Alternating expression levels of WWOX tumor suppressor and cancer-related genes in patients with bladder cancer

KLHDC7B as a novel diagnostic biomarker in urine exosomal mRNA promotes bladder urothelial carcinoma cell proliferation and migration, inhibits apoptosis

Bladder cancer is a common kind of urinary system cancer, in which bladder urothelial carcinoma (BLCA) comprises approximately 90% of all bladder cancer types. In our previous study, we discovered KLHDC7B in urine exosomal messenger RNA (mRNA) as a prospective molecular marker for bladder cancer detection. To systematically study the role and mechanism of KLHDC7B in BLCA, we focused on the most common type of BLCA in this study. First, we used RNA sequencing to discover that KLHDC7B was considerably increased in BLCA patients' urine exosomes compared to healthy controls. Then, we validated this result in an independent cohort and identified it as an effective tool for diagnosing and distinguishing high-grade and low-grade BLCA. Finally, we studied the role and mechanism of KLHDC7B in BLCA at the cellular level, providing a functional basis for its expression as a novel laboratory diagnostic biomarker for BLCA exosomal mRNA, which has important theoretical and clinical significance.

WWOX Modulates ROS-Dependent Senescence in Bladder Cancer

The tumor-suppressor gene, WW domain-containing oxidoreductase (WWOX), has been found to be lost in various types of cancers. ROS result as a tightly regulated signaling process for the induction of cell senescence. The aim of this study was to investigate the role of WWOX in the regulation of ROS and cell senescence, which is intriguing in terms of the possible mechanism of WWOX contributing to bladder cancer. In this study, we used the AY-27 rat bladder tumor cell line and F344 orthotopic bladder tumor models to reveal the pro-senescence effects of WWOX and the corresponding underlying mechanism in bladder cancer. WWOX-overexpressing lentivirus (LV-WWOX) remarkably stimulated cellular senescence, including increased senescence-associated secretory phenotype (SASP) formation, enlarged cellular morphology, and induced SA-β-Gal-positive staining. A further mechanism study revealed that the pro-senescence effect of LV-WWOX was dependent on increased intercellular reactive oxygen species (ROS) generation, which subsequently triggered p21/p27. Moreover, LV-WWOX significantly inhibited the tumor size by 30.49% in the F344/AY-27 rat orthotopic model (p < 0.05) by activating cellular senescence. The expression of p21 was significantly enhanced in the orthotopic bladder tumors under WWOX treatment. The orthotopic bladder tumors in the groups of rats verified the effect in vivo. Our study suggests that WWOX, an ROS-dependent senescence-induced gene, could be further studied for its therapeutic implications in bladder cancer.

In vitro and in silico assessment of the effect of WWOX expression on invasiveness pathways associated with AP-2 transcription factors in bladder cancer

BACKGROUND

WW Domain Containing Oxidoreductase (WWOX) belongs to the unusual tumor suppressors, whose molecular function is not fully understood in bladder cancer, especially regarding interaction with Activator Protein 2 (AP-2) α/γ transcription factors. Thus, using lentiviral systems we created an in vitro model overexpressing or downregulating WWOX in CAL-29 cell line to assess invasiveness pathways. Surprisingly, while WWOX overexpression was accompanied with increased expression of both AP-2 factors, its downregulation only affected AP-2α level but not AP-2γ which remained high.

METHODS

Using cellular models and unpaired t-test or Wilcoxon test, we investigated significant changes in biological processes: clonogenicity, extracellular matrix adhesion, metalloproteinases activity, 3D culture growth, proliferation, mitochondrial redox potential and invasiveness. Relative gene expression acquired through Real-Time qPCR has been analyzed by Welch's t-test. Additionally, using oncoprint analysis we distinguished groups for bioinformatics analyzes in order to perform a follow-up of in vitro experiments.

