Downregulation of miR-133b predict progression and poor prognosis in patients with urothelial carcinoma of bladder

Epigenetic Biomarkers as a New Diagnostic Tool in Bladder Cancer-From Early Detection to Prognosis

Bladder cancer (BC) currently ranks as the 9th most common cancer worldwide. It is characterised by very high rates of recurrence and metastasis. Most cases of BC are of urothelial origin, and due to its ability to penetrate muscle tissue, BC is divided into non-muscle-invasive BC (NMIBC) and muscle-invasive BC (MIBC). The current diagnosis of BC is still based primarily on invasive cystoscopy, which is an expensive and invasive method that carries a risk of various complications. Urine sediment cytology is often used as a complementary test, the biggest drawback of which is its very low sensitivity concerning the detection of BC at early stages, which is crucial for prompt implementation of appropriate treatment. Therefore, there is a great need to develop innovative diagnostic techniques that would enable early detection and accurate prognosis of BC. Great potential in this regard is shown by epigenetic changes, which are often possible to observe long before the onset of clinical symptoms of the disease. In addition, these changes can be detected in readily available biological material, such as urine or blood, indicating the possibility of constructing non-invasive diagnostic tests. Over the past few years, many studies have emerged using epigenetic alterations as novel diagnostic and prognostic biomarkers of BC. This review provides an update on promising diagnostic biomarkers for the detection and prognosis of BC based on epigenetic changes such as DNA methylation and expression levels of selected non-coding RNAs (ncRNAs), taking into account the latest literature data.

Urinary microRNA-10a levels in diagnosis and prognosis of urinary bladder cancer

Background

Urinary bladder cancer (UBC) is a disease quite common in developed countries; however, its incidence is increasing in developing countries as well. The diagnosis of UBC is generally based on a number of methods, of which urinary cytology is a very commonly used one. But it is not very reliable. Therefore many new markers and methods are being investigated to make non-invasive diagnosis of UBC easy and reliable.

Objective

This study was carried out to find the usefulness of microRNA (miRNA)-10a as a diagnostic and prognostic marker in non-muscle-invasive urinary bladder carcinoma.

Material and Method

Twenty patients with UBC were taken as cases with 20 controls. Urine cytological examination was done, as well as histopathological examination of tumor tissue of cases. Urinary miRNA-10a estimation of both the cases and controls were done.

Result and Conclusion

It was found that miRNA-10a is significantly high in urine of patients with UBC. Its value also significantly correlated with the grade and stage of the tumor. Hence it can be concluded that urinary miRNA-10a is a potential candidate in the diagnosis and prognosis of UBC.

MiR-133b regulates the proliferation, colony formation, and invasion of bladder cancer cells via inhibiting SOX4

OBJECTIVES

Bladder cancer is one of the most common urothelial tumors with high incidence and mortality rates. Although it has been reported that microRNA (miR)-133b can regulate tumorigenesis of bladder cancer, the mechanism remains unclear. Sex-determining region Y-box transcription factor 4 (SOX4) exhibits an important role in tumorigenesis, but it is unclear whether SOX4 and miR-133b are associated with regulation of pathogenesis of bladder cancer. This study aims to determine the expressions of SOX4 and miR-133b in bladder cancer tissues and cells, investigate their effects on the proliferation, colony formation, and invasion of bladder cancer cells, and to explore the association between miR-133b and SOX4 in regulating biological featurss of bladder cancer cells.

METHODS

The bladder cancer and adjacent tissue samples of 10 patients who underwent surgical resection in the Second Xiangya Hospital of Central South Universty from Januray to June 2015 were obtained. The levels of miR-133b were tested by real-time PCR, and the protein levels of SOX4 were evaluated using Western blotting in bladder cancer tissues, matched adjacent tissues, and cell lines. The correlation between miR-133b expression and SOX4 expression in bladder cancer tissues was analyzed. Using the online database TargetScan, the relationship between SOX4 and miR-133b was predicted. MiR-133b mimics, miR-133b inhibitor, and short hairpin RNA (shRNA)-SOX4 were transfected into T24 cells by Lipofectamine 2000. The relationship between miR-133b and SOX4 was also verified by a dual-luciferase reporter assay. The proliferation of T24 cells cultured for 0, 12, 48, 72, and 96 h was evaluated by cell counting kit-8 (CCK-8) assay. The colony formation capacity of bladder cancer cells was tested after 14-day culture, and cell invasion capacity was evaluated with Transwell invasion assay.

