MicroRNA-219-5p exerts tumor suppressor function by targeting ROBO1 in glioblastoma

MicroRNA-588 regulates the invasive, migratory and vasculogenic mimicry-forming abilities of hypoxic glioma cells by targeting ROBO1

BACKGROUND

The microenvironment of hypoxia is an important factor contributing to the development of glioblastoma (GBM). MicroRNA-588 and its potential target Roundabout-directed receptor 1 (ROBO1) have been reported to promote tumor invasion and proliferation in diseases such as gastric, pancreatic and hepatocellular carcinoma, while their function in GBM and response to hypoxic states remain elusive.

METHODS

A microarray was leveraged to identify differentially expressed microRNAs in U251 glioma cells cultured under normoxic and hypoxic conditions. The expression of miR-588 was assessed using quantitative real-time PCR (qRT‒PCR). Gain- and loss-of-function studies were used to evaluate the role of miR-588 under hypoxic and normoxic conditions. Cell invasion, migration, proliferation, and vasculogenic mimicry (VM) formation experiments were performed. The relationship between miR-588 and ROBO1 was confirmed using western blot and luciferase reporter assays. Intracranial xenograft tumor mouse models were used to study the function of miR-588 in vivo.

RESULTS

The expression of miR-588 was significantly upregulated in hypoxic glioma cells relative to normoxic glioma cells. miR-588 inhibited the invasive, migratory and VM-forming abilities of glioma cells in vitro and in vivo. Mechanistically, roundabout guidance receptor 1 (ROBO1) is a direct, functionally relevant target of miR-588 in glioma. ROBO1 knockdown suppressed the expression of matrix metallopeptidase 2 (MMP2) and matrix metallopeptidase 9 (MMP9), thereby inhibiting the invasive, migratory and VM-forming abilities of glioma.

CONCLUSIONS

MiR-588 regulated the behaviors of hypoxic glioma cells by targeting ROBO1. miR-588 can be used as a prognostic marker for glioma and has potential implications in glioma gene therapy.

MicroRNA-219 loaded chitosan nanoparticles for treatment of glioblastoma

Recent evidence has implicated microRNA-219 (miR-219) in regulation of gene contributed in glioblastoma (GBM) pathogenesis. This study aimed to prepare miR-219 in chitosan (CS) nanoparticles (NPs), characterize and investigate their efficacy on human GBM cell line (U87 MG). NPs were prepared using ionic gelation method. The influence of process parameters on physicochemical characteristics of NPs was investigated. Apoptotic effect of miR-219 was examined on U87 MG cells. Formulated NPs showed particle size of 109 ± 2.18 nm, with poly dispersity index equal to 0.2 ± 0.05, and zeta potential of +20.5 ± 0.7 mV. Entrapment efficiency of miR-219 in loaded NP has reached 95%. The in vitro release study demonstrated sustained release pattern of miR-219 from CS-NPs. Gel retardation assay has confirmed the integrity of miR-219 after production process. The fabricated NPs reduced the survival of U87 MG cells to 78% after 24 h of post-transfection, and into 67.5% after 48 h. However, fibroblasts were not affected by the NPs, revealing their specificity for GBM cells. Given the tumour suppressing function of miR-219, and advantage of CS-NPs for gene delivery to the central nervous system, the presented NPs have a great potential for treatment of GBM.

miR-219-5p targets TBXT and inhibits breast cancer cell EMT and cell migration and invasion

miR-219-5p has been reported to act as either a tumor suppressor or a tumor promoter in different cancers by targeting different genes. In the present study, we demonstrated that miR-219-5p negatively regulated the expression of TBXT, a known epithelial–mesenchymal transition (EMT) inducer, by directly binding to TBXT 3′-untranslated region. As a result of its inhibition on TBXT expression, miR-219-5p suppressed EMT and cell migration and invasion in breast cancer cells. The re-introduction of TBXT in miR-219-5p overexpressing cells decreased the inhibitory effects of miR-219 on EMT and cell migration and invasion. Moreover, miR-219-5p decreased breast cancer stem cell (CSC) marker genes expression and reduced the mammosphere forming capability of cells. Overall, our study highlighted that TBXT is a novel target of miR-219-5p. By suppressing TBXT, miR-219-5p plays an important role in EMT and cell migration and invasion of breast cancer cells.

