Downregulation of microRNA-382 is associated with poor outcome of esophageal squamous cell carcinoma

microRNA-382 as a tumor suppressor? Roles in tumorigenesis and clinical significance

MicroRNAs (miRNAs) are small single-stranded RNAs belonging to a class of non-coding RNAs with an average length of 18-22 nucleotides. Although not able to encode any protein, miRNAs are vastly studied and found to play role in various human physiologic as well as pathological conditions. A huge number of miRNAs have been identified in human cells whose expression is straightly regulated with crucial biological functions, while this number is constantly increasing. miRNAs are particularly studied in cancers, where they either can act with oncogenic function (oncomiRs) or tumor-suppressors role (referred as tumor-suppressor/oncorepressor miRNAs). miR-382 is a well-studied miRNA, which is revealed to play regulatory roles in physiological processes like osteogenic differentiation, hematopoietic stem cell differentiation and normal hematopoiesis, and liver progenitor cell differentiation. Notably, miR-382 deregulation is reported in pathologic conditions, such as renal fibrosis, muscular dystrophies, Rett syndrome, epidural fibrosis, atrial fibrillation, amelogenesis imperfecta, oxidative stress, human immunodeficiency virus (HIV) replication, and various types of cancers. The majority of oncogenesis studies have claimed miR-382 downregulation in cancers and suppressor impact on malignant phenotype of cancer cells in vitro and in vivo, while a few studies suggest opposite findings. Given the putative role of this miRNA in regulation of oncogenesis, assessment of miR-382 expression is suggested in a several clinical investigations as a prognostic/diagnostic biomarker for cancer patients. In this review, we have an overview to recent studies evaluated the role of miR-382 in oncogenesis as well as its clinical potential.

Antisense lncRNA NNT-AS1 promoted esophageal squamous cell carcinoma progression by regulating its sense gene NNT expression

Antisense lncRNAs were endogenous productions from the antisense strand of coding genes and were transcribed in the reverse direction of the sense gene. The purpose of this study was to evaluate the roles and functions of antisense lncRNAs in esophageal squamous cell carcinoma (ESCC). Differentially expressed antisense lncRNAs were initially screened based on transcriptome data of 119 paired ESCC samples in GSE53624 and were further validated in 6 paired ESCC samples from our institution. Log-rank test was adopted to identify ESCC prognosis-associated lncRNAs. Finally, functional assays were performed to reveal the functions of our identified antisense lncRNAs. In total, 174 antisense lncRNAs were differentially expressed in both GSE53624 and JSPH databases. Five of them were significantly associated with ESCC prognosis (NNT-AS1, NKILA, CCDC18-AS1, SLCO4A1-AS1, and AC110619.1). Of note, NNT-AS1 showed the most significant association with ESCC prognosis. The upregulation of NNT-AS1 was further confirmed in ESCC cells. Knockdown of NNT-AS1 inhibited ESCC cell proliferation, migration, promoted ESCC cells apoptosis, and induced cell cycle arrest in the G2/M stage. NNT-AS1 expression significantly correlated with its sense gene NNT. As expected, NNT-AS1 knockdown suppressed NNT expression. Inhibition of NNT repressed ESCC cell proliferation and migration, and accelerated ESCC cell apoptosis. Overexpression of NNT could rescue the suppressed proliferation and migration of ESCC cells induced by the silencing of NNT-AS1. In terms of mechanism, NNT-AS1 served as a competing endogenous RNA to sponge the miR-382-5p, which could inhibit NNT expression. Pathway enrichment analysis and western blot assay indicated that NNT-AS1 and NNT could regulate the cell cycle pathway. In conclusion, antisense lncRNA NNT-AS1 facilitated ECSS progression by targeting its sense gene NNT through sponging miR-382-5p. This study provided us with a deeper insight into the roles of antisense lncRNAs in ESCC and identified novel potential therapeutic targets.