RESULTS

Downregulation of WWOX in bladder cancer cell line intensified ability of single cell to grow into colony, mitochondrial redox potential and proliferation rate. Moreover, these cells shown elevated pro-MMP-2/9 activity but reduced adhesion to collagen I or laminin I, as well as distinct 3D culture growth. Through global in silico profiling we determined that WWOX alters disease-free survival of bladder cancer patients and modulates vital processes through AP-2 downstream effectors.

CONCLUSIONS

Our research indicates that WWOX possesses tumor suppressor properties in bladder cancer but consecutive examination is required to entirely understand the contribution of AP-2γ or AP-2α.

Fragile Gene WWOX Guides TFAP2A/TFAP2C-Dependent Actions Against Tumor Progression in Grade II Bladder Cancer

INTRODUCTION

The presence of common fragile sites is associated with no-accidental chromosomal instability which occurs prior to carcinogenesis. The WWOX gene spans the second most active fragile site: FRA16D. Chromosomal breakage at this site is more common in bladder cancer patients who are tobacco smokers which suggests the importance of WWOX gene loss regarding bladder carcinogenesis. Tryptophan domains of WWOX are known to recognize motifs of other proteins such as AP-2α and AP-2γ allowing protein-protein interactions. While the roles of both AP-2 transcription factors are important for bladder carcinogenesis, their nature is different. Based on the literature, AP-2γ appears to be oncogenic, whereas AP-2α mainly exhibits tumor suppressor character. Presumably, the interaction between WWOX and both transcription factors regulates thousands of genes, hence the aim of the present study was to determine WWOX, AP-2α, and AP-2γ function in modulating biological processes of bladder cancer.

METHODS

RT-112 cell line (grade II bladder cancer) was subjected to two stable lentiviral transductions. Overall, this resulted in six variants to investigate distinct WWOX, AP-2α, or AP-2γ function as well as WWOX in collaboration with a particular transcription factor. Cellular models were examined with immunocytochemical staining and in terms of differences in biological processes using assays investigating cell viability, proliferation, apoptosis, adhesion, clonogenicity, migration, activity of metalloproteinases and 3D culture growth.

RESULTS

WWOX overexpression increased apoptosis but decreased cell viability, migration and large spatial colonies. AP-2α overexpression decreased tumor cell viability, migratory potential, matrix metalloproteinase-2 activity and clonogenicity. AP-2γ overexpression decreased matrix metalloproteinase-2 activity but increased wound healing, adhesion, clonogenicity and spatial colony formation. WWOX and AP-2α overexpression induced apoptosis but decreased cell viability, adhesion, matrix metalloproteinase-2 activity, overall number of cultured colonies and migration rate. WWOX and AP-2γ overexpression decreased tumor cell viability, proliferation potential, adhesion, clonogenicity and the ability to create spatial structures, but also increased apoptosis or migration rate.

CONCLUSION

Co-overexpression of WWOX with AP-2α or WWOX with AP-2γ resulted in a net anti-tumor effect. However, considering this research findings and the difference between AP-2α and AP-2γ, we suggest that this similarity is due to a divergent behavior of WWOX.

The WWOX gene in brain development and pathology

Shortly after its discovery in 2000, WWOX was hailed as a tumor suppressor gene. In subsequent years of research, this function was confirmed indisputably. Majority of tumors show high rate of loss of heterozygosity and decreased expression of WWOX. Nevertheless, over the years, the range of its known functions, at the cellular, organ and system levels, has expanded to include metabolism and endocrine system control and CNS differentiation and functioning. Despite of its function as a tumor suppressor gene, WWOX genetic alternations were found in a number of metabolic and neural diseases. A lack of WWOX protein as a consequence of germline mutations results in brain development disturbances and malfunctions.