MicroRNA-219-5p participates in cyanotic congenital heart disease progression by regulating cardiomyocyte apoptosis

MicroRNAs (miRs) play important roles in the protection against and development of congenital heart disease (CHD). However, the role and potential mechanisms of miR-219-5p in cyanotic CHD remains unclear. Reverse transcription-quantitative PCR (RT-qPCR) was used to measure miR-219-5p levels in cyanotic CHD and hypoxia-induced H9C2 cells. Dual luciferase reporter gene assay was used to confirm whether liver receptor homolog-1 (LRH-1) was a direct target of miR-219-5p. miR-219-5p inhibitor and LRH-1-small interfering RNA were transfected into H9C2 cells under hypoxic conditions to investigate the role of miR-219-5p in hypoxia-induced H9C2 cells. Subsequently, cell viability was detected using an MTT assay and cell apoptosis was detected using flow cytometry. In addition, RT-qPCR and western blotting assays were performed to detect the mRNA and protein expression of LRH-1, cyclin D1 and β-catenin, respectively. The data showed that miR-219-5p expression was higher in patients with cyanotic CHD compared with patients with acyanotic CHD gradually increased in H9C2 cells with prolonged hypoxia time. Dual luciferase reporter assay results showed that LRH-1 was a direct target gene of miR-219-5p. Inhibition of miR-219-5p reversed hypoxia-induced cell viability reduction and attenuated hypoxia-induced cell apoptosis. In addition, hypoxia induction inhibited the expression of LRH-1, cyclin D1 and β-catenin, which was reversed by miR-219-5p inhibitor. However, LRH-1 downregulation reversed the miR-219-5p inhibitor enhanced cell viability, decreased cell apoptosis and increased expression of LRH-1, cyclin D1 and β-catenin in hypoxia-treated cardiomyocytes. The present results demonstrated that downregulation of miR-219-5p promoted the expression of the LRH-1/Wnt/β-catenin signaling pathway-associated components, reduced cardiomyocyte apoptosis and increased cell growth under hypoxic conditions. miR-219-5p may be a potential therapeutic target for cyanotic CHD therapy.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

Regulatory noncoding RNAs and the major histocompatibility complex

The Major Histocompatibility Complex (MHC) is a 4 Mbp genomic region located on the short arm of chromosome 6. The MHC region contains many key immune-related genes such as Human Leukocyte Antigens (HLAs). There has been a growing realization that, apart from MHC encoded proteins, RNAs derived from noncoding regions of the MHC-specifically microRNAs (miRNAs) and long noncoding RNAs (lncRNAs)-play a significant role in cellular regulation. Furthermore, regulatory noncoding RNAs (ncRNAs) derived from other parts of the genome fine-tune the expression of many immune-related MHC proteins. Although the field of ncRNAs of the MHC is a research area that is still in its infancy, ncRNA regulation of MHC genes has already been shown to be vital for immune function, healthy pregnancy and cellular homeostasis. Dysregulation of this intricate network of ncRNAs can lead to serious perturbations in homeostasis and subsequent disease.

Upregulation of microRNA-219-5p relieves ulcerative colitis through balancing the differentiation of Treg/Th17 cells

OBJECTIVE

This study aimed to investigate the specific regulatory roles of microRNA-219-5p (miR-219-5p) on ulcerative colitis (UC), and reveal the potential mechanisms relating with the differentiation of Treg/Th17 cells.

METHODS

The mouse model of chronic UC was established by oral administration of 3% dextran sodium sulfate for three cycles. After intravenous injected with lentivirus (LV)-miR-219-5p for 24 h, the disease activity index (DAI), colon length, as well as the serum levels of Interleukin (IL)-6, -17A, -21, and -23 were measured. In addition, the histopathological changes in colon tissues were observed by Hematoxylin-eosin staining. The differentiation of Treg/Th17 cells was detected by Flow cytometry, and the expression of retinoic acid-related orphan receptor (RORrt), signal transducer and activator of transcription 3 (STAT3), and forkhead box p3 (Foxp3) were detected by quantitative real-time PCR and Western blot.