RESULTS

Bladder cancer tissue and bladder cancer cells had low level of miR-133b but high level of SOX4, compared with matched adjacent tissues and normal bladder epithelial cells. A negative correlation between miR-133b mRNA and SOX4 protein levels in bladder cancer tissues was also found (r=-0.84). The results of online database TargetScan showed that miR-133b targets at SOX4, and overexpression of miR-133b significantly attenuated the expression of SOX4 in T24 cells. Both overexpression of miR-133b and knockdown of SOX4 significantly inhibited the proliferation, colony formation, and invasion capacity of bladder cancer cells in vitro. SOX4 down-regulation restored the effects of miR-133b inhibitor on the proliferation, colony formation, and invasion capacity of T24 cells.

CONCLUSIONS

The up-regulation of SOX4 contributes to the progression of bladder cancer, and miR-133b can regulate the proliferation, colony formation, and invasion of bladder cancer cells via inhibiting SOX4.

miR-19a-3p Promotes Tumor-Relevant Behaviors in Bladder Urothelial Carcinoma via Targeting THBS1

OBJECTIVE

miR-19a-3p is widely increased in several cancers and can be used as an oncogenic factor in these cancers. However, the molecular mechanism of miR-19a-3p in bladder urothelial carcinoma (BLCA) is still open. So, the study was aimed at exploring the mechanism of miR-19a-3p in BLCA cells.

METHODS

Bioinformatics analysis was employed to find the differential miRNAs and mRNAs, and the target miRNA and mRNA were determined. Real-time quantitative PCR was used to evaluate miR-19a-3p and THBS1 levels in human urethral epithelial cells and BLCA cells. Western blot was carried out to assay protein expression of THBS1 in human urethral epithelial cells and BLCA cells. Behaviors of BLCA cells were detected through cellular functional assays. Dual-luciferase gene assay was conducted to validate the binding of miR-19a-3p and THBS1.

RESULTS

miR-19a-3p was increased in BLCA cells, while THBS1 was less expressed in BLCA cells. The miR-19a-3p functions as an oncogene in BLCA. THBS1 was a target of miR-19a-3p, and it could reverse the promotion of miR-19a-3p on cell malignant behaviors in BLCA.

CONCLUSION

miR-19a-3p facilitates cell progression in BLCA via binding THBS1, which may be an underlying therapeutic target for BLCA treatment.

Emerging Biomarkers for Predicting Bladder Cancer Lymph Node Metastasis

Bladder cancer is one of the leading causes of cancer deaths worldwide. Early detection of lymph node metastasis of bladder cancer is essential to improve patients' prognosis and overall survival. Current diagnostic methods are limited, so there is an urgent need for new specific biomarkers. Non-coding RNA and m6A have recently been reported to be abnormally expressed in bladder cancer related to lymph node metastasis. In this review, we tried to summarize the latest knowledge about biomarkers, which predict lymph node metastasis in bladder cancer and their mechanisms. In particular, we paid attention to the impact of non-coding RNA on lymphatic metastasis of bladder cancer and its specific molecular mechanisms, as well as some prediction models based on imaging, pathology, and biomolecules, in an effort to find more accurate diagnostic methods for future clinical application.

Identification of the miRNA-mRNA regulatory pathways and a miR-21-5p based nomogram model in clear cell renal cell carcinoma

Background

The purpose of this study was to determine the key microRNAs (miRNAs) and their regulatory networks in clear cell renal cell carcinoma (ccRCC).

Methods

Five mRNA and three microRNA microarray datasets were downloaded from the Gene Expression Omnibus database and used to screen the differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs). Gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed with Metascape. A miRNA-mRNA network was mapped with the Cytoscape tool. The results were validated with data from The Cancer Genome Atlas (TCGA) and qRT-PCR. A nomogram model based on independent prognostic key DEMs, stage and grade was constructed for further investigation.

