MicroRNA-31 functions as a tumor suppressor and increases sensitivity to mitomycin-C in urothelial bladder cancer by targeting integrin α5

Selective targeting of α7 nicotinic acetylcholine receptor by synthetic peptide mimicking loop I of human SLURP-1 provides efficient and prolonged therapy of epidermoid carcinoma in vivo

α7-Type nicotinic acetylcholine receptor (α7-nAChR) promotes the growth and metastasis of solid tumors. Secreted Ly6/uPAR-Related Protein 1 (SLURP-1) is a specific negative modulator of α7-nAChR produced by epithelial cells. Here, we investigated mechanisms of antiproliferative activity of recombinant SLURP-1 in epidermoid carcinoma A431 cells and activity of SLURP-1 and synthetic 21 a.a. peptide mimicking its loop I (Oncotag) in a xenograft mice model of epidermoid carcinoma. SLURP-1 inhibited the mitogenic pathways and transcription factors in A431 cells, and its antiproliferative activity depended on α7-nAChR. Intravenous treatment of mice with SLURP-1 or Oncotag for 10 days suppressed the tumor growth and metastasis and induced sustained changes in gene and microRNA expression in the tumors. Both SLURP-1 and Oncotag demonstrated no acute toxicity. Surprisingly, Oncotag led to a longer suppression of pro-oncogenic signaling and downregulated expression of pro-oncogenic miR-221 and upregulated expression of KLF4 protein responsible for control of cell differentiation. Affinity purification revealed SLURP-1 interactions with both α7-nAChR and EGFR and selective Oncotag interaction with α7-nAChR. Thus, the selective inhibition of α7-nAChRs by drugs based on Oncotag may be a promising strategy for cancer therapy.

Identification of a new anoikis-related gene signature for prognostic significance in head and neck squamous carcinomas

Anoikis, a mode of programmed cell death, is essential for normal development and homeostasis in the organism and plays an important role in the onset and progression of cancers. The authors of this research sought to establish a gene signature associated with anoikis to predict therapy outcomes and patient prognosis for individuals with head and neck squamous cell carcinoma (HNSCC). Transcriptome data of anoikis-related genes (ARGs) in individuals with HNSCC were retrieved from public databases to aid in the formulation of the gene signature. A novel ARG signature was then created using a combination of the Least Absolute Shrinkage and Selection Operator regression and Cox regression analysis. The relationship between ARGs and tumor immune microenvironment in HNSCC was explored using single-cell analysis. HNSCC individuals were classified into high-risk and low-risk groups as per the median value of risk score. The study also investigated the variations in the infiltration status of immune cells, tumor microenvironment, sensitivity to immunotherapy and chemotherapeutics, as well as functional enrichment between the low-risk and high-risk categories. A total of 18 ARGs were incorporated in the formulation of the signature. Our signature's validity as a standalone predictive predictor was validated by multivariate Cox regression analysis and Kaplan-Meier survival analysis. Generally, the prognosis was worse for high-risk individuals. Subjects in the low-risk groups had a better prognosis and responded in a better way to combination immunotherapy, had higher immunological ratings and activity levels, and had more immune cell infiltration. In addition, gene set enrichment analysis findings showed that the low-risk subjects exhibited heightened activity in several immune-related pathways. However, the high-risk patients responded better to chemotherapy. The aim of this research was to develop a new ARG signature to predict the prognosis and sensitivity to immunotherapeutic and chemotherapeutic schemes for HNSCC patient. As a result, this could help spur the creation of new chemotherapeutics and immunotherapeutic approaches for patients with HNSCC.

Targeting integrin α5β1 in urological tumors: opportunities and challenges

Urological tumors, such as prostate cancer, renal cell carcinoma, and bladder cancer, have shown a significant rise in prevalence in recent years and account for a significant proportion of malignant tumors. It has been established that metastasis to distant organs caused by urological tumors is the main cause of death, although the mechanisms underlying metastasis have not been fully elucidated. The fibronectin receptor integrin α5β1 reportedly plays an important role in distant metastasis and is closely related to tumor development. It is widely thought to be an important cancer mediator by interacting with different ligands, mediating tumor adhesion, invasion, and migration, and leading to immune escape. In this paper, we expound on the relationship and regulatory mechanisms of integrin α5β1 in these three cancers. In addition, the clinical applications of integrin α5β1 in these cancers, especially against treatment resistance, are discussed. Last but not least, the possibility of integrin α5β1 as a potential target for treatment is examined, with new ideas for future research being proposed.

The Roles of miRNAs in Predicting Bladder Cancer Recurrence and Resistance to Treatment

Bladder cancer (BCa) is associated with significant morbidity, with development linked to environmental, lifestyle, and genetic causes. Recurrence presents a significant issue and is managed in the clinical setting with intravesical chemotherapy or immunotherapy. In order to address challenges such as a limited supply of BCG and identifying cases likely to recur, it would be advantageous to use molecular biomarkers to determine likelihood of recurrence and treatment response. Here, we review microRNAs (miRNAs) that have shown promise as predictors of BCa recurrence. MiRNAs are also discussed in the context of predicting resistance or susceptibility to BCa treatment.

Modulating Effects of Cancer-Derived Exosomal miRNAs and Exosomal Processing by Natural Products

Cancer-derived exosomes exhibit sophisticated functions, such as proliferation, apoptosis, migration, resistance, and tumor microenvironment changes. Several clinical drugs modulate these exosome functions, but the impacts of natural products are not well understood. Exosome functions are regulated by exosome processing, such as secretion and assembly. The modulation of these exosome-processing genes can exert the anticancer and precancer effects of cancer-derived exosomes. This review focuses on the cancer-derived exosomal miRNAs that regulate exosome processing, acting on the natural-product-modulating cell functions of cancer cells. However, the role of exosomal processing has been overlooked in several studies of exosomal miRNAs and natural products. In this study, utilizing the bioinformatics database (miRDB), the exosome-processing genes of natural-product-modulated exosomal miRNAs were predicted. Consequently, several natural drugs that modulate exosome processing and exosomal miRNAs and regulate cancer cell functions are described here. This review sheds light on and improves our understanding of the modulating effects of exosomal miRNAs and their potential exosomal processing targets on anticancer treatments based on the use of natural products.