Spectrum of microRNAs and their target genes in cancer: intervention in diagnosis and therapy

Till date, several groups have studied the mechanism of microRNA (miRNA) biogenesis, processing, stability, silencing, and their dysregulation in cancer. The miRNA coding genes recurrently go through abnormal amplification, deletion, transcription, and epigenetic regulation in cancer. Some miRNAs function as tumor promoters while few others are tumor suppressors based on the transcriptional regulation of target genes. A review of miRNAs and their target genes in a wide range of cancers is attempted in this article, which may help in the development of new diagnostic tools and intervention therapies. The contribution of miRNAs for drug sensitivity or resistance in cancer therapy and opportunities of miRNAs in cancer prognosis or diagnosis and therapy is also presented in detail.

Circ-SAR1A Promotes Renal Cell Carcinoma Progression Through miR-382/YBX1 Axis

Background

Accumulating evidence points to a role for circular RNAs (circRNAs) in important regulatory function in tumor advancement. We explored the effect and function of circ-SAR1A in renal cell carcinoma (RCC).

Methods

circ-SAR1A expression in RCC tissues and cell lines was explored by qRT-PCR. The roles of circ-SAR1A on RCC progression were explored by in vitro function assays. Moreover, we determined the underlying mechanism of circ-SAR1A in RCC progression through bioinformatics analysis and dual-luciferase reporter assays.

Results

Our data reveal that circ-SAR1A is significantly high in RCC tissues and cell lines. High circ-SAR1A levels are correlated to advanced Fuhrman grade, and lymph-node metastasis in RCC patients. Functional experiments indicate that circ-SAR1A suppression decreased RCC cell growth and invasion abilities in vitro. Mechanistically, circ-SAR1A upregulated YBX1 expression by sponging miR-382, resulting in promoting the growth and invasion in RCC cells.

Conclusion

Our data indicate that the circ-SAR1A/miR-382/YBX1 axis plays a critical role in RCC progression, which serve as a potential novel treatment strategy of RCC.

Clinical significance and prognostic role of hypoxia-induced microRNA 382 in gastric adenocarcinoma

Hypoxia and angiogenesis are critical components in the progression of solid cancer, including gastric cancers (GCs). miR-382 has been identified as a hypoxia-induced miR (hypoxamiR), but the clinical significance in GCs has not been identified yet. To explore the clinical and prognostic importance of miR-382 in GCs, the surgical specimens of 398 patients with GCs in KNU hospital in Korea, the total of 183 patients was randomly selected using simple sampling methods and big data with 446 GCs and 45 normal tissues from the data portal (https://portal.gdc.cancer.gov/) were analysed. Expression of miR-382 as well as miR-210, as a positive control hypoxamiR by qRT-PCR in histologically malignant region of GCs showed significantly positive correlation (R = 0.516, p<0.001). High miR-210 and miR-382 expression was significantly correlated with unfavorable prognosis including advanced GCs (AGC), higher T category, N category, pathologic TNM stage, lymphovascular invasion, venous invasion, and perinueral invasion, respectively (all p<0.05). In univariate analysis, high miR-210 expression was significantly associated with worse overall survival (OS) (p = 0.036) but not high miR-382. In paired 60 gastric normal and cancer tissues, miR-382 expression in cancer tissues was significantly higher than normal counterpart (p = 0.003), but not miR-210 expression. However, by increasing the patient number from the big data analysis, miR-210 as well as miR-382 expression in tumor tissues was significantly higher than the normal tissues. Our results suggest that miR-382, as novel hypoxamiR, can be a prognostic marker for advanced GCs and might be correlated with metastatic potential. miR-382 might play important roles in the aggressiveness, progression and prognosis of GCs. In addition, miR-382 give a predictive marker for progression of GCs compared to the normal or preneoplastic lesion.