Results

A total of 26 key DEMs and 307 DEGs were identified. Dysregulation of four key DEMs (miR-21-5p, miR-142-3p, miR-155-5p and miR-342-5p) was identified to correlate with overall survival. The results were validated with TCGA data and qRT-PCR. The nomogram model showed high accuracy in predicting the prognosis of patients with ccRCC.

Conclusion

We identified 26 DEMs that may play vital roles in the regulatory networks of ccRCC. Four miRNAs (miR-21-5p, miR-142-3p, miR-155-5p and miR-342-5p) were considered as potential biomarkers in the prognosis of ccRCC, among which only miR-21-5p was found to be an independent prognostic factor. A nomogram model was then created on the basis of independent factors for better prediction of prognosis for patients with ccRCC. Our results suggest a need for further experimental validation studies.

Expression levels and clinical significance of miR-203 and miR-133b in laryngeal carcinoma

The present study aimed to investigate the expression levels and clinical significance of microRNA (miR)-203 and miR-133b in laryngeal carcinoma. A total of 154 patients with laryngeal carcinoma (research group) along with 100 healthy individuals (control group) were enrolled in the study. The patients were admitted to Yidu Central Hospital of Weifang (Weifang, China) from February 2016 to October 2018. Fasting venous blood (5 ml) was extracted from all subjects to determine the expression levels of serum miR-203 and miR-133b by reverse transcription-quantitative polymerase chain reaction (PCR) and to compare them among patients with different pathological characteristics. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic values of miR-203 and miR-133b for laryngeal carcinoma. The research group showed significantly lower expression levels of miR-203 and miR-133b than the control group (P<0.05). According to ROC curve analysis, when the cut-off value was 0.659, the sensitivity and specificity of miR-203 in diagnosing laryngeal carcinoma were 60.00 and 90.26%, respectively, whereas when the cut-off value was 1.398, the sensitivity and specificity of miR-133b were 55.00 and 87.66%, respectively. The sensitivity and specificity of the joint detection were 70.00 and 83.77%, respectively, when the cut-off value was 0.416. In the research group, miR-203 was expressed significantly different in patients with different pathological stages and tumor types (P<0.050). The expression of miR-133b varied significantly in patients with different pathological stages, differentiation degrees and lymph node metastasis (P<0.050). In conclusion, miR-203 and miR-133b were expressed at low levels in patients with laryngeal carcinoma. The expression of miR-203 was related to tumor-node-metastasis (TNM) stage and tumor type, whereas the expression of miR-133b was related to TNM stage, differentiation degree, as well as lymph node metastasis. Joint detection of miR-203 and miR-133b is expected to be an excellent marker for the diagnosis and treatment of laryngeal carcinoma.

Exosome-transmitted microRNA-133b inhibited bladder cancer proliferation by upregulating dual-specificity protein phosphatase 1

Bladder Cancer (BC) is the ninth most common tumor in the world and one of the most common malignant tumors of the urinary system. Some studies reported that miR‐133b expression is reduced in BC, but whether it plays a role in the development of BC and its mechanism is unclear. microRNAs can be packaged into exosomes to mediate communication between tumor cells, affecting their proliferation and apoptosis. The objective of this study was to investigate the effect of exosomal miR‐133b on BC proliferation and its molecular mechanism. Firstly, the expression of miR‐133b was evaluated in BC and adjacent normal tissues, as well as in serum exosomes of BC patients and healthy controls. Then the delivery and internalization of exosomes in cells was observed through fluorescence localization. Cell viability and apoptosis were assessed in BC cells transfected with mimics and incubated with exosomes. The role of exosomal miR‐133b was also analyzed in nude mice transplant tumors. Furthermore, the target gene of miR‐133b was predicted through bioinformatics. The level of miR‐133b was significantly decreased in BC tissues and in exosomes from serum of patients, which was correlated with poor overall survival in TCGA. Exosomal miR‐133b could be obtained using BC cells after transfection with miR‐133b mimics. The miR‐133b expression increased after incubation with exosomal miR‐133b, which lead to the inhibition of viability and increase of apoptosis in BC cells. Exosomal miR‐133b could suppress tumor growth in vivo. In addition, we found that exosomal miR‐133b may play a role in suppressing BC proliferation by upregulating dual‐specificity protein phosphatase 1 (DUSP1). These findings may offer promise for new therapeutic directions of BC.