ITGA5 Promotes Tumor Progression through the Activation of the FAK/AKT Signaling Pathway in Human Gastric Cancer

Background

ITGA5 is an adhesion molecule that integrates the intracellular structures with the extracellular matrix to perform biological functions. However, ITGA5 is highly expressed in a variety of tumors and is involved in tumor progression by promoting cell proliferation and metastasis. Nevertheless, little research has been performed on its function in gastric cancer. Therefore, the aim of this study was to investigate the role of ITGA5 in gastric cancer, focusing on the mechanism regulating the proliferation, invasion and migration.

Methods

The expression of ITGA5 in gastric cancer tissues was assessed by the use of molecular bioinformatics databases and high-throughput sequencing of gastric cancer tissues from patients. Western blot, qPCR, and immunohistochemistry were performed to detect the expression of ITGA5 in samples from gastric cancer patients and gastric cancer cell lines. Furthermore, the ITGA5 gene was silenced and overexpressed in gastric cancer cells, and the effect on proliferation, invasion, migration, and tumorigenic ability was assessed.

Results

ITGA5 mRNA and protein expression were upregulated in gastric cancer cell lines and tissues from patients, and its expression was closely associated with tumor size, lymph node metastasis, and TNM stage. In vitro and in vivo experiments showed that ITGA5 silencing resulted in the inhibition of proliferation, invasion, migration, and graft growth of gastric cancer cells; conversely, the overexpression resulted in the promotion of these cell functions. Our results finally showed that the effect of ITGA5 on proliferation, invasion, and migration of gastric cancer cells was performed through the activation of the FAK/AKT pathway.

Conclusions

ITGA5 promotes proliferation, invasion, and migration of gastric cancer cells through the activation of FAK/AKT signaling pathway, suggesting that ITGA5 may be potentially considered as a new target in gastric cancer therapy.

miRNA in Molecular Diagnostics

MicroRNAs are a class of small non-coding RNA molecules that regulate gene expression on post-transcriptional level. Their biogenesis consists of a complex series of sequential processes, and they regulate expression of many genes involved in all cellular processes. Their function is essential for maintaining the homeostasis of a single cell; therefore, their aberrant expression contributes to development and progression of many diseases, especially malignant tumors and viral infections. Moreover, they can be associated with certain states of a specific disease, obtained in the least invasive manner for patients and analyzed with basic molecular methods used in clinical laboratories. Because of this, they have a promising potential to become very useful biomarkers and potential tools in personalized medicine approaches. In this review, miRNAs biogenesis, significance in cancer and infectious diseases, and current available test and methods for their detection are summarized.

A sensing system constructed by combining a structure-switchable molecular beacon with nicking-enhanced rolling circle amplification for highly sensitive miRNA detection

A novel amplification assay strategy is developed for the highly sensitive detection of miRNA-21 based on a combination of a structure-switchable molecular beacon with nicking-enhanced rolling circle amplification.

Bladder Cancer-related microRNAs With In Vivo Efficacy in Preclinical Models

Progressive and metastatic bladder cancer remain difficult to treat. In this review, we critique seven up-regulated and 25 down-regulated microRNAs in order to identify new therapeutic entities and corresponding targets. These microRNAs were selected with respect to their efficacy in bladder cancer-related preclinical in vivo models. MicroRNAs and related targets interfering with chemoresistance, cell-cycle, signaling, apoptosis, autophagy, transcription factor modulation, epigenetic modification and metabolism are described. In addition, we highlight microRNAs targeting transmembrane receptors and secreted factors. We discuss druggability issues for the identified targets.

Punica granatum Extract Inhibits Bladder Cancer Cell Viability, Invasion and Migration through Down-Regulation of HOXD10 Signalling Pathway

The present study investigated Punica granatum extract (PGE) as potential proliferation inhibitory agent for bladder cancer cells and elucidated the possible mechanism. PGE reduced viabilities of HT-1197 and RT4 cells in concentration-based manner at 72 h. Colony forming potential of HT-1197 and RT4 cells was also significantly (p < 0.05) inhibited on exposure to 2 and 12 mg/mL PGE. Exposure to 12 mg/mL PGE for 72 h significantly (p < 0.05) decreased miR‑10b expression and suppressed migration potential of HT-1197 and RT4 cells. In PGE exposed HT-1197 and RT4 cells, invasiveness was reduced to 30.25 and 33.47%, respectively. PGE treatment of HT-1197 and RT4 cells caused a significant (p < 0.05) elevation in HOXD10 protein and mRNA levels compared to control. The miR‑10b mimic transfection in HT-1197 and RT4 cells reversed inhibitory effect of PGE on cell viability. Thus, PGE exhibited cytotoxicity and anti-invasive effect on HT-1197 and RT4 cells through targeting miR‑10b and up-regulation of HOXD10 expression. Thus, PGE may be developed as therapeutic agent for treatment of bladder cancer.

miR-31 Displays Subtype Specificity in Lung Cancer

miRNA rarely possess pan-oncogenic or tumor-suppressive properties. Most miRNAs function under tissue-specific contexts, acting as either tumor suppressors in one tissue, promoting oncogenesis in another, or having no apparent role in the regulation of processes associated with the hallmarks of cancer. What has been less clear is the role of miRNAs within cell types of the same tissue and the ability within each cell type to contribute to oncogenesis. In this study, we characterize the role of one such tissue-specific miRNA, miR-31, recently identified as the most oncogenic miRNA in lung adenocarcinoma, across the histologic spectrum of human lung cancer. Compared with normal lung tissue, miR-31 was overexpressed in patient lung adenocarcinoma, squamous cell carcinoma, and large-cell neuroendocrine carcinoma, but not small-cell carcinoma or carcinoids. miR-31 promoted tumor growth in mice of xenografted human adenocarcinoma and squamous cell carcinoma cell lines, but not in large- or small-cell carcinoma lines. While miR-31 did not promote primary tumor growth of large- and small-cell carcinoma, it did promote spontaneous metastasis. Mechanistically, miR-31 altered distinct cellular signaling programs within each histologic subtype, resulting in distinct phenotypic differences. This is the first report distinguishing diverse functional roles for this miRNA across the spectrum of lung cancers and suggests that miR-31 has broad clinical value in human lung malignancy. SIGNIFICANCE: These findings demonstrate the oncogenic properties of miR-31 in specific subtypes of lung cancer and highlight it as a potential therapeutic target in these subtypes. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/1942/F1.large.jpg.