MiR-382 functions as tumor suppressor and chemosensitizer in colorectal cancer

Increasing evidence suggests that microRNAs (miRNAs) play a critical role in tumorigenesis. Decreased expression of miR-382 has been observed in various types of cancers. However, the biological function of miR-382 in colorectal cancer (CRC) is still largely unknown. Here, we found that miR-382 was down-regulated in human colorectal cancer tissues and cell lines associated with it. MiR-382 inhibited colorectal cancer cell proliferation, migration, invasion, and enhance chemosensitivity. Furthermore, we identified Krüppel-like factor 12 (KLF12) and homeodomain-interacting protein kinase 3 (HIPK3) as the target of miR-382, and miR-382 rescued the promotion effect of KFL12 on migration and enhanced chemosensitivity in colorectal cancer cell lines. Collectively, these findings revealed that miR-382 inhibits migration and enhances chemosensitivity by targeting KLF12 and HIPK3 in colorectal cancer. These findings might serve as a tumor suppressor in CRC.

Identification of crucial miRNAs and genes in esophageal squamous cell carcinoma by miRNA-mRNA integrated analysis

Esophageal squamous cell carcinoma (ESCC) is a malignancy that severely threatens human health and carries a high incidence rate and a low 5-year survival rate. MicroRNAs (miRNAs) are commonly accepted as a key regulatory function in human cancer, but the potential regulatory mechanisms of miRNA-mRNA related to ESCC remain poorly understood.The GSE55857, GSE43732, and GSE6188 miRNA microarray datasets and the gene expression microarray datasets GSE70409, GSE29001, and GSE20347 were downloaded from Gene Expression Omnibus databases. The differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were obtained using GEO2R. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction (PPI) network and functional modules were established using the STRING database and were visualized by Cytoscape. Kaplan-Meier analysis was constructed based on The Cancer Genome Atlas (TCGA) database.In total, 26 DEMs and 280 DEGs that consisted of 96 upregulated and 184 downregulated genes were screened out. A functional enrichment analysis showed that the DEGs were mainly enriched in the ECM-receptor interaction and cytochrome P450 metabolic pathways. In addition, MMP9, PCNA, TOP2A, MMP1, AURKA, MCM2, IVL, CYP2E1, SPRR3, FOS, FLG, TGM1, and CYP2C9 were considered to be hub genes owing to high degrees in the PPI network. MiR-183-5p was with the highest connectivity target genes in hub genes. FOS was predicted to be a common target gene of the significant DEMs. Hsa-miR-9-3p, hsa-miR-34c-3p and FOS were related to patient prognosis and higher expression of the transcripts were associated with a poor OS in patients with ESCC.Our study revealed the miRNA-mediated hub genes regulatory network as a model for predicting the molecular mechanism of ESCC. This may provide novel insights for unraveling the pathogenesis of ESCC.

The role of miR-382-5p in glioma cell proliferation, migration and invasion

Background: Dysregulation of a single miRNA can play an essential role in tumor development and progression. Recent studies have shown that miR-382-5p can function as an oncogene or as a tumor suppressor in different types of cancers. However, the role of miR-382-5p in glioma growth and expansion has not been characterized.

Methods: Quantitative real time-PCR (qRT-PCR) was used to measure miR-382-5p levels in glioma tissues. The miR-382-5p mimics and inhibitors were employed to upregulate and downregulate miR-382-5p expression respectively in glioma cells. EdU assay was used to assess cell proliferation. Wound healing and Transwell assays were employed to evaluate cell migration and invasion. Western blot was used to measure the changes of epithelial-to-mesenchymal transition (EMT) markers and the potential miR-382-5p target genes.

Results: We found that miR-382-5p levels were low in glioma tissues as determined by qRT-PCR. EdU assay showed that upregulation of miR-382-5p significantly decreased cell proliferation in both U87 and U251 cells. Wound healing rate was significantly decreased in response to miR-382-5p mimics and significantly increased in response to miR-382-5p inhibitors. Transwell migration assays further confirmed the inhibitory effects of miR-382-5p on the migration in both U251 and U87 cells. Transwell invasion assays showed that upregulation of miR-382-5p resulted in a remarkable decrease in the number of invading cells, whereas downregulation of miR-382-5p led to a significant increase in the numbers of invading U87 and U251 cells. In addition, overexpression of miR-382-5p decreased the protein levels of N-cadherin, Snail and Slug, and increased E-cadherin levels, in glioma cells. Furthermore, miR-382-5p levels negatively correlated with Y box-binding protein 1 (YBX1) in lower grade glioma tissues, and negatively regulated the expression of YBX1 in glioma cells.