The WWOX Gene Influences Cellular Pathways in the Neuronal Differentiation of Human Neural Progenitor Cells

The brain is the most functionally organized structure of all organs. It manages behavior, perception and higher cognitive functions. The WWOX gene is non-classical tumor suppressor gene, which has been shown to have an impact on proliferation, apoptosis and migration processes. Moreover, genetic aberrations in WWOX induce severe neuropathological phenotypes in humans and rodents. The aim of the present study was to investigate in detail the impact of WWOX on human neural progenitor cell (hNPC) maintenance and how depletion of WWOX disturbs signaling pathways playing a pivotal role in neuronal differentiation and central nervous system (CNS) organogenesis. hNPC with a silenced WWOX gene exhibited lowered mitochondrial redox potential, enhanced adhesion to fibronectin and extracellular matrix protein mixture, downregulation of MMP2/9 expression and impaired 3D growth. Global transcriptome analysis using cap analysis of gene expression (CAGE) found that WWOX downregulation significantly changes the expression of multiple genes engaged in cytoskeleton organization, adhesion, cell signaling and chromatin remodeling. The massive changes in gene expression caused by WWOX silencing may strongly affect the differentiation and migration of neurons in organogenesis, brain injury, cancerogenesis or neurodifferentiation. WWOX gene appears to be an important regulator of neural tissue architecture and function.

Functional genetic variant of WW domain containing oxidoreductase gene associated with urothelial cell carcinoma clinicopathologic characteristics and long-term survival

OBJECTIVES

In Taiwan, urothelial cell carcinoma (UCC) is a common malignancy of urinary tract that is associated with genetic and environmental carcinogens. WW domain-containing oxidoreductase (WWOX) has been identified as a tumor suppressor gene that associated with several cancers development and progression. The study aimed to explore the impact of WWOX gene polymorphisms on the clinicopathological status and prognosis of patients with UCC.

MATERIALS AND METHODS

A total of 1,293 participants, including 431 patients with UCC and 862 healthy controls, were recruited for this study. Five polymorphisms of the WWOX gene were examined by a real-time PCR assay.

RESULTS

We found that individuals carrying TT polymorphism at rs11545028 and at least 1 G allele at rs3764340 associated with more susceptible to UCC. At least 1 A allele at rs12918952 associated with more advance disease and high grade tumor. Patients with T allele at rs11545028 associated with worse relapse free survival in all patients and worse disease specific survival (DSS) in male. Patients with A allele at rs12918952 associated with worse DSS in all patients and worse relapse free survival, DSS and overall survival in male.

CONCLUSIONS

This is the first reported correlation between WWOX polymorphisms and UCC risk and clinicopathologic feature. Genetic variants of WWOX contribute to the pathologic staging, grading, and prognosis. The findings regarding these biomarkers provided a potential prediction of UCC progression.

Ectopic WWOX Expression Inhibits Growth of 5637 Bladder Cancer Cell In Vitro and In Vivo

WW domain-containing oxidoreductase (WWOX) gene located in the common fragile site FRA16D region exhibits loss or reduction of expression in multiple types of carcinomas including bladder cancer. However, the role of WWOX in the tumorigenesis and development of bladder cancer remains elusive. In this study, WWOX overexpression construct was transfected into 5637 bladder cancer cell line in which WWOX expression was compromised. Constitutive expression of ectopic WWOX in 5637 cells suppressed cell proliferation and cell cycle progression, which was associated with downregulation of Cyclin B, D1, and E. Moreover, WWOX overexpression promoted apoptosis in 5637 cells and resulted in upregulation of Bax, downregulation of Bcl-2, and elevated levels of cleaved caspase-3 and cleaved PARP, indicating activation of the intrinsic apoptosis pathway. Furthermore, WWOX overexpression suppressed tumorigenicity of 5637 cells and promoted apoptosis in the xenograft tumors as demonstrated in a xenograft mouse model. In summary, our data indicate that WWOX plays a critical role in the regulation of proliferation, cell cycle, apoptosis, and tumorigenesis of bladder cancer cells, suggesting that WWOX may have potential clinical implications in bladder cancer therapy.