MicroRNAs: Their Role in Metastasis, Angiogenesis, and the Potential for Biomarker Utility in Bladder Carcinomas

Angiogenesis is the process of generating new capillaries from pre-existing blood vessels with a vital role in tumor growth and metastasis. MicroRNAs (miRNAs) are noncoding RNAs that exert post-transcriptional control of protein regulation. They participate in the development and progression of several cancers including bladder cancer (BLCA). In cancer tissue, changes in microRNA expression exhibit tissue specificity with high levels of stability and detectability. miRNAs are less vulnerable to degradation, making them novel targets for therapeutic approaches. A suitable means of targeting aberrant activated signal transduction pathways in carcinogenesis of BLCA is possibly through altering the expression of key miRNAs that regulate them, exerting a strong effect on signal transduction. Precaution must be taken, as the complexity of miRNA regulation might result in targeting several downstream tumor suppressors or oncogenes, enhancing the effect further. Since exosomes contain both mRNA and miRNA, they could therefore possibly be more effective in targeting a recipient cell if they deliver a specific miRNA to modify the recipient cell protein production and gene expression. In this review, we discuss the molecules that have been shown to play a significant role in BLCA tumor development. We also discuss the roles of various miRNAs in BLCA angiogenesis and metastasis. Advances in the management of metastatic BLCA have been limited; miRNA mimics and molecules targeted at miRNAs (anti-miRs) as well as exosomes could serve as therapeutic modalities or as diagnostic biomarkers.

MicroRNAs and target molecules in bladder cancer

Bladder cancer (BC) is considered as one of the most common malignant tumors in humans with complex pathogenesis including gene expression variation, protein degradation, and changes in signaling pathways. Many studies on involved miRNAs in BC have demonstrated that they could be used as potential biomarkers in the prognosis, response to treatment, and screening before the cancerous phenotype onset. MicroRNAs (miRNAs) regulate many cellular processes through their different effects on special targets along with modifying signaling pathways, apoptosis, cell growth, and differentiation. The diverse expression of miRNAs in cancerous tissues could mediate procedures leading to the oncogenic or suppressor behavior of certain genes in cancer cells. Since a specific miRNA may have multiple targets, an mRNA could also be regulated by multiple miRNAs which further demonstrates the actual role of miRNAs in cancer. In addition, miRNAs can be utilized as biomarkers in some cancers that cannot be screened in the early stages. Hence, finding blood, urine, or tissue miRNA biomarkers by novel or routine gene expression method could be an essential step in the prognosis and control of cancer. In the present review, we have thoroughly evaluated the recent findings on different miRNAs in BC which can provide comprehensive information on better understanding the role of diverse miRNAs and better decision making regarding the new approaches in the diagnosis, prognosis, prevention, and treatment of BC.

Effects of Epigallocatechin Gallate (EGCG) on Urinary Bladder Urothelial Carcinoma-Next-Generation Sequencing and Bioinformatics Approaches

Background and objectives: Bladder urothelial carcinoma is the most common type of genitourinary cancer. Patients with bladder cancer may have limited treatment efficacy related to drug toxicity, resistance or adverse effects, and novel therapeutic strategies to enhance treatment efficacy or increase sensitivity to drugs are of high clinical importance. Epigallocatechin gallate (EGCG) is a polyphenolic compound found in green tea leaves, and a potential anti-cancer agent in various cancer types through modulating and regulating multiple signaling pathways. The current study aimed to explore the role and novel therapeutic targets of EGCG on bladder urothelial carcinoma. Materials and Methods: The BFTC-905 cells, human urinary bladder transitional cell carcinoma (TCC) cell line, were treated with EGCG or water for 24 hours, and the expression profiles of mRNAs and microRNAs were analyzed using next generation sequencing (NGS). The enriched biological functions were determined using different bioinformatics databases. Results: A total of 108 differentially expressed genes in EGCG-treated bladder TCC cells were identified, which were mainly involved in nicotinamide adenine dinucleotide (NAD) biogenesis, inflammatory response and oxidation-reduction metabolism. Moreover, several microRNA-mRNA interactions that potentially participated in the response of bladder TCC to EGCG treatment, including miR-185-3p- ARRB1 (arrestin beta 1), miR-3116- MGAT5B (alpha-1,6-mannosylglycoprotein 6-beta-N-acetylglucosaminyltransferase B), miR-31-5p-TNS1 (tensin 1), miR-642a-5p-TNS1, miR-1226-3p- DLG2 (discs large homolog 2), miR-484-DLG2, and miR-22-3p- PPM1K (protein phosphatase 1K). Conclusions: The current findings provide insights into novel therapeutic targets and underlying mechanisms of action of EGCG treatment in bladder cancer.

Propofol exhibits a tumor-suppressive effect and regulates cell viability, migration and invasion in bladder carcinoma by targeting the microRNA-10b/HOXD10 signaling pathway

2,6-diisopropylphenol (propofol) is a commonly used intravenous anesthetic drug, which has been reported to serve an antitumor role in human cancers. The current study aimed to assess the effects of propofol on the biological behaviors of human bladder cancer cells and to elucidate its potential molecular mechanism. The results of MTT, wound healing and Matrigel invasion assays demonstrated that propofol significantly inhibited the viability, migration and invasion of bladder cancer T24 cells in vitro. Reverse transcription-quantitative PCR and western blotting revealed that propofol decreased the expression levels of microRNA (miR)-10b and increased the expression levels of homeobox D10 (HOXD10) in T24 cells. Luciferase reporter assay revealed that HOXD10 was a direct target of miR-10b in T24 cells. T24 cells transfected with a miR-10b mimic significantly reduced the mRNA and protein expression levels of HOXD10. In addition, overexpression of miR-10b partly reversed the inhibitory effect of propofol on T24 cell viability, migration and invasion induced by upregulation of HOXD10. In summary, the present study focused on the role of propofol in the treatment of bladder cancer and demonstrated that propofol may serve a tumor-suppressive role and control cell viability, migration and invasion of T24 cells by targeting the miR-10b/HOXD10 signaling pathway, which indicated that propofol may be used as an effective therapeutic drug for the treatment of bladder cancer.