RESULTS

MiR-219-5p was downregulated in colonic mucosal tissues of UC mice (P < 0.05). UC mice injected with LV-miR-219-5p exhibited significantly relieved histopathological changes of colon tissues, increased colon length, decreased DAI, as well as decreased serum levels of IL-6, -17A, -21, and -23 (P < 0.05). In addition, the injection of LV-miR-219-5p significantly increased the percentage of Treg cells via upregulating Foxp3, and decreased the percentage of Th17 cells via downregulating RORrt and STAT3 in UC mice (P < 0.05).

CONCLUSION

The upregulation of miR-219-5p relieved the colonic damage and inflammation of UC through balancing the differentiation of Treg/Th17 cells.

Upregulation of miR-219a-5p Decreases Cerebral Ischemia/Reperfusion Injury In Vitro by Targeting Pde4d

BACKGROUND

Ischemic stroke is the leading cause of disability and death globally. Micro-RNAs (miRNAs) have been reported to play important roles in the development and pathogenesis of the nervous system. However, the exact function and mechanism of miRNAs have not been fully elucidated about brain damage caused by cerebral ischemia/reperfusion (I/R).

METHODS

In this study, we explored the neuroprotective effects of miR-219a-5p on brain using an in vitro ischemia model (mouse neuroblastoma N2a cells treated with oxyglucose deprivation and reperfusion), and in vivo cerebral I/R model in mice. Western blot assay and Reverse Transcription-Polymerase Chain Reaction were used to check the expression of molecules involved. Flow cytometry and cholecystokinin were used to examine cell apoptosis, respectively.

RESULTS

Our research shows that miR-219a-5p gradually decreases in cerebral I/R models in vivo and in vitro. In vitro I/R, we find that miR-219a-5p mimics provided evidently protection for cerebral I/R damage, as shown by increased cell viability and decreased the release of LDH and cell apoptosis. Mechanically, our findings indicate that miR-219a-5p binds to cAMP specific 3', 5'-cyclic phosphodiesterase 4D (PDE4D) mRNA in the 3'-UTR region, which subsequently leads to a decrease in Pde4d expression in I/R N2a cells.

CONCLUSIONS

Our results provide new ideas for the study of the mechanism of cerebral ischemia/reperfusion injury, and lay the foundation for further research on the treatment of brain I/R injury. Upregulation of miR-219a-5p decreases cerebral ischemia/reperfusion injury by targeting Pde4d in vitro.

MicroRNA Profile Identifies miR-6165 Could Suppress Gastric Cancer Migration and Invasion by Targeting STRN4

Background

Recent studies showed that aberrant expression of miRNAs causes tumor-suppressing or promoting effects in various cancers including gastric cancer (GC). Our previous studies showed that lots of miRNAs and mRNA expressed differentially in GC and normal tissues. However, the critical miRNAs and mRNA need to be clarified.

Materials and Methods

Microarray sequencing was used to profile the differential expression of miRNAs and mRNA in GC and normal tissues. Bioinformatics analysis and database prediction were used to search the critical miRNAs and mRNA. Real-time quantitative polymerase chain reaction (RT-qPCR), luciferase reporter assay, immunohistochemistry (IHC), wound healing assay and transwell assay were used to clarify the relationship between the target miRNAs and mRNA. Statistical analysis was used to seek their value of diagnosis and prognosis.

Results

We identified microRNA-6165 (miR-6165) as a novel cancer-related miRNA in GC through high-throughput microarray sequencing. By bioinformatics analysis and luciferase reporter assay, we found STRN4 was the target of miR-6165. Via a series of cell experiments, we determined that miR-6165 suppressed GC cells migration and invasion by targeting STRN4. Also, we discovered the potential diagnosis and prognosis value of miR-6165 and STRN4.

Conclusion

It was found that miR-6165 might suppress GC migration and invasion by targeting STRN4 in vitro, and the further research should focus more on the potential diagnosis and prognosis value of miR-6165 and STRN4 in gastric cancer patients.

miR-219a-5p Ameliorates Hepatic Ischemia/Reperfusion Injury via Impairing TP53BP2

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is a serious complication that occurs upon hypovolemic shock, liver resection, and transplantation. A significant age-dependent difference in the injury response to hepatic I/R in both human and animal models has been reported. Nevertheless, the molecular mechanism is currently unclear.