Conclusion: In summary, miR-382-5p inhibited proliferation, migration, invasion, and the EMT in glioma cells, possibly through targeting the oncogene YBX1.

Prognostic Value of MicroRNAs in Esophageal Carcinoma: A Meta-Analysis

Background

Numerous articles have reported that abnormal expression levels of microRNAs (miRNAs) are related to the survival times of esophageal carcinoma (EC) patients, which contains esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Nevertheless, there has not been a comprehensive meta-analysis to assess the accurate prognostic value of miRNAs in EC.

Methods

Studies published in English up to April 12, 2018 that evaluated the correlation of the expression levels of miRNAs with overall survival (OS) in EC were identified by online searches in PubMed, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews performed by two independent authors. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate the correlation between OS and miRNA expression. HR ≥ 2 was considered cutoff for considering the miRNA as prognostic candidate.

Results

Forty-four pertinent articles with 22 miRNAs and 4310 EC patients were ultimately included. EC patients with tissue expression levels of high miR-21 or low miR-133a (HR = 2.48, 95% CI = 1.50–4.12), miR-133b (HR = 2.15, 95% CI = 1.27–3.62), miR-138 (HR = 2.27, 95% CI = 1.68–3.08), miR-203 (HR = 2.83, 95% CI = 1.35–5.95), miR-375 and miR-655 (HR = 2.66, 95% CI = 1.16–6.12) had significantly poorer OS (P < 0.05). In addition, EC patients with blood expression levels of high miR-21 (HR = 2.19, 95% CI = 1.31–3.68) and miR-223 had significantly shorter OS (P < 0.05).

Conclusions

In conclusion, tissue expression levels of miR-21, miR-133a, miR-133b, miR-138, miR-203, miR-375, and miR-655 and blood expression levels of miR-21 and miR-223 demonstrate significant prognostic value. Among them, the expression levels of miR-133a, miR-133b, miR-138, miR-203, and miR-655 in tissue and the expression level of miR-21 in blood are potential prognostic candidates for predicting OS in EC.

Repression of microRNA-382 inhibits glomerular mesangial cell proliferation and extracellular matrix accumulation via FoxO1 in mice with diabetic nephropathy

OBJECTIVES

Diabetic nephropathy (DN) is a nerve damaging disorder, characterized by glomerular mesangial cell expansion and accumulation of extracellular matrix (ECM) proteins. In this study, we aimed to investigate mesangial cell proliferation and ECM accumulation when promoting or suppressing endogenous miR-382 in glomerular mesangial cells of DN.

MATERIALS AND METHODS

Model establishment consisted of DN induction by streptozotocin (STZ) in mice. The underlying regulatory mechanisms of miR-382 were analysed in concert with the treatment of miR-382 mimics, miR-382 inhibitors or siRNA against FoxO1 in cultured glomerular mesangial cells isolated from DN mice.

RESULTS

FoxO1 was identified as the downregulated gene in DN based on the microarray data of GSE1009. We found that miR-382 was significantly upregulated in renal tissues of DN mice and its downregulation dephosphorylated FoxO1, reduced glomerular mesangial cell proliferation and ECM accumulation in vitro. The determination of luciferase activity suggested that miR-382 negatively targeted FoxO1. Expectedly, distinct levels of phosphorylated FoxO1 were observed in the renal cortices of DN mice, while the silencing of FoxO1 was found to increase glomerular mesangial cell proliferation and ECM accumulation in vitro. Reduced glomerular mesangial cell proliferation and ECM accumulation elicited by miR-382 inhibitors were reversed by silencing FoxO1.

CONCLUSIONS

This study demonstrates miR-382 suppression exerts a potent anti-proliferative effect that may be applied to inhibit glomerular mesangial cell proliferation and ECM accumulation in DN.