The effect of miR-124-3p on cell proliferation and apoptosis in bladder cancer by targeting EDNRB

INTRODUCTION

Endothelin receptor type B (EDNRB) is a potential target gene of miR-124-3p, but the association between miR-124-3p and EDNRB has not yet been reported. The aim of this study was to investigate the role of miR-124-3p in bladder cancer (BC) and to determine whether miR-124-3p regulates cell proliferation by targeting EDNRB.

MATERIAL AND METHODS

Bladder cancer tissues and cell lines were obtained in order to analyze the miR-124-3p and EDNRB expression through quantitative RT-PCR (qRT-PCR) and western blotting analysis. The dual-luciferase reporter assay was employed to confirm the relationship between miR-124-3p and EDNRB. The manipulation of miR-124-3p and EDNRB expression was achieved through cell transfection. Cell proliferation and apoptosis were evaluated by MTS assay, colony forming assay and flow cytometry. A nude mouse tumorigenicity assay was used to detect the effects of miR-124-3p in vivo.

RESULTS

There was an inverse correlation between the expression of miR-124-3p and EDNRB; miR-124-3p was down-regulated and EDNRB was up-regulated in BC tissues and cell lines. MiR-124-3p was observed to target EDNRB and suppress its expression. Other studies have suggested that the transfection of miR-124-3p mimics and EDNRB siRNA can suppress BC cell proliferation and induce cell apoptosis.

CONCLUSIONS

miR-124-3p regulates the proliferation and apoptosis of BC cells by suppressing EDNRB expression.

MicroRNA-124-3p suppresses cell migration and invasion by targeting ITGA3 signaling in bladder cancer

BACKGROUND

A growing body of studies have demonstrated the aberrant expression of microRNAs (miRNAs) contributes to human tumor metastasis. MicroRNA-124-3p (miR-124-3p), which is down-regulated in various cancers, has been found to be involved in several signaling pathways relevant to tumor cell migration and invasion. However, the roles of miR-124-3p in human bladder cancer remain unclear. This study aims to investigate the functional significance of miR-124-3p and to understand how it targets the integrin receptor, and thus affects the progression of human bladder cancer.

METHODS

Clinical specimens from 36 patients and three human bladder cancer cell lines were analyzed for miR-124-3p and integrin α3 (ITGA3) . To investigate the effects of miR-124-3p and ITGA3 on proliferation of bladder cancer cells, the MTT assay, colon-formation assay and flow cytometry were performed. In addition, wound healing assay and transwell assay were carried out to examine the migration and invasion of the bladder cancer cells transfected with miR-124-3p mimics or si-ITGA3. The luciferase reporter assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to validate the miR-124-3p directly binding with ITGA3. Finally, western blot was used to examine the expression level of the proteins involved in FAK/PI3K/AKT and FAK/Src signal pathway as well as epithelial-mesenchymal transition (EMT) process.

RESULTS

The down-regulation of miR-124-3p and up-regulation of ITGA3 were observed in clinical specimens and bladder cancer cell lines. Overexpression of miR-124-3p or silencing ITGA3 inhibited tumor cell migration and invasion. Luciferase assay confirmed miR-124-3p directly targets ITGA3, and western blot suggested that miR-124-3p plays a crucial role in the EMT and metastasis of human bladder cancer through FAK/PI3K/AKT and FAK/Src signaling mechanism. Also, by targeting ITGA3, miR-124-3p can modulate the expression of N- and E-cadherin, and thus inhibit the EMT.

CONCLUSIONS

By targeting ITGA3 and downstream FAK/PI3K/AKT and FAK/Src signaling pathways, miR-124-3p suppresses cell migration and invasion in bladder cancer. Our study reasonably speculates that miR-124-3p can be potentially developed as a therapeutic target and prognostic biomarker for bladder cancer.

Mechanisms behind Temsirolimus Resistance Causing Reactivated Growth and Invasive Behavior of Bladder Cancer Cells In Vitro

Background: Although mechanistic target of rapamycin (mTOR) inhibitors, such as temsirolimus, show promise in treating bladder cancer, acquired resistance often hampers efficacy. This study evaluates mechanisms leading to resistance. Methods: Cell growth, proliferation, cell cycle phases, and cell cycle regulating proteins were compared in temsirolimus resistant (res) and sensitive (parental—par) RT112 and UMUC3 bladder cancer cells. To evaluate invasive behavior, adhesion to vascular endothelium or to immobilized extracellular matrix proteins and chemotactic activity were examined. Integrin α and β subtypes were analyzed and blocking was done to evaluate physiologic integrin relevance. Results: Growth of RT112res could no longer be restrained by temsirolimus and was even enhanced in UMUC3res, accompanied by accumulation in the S- and G2/M-phase. Proteins of the cdk-cyclin and Akt-mTOR axis increased, whereas p19, p27, p53, and p73 decreased in resistant cells treated with low-dosed temsirolimus. Chemotactic activity of RT112res/UMUC3res was elevated following temsirolimus re-exposure, along with significant integrin α2, α3, and β1 alterations. Blocking revealed a functional switch of the integrins, driving the resistant cells from being adhesive to being highly motile. Conclusion: Temsirolimus resistance is associated with reactivation of bladder cancer growth and invasive behavior. The α2, α3, and β1 integrins could be attractive treatment targets to hinder temsirolimus resistance.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

Alkylating anticancer agents and their relations to microRNAs

Alkylating agents represent an important class of anticancer drugs. The occurrence and emergence of tumor resistance to the treatment with alkylating agents denotes a severe problem in the clinics. A detailed understanding of the mechanisms of activity of alkylating drugs is essential in order to overcome drug resistance. In particular, the role of non-coding microRNAs concerning alkylating drug activity and resistance in various cancers is highlighted in this review. Both synthetic and natural alkylating agents, which are approved for cancer therapy, are discussed concerning their interplay with microRNAs.

Integrin-α5 promoted the progression of oral squamous cell carcinoma and modulated PI3K/AKT signaling pathway

BACKGROUND

Integrin-α5 (ITGA5) gene has been reported to be critical for the progression of several cancers. However, the effects of ITGA5 in oral squamous cell carcinoma (OSCC) remain unclear.