AIMS

To clarify the reason why aged animals or people were more vulnerable to hepatic I/R injury.

METHODS

In the present study, we found decreased miR-219a-5p expression in the old mice more vulnerable to hepatic I/R injury. Administrated with agomir-miR-219a-5p diminished the severity of hepatic I/R injury in old mice, as indicated by lower serum ALT and AST, oxidative parameters including MDA, TOA, and OSI, and decreased apoptotic cell number. The effect of miR-219a-5p was also confirmed in the H₂O₂-induced apoptosis model in AML-12 and NCTC1469 cells. After miR-219a-5p overexpression, two key apoptosis-related proteins Bax and P21, target genes of TP53, were decreased. Furthermore, TP53BP2 interacts with p53 family members and promotes their transcriptional activities toward pro-apoptosis genes.

RESULTS

RNA sequencing, western blot, and luciferase reporter assay proved that TP53BP2, a crucial TP53 transcriptional activity enhancer in vivo, was directly regulated by miR-219a-5p.

CONCLUSIONS

In summary, our study demonstrated that age-related miR-219a-5p can attenuate hepatic I/R injury through inhibiting TP53BP2 and downstream TP53-dependent apoptosis of hepatic cells in mice.

MiR-219-5p suppresses cell proliferation and cell cycle progression in esophageal squamous cell carcinoma by targeting CCNA2

Background

We investigated the potential regulatory role of miR-219-5p in esophageal squamous cell carcinoma (ESCC) and looked at the underlying mechanisms in ESCC.

Methods

Real-time PCR was used to determine the levels of miR-219-5p in ESCC tissues and cell lines. The effects of miR-219-5p and cyclin A2 (CCNA2) on cell proliferation and cell cycle progression were evaluated using MTT, colony formation and flow cytometry assays with ESCC cell lines EC9706 and TE-9. Bioinformatics techniques and the luciferase reporter assay were applied to validate CCNA2 as the miR-219-5p target in ESCC cells. The mRNA and protein levels of CCNA2 were measured using real-time PCR and western blotting.

Results

MiR-219-5p expression was significantly lower in ESCC tissues and cells than in healthy tissues. Upregulation of miR-219-5p repressed cell proliferation and induced cell cycle arrest at the G2/M phase. CCNA2 was identified and confirmed as a direct downstream target of miR-219-5p and its expression negatively correlated with miR-219-5p profiles in ESCC tissues. Knockdown of CCNA2 potentiated the effects of miR-219-5p on cell proliferation and cell cycle distribution.

Conclusions

Our results demonstrate that miR-219-5p might function as a tumor suppressor by directly targeting CCNA2 expression. It could serve as a new therapeutic target for ESCC.

Oligodendrocyte Progenitor Cells and Macrophages/Microglia Produce Glioma Stem Cell Niches at the Tumor Border

Glioblastoma (GBM) usually develops in adult brain white matter. Even after complete resection, GBM recurs around the tumor removal cavity, where GBM cells acquire chemo-radioresistance. Characterization of the tumor border microenvironment is critical for improving prognosis in patients with GBM. Here, we compared microRNA (miRNA) expression in samples from the tumor, tumor border, and periphery by miRNA microarray. The top three of miRNAs showing higher expression in the tumor border were related to oligodendrocyte differentiation, and pathologically oligodendrocyte lineage cells were increased in the border, where macrophages and microglia also colocalized. Medium cultured with oligodendrocyte progenitor cells (OPCs) and macrophages induced stemness and chemo-radioresistance in GBM cells, similar to that produced by FGF1, EGF and HB-EGF, IL-1β, corresponding to OPCs and macrophages, respectively. Thus, OPCs and macrophages/microglia may form a glioma stem cell niche at the tumor border, representing a promising target for prevention of recurrence.

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Most cases of glioblastoma recur in white matter around the removal cavity after total resection plus chemo-radiotherapy.

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miRNAs showing characteristically higher expression in the tumor border were related to oligodendrocyte differentiation.