MicroRNAs in esophageal squamous cell carcinoma: Potential biomarkers and therapeutic targets

Esophageal cancer is a common cause of cancer-related deaths worldwide. Squamous cell carcinoma (SCC) is the major histological type of esophageal cancer in developing countries including China, and the prognosis is very poor. Many microRNAs are involved in several important biological and pathologic processes, and promote tumorigenesis. To better understand the prognostic and therapeutic roles of microRNAs in ESCC, we reviewed the diagnosis and prognosis associated oncogenic microRNAs (e.g. miR-21 and miR-17-92 cluster) and tumor suppressor microRNAs (e.g. miR-375, miR-133a and miR-133b), and diagnosis and prognosis associated oncogenic target genes (e.g. PDCD4 and CCND1) and tumor suppressor target genes (e.g. EZH2 and PDK1). We also summarized the prognostic microRNA and target gene pairs (e.g. miR-296 and CCND1, miR214 and EZH2). Taken together, our review highlights the opportunities and challenges for microRNAs in the molecular diagnosis and target therapy of ESCC.

Downregulation of SETD8 by miR-382 is involved in glioma progression

BACKGROUND

SETD8 (named PR-SET7 or KMT5a) has been reported to regulate various biological processes including carcinogenesis. However, the role of SETD8 in glioma progression has not been investigated.

METHOD

qPCR and western blot were used to detect the expression levels of miR-382 and SETD8. MTT and wound healing assay used to detect the cell proliferation and migratory capability. A predicted target of miR-382 (SETD8) was first validated using a luciferase assay.

RESULTS

In this study, we found that SETD8 expression was evidently upregulated in glioma tissues and glioma cells, compared with the adjacent normal tissues and normal human astrocytes (NHA). Next, we showed that SETD8 evidently induced cell proliferation and migration in vitro and in vivo. In addition,dual-luciferase assays revealed that miR-382 directly regulates oncogenic SETD8 expression in U87 and U251 cells. Finally a statistically significant inverse correlation of miR-382 and SETD8 expression was observed in 30 glioma patients.

CONCLUSION

These data indicated that oncogenic SETD8 was regulated by miR-382 and involved glioma progression, revealing new therapeutic targets for glioma cancer.

miR-106b promotes cell invasion and metastasis via PTEN mediated EMT in ESCC

MicroRNA (miR)-106b serves an essential function in a variety of human cancer types, particularly in the process of invasion and metastasis. However, the function and mechanism of miR-106b in the invasion and metastasis of esophageal squamous cell carcinoma (ESCC) has remained elusive. In the present study, it was demonstrated that miR-106b was upregulated in ESCC tissues and cell lines. Furthermore, miR-106b expression in ESCC tissues was positively associated with lymphatic metastasis. Inhibition of miR-106b in EC-1 and EC9706 cells decreased not only the invasion and metastasis ability but also the proliferation ability of EC-1 and EC9706 cells. In addition, miR-106b had the ability to induce epithelial-to-mesenchymal transition (EMT) in EC-1 and EC9706 cells. In terms of the underlying mechanism, it was revealed that miR-106b promoted the invasion, metastasis and proliferation ability of EC-1 and EC9706 cells by directly targeting phosphatase and tension homolog (PTEN). Furthermore, miR-106b induced EMT in EC-1 and EC9706 cells by suppressing the expression of PTEN. In summary, the present study revealed that miR-106b contributed to invasion and metastasis in ESCC by regulating PTEN mediated EMT. Downregulation of miR-106b may be a novel strategy for preventing tumor invasion and metastasis.