METHODS

We firstly used bioinformatics methods to analyze the ITGA5 gene expression based on the public dataset. HO1-N-1 and SCC-9 cells with silenced ITGA5 were constructed using siRNA. Then, we determined the biological functions of ITGA5 in OSCC cells using cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and transwell assays. The expression of PI3K, p-PI3K, AKT, p-AKT, ERK and pERK were determined by western blot.

RESULTS

Our results revealed that ITGA5 expression was up-regulated in OSCC. The biological experiments further confirmed that ITGA5 expression was higher in OSCC cell lines. Moreover, we found that knockdown of ITGA5 inhibited the proliferation, migration and invasion of OSCC cells. The expression of phosphorylated-(p) PI3K, p-AKT and p-ERK obviously decreased after knockdown of ITGA5 in OSCC cells.

CONCLUSION

In summary, ITGA5 could promote the progression of OSCC via activating the PI3K/AKT signaling pathway, and it can be regarded as a potential biomarker for OSCC treatment.

MicroRNA-31 triggers G2/M cell cycle arrest, enhances the chemosensitivity and inhibits migration and invasion of human gastric cancer cells by downregulating the expression of zeste homolog 2 (ZH2)

Gastric cancer is the second most leading cause of cancer related mortality across the world over. Although the incidence of GC has declined to some extent but it is still the fourth highly diagnosed cancer across the world. GC generally remains undiagnosed till advanced stages due to unavailability of biomarkers and when diagnosed it becomes difficult to manage due to the lack of therapeutic targets and efficient chemotherapy. There are concrete evidences suggesting that miRNAs may prove important therapeutic targets for the treatment of devastating diseases such as cancer. The study was designed to investigate the tumor suppressive role of miR-31 via regulation of zeste homolog 2 (ZH2). It was found that miR-31 is significantly downregulated in GC cell lines. Overexpression of miR-31 causes significant (P < 0.05) decrease in the viability and colony formation via initiation of G2/M cell cycle arrest of the AGS cancer cells. Moreover, miR-31 overexpression also enhanced the chemosensitivity of miR-31 to the anticancer drug 5-fluorouracil. In silico analysis together with dual luciferase reporter assay indicated zeste homolog 2 (ZH2) to be the potential target of miR-31 in AGS cells. Investigation of ZH2 expression in GC cell lines showed it to be significantly (P < 0.05) upregulated. Nonetheless, overexpression of miR-31 in AGS cells resulted in the suppression of ZH2 expression. Additionally, silencing of ZH2 in the AGS cells also caused inhibition of AGS cell proliferation and colony formation via G2/M arrest. Moreover, overexpression of ZH2 could at least partially reverse the tumor suppressive effects of miR-31 indicating direct involvement of ZH2 in the miR-31 mediated inhibitory effects on AGS cell proliferation. Finally, miR-31 overexpression caused significant (P < 0.05) inhibition of the migration and invasion of the AGS gastric cancer cells. The overexpression of miR-31 also caused downregulation of mesenchymal markers (Vimentin and N-cadherin) and upregulation of epithelial marker (E-cadherin) protein expression was in AGS cells. It is therefore concluded that miR-31 acts as a tumor suppressor and may prove essential in the treatment of GC.

MiR-99a-5p inhibits bladder cancer cell proliferation by directly targeting mammalian target of rapamycin and predicts patient survival

Bladder cancer is a common malignancy and miR-99a-5p has been reported to be downregulated in bladder cancer, but its function and the underlying mechanism in bladder cancer development remains largely unclear. Here, we report that miR-99a-5p expression was decreased in bladder cancer compared with the adjacent normal tissues. Receiver operating characteristic curve revealed that miR-99a-5p expression signature had area under curve value of 0.7989 in differing bladder cancer from the adjacent normal tissues. Bladder cancer patients with low expression of miR-99a-5p had a poor survival rate. Gain-of-function and loss-of-function approaches demonstrated that miR-99a-5p inhibited bladder cell proliferation and cell cycle. Furthermore, we identified that mammalian target of rapamycin (mTOR) was a direct target of miR-99a-5p and mTOR restore could rescue the proliferative ability of bladder cancer cells. Moreover, miR-99a-5p/mTOR axis regulated S6K1 phosphorylation. These suggested that miR-99a-5p/mTOR axis might be a therapeutic target for bladder cancer.

Circ-BPTF promotes bladder cancer progression and recurrence through the miR-31-5p/RAB27A axis

Circ-BPTF (hsa_circ_0000799) is a novel circular RNA derived from BPTF exons. Although BPTF is a well-studied predecessor gene, the characteristics and functions of circ-BPTF have not yet been reported. Here, we show that expression of circ-BPTF is increased in bladder cancer (BCa) tissues and cell lines compared with noncancerous tissues and cell lines. Consistently, BCa patients with higher expression levels of circ-BPTF were found to have higher tumor grades and poorer prognosis. Functionally, knockdown of circ-BPTF inhibited tumor progression in vitro and in vivo. Mechanistically, a target microRNA of circ-BPTF was confirmed to be miR-31-5p, and miR-31-5p mimics partially reversed the effect of circ-BPTF. Furthermore, RAB27A was predicted and shown to be a target of miR-31-5p, and circ-BPTF attenuated the anti-oncogenic effect of miR-31-5p and consequently enhanced RAB27A expression. In summary, our findings reveal that circ-BPTF promotes BCa progression through the miR-31-5p/RAB27A axis, suggesting that circ-BPTF may be a potential target for BCa treatment.

MicroRNA-195 inhibits epithelial-mesenchymal transition via downregulating CDK4 in bladder cancer

Bladder cancer is one of the most common cancers in the world. Despite advanced development made to improve the diagnosis and therapy techniques for bladder cancer, patients always have a poor outcome based on its high potential for metastasis. MiR-195 was reported to have close relevance with the process of bladder cancer. However, the molecular mechanism of miR-195 underlying bladder cancer metastasis and epithelial-mesenchymal transition (EMT) remains unclear. The present study was done to explore the function of miR-195 on EMT and cell migration in bladder cancer. In the present study, we detected the level of miR-195 in 25 matched human bladder cancer tissues and normal adjacent tissues, as well as bladder cancer cell lines or normal cells. Additionally, we determined the effects of miR-195 on expression of CDK4, and the miR-195/CKD4 signaling cascade on cell cycle, invasion, migration, and viability. Results showed that miR-195 was down expressed in bladder cancer tissues and cell lines, which inhibited EMT, cell migration, and invasion. We identify CDK4, an early G1 cell cycle regulator, as a downstream target of miR-195. Also, we found that miR-195 could induce G1-phase arrest, inhibit cell invasion, migration, and viability through down-regulation of CDK4 expression in 5637 and BIU-87 cells. Our experimental data suggest an important role for miR-195/CDK4 in bladder tumorigenesis and provide a potential therapeutic strategy for bladder cancer.