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Increased oligodendrocyte progenitor cells and macrophages enhance stemness and chemo-radioresistance in glioma cells.

Glioblastoma (GBM) occurs in adult brain and shows rapid growth and invasion. Despite intensive treatment, the mean 5-year survival rate is still <10%. Most cases of GBM recur locally even after total resection of gadolinium-enhanced lesions observed with MRI, indicating that chemo-radioresistant GBM cells survive there. MicroRNAs showing characteristically higher expression in the tumor border were related to oligodendrocyte differentiation. Oligodendrocyte progenitor cells (OPCs) and macrophages/microglia increased at tumor borders, and induced stemness and chemo-radioresistance in GBM cells in vivo. Thus, OPCs and macrophages/microglia formed characteristic microenvironments and may be promising targets to prevent GBM recurrence.

miR-219a-5p inhibits breast cancer cell migration and epithelial-mesenchymal transition by targeting myocardin-related transcription factor A

Although many miRNAs are reported to be involved in tumor formation and progression, the effect of miR-219a-5p on breast cancer metastasis is not well-known. The aim of this study is to investigate the effect of miR-219a-5p on the migratory ability and epithelial-mesenchymal transition (EMT) of breast cancer cells. First, miR-219a-5p was found to be highly expressed in low-invasive breast cancer MCF-7 cells, but lowly expressed in high-invasive breast cancer MDA-MB-231 cells. Wound scratch assay and transwell assay showed that miR-219a-5p inhibited the migratory ability of MDA-MB-231 cells. miR-219a-5p also suppressed the cellular EMT, confirmed by suppressing the expression of mesenchymal markers vimentin and N-cadherin and increasing the expression of epithelial marker E-cadherin. Using the epithelial-mesenchymal-epithelial model in MCF-7 cells, we confirmed that the level of miR-219a-5p was highly expressed in epithelial-type cells and lowly expressed in mesenchymal-type cells. Importantly, we identified myocardin-related transcription factor A (MRTF-A) as a novel potential target gene of miR-219a-5p. Overexpression of miR-219a-5p in MDA-MB-231 cells could inhibit the expression of MRTF-A as revealed by real-time PCR and western blot analysis. miR-219a-5p inhibited the transcription of MRTF-A by targeting the 3'UTR of MRTF-A, which was confirmed by wild-type or mutant MRTF-A 3'UTR luciferase reporter system. Furthermore, knockdown of MRTF-A using siRNA for MRTF-A could depress breast cell migration. In conclusion, our present study revealed the tumor suppressive role of miR-219a-5p in regulating breast cancer migration by targeting MRTF-A, suggesting that miR-219a-5p might be a therapeutic target in breast cancer through regulating EMT.

MicroRNA-219 exerts a tumor suppressive role in glioma via targeting Sal-like protein 4

MicroRNAs (miRs) serve important roles in the development and progression of various human cancer types, including glioma. Recently, miR-219 has been suggested to function as a tumor suppressor in glioma; however, the underlying mechanism remains largely unknown. The aim of this study was to investigate the regulatory mechanism of miR-219 in the malignant phenotypes of glioma cells. Quantitative polymerase chain reaction (qPCR) and western blotting were conducted to examine the mRNA and protein expression. An MTT assay, wound healing assay and Transwell assay were used to study cell proliferation, migration and invasion. The qPCR data indicated that the expression of miR-219 was significantly decreased in glioma tissues compared with normal brain tissues. In addition, a low expression of miR-219 was identified to be associated with an advanced pathological grade. In vitro experiments demonstrated that miR-219 was also downregulated in several common glioma cell lines, including A172, U87, U251 and U373, when compared with that in normal astrocytes. Ectopic expression of miR-219 caused a significant decrease in U87 cell proliferation, migration and invasion. Luciferase reporter assay data indicated that Sal-like protein 4 (SALL4) was a direct target gene of miR-219, while the protein expression of SALL4 was negatively regulated by miR-219 in U87 cells. Furthermore, SALL4 was significantly upregulated in glioma tissues and cell lines, and upregulation of SALL4 was associated with a higher pathological grade. Furthermore, overexpression of SALL4 significantly attenuated the suppressive effects of miR-219 on U87 cell proliferation, migration and invasion, suggesting that miR-219 serves a suppressive role in glioma growth and metastasis via targeting SALL4. Therefore, the present study highlighted the clinical significance of the miR-219/SALL4 axis in glioma.