The role of miRNA-133b and its target gene SIRT1 in FAP-derived desmoid tumor

Signaling pathways have a key role in driving the uncontrolled development of familial adenomatous polyposis (FAP)- associated and sporadic desmoid tumors (DTs).

The relationship between the Wnt/b-catenin signaling pathway and DTs has been extensively studied, but no reliable biomarkers able to detect their histological subtype have been identified for the accurate diagnosis.

In this study we studied the differences in miRNA expression between sporadic (20 patients) and FAP-associated DTs (7 patients) using microarray confirmed by quantitative PCR (qPCR). The analysis showed 19 dysregulated miRNAs. Among them miR-133b levels were significantly lower in FAP-associated DT than in sporadic DT. Therefore, two mRNAs, associated to miR-133b and β-catenin expression, the SIRT1 and ELAVL1were analyzed.

The qPCR analysis showed that SIRT1 mRNA levels were significantly up-regulated in FAP-associated DT than in sporadic DT, whereas no differences in ELAVL1 expression was observed between these two DT types. In addition, a negative correlation was observed between miR-133b and SIRT1 in FAP-associated DTs, but not in sporadic DTs.

The miR-133b-SIRT1-β-catenin axis may represent a novel mechanism underlying progression of FAP-associated DT.

Identification of a three-m6A related gene risk score model as a potential prognostic biomarker in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent malignancies worldwide, N6-methyladenosine (m6A) has been shown to play important roles in regulating gene expression and phenotypes in both health and disease. Here, our purpose is to construct a m6A-regulrator-based risk score (RS) for prediction of the prognosis of ccRCC.

Methods

We used clinical and expression data of m6A related genes from The Cancer Genome Atlas (TCGA) dataset and the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analysis to develop an RS to predict survival of patients with ccRCC, and analyzed correlations between RS and other clinical indicators such as age, grade and stage. Validation of this RS was then engaged in another cohort, E-MTAB-1980 from the ArrayExpress dataset. Finally, we used quantitative real-time PCR to analyze the expression profile of genes consists of the RS.

Results

A three-gene RS including METTL3, METTL14 and HNRNPA2B1 which can predict overall survival (OS) of ccRCC patients from TCGA. After applying this RS into the validation cohort from Arrayexpress, we found that it successfully reproduced the result; furthermore, the results of PCR validation were in line with our analysis.

Conclusion

To sum up, our study has identified an RS composed of m6A related genes that may predict the prognosis of ccRCC patients, which might be helpful for future therapeutic strategies. Our results call for further experimental studies for validations.

LGALS4 as a Prognostic Factor in Urothelial Carcinoma of Bladder Affects Cell Functions

BACKGROUND

To identify the hub genes related to urothelial carcinoma of the bladder prognosis and to understand their underlying mechanism.

METHODS

The expression profiles of 18 pairs of urothelial carcinoma of the bladder patient tissue and paired adjacent tissue obtained from the Cancer Genome Atlas were performed. Weighted gene coexpression network analysis was employed to screen gene modules and hub genes with significant differential expressions in urothelial carcinoma of the bladder. The hub genes expression in urothelial carcinoma of the bladder tissues was validated by reverse transcription-quantitative polymerase chain reaction. The overall survival curve and disease-free survival curve of prognostic factor (LGALS4) were plotted using the Kaplan-Meier method. Furthermore, LGALS4 messenger RNA and protein expression were also assessed in 2 urothelial carcinoma of the bladder cell lines (T24 and 5637) by quantitative reverse transcription-polymerase chain reaction and Western blot. The functions of urothelial carcinoma of the bladder cells with transfected pcDNA3.1-LGALS4 were identified through MTT assay, plate clone formation assay, flow cytometry, and cell migration experiments.