MicroRNA‑382 inhibits cell proliferation and invasion of retinoblastoma by targeting BDNF‑mediated PI3K/AKT signalling pathway

It has previously been demonstrated that multiple microRNAs (miRNAs or miRs) are aberrantly expressed in retinoblastoma (RB) and contribute to RB initiation and progression. miR‑382 has been revealed to be aberrantly expressed and therefore exhibits a key role in the progression of various types of cancer. However, the expression pattern, functional roles and underlying molecular mechanism of miR‑382 in RB remain unknown. The present study investigated the expression levels of miR‑382 and its effects on RB cells and the underlying regulatory mechanism of its action. It was demonstrated that miR‑382 was downregulated in RB tissues and cell lines. Upregulation of miR‑382 inhibited RB cell proliferation and invasion in vitro. Additionally, brain‑derived neurotrophic factor (BDNF) was identified as a novel target of miR‑382 in RB. BDNF was upregulated in RB tissues and negatively associated with miR‑382 expression levels. Furthermore, BDNF overexpression rescued the tumour‑suppressing effects on RB cells induced by miR‑382. miR‑382 inactivated the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signalling pathway in RB. These findings suggested that miR‑382 serves as a tumour suppressor in RB, in part, by targeting the BDNF‑mediated PI3K/AKT signalling pathway. The results of the present study suggest a potential therapeutic strategy for treating RB patients in the future.

miR-382 functions as a tumor suppressor against esophageal squamous cell carcinoma

AIM

To explore the effect of miR-382 on esophageal squamous cell carcinoma (ESCC) in vitro and its possible molecular mechanism.

METHODS

Eca109 cells derived from human ESCC and Het-1A cells derived from human normal esophageal epithelium were used. Lentivirus-mediated miR-382 was overexpressed in Eca109 cells. The effect of miR-382 on cell proliferation was evaluated by MTT and colony formation assay. For cell cycle analysis, cells were fixed and stained for 30 min with propidium iodide (PI) staining buffer containing 10 mg/mL PI and 100 mg/mL RNase A, and analyzed by BD FACSCalibur™ flow cytometer. For cell apoptosis assay, cells were stained with an Annexin V-FITC/PI Apoptosis Detection Kit according to the manufacturer’s instructions and analyzed by a dual-laser flow cytometer. Cell invasion and migration abilities were determined through use of transwell chambers, non-coated or pre-coated with matrigel. Levels of proteins related to cell growth and migration were examined by western blotting.

RESULTS

Endogenous miR-382 was down-regulated in Eca109 cells compared with Het-1A. Introduction of miR-382 not only significantly inhibited proliferation and colony formation, but also arrested cell cycle at the G2/M phase, as well as promoted apoptosis and autophagy in Eca109 cells. Migration, invasion and epithelial-mesenchymal transition of Eca109 cells were suppressed by overexpressing miR-382. Western blotting results showed that miR-382 inhibited the phosphorylation of mTOR and 4E-BP1.

CONCLUSION

miR-382 functions as a tumor suppressor against ESCC development and metastasis, and could be considered as a potential drug source for the treatment of ESCC patients.

MicroRNA-196a as a Potential Diagnostic Biomarker for Esophageal Squamous Cell Carcinoma

We observed significant up-regulation of miR-196a in esophageal squamous cell carcinoma (ESCC) as compared with their adjacent normal tissue (p = .002). Receiver operating characteristics curve analysis confirmed the suitability of miR-196a as a potential tumor marker for diagnosis of ESCC. Furthermore, analysis of miR-196a levels in saliva samples determined an average of 27-fold up-regulations in ESCC patients compared with healthy group. Our results suggest that salivary miR-196a may be a suitable noninvasive biomarker for diagnosis of ESCC. In addition, molecular pathway enrichment analysis of microRNA (miR)-196a determined focal adhesion, spliceosome and p53 signaling pathways as the most relevant pathways with miR-196a targetome.

miR-382 inhibits tumor progression by targeting SETD8 in non-small cell lung cancer

Previous studies showed that miR-382 plays important roles in several types of cancers. Nevertheless, its expression and function in non-small cell lung cancer (NSCLC) remains largely unknown. In this study, we found that miR-382 expression was evidently downregulated in NSCLC tissue and cell lines in comparison with the adjacent normal tissues and human bronchial epithelial cell line (16HBE). Moreover, the expression levels of miR-382 were significantly associated with last-stage and tumor metastasis in NSCLC patients. In addition, exogenous miR-382 evidently inhibited NSCLC cell proliferation, migration and invasion in vitro. We also revealed SETD8 as a direct target of miR-382 in NSCLC, and restored SETD8 partially reversed the negative effects miR-382 on NSCLC cells. In total, our study demonstrated that miR-382 dysregulated in NSCLC and involved in NSCLC tumorigenesis and metastasis by suppressing SETD8 expression, which may help to identify effective therapies for NSCLC treatment.