MicroRNA31-NDRG3 regulation axes are essential for hepatocellular carcinoma survival and drug resistance

BACKGROUNDS

Hepatocellular carcinoma (HCC) is an epithelial cancer that originates from hepatocytes and it is the most common primary malignant tumor of the liver. Till now the prognosis of HCC patients is generally poor. The molecular mechanism giving rise to HCC development and recurrence is still largely unknown. MicroRNA-31 (miR-31) is among the most commonly altered microRNAs in human cancers, and alternations of miR-31 expression were reported to play pivotal roles in tumorigenesis and tumor progression.

METHODS

In this work, the primary biological function of miR-31 in HCC tumorigenesis was investigated.

RESULTS

Our data showed that overexpression of miR-31 induced markedly inhibition of HCC cell proliferation, migration in vitro and inhibited xenograft tumor growth in vivo. One target gene of miR-31, NDRG3, was also demonstrated indispensable for HCC cell survival. Furthermore, miR-31 and NDRG3 were both essential for HCC cell drug resistance in adriamycin.

CONCLUSIONS

We conclude that miR-31 is a crucial regulator in hepatocellular carcinoma, miR-31 and its target gene NDRG3 may be potential therapeutic targets for HCC treatment in the future.

Circulating miR-31 as an effective biomarker for detection and prognosis of human cancer: a meta-analysis

PURPOSE

Circulating miR-31 was found to be associated with cancers detection and prognosis. The present meta-analysis aimed to explore the effect of circulating miR-31 on cancer detection and prognosis.

METHOD

The studies were accessed using multiple databases. RevMan5.3, Meta-DiSc 1.4, and STATA14.0 were used to estimate the pooled effects, heterogeneity among studies, and publication bias.

RESULTS

A total of 14 studies with 1397 cancer patients and 1039 controls were included. For the 12 prognostic tests, the adjusted pooled-AUC was 0.79 (95% CI: 0.73-0.86) as the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odd ratio (DOR) from 10 tests was 0.79 (95% CI: 0.76-0.82), 0.79 (95% CI: 0.76-0.82), 3.81 (95% CI: 2.90-5.01), 0.26 (95% CI: 0.20-0.35), and 16.81 (95% CI: 9.67-29.25), respectively. For the 5 prognosis analyses, the pooled HR (hazard ratio) of overall survival (OS) was 1.55 (95% CI 1.30-1.86) for high versus low circulating miR-31 expression. However, high expression of circulating miR-31 did not significantly increase the risk of poor differentiation (pooled OR=1.39, 95% CI: 0.56-3.47) and LNM (pooled OR=3.46, 95% CI: 0.96-12.42) in lung cancer.

CONCLUSION

Circulating miR-31 is an effective biomarker and could be used as a component of miRs signature for cancer detection and prognosis surveillance.

Dysregulation of miRNAs in bladder cancer: altered expression with aberrant biogenesis procedure

Aberrant expression profiles of miRNAs are widely observed in the clinical tissue specimens and urine samples as well as the blood samples of bladder cancer patients. These profiles are closely related to the pathological features of bladder cancer, such as the tumour stage/grade, metastasis, recurrence and chemo-sensitivity. MiRNA biogenesis forms the basis of miRNA expression and function, and its dysregulation has been shown to be essential for variations in miRNA expression profiles as well as tumourigenesis and cancer progression. In this review, we summarize the up-to-date and widely reported miRNAs in bladder cancer that display significantly altered expression. We then compare the miRNA expression profiles among three different sample types (tissue, urine and blood) from patients with bladder cancer. Moreover, for the first time, we outline the dysregulated miRNA biogenesis network in bladder cancer from different levels and analyse its possible relationship with aberrant miRNA expression and the pathological characteristics of the disease.

MicroRNA-191-5p exerts a tumor suppressive role in renal cell carcinoma

Renal cell carcinoma (RCC) is a common tumor of the urinary system. Previously, miR-191-5p has been reported to be associated with various types of cancer; however, its specific functions in RCC have not been investigated to date. In the present study, the expression of miR-191-5p in the 786-O and ACHN cell lines was detected in vitro by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results of RT-qPCR revealed that miR-191-5p was significantly downregulated in the two cell lines compared with the 293T cell line. miR-191-5p was also significantly downregulated in RCC tissue compared with paired normal tissue. In addition, the effects of miR-191-5p on cell proliferation, migration, invasion and apoptosis were examined by CCK-8, MTT, wound scratch, Transwell and flow cytometry assays. Downregulation of miR-191-5p was observed to promote cell proliferation, migration and invasion, as well as to repress the cell apoptosis of 786-O and ACHN cells. Therefore, the current study suggests that miR-191-5p functions as a tumor suppressor in RCC. Further studies are required to uncover the underlying signaling pathway of miR-191-5p and its potential role as a biomarker for early detection and prognosis prediction, and as a therapeutic target of RCC.

Expression of miR-149-3p inhibits proliferation, migration, and invasion of bladder cancer by targeting S100A4

MicroRNAs play key roles during various crucial cell processes, such as proliferation, migration, and invasion. In addition, microRNAs have been shown to possess oncogenic and tumor suppressive functions in human cancers. Increasing evidence has clarified that miR-149-3p, a novel cancer-related microRNA, plays an important role in suppression of proliferation, migration, and invasion; however, the effect and mechanisms underlying the miR-149-3p effect in bladder cancer (BCa) remain unclear. In the current study we found that the increased expression of miR-149-3p significantly suppressed cell proliferation, migration, and invasion ability in BCa. The suppressive effect was related to S100A4. A further investigation showed that miR-149-3p negatively regulated S100A4, as verified by the luciferase reporter assay. Furthermore, our study showed that S100A4 mediated the anti-metastatic effects of miR-149-3p on proliferation, migration, and invasion of BCa cells. Analysis of a xenograft mouse model showed that miR-149-3p expression significantly decreased tumor growth by targeting S100A4. Taken together, these data indicate that S100A4 promotes cell growth, migration, and invasion and can by reversed by miR-149-3p in BCa.