MicroRNA-219 is downregulated in non-small cell lung cancer and inhibits cell growth and metastasis by targeting HMGA2

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-associated mortality worldwide. Non-small cell lung cancer (NSCLC) is the predominant type of lung cancer, and accounts for ~85% of all lung cancer cases. An increasing number of studies suggest that microRNAs (miRs) may be involved in the regulation of NSCLC carcinogenesis and progression. However, the expression and function of miRNA-219 in NSCLC, and its underlying mechanisms of action, remain unknown. In the present study, miR-219 expression in NSCLC tissues and cell lines was determined using reverse transcription-quantitative polymerase chain reaction. Following transfection with miR-219 mimics, the effects of miR-219 overexpression on NSCLC cell proliferation, migration and invasion were examined. Furthermore, the miR-219 target in NSCLC was investigated. miR-219 was observed to be downregulated in NSCLC tissues and NSCLC cell lines. In addition, miR-219 was demonstrated to function as a tumor suppressor in NSCLC, through inhibiting cell proliferation, migration and invasion in vitro. Furthermore, high mobility group AT-hook 2 (HMGA2) was identified to be a direct target of miR-219 in NSCLC, and downregulation of HMGA2 suppressed NSCLC cell proliferation, migration and invasion in vitro. HMGA2 expression was upregulated in NSCLC tissues, and was inversely correlated with miR-219 expression. In conclusion, miR-219 functions as a tumor suppressor and may be important in inhibiting the growth and metastasis of NSCLC cells via directly targeting HMGA2. Therefore, miR-219 may present a potential novel therapeutic target for NSCLC.

microRNA-219-5p inhibits epithelial-mesenchymal transition and metastasis of colorectal cancer by targeting lymphoid enhancer-binding factor 1

Aberrant expression of microRNAs (miRs) has been shown to play a critical role in the pathogenesis and progression of tumors. microRNA‐219‐5p (miR‐219‐5p) has been reported to be abnormally expressed in some types of human tumors. However, the mechanism between miR‐219‐5p and colorectal cancer (CRC) metastasis remains unclear. In the present study, miR‐219‐5p was found to be downregulated in CRC tissue compared with matched normal tissue. Through luciferase reporter assay, we demonstrated lymphoid enhancer‐binding factor 1 (LEF1) as a direct target of miR‐219‐5p. Overexpression of miR‐219‐5p could inhibit motility, migration and invasion of CRC cells, and inhibit epithelial‐mesenchymal transition (EMT). Furthermore, silencing LEF1 phenocopied this metastasis‐suppressive function. The recovery experiment showed that re‐expression of LEF1 rescued this suppressive effect on tumor metastasis and reversed the expression of EMT markers caused by miR‐219‐5p. Additionally, we demonstrated that miR‐219‐5p exerted this tumor‐suppressive function by blocking activation of the AKT and ERK pathways. Finally, a nude mice experiment showed that miR‐219‐5p reduced the lung metastasis ability of CRC cells. Taken together, our findings indicate that miR‐219‐5p inhibits metastasis and EMT of CRC by targeting LEF1 and suppressing the AKT and ERK pathways, which may provide a new antitumor strategy to delay CRC metastasis.

Retinoic acid-induced upregulation of miR-219 promotes the differentiation of embryonic stem cells into neural cells

MicroRNAs (miRNAs) regulate critical cell processes, such as apoptosis, proliferation, and development. However, the role of miRNAs in embryonic stem cell (ESC) neural differentiation induced by retinoic acid (RA) and factors that govern neural directional differentiation remain poorly understood. In this study, we demonstrated that miR-219 is sufficient in promoting mouse ESCs to undergo neural differentiation. We discovered that Foxj3 and Zbtb18, two target genes of miR-219, are not able to determine the process of RA-induced differentiation, however they prevent ESCs from differentiating into neural cells. We identified four downstream genes, namely, Olig1, Zic5, Erbb2, and Olig2, which are essential to the gene interaction networks for neural differentiation. These data explain the mechanism of RA-induced neural differentiation of mESCs on the basis of miRNAs and support the crucial role of miR-219 in neurodevelopment.