CMTM8 inhibits the carcinogenesis and progression of bladder cancer

Bladder cancer is the most common tumor of the urinary tract. The incidence of bladder cancer has increased in the last few decades, thus novel molecular markers for early diagnosis and more efficacious treatment are urgently needed. Chemokine‑like factor (CKLF)‑like MARVEL transmembrane domain containing 8 (CMTM8) is downregulated in several types of cancers and is associated with tumor progression. However, CMTM8 expression has been unexplored in bladder cancer to date. Our results revealed that the expression of CMTM8 was negative in 46 of 74 (62.2%) bladder cancer samples via immunohistochemistry assay. CMTM8 downregulation was associated with advancing tumor stage and tumor grade. CMTM8 was successfully overexpressed by lentivirus in EJ and T24 cells, and the CCK‑8 and Transwell assays showed that CMTM8 overexpression decreased cell proliferation, migration and invasion in vitro. In tumor xenografts upregulation of CMTM8 inhibited tumor growth and lymph node metastasis in vivo. In conclusion, overexpression of CMTM8 in bladder cancer results in reduced malignant cell growth, migration and invasion, which could make it a potential therapeutic target in the treatment of bladder cancer.

BcCluster: A Bladder Cancer Database at the Molecular Level

BACKGROUND

Bladder Cancer (BC) has two clearly distinct phenotypes. Non-muscle invasive BC has good prognosis and is treated with tumor resection and intravesical therapy whereas muscle invasive BC has poor prognosis and requires usually systemic cisplatin based chemotherapy either prior to or after radical cystectomy. Neoadjuvant chemotherapy is not often used for patients undergoing cystectomy. High-throughput analytical omics techniques are now available that allow the identification of individual molecular signatures to characterize the invasive phenotype. However, a large amount of data produced by omics experiments is not easily accessible since it is often scattered over many publications or stored in supplementary files.

OBJECTIVE

To develop a novel open-source database, BcCluster (http://www.bccluster.org/), dedicated to the comprehensive molecular characterization of muscle invasive bladder carcinoma.

MATERIALS

A database was created containing all reported molecular features significant in invasive BC. The query interface was developed in Ruby programming language (version 1.9.3) using the web-framework Rails (version 4.1.5) (http://rubyonrails.org/).

RESULTS

BcCluster contains the data from 112 published references, providing 1,559 statistically significant features relative to BC invasion. The database also holds 435 protein-protein interaction data and 92 molecular pathways significant in BC invasion. The database can be used to retrieve binding partners and pathways for any protein of interest. We illustrate this possibility using survivin, a known BC biomarker.

CONCLUSIONS

BcCluster is an online database for retrieving molecular signatures relative to BC invasion. This application offers a comprehensive view of BC invasiveness at the molecular level and allows formulation of research hypotheses relevant to this phenotype.

Effects of siRNA Livin on EJ human bladder cancer cells treated with mitomycin-C

The aim of this study was to observe the inhibitory and therapeutic effects of small interfering RNA (siRNA) targeting Livin in EJ human bladder cancer cells. Specific siRNA targeting Livin was synthesized and transfected into EJ human bladder cancer cells treated or not treated with mitomycin-C (MMC). Livin mRNA and protein, as well as proliferation and apoptosis of EJ cells was examined with reverse transcription-polymerase chain reaction, western blotting, Cell Counting Kit-8 assay and flow cytometry, respectively. The results indicated that the expression of Livin mRNA and protein in EJ cells was significantly decreased by siRNA Livin. The proliferation of EJ cells was significantly inhibited by treatment with MMC and transfection of siRNA Livin. The inhibition of cell proliferation by treatment with MMC was further enhanced by transfection of siRNA Livin. The apoptotic rate of cells transfected with siRNA Livin and treated with MMC was significantly higher than those cells receiving a single transfection of siRNA Livin and single treatment of MMC. In conclusion, the present study demonstrates that transfection of siRNA Livin induces growth suppression and apoptosis in EJ human bladder cancer cells, and increases the chemotherapeutic sensitivity of cells to MMC.