MicroRNA-31 suppresses the self-renewal capability of α2δ1+ liver tumor-initiating cells by targeting ISL1

Accumulating evidence demonstrates that miRNAs, a class of small non-coding RNAs, are involved in the regulation of tumor-initiating cells (TICs) which are considered to be the origin of cancer development according to the cancer stem cell hypothesis. We have previously identified that miR-31 may play suppressive roles in α2δ1⁺ hepatocellular carcinoma (HCC) TICs. Here, we confirm that the expression of miR-31 is significantly downregulated in α2δ1⁺ HCC TICs. Overexpression of miR-31 in α2δ1⁺ HCC TICs results in significant suppression of the self-renewal and tumorigenicity abilities of these cells. Conversely, knockdown the expression of miR-31 in PLC/PRF/5 cells is able to reprogram them into TICs with stem cell-like properties. Furthermore, the expression of ISL LIM Homeobox 1(ISL1), a transcription factor involved in recognition of undifferentiated cardiac progenitors, is negatively regulated by miR-31, and the luciferase reporters’ activities with the 3′-UTRs of ISL1 are inhibited significantly by miR-31. Collectively, our results suggest that miR-31 can negatively regulate the self-renewal ability of α2δ1⁺ liver TICs via silencing ISL1.

Targeting of CCN2 suppresses tumor progression and improves chemo-sensitivity in urothelial bladder cancer

Urothelial bladder cancer (UBC) is the most common urinary neoplasm in China. CCN family protein 2 (CCN2), a cysteine-rich matricellular protein, is abnormally expressed in several cancer types and involved in tumor progression or chemo-resistance. However, detailed expression patterns and effects of CCN2 in UBC still remain unknown. We found that down-regulation of CCN2 suppressed proliferation, migration and invasion of UBC cells in vitro and targeting of CCN2 decelerated xenograft growth in vivo. When treated with mitomycin C (MMC), CCN2-scilencing UBC cells showed lower survival and higher apoptotic rates and these effects were probably mediated via inactivation of Akt and Erk pathways. We also demonstrated the clinical significance of CCN2 expression, which was higher in UBC tissues and associated with advanced tumor stage and high pathologic grade. Taken together, our data suggest that CCN2 is an oncogene in UBC and might serve as a matricellular target for improving chemotherapeutic efficacy.

Identification of aminosulfonylarylisoxazole as microRNA-31 regulators

The discovery of small-molecule regulators of microRNAs remains challenging, but a few have been reported. Herein, we describe small-molecule inhibitors of miR-31, a tumor-associated microRNA (miRNA), identified by high-throughput screening using a cell-based reporter assay. Aminosulfonylarylisoxazole compounds exhibited higher specificity for miR-31 than for six other miRNAs, i.e., miR-15a, miR-16, miR-21, miR-92a-1, miR-146a, and miR-155, and increased the expression of miR-31 target genes. The down-regulation of mature miR-31 was observed, while its precursor form increased following treatment with the compounds. Thus, the compounds may target the processing of pre-miR-31 into mature miR-31 and thereby inhibit the production of mature miR-31.

The cancer cell adhesion resistome: mechanisms, targeting and translational approaches

Cell adhesion-mediated resistance limits the success of cancer therapies and is a great obstacle to overcome in the clinic. Since the 1990s, where it became clear that adhesion of tumor cells to the extracellular matrix is an important mediator of therapy resistance, a lot of work has been conducted to understand the fundamental underlying mechanisms and two paradigms were deduced: cell adhesion-mediated radioresistance (CAM-RR) and cell adhesion-mediated drug resistance (CAM-DR). Preclinical work has evidently demonstrated that targeting of integrins, adapter proteins and associated kinases comprising the cell adhesion resistome is a promising strategy to sensitize cancer cells to both radiotherapy and chemotherapy. Moreover, the cell adhesion resistome fundamentally contributes to adaptation mechanisms induced by radiochemotherapy as well as molecular drugs to secure a balanced homeostasis of cancer cells for survival and growth. Intriguingly, this phenomenon provides a basis for synthetic lethal targeted therapies simultaneously administered to standard radiochemotherapy. In this review, we summarize current knowledge about the cell adhesion resistome and highlight targeting strategies to override CAM-RR and CAM-DR.

Understanding the Role of Non-Coding RNAs in Bladder Cancer: From Dark Matter to Valuable Therapeutic Targets

The mortality and morbidity that characterize bladder cancer compel this malignancy into the category of hot topics in terms of biomolecular research. Therefore, a better knowledge of the specific molecular mechanisms that underlie the development and progression of bladder cancer is demanded. Tumor heterogeneity among patients with similar diagnosis, as well as intratumor heterogeneity, generates difficulties in terms of targeted therapy. Furthermore, late diagnosis represents an ongoing issue, significantly reducing the response to therapy and, inevitably, the overall survival. The role of non-coding RNAs in bladder cancer emerged in the last decade, revealing that microRNAs (miRNAs) may act as tumor suppressor genes, respectively oncogenes, but also as biomarkers for early diagnosis. Regarding other types of non-coding RNAs, especially long non-coding RNAs (lncRNAs) which are extensively reviewed in this article, their exact roles in tumorigenesis are—for the time being—not as evident as in the case of miRNAs, but, still, clearly suggested. Therefore, this review covers the non-coding RNA expression profile of bladder cancer patients and their validated target genes in bladder cancer cell lines, with repercussions on processes such as proliferation, invasiveness, apoptosis, cell cycle arrest, and other molecular pathways which are specific for the malignant transformation of cells.