Integrative bioinformatics analysis identifies ROBO1 as a potential therapeutic target modified by miR-218 in hepatocellular carcinoma

Patients diagnosed with advanced hepatocellular carcinoma (HCC) presented poor prognosis and short survival time. Althouth accumulating contribution of continuous research has gradually revealed complex tumorigenesis mechanism of HCC with numerous and jumbled biomarkers, those specific ones for HCC diagnose and therapeutic treatment are required illustration. Multiple genes over-expressed in HCC specimens with at least 1.5 fold change were cohorted, compared with the non-cancerous tissues through integrative bioinformatics analysis from Gene Expression Omnibus (GEO) datasets GSE14520 and GSE6764, including 445 and 45 cases of samples spearatly, along with intensive exploration on the Cancer Genome Altas (TCGA) dataset of liver cancer. Thirteen genes significantly highly expressed, overlapping in the datasets above. The Database for Annotation Visualization and Integrated Discovery (DAVID) program was utilized for functional pathway enrichment analysis. Protein-protein Interaction (PPI) analysis was conducted through the Search Tool for the Retrieval of Interacting Genes (STRING) database. ROBO1 was highlighted as one of the most probable molecules among the 13 candidates participating in cancer process. Cancer Cell Line Encycolopedia (CCLE) database was utilized exploring ROBO1 expression in cell lines. Immunochemistry analysis and qRT-PCR assay were performed in our medical center, which indicates significant over-expression status in either HCC tumor specimens and 3 HCC cell lines. Furtherly, we recognized that miR-218, a tumor suppressor, might be an upstream regulator for ROBO1 directly binding to the mRNA 3’UTR and potentially modifying the expression and function of ROBO1. Herein, we conclude that ROBO1 is a mighty therapeutic targets modified by miR-218 in HCC deserving further investigation.

miR-219-5p suppresses the proliferation and invasion of colorectal cancer cells by targeting calcyphosin

MicroRNAs (miRNAs) are small non-coding RNAs involved in an array of biological processes, and their dysregulation is associated with tumor development and progression. One such miRNA, miR-219-5p, is abnormally expressed in patients with colorectal cancer (CRC). In the present study, reverse transcription-quantitative polymerase chain reaction was performed to measure miR-219-5p expression in cells from both CRC tumors, and surrounding healthy tissue. MTT and invasion assays were used to determine the role of miR-219-5p in regulating CRC cell proliferation and invasion, respectively. A luciferase assay was then performed to assess the binding of miR-219-5p to the CAPS gene that encodes calcyphosin protein. The present study confirmed that miR-219-5p expression is significantly downregulated in CRC tissue. miR-219-5p knockdown promoted the growth of HCT-8 cells and increased the expression of calcyphosin protein (CAPS). On the other hand, overexpressing miR-219-5p inhibited HCT-8 cell growth and invasion, and downregulated CAPS expression. In addition, CAPS was identified as the functional downstream target of miR-219-5p by directly targeting its 3'-untranslated region. Therefore, miR-219-5p may function as a tumor suppressor by decreasing CAPS expression, and subsequently inhibit tumor proliferation and invasion. These results indicate that novel therapeutic strategies that increase miR-219-5p expression may be developed to treat CRC.

MicroRNA-219-5p Represses the Proliferation, Migration, and Invasion of Gastric Cancer Cells by Targeting the LRH-1/Wnt/β-Catenin Signaling Pathway