RESULTS

LGALS4 was the hub gene of pink module and it was related to prognosis. Higher LGALS4 expression predicted higher probabilities of overall survival and disease-free survival. Overexpression of LGALS4 in urothelial carcinoma of the bladder cells suppressed cell viability and migration but induced apoptosis.

CONCLUSION

LGALS4 played a critical role in the progression of urothelial carcinoma of the bladder and held a promise to be the biomarker for diagnosis and treatment of urothelial carcinoma of the bladder. It predicted good prognosis of urothelial carcinoma of the bladder and restrained the growth and migration of urothelial carcinoma of the bladder cells.

Connecting the dots between different networks: miRNAs associated with bladder cancer risk and progression

BACKGROUND

Bladder cancer (BC) is a common urothelial malignancy, characterized by a high recurrence rate. The biology of bladder cancer is complex and needs to be deciphered. The latest evidence reveals the critical role of the non-coding RNAs, particularly microRNAs (miRNAs), as vital regulatory elements in cancer.

METHOD

We performed a miRNAs microarray using paired tissues (tumor and adjacent normal bladder tissue), followed by the validation with qRT-PCR of five selected transcripts. Additional next-generation sequencing investigation established the interconnection among the altered miRNAs and mutated genes. Based on the overlapping between TCGA data and data obtained in the study, we focused on the systematic identification of altered miRNAs and genes mutated involved in bladder cancer tumorigenesis and progression.

RESULTS

By overlapping the miRNAs expression data, the two patient cohorts, we identified 18 miRNAs downregulated and, 187 miRNAs upregulated. qRT-PCR validation was completed using a selected panel of two downregulated (miR-139-5p and miR-143-5p) and three up-regulated miRNAs (miR-141b, miR-200 s or miR-205). Altered miRNAs patterns are interrelated to bladder tumorigenesis, allowing them to be used for the development of novel diagnostic and prognostic biomarkers. Three EMT-related upregulated miRNAs have an essential role in the molecular mechanisms, specifically key processes underlying tumorigenesis, invasion and metastasis. Using the Ampliseq Cancer Panel kit and Ion Torrent PGM Next-Generation Sequencing an increased mutation rate for TP53, FGFR3, KDR, PIK3CA and ATM were observed, but the mutational status for only TP53 was correlated to the survival rate. The miRNAs pattern, along with the gene mutation pattern attained, can assist for better patient diagnosis.

CONCLUSION

This study thereby incorporates miRNAs as critical players in bladder cancer prognosis, where their altered gene expression profiles have a critical biological function in relationship with tumor molecular phenotype. The miRNA-mRNA regulatory networks identified in BC are ripe for exploitation as biomarkers or targeted therapeutic strategies.

Emerging Biomarkers in Bladder Cancer Identified by Network Analysis of Transcriptomic Data

Bladder cancer is a very common malignancy. Although new treatment strategies have been developed, the identification of new therapeutic targets and reliable diagnostic/prognostic biomarkers for bladder cancer remains a priority. Generally, they are found among differentially expressed genes between patients and healthy subjects or among patients with different tumor stages. However, the classical approach includes processing these data taking into consideration only the expression of each single gene regardless of the expression of other genes. These complex gene interaction networks can be revealed by a recently developed systems biology approach called Weighted Gene Co-expression Network Analysis (WGCNA). It takes into account the expression of all genes assessed in an experiment in order to reveal the clusters of co-expressed genes (modules) that, very probably, are also co-regulated. If some genes are co-expressed in controls but not in pathological samples, it can be hypothesized that a regulatory mechanism was altered and that it could be the cause or the effect of the disease. Therefore, genes within these modules could play a role in cancer and thus be considered as potential therapeutic targets or diagnostic/prognostic biomarkers. Here, we have reviewed all the studies where WGCNA has been applied to gene expression data from bladder cancer patients. We have shown the importance of this new approach in identifying candidate biomarkers and therapeutic targets. They include both genes and miRNAs and some of them have already been identified in the literature to have a role in bladder cancer initiation, progression, metastasis, and patient survival.

