly blocked cell proliferation, DNA replication, colony formation, and invasion in SCC25 and CAL27 cells. Ectopic expression of miR-resistant PKCε was sufficient to partially rescue the loss-of-function phenotype in miR-107-overexpressing SCC25 cells. Tumor growth in nude mice was retarded by 93 ± 7% in CAL27/miR-107 cells compared to CAL27/miR-control cells. Lastly, human primary HNSCC tumors with elevated PKCε had reduced miR-107 expression. Our results demonstrate that PKCε is directly regulated by miR-107 and moreover, suggest that miR-107 may be a potential anti-cancer therapeutic for HNSCC.

A systematic analysis on DNA methylation and the expression of both mRNA and microRNA in bladder cancer

BACKGROUND

DNA methylation aberration and microRNA (miRNA) deregulation have been observed in many types of cancers. A systematic study of methylome and transcriptome in bladder urothelial carcinoma has never been reported.

METHODOLOGY/PRINCIPAL FINDINGS

The DNA methylation was profiled by modified methylation-specific digital karyotyping (MMSDK) and the expression of mRNAs and miRNAs was analyzed by digital gene expression (DGE) sequencing in tumors and matched normal adjacent tissues obtained from 9 bladder urothelial carcinoma patients. We found that a set of significantly enriched pathways disrupted in bladder urothelial carcinoma primarily related to "neurogenesis" and "cell differentiation" by integrated analysis of -omics data. Furthermore, we identified an intriguing collection of cancer-related genes that were deregulated at the levels of DNA methylation and mRNA expression, and we validated several of these genes (HIC1, SLIT2, RASAL1, and KRT17) by Bisulfite Sequencing PCR and Reverse Transcription qPCR in a panel of 33 bladder cancer samples.

CONCLUSIONS/SIGNIFICANCE

We characterized the profiles between methylome and transcriptome in bladder urothelial carcinoma, identified a set of significantly enriched key pathways, and screened four aberrantly methylated and expressed genes. Conclusively, our findings shed light on a new avenue for basic bladder cancer research.