MicroRNAs (miRNAs) are reportedly involved in gastric cancer development and progression. In particular, miR-219-5p has been reported to be a tumor-associated miRNA in human cancer. However, the role of miR-219-5p in gastric cancer remains unclear. In this study, we investigated for the first time the potential role and underlying mechanism of miR-219-5p in the proliferation, migration, and invasion of human gastric cancer cells. miR-219-5p was found to be markedly decreased in gastric cancer tissues and cell lines compared with adjacent tissues and normal gastric epithelial cells. miR-219-5p mimics or anti-miR-219-5p was transfected into gastric cancer cell lines to overexpress or suppress miR-219-5p expression, respectively. Results showed that miR-219-5p overexpression significantly decreased the proliferation, migration, and invasion of gastric cancer cells. Conversely, miR-219-5p suppression demonstrated a completely opposite effect. Bioinformatics and luciferase reporter assays indicated that miR-219-5p targeted the 3′-untranslated region of the liver receptor homolog-1 (LRH-1), a well-characterized oncogene. Furthermore, miR-219-5p inhibited the mRNA and protein levels of LRH-1. LRH-1 mRNA expression was inversely correlated with miR-219-5p expression in gastric cancer tissues. miR-219-5p overexpression significantly decreased the Wnt/β-catenin signaling pathway in gastric cancer cells. Additionally, LRH-1 restoration can markedly reverse miR-219-5p-mediated tumor suppressive effects. Our study suggests that miR-219-5p regulated the proliferation, migration, and invasion of human gastric cancer cells by suppressing LRH-1. miR-219-5p may be a potential target for gastric cancer therapy.

MiR-508-5p Inhibits the Progression of Glioma by Targeting Glycoprotein Non-metastatic Melanoma B

Glioma is a severe and highly lethal brain cancer, a malignancy largely stemming from growing in a relatively restrained area of the brain. Hence, the understanding of the molecular regulation of the growth of glioma is critical for improving its treatment. MicroRNA has become a hotspot in research on diseases, especially in the initiation and progression of different types of cancer. However, the molecular function and mechanisms of miR-508-5p in gliomagenesis are still unclear. The aim of this study was to investigate miR-508-5p expression in glioma and determine its effects on proliferation. miR-508-5p expression levels, both in glioma cell lines and in tissue, were significantly lower than in a normal human astrocyte cell line or adjacent tissues. Cell growth was analyzed using a MTT assay and over-expression of miR-508-5p was found to decrease glioma cell growth. Moreover, a bioinformatic analysis was performed, showing that glycoprotein non-metastatic melanoma B (GPNMB) was a direct target for miR-508-5p in glioma cells. Furthermore, in vivo treatment with miR-508-5p reduced GPNMB protein levels in the tumor. Additionally, overexpression of GPNMB without 3'-UTR partially reversed the cell growth arrest induced by miR-508-5p over-expression in glioma cells. In conclusion, these results indicate that increased expression of miR-508-5p might be related to glioma progression, indicating a potential role of miR-508-5p for clinical therapy.

MicroRNA-663 inhibits the proliferation, migration and invasion of glioblastoma cells via targeting TGF-β1

Cell migration and invasion are key processes involved during tumor metastasis. Recently, microRNAs (miRs) have been demonstrated to play important roles in the regulation of cancer metastasis. However, the underlying mechanisms remain unknown. Here, we aimed to investigate the exact role of miR-663 in the metastasis of glioblastoma as well as the underlying mechanisms. By performing quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis, we demonstrated that miR-663 was significantly downregulated in glioblastoma tissues (n=25), when compared to that in normal brain tissues (n=15). In addition, its expression levels were also reduced in human glioblastoma cell lines, A172 and U87. Furthermore, restoration of miR-663 expression led to a significant decrease in the cell proliferation, migration and invasion of human glioblastoma A172 and U87 cells. We further identified TGF-β1 as a direct target of miR-663, and found that the expression of TGF-β1 was negatively mediated by miR-663 at the post-transcriptional level in glioblastoma cells. Moreover, overexpression of TGF-β1 significantly reversed the inhibitory effects of miR-663 upregulation on the proliferation, migration and invasion in A172 and U87 cells. In addition, our data suggest that MMP2 and E-cadherin, a key factor in epithelial-mesenchymal transition (EMT), are involved in the miR-633/TGF-β1-mediated metastasis of glioblastoma. In summary, miR-663 plays an inhibitory role in the regulation of proliferation, migration and invasion of glioblastoma cells, partly at least, via direct mediation of TGF-β1 as well as downstream MMP2 and E-cadherin. Therefore, we suggest that miR-663 is a potential candidate for the prevention of glioblastoma metastasis.