An integrated bioinformatical analysis to evaluate the role of KIF4A as a prognostic biomarker for breast cancer

Purpose

The aim of this study was to investigate the diagnostic and prognostic value of human kinesin family member 4A (KIF4A) as an effective biomarker for breast cancer.

Materials and methods

Cancer Genome Atlas data and 12 independent public breast cancer microarray data sets were downloaded and analyzed using individual and pooled approaches.

Results

The results of our study revealed a strong and positive correlation between KIF4A expression and malignant features of breast cancer. KIF4A had a strong prognostic value in both ER-positive and ER-negative breast cancers comparable to or even better than tumor size, lymph node invasion, and Elston grade. We also found that KIF4A might be the target gene of microRNA-335, which can suppress KIF4A expression by targeting the 3′-untranslated region of its mRNA.

Conclusion

KIF4A might serve as a robust prognostic predictor for breast cancer. Targeting KIF4A activity could be a promising therapeutic option in breast cancer treatment.

miR-133b, a particular member of myomiRs, coming into playing its unique pathological role in human cancer

MicroRNAs, a family of single-stranded and non-coding RNAs, play a crucial role in regulating gene expression at posttranscriptional level, by which it can mediate various types of physiological and pathological process in normal developmental progress and human disease, including cancer. The microRNA-133b originally defined as canonical muscle-specific microRNAs considering their function to the development and health of mammalian skeletal and cardiac muscles, but new findings coming from our group and others revealed that miR-133b have frequently abnormal expression in various kinds of human cancer and its complex complicated regulatory networks affects the tumorigenicity and development of malignant tumors. Very few existing reviews on miR-133b, until now, are principally about its role in homologous cluster (miR-1, −133 and -206s), however, most of constantly emerging new researches now are focused mainly on one of them, so In this article, to highlight the unique pathological role of miR-133b playing in tumor, we conduct a review to summarize the current understanding about one of the muscle-specific microRNAs, namely miR-133b, acting in human cancer. The review focused on the following four aspects: the overview of miR-133b, the target genes of miR-133b involved in human cancer, the expression of miR-133b and regulatory mechanisms leading to abnormal expression of miR-133b.

MicroRNAs in Smoking-Related Carcinogenesis: Biomarkers, Functions, and Therapy

Long-term heavy cigarette smoking is a well-known high-risk factor for carcinogenesis in various organs such as the head and neck, lungs, and urinary bladder. Furthermore, cigarette smoking can systemically accelerate aging, and as the result, promoting carcinogenesis via changing the host microenvironment. Various inflammatory factors, hormones, and chemical mediators induced by smoking mediate carcinoma-related molecules and induce carcinogenesis. MicroRNAs (miRNAs) are a family of short noncoding RNA molecules that bind to mRNAs and inhibit their expression. Cigarette smoke induces the expression of various miRNAs, many of which are known to function in the post-transcriptional silencing of anticancer molecules, thereby leading to smoking-induced carcinogenesis. Analysis of expression profiles of smoking-induced miRNAs can help identify biomarkers for the diagnosis and prognosis of smoking-related cancers and prediction of therapeutic responses, as well as revealing promising therapeutic targets. Here, we introduce the most recent and useful findings of miRNA analyses focused on lung cancer and urinary bladder cancer, which are strongly associated with cigarette smoking, and discuss the utility of miRNAs as clinical biomarkers.

miR-133b induces chemoresistance of osteosarcoma cells to cisplatin treatment by promoting cell death, migration and invasion