Preclinical studies for the combination of paclitaxel and curcumin in cancer therapy (Review)

Cancer is one of the most common causes of death and remains the first in China and the second in the US. The common treatments for cancer include surgery, radiation, chemotherapy, targeted therapy and immunotherapy, while chemotherapy remains one of the most important treatments. However, the efficacy of chemotherapy is limited due to drug induced-toxicities and resistance, particularly multiple drug resistance (MDR). Therefore, discovery and development of novel therapeutic drugs and/or combination therapy are urgently needed to reduce toxicity and improve efficacy. Paclitaxel has been widely used to treat various cancers including cervical, breast, ovarian, brain, bladder, prostate, liver and lung cancers. However, its therapeutic efficacy is limited and MDR is a major obstacle. Recently, numerous preclinical studies have shown that the combination of paclitaxel and curcumin may be an ideal strategy to reverse MDR and synergistically improve their therapeutic efficacy in cancer therapy. This review mainly focuses on the current development and progress of the combination of paclitaxel and curcumin in cancer therapy preclinically.

miR-138-5p contributes to cell proliferation and invasion by targeting Survivin in bladder cancer cells

Background

Survivin (encoded by the gene BIRC5) plays an important role in the carcinogenesis of bladder cancer. Identifying miRNAs that target Survivin in the setting of bladder cancer will help to develop Survivin-based therapies for bladder cancer.

Methods

The expression levels of miR-138-5p and Survivin protein were measured in 12 resected bladder cancer specimens. The correlation between miR-138-5p and Survivin was further examined by evaluating Survivin expression in human bladder cancer cell lines that either overexpressed or knocked down miR-138-5p. A luciferase reporter assay was performed to test the direct binding of miR-138-5p to the target gene BIRC5. We also investigated the biological role of miR-138-5p targeting to Survivin in bladder cancer cell lines both in vivo and in vitro.

Results

In this study, we found that the Survivin protein was either absent or weakly expressed in normal adjacent tissues and consistently up-regulated in bladder cancer tissues; however, the mRNA levels did not vary as much, suggesting that a post-transcriptional mechanism was involved. Because microRNAs are powerful post-transcriptional regulators of gene expression, we used bioinformatic analyses to search for microRNAs that could potentially target BIRC5 in the setting of bladder cancer. We identified 2 specific targeting sites for miR-138-5p in the 3′ untranslated region (3′-UTR) of BIRC5. We further identified an inverse correlation between miR-138-5p and Survivin protein levels in bladder cancer tissue samples. By overexpressing or knocking down miR-138-5p in bladder cancer cells, we experimentally confirmed that miR-138-5p directly recognizes the 3′-UTR of the BIRC5 transcript and regulates Survivin expression. Furthermore, the biological consequences of the targeting of BIRC5 by miR-138-5p were examined in vitro via cell proliferation and invasion assays and in vivo using a mouse xenograft tumor model. We demonstrated that BIRC5 repression by miR-138-5p suppressed the proliferative and invasive characteristics of bladder cancer cells and that miR-138-5p exerted an anti-tumor effect by negatively regulating BIRC5 in a xenograft mouse model.

Conclusions

Taken together, our findings provide the first clues regarding the role of miR-138-5p as a tumor suppressor in bladder cancer by inhibiting BIRC5 translation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-016-0569-4) contains supplementary material, which is available to authorized users.

Non-coding RNA/microRNA-modulatory dietary factors and natural products for improved cancer therapy and prevention: Alkaloids, organosulfur compounds, aliphatic carboxylic acids and water-soluble vitamins

Non-coding small RNA molecules, the microRNAs (miRNAs), contribute decisively to the epigenetic regulation processes in cancer cells. Problematic pathogenic properties of cancer cells and the response of cancers towards anticancer drugs are highly influenced by miRNAs. Both increased drug activity and formation of tumor resistance are regulated by miRNAs. Further to this, the survival and proliferation of cancer cells and the formation of metastases is based on the modulated expression of certain miRNAs. In particular, drug-resistant cancer stem-like cells (CSCs) depend on the presence and absence of specific miRNAs. Fortunately, several small molecule natural compounds were discovered that target miRNAs involved in the modulation of tumor aggressiveness and drug resistance. This review gives an overview of the effects of a selection of naturally occurring small molecules (alkaloids, organosulfur compounds, aliphatic carboxylic acids and water-soluble vitamins) on miRNAs that are closely tangled with cancer diseases.

Linc00152 Functions as a Competing Endogenous RNA to Confer Oxaliplatin Resistance and Holds Prognostic Values in Colon Cancer

Long noncoding RNAs act as crucial regulators in plenty of human cancers, yet their potential roles and molecular mechanisms in chemoresistance are poorly understood. This study showed that a novel lncRNA, long intergenic noncoding RNA 152 (Linc00152 ), promoted tumor progression and conferred resistance to oxaliplatin (L-OHP)-induced apoptosis in vitro and in vivo. It antagonized chemosensitivity through acting as a competing endogenous RNA to modulate the expression of miR-193a-3p, and then erb-b2 receptor tyrosine kinase 4 (ERBB4). Knockdown of ERBB4 in colon cancer cells decreased AKT phosphorylation, which resulted in decreased L-OHP resistance. Consistent with above findings, the specific AKT signaling inhibitor and activator were used, respectively, which demonstrated that Linc00152 contributed to L-OHP resistance at least partly through activating AKT pathway. Further studies indicated that Linc00152 was increased and appeared to be an independent prognostic factor for decreased survival and increased disease recurrence in stage II and III colon cancer patients undergoing L-OHP-based chemotherapy after surgery. Collectively, our findings established Linc00152 as a candidate prognostic indicator of outcome and drug responsiveness in colon cancer patients, and the involvement of competing endogenous RNAs mechanism in Linc00152/miR-193a-3p/ERBB4/AKT signaling axis may provide a novel choice in the investigation of drug resistance.

Decreased expression of LncRNA MIR31HG in human bladder cancer

OBJECTIVE

In this study, we examined the relationships between the expression level of long non-coding RNA MIR31HG in bladder cancer and the clinical characteristics.

METHODS

A total of 55 tissue samples from patients with bladder cancer were collected, and the lncRNA MIR31HG levels in cancer, paired non-cancer tissues and BC cell lines were detected by real-time quantitative RT-PCR (qRT-PCR). The relationships between MIR31HG level and the clinical characteristics were evaluated.

RESULTS

MIR31HG expression was remarkably decreased in bladder cancer tissues compared with adjacent noncancerous tissues (P < 0.05). MIR31HG expression was also significantly down-regulated in four bladder cancer cell lines (P < 0.001). Clinicopathologic analysis revealed that MIR31HG expression was negatively associated with TNM stage (P = 0.010), but not with other clinicopathological characteristics.

CONCLUSIONS

These findings revealed that MIR31HG may function as a cancer-suppressor gene to participate in the bladder cancer carcinogenesis and development.