MicroRNA-382 inhibits prostate cancer cell proliferation and metastasis through targeting COUP-TFII

MicroRNAs (miRNAs) have emerged as important regulators in cancer that are implicated in regulation of various cellular processes. miR-382 has been proposed as a tumor suppressor by several recent studies. However, the function of miR-382 in prostate cancer remains unknown. In this study, we aimed to investigate the potential function of miR-382 in prostate cancer. We found that miR-382 was significantly decreased in prostate cancer specimens and cancer cell lines. The overexpression of miR-382 in prostate cancer cells markedly inhibited cell proliferation, migration, and invasion. In contrast, miR-382 suppression exhibited an opposite effect. Target analysis predicted that chicken ovalbumin upstream promoter transcription factor II (COUP‑TFII) was a direct target of miR-382. This prediction was experimentally confirmed by dual-luciferase reporter assay, real-time quantitative polymerase chain reaction, and western blot analysis. Our results further demonstrated that miR-382 inhibited the downstream genes of COUP‑TFII, including Snail and matrix metalloproteinase 2 (MMP2). Moreover, the restoration of COUP‑TFII expression significantly blocked the inhibitory effect of miR-382 on cell proliferation, migration, and invasion, and Snail expression. Taken together, this study suggests that miR-382 inhibits prostate cancer cell proliferation and metastasis through inhibiting COUP‑TFII, representing an important new mechanism for understanding prostate cancer pathogenesis and providing a novel therapeutic candidate target for prostate cancer therapy.

The role of microRNA in esophageal squamous cell carcinoma

MicroRNAs (miRNA) are 22-nucleotide non-coding RNAs that post-transcriptionally regulate gene expression by base pairing to partially complementary sequences in the 3'-untranslated region of their target messenger RNA. Altered miRNA expression also changes the expression of oncogenes and tumor suppressors, affecting the proliferation, apoptosis, motility and invasibility of gastrointestinal cancer cells, including the cells of esophageal squamous cell carcinoma (ESCC). It has been suggested that various miRNA expression profiles may provide useful biomarkers and therapeutic targets, but to date few studies have been published on the role of miRNA in ESCC. In this review we summarize the identification and characterization of miRNAs involved in ESCC and discuss their potential as biomarkers and therapeutic targets.

Clinical potential of miR-3651 as a novel prognostic biomarker for esophageal squamous cell cancer

Accumulating evidence indicates that dysregulated microRNA-3651(miR-3651) is involved in tumorigenesis and cancer progression. In this study, we investigated the expression of miR-3651 in esophageal squamous cell cancer(ESCC) and its relationship with tumor progression and clinical prognosis. The expression level of miR-3651 was examined by quantitative Real-time PCR (qRT-PCR) in fresh ESCC tissues and FFPE tissues. The correlation between miR-3651 expression and clinical features and prognosis were statistically analyzed. The results showed that the miR-3651 expression was significantly down-regulated in tumor tissues compared with the paracancerous tissues. Moreover, miR-3651 expression was negatively correlated with T stage of ESCC (P = 0.022) and tumor length (P = 0.015). Kaplan-Meier analysis demonstrated that low miR-3651 expression level was associated with poorer overall survival (OS) (P = 0.004) and disease-free survival (DFS) (P = 0.001). Multivariate analysis identified miR-3651 expression as independent prognostic factor for OS and DFS (P = 0.001 and P = 0.001, resp.). Further stratified analysis revealed the significant association between low miR-3651 expression and worse survival in early patients, but not in the advanced patients. Taken together, miR-3651 was down-regulated in cancerous tissues of ESCC. It may play an important role in cancer progression and could be used as an independent prognostic biomarker for ESCC patients.