As an important chemotherapeutic agent for the treatment of osteosarcoma, the effectiveness of cisplatin is considered to be due to its unique properties, which allow it to penetrate the cell membrane and form various DNA-platinum adducts, resulting in genetic alterations or DNA damage. However, chemoresistance to cisplatin remains a major challenge for its use and chemotherapeutic effects. In the present study, an isogenic model of a cisplatin resistant osteosarcoma cell line, MG63-DDP, was generated from the original MG63 cell line. The expression level of microRNA (miR)-133b in the MG63-DDP cisplatin-resistant osteosarcoma cell line was analyzed by reverse transcription-quantitative polymerase chain reaction (PCR). Cisplatin-DNA adduct formation, cell death (carboxyfluorescein succinimidyl ester/propidium iodide staining) and clonogenic survival assays (crystal violet staining) were performed, comparing various cell types. The effect of miR-133b on migration (scratch wound assay) and invasion (Transwell assay) was also evaluated. Characterization studies have previously revealed an increased level of miR-133b in MG63-DDP cells compared with normal MG63 cells. Upregulation of miR-133b was associated with the accumulation of cisplatin-DNA adducts and an increase in cisplatin-induced cell death. Furthermore, increased miR-133b expression levels enhanced the migration and invasion of MG63 cells under cisplatin stress. Concordantly, in MG63-DDP cells the neutralization of miR-133b demonstrated opposite effects, as compared with the upregulation of miR-133b. To the best of our knowledge, the present study demonstrated for the first time that cisplatin-resistant MG63 cells exhibit an increased level of miR-133b expression. The endogenous expression level of miR-133b is sufficient for inducing cisplatin resistance, which suggests that miR-133b may be a biomarker for cisplatin resistance in osteosarcoma.

miR-133b suppresses metastasis by targeting HOXA9 in human colorectal cancer

Functions and mechanisms of microRNA (miRNA) involved in colorectal cancer (CRC) metastasis are largely unknown. Here, a miRNA microarray analysis was performed in CRC primary tissues and metastatic hepatic tissues to disclose crucial miRNA involved in CRC metastasis. MiR-133b was decreased and negatively correlated with metastasis in CRC. Overexpression of miR-133b significantly suppressed metastasis of CRC in vitro and in vivo. HOXA9 was identified as a direct and functional target of miR-133b. In addition, HOXA9 was negatively correlated with miR-133b and promoted CRC malignant progress. Moreover, miR-133b decreased HOXA9 expression, and subsequently downregulated ZEB1 and upregulated E-cadherin expression. Intriguingly, lower miR-133b and higher HOXA9 expression significantly contributed to poorer outcomes in CRC patients. Multivariate analysis indicated that miR-133b was an independent and significant predictor of CRC patient overall survival. In conclusion, we newly determined that miR-133b targeted the HOXA9/ZEB1 pathway to promote tumor metastasis in CRC cells. This axis provided insights into the mechanism underlying miRNA regulation of CRC metastasis and a novel therapeutic target for CRC treatment.

Downregulation of miR-133b predict progression and poor prognosis in patients with urothelial carcinoma of bladder

We found microRNA-133b (miR-133b) was downregulated in urothelial carcinoma of the bladder (UCB) tissues, and it could inhibit the proliferation and induce apoptosis in UCB cells. Consequently, we intend to explore the clinical significance of miR-133b in UCB patients. Expression of miR-133b in 146 UCB specimens and matched adjacent non-neoplastic bladder tissues were measured by quantitative real-time polymerase chain reaction. The overall survival (OS) curve and progression-free survival (PFS) curve were plotted using the Kaplan-Meier method. Prognostic factors for OS and PFS were identified by univariate and multivariate analyses using the Cox proportional hazards regression model. The expression of miR-133b was significantly downregulated in UCB tissues compared with those in adjacent non-neoplastic bladder tissues (P < 0.001). Among UCB patients, low expression of miR-133b significantly correlated with aggressive clinicopathological features. Multivariate analysis indicated that the expression of miR-133b was the independent prognostic factors for predicting PFS (RR: 2.97; 95% CI: 1.78-6.44; P = 0.009) and OS (RR: 4.23; 95% CI: 1.51-11.8; P = 0.011) in patients with UCB. Our study demonstrated that downregulation of miR-133b associated with aggressive clinicopathological features and predicted unfavorable prognosis in patients with UCB, might serve as feasible biomarker for clinical outcome of UCB patients after surgery and potential therapeutic target in the future.