miR-137 acts as a tumor suppressor in astrocytoma by targeting RASGRF1

Identification of potential crucial genes and mechanisms associated with metabolically unhealthy obesity based on the gene expression profile

Background

Obesity is an epidemic and systemic metabolic disease that seriously endangers human health. This study aimed to understand the transcriptomic characteristics of the blood of metabolically unhealthy obesity (MUO) and provide insight into the target genes of differently expressed microRNAs in the occurrence and development of MUO.

Methods

The GSE146869, GSE145412, GSE23561, and GSE169290 datasets were analyzed to understand the transcriptome characteristics of the blood of MUO and provide insights into the target genes of differently expressed microRNAs (DEMs) in MUO. Functional and pathway enrichment analyses and gene interaction network analyses were performed to profile the function of differentially expressed genes (DEGs). In addition, miRNet 2.0, TransmiR v2.0, RNA22, TargetScan 7.2, miRDB, and miRWalk databases were used to predict the target genes of effective microRNAs.

Results

A total of 189 co-DEGs were identified in at least two datasets. The 156 co-upregulated genes were enriched into 29 biological process (BP) terms and 12 KEGG pathways. Among the 29 BP terms, the immune- and metabolism-related BP terms were enriched. The 33 co-downregulated genes were enriched into two BP terms, including apoptotic process and regulation of the apoptotic process, with no KEGG pathway. The hub genes EGF, STAT3, IL1B, PF4, SELP, and ITGA2B in the gene interaction network might play important roles in abnormal BP in MUO. Among the 19 DEMs identified in the blood of the MUO group by the GSE169290 dataset, 18 microRNAs targeted 85 genes as risk factors in MUO.

Conclusion

A network consisting of 18 microRNAs and 85 target genes might serve as a risk factor for metabolically unhealthy obesity.

Differential Expression of Proteins and Genes at the Tumor-Brain Interface in Invasive Meningioma

Most meningiomas are dural-based extra-axial tumors in close contact with the brain. Expression of genes and proteins at the tumor-brain interface in brain-invasive meningioma is basically unknown. Using the NanoString pan-cancer panel, differential expression of genes in the invasive edge versus main tumor body was determined in 12 invasive meningiomas (comprising the discovery cohort), and 6 candidate genes: DTX1, RASGRF1, GRIN1, TNR, IL6, and NR4A1, were identified. By immunohistochemistry, DTX1 and RASGRF1 expression correlated with gene expression, and were studied in an expanded cohort of 21 invasive and 15 noninvasive meningiomas, together with Ki-67. Significantly higher expression of DTX1, RASGFR1, and Ki-67 was found in the invasive edge compared with the main tumor body. Increased expression of RASGRF1 and Ki-67 was more clearly associated with brain invasion. The situation with DTX1 was less definitive since increased expression was observed in meningiomas both at the invasive edge and when in close contact with brain but without invasion. Pathway analyses identified significant links between DTX1 and RASGRF1 and key biological processes, including cell-cell adhesion, and signaling pathways including Notch, RAS, MAPK, and Rho. Higher expression of DTX1, RASGRF1, and Ki-67 in the brain-invasive area of meningiomas suggests that these proteins play a role in the process of brain invasion.

Upregulation of RasGRF1 ameliorates spatial cognitive dysfunction in mice after chronic cerebral hypoperfusion

Chronic cerebral hypoperfusion (CCH)-mediated cognitive impairment is a serious problem worldwide. However, given its complexity, the underlying mechanisms by which CCH induces cognitive dysfunction remain unclear, resulting in a lack of effective treatments. In this study, we aimed to determine whether changes in the expression of RasGRF1, an important protein associated with cognition and synaptic plasticity, underlie the associated impairments in cognition after CCH. We found that RasGRF1 levels markedly decreased following CCH. Through prediction and validation studies, we observed that miRNA-323-3p was upregulated after CCH and could bind to the 3'-untranslated region of Rasgrf1 mRNA and regulate its expression in vitro. Moreover, the inhibition of miRNA-323-3p upregulated Rasgrf1 expression in the hippocampus after CCH, which was reversed by Rasgrf1 siRNA. This suggests that miRNA-323-3p is an important regulator of Rasgrf1. The Morris water maze and Y maze tests showed that miRNA-323-3p inhibition and Rasgrf1 upregulation improved spatial learning and memory, and electrophysiological measurements revealed deficits in long-term potentiation after CCH that were reversed by Rasgrf1 upregulation. Dendritic spine density and mature mushroom spine density were also improved after miRNA-323-3p inhibition and Rasgrf1 upregulation. Furthermore, Rasgrf1 upregulation by miRNA-323-3p inhibition improved dendritic spine density and mature mushroom spine density and ameliorated the deterioration of synapses and postsynaptic density. Overall, RasGRF1 regulation attenuated cognitive impairment, helped maintain structural and functional synaptic plasticity, and prevented synapse deterioration after CCH. These results suggest that Rasgrf1 downregulation by miRNA-323-3p plays an important role in cognitive impairment after CCH. Thus, RasGRF1 and miRNA-323-3p may represent potential therapeutic targets for cognitive impairment after CCH.

Comprehensive analysis of the LncRNAs, MiRNAs, and MRNAs acting within the competing endogenous RNA network of LGG

Messenger RNA (mRNA) and long noncoding RNA (lncRNA) targets interact via competitive microRNA (miRNA) binding. However, the roles of cancer-specific lncRNAs in the competing endogenous RNA (ceRNA) networks of low-grade glioma (LGG) remain unclear. This study obtained RNA sequencing data for normal solid tissue and LGG primary tumour tissue from The Cancer Genome Atlas database. We used a computational method to analyse the relationships among the mRNAs, lncRNAs, and miRNAs in these samples. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was used to predict the biological processes (BPs) and pathways associated with these genes. Kaplan-Meier survival analysis was used to evaluate the association between the expression levels of specific mRNAs, lncRNAs, and miRNAs and overall survival. Finally, we created a ceRNA network describing the relationships among these mRNAs, lncRNAs, and miRNAs using Cytoscape 3.5.1. A total of 2555 differentially expressed (DE) mRNAs, 218 DElncRNAs, and 192 DEmiRNAs were identified using R. In addition, GO and KEGG pathway analysis of the mRNAs and lncRNAs in the ceRNA network identified 10 BPs, 10 cell components, 10 molecular functions, and 48 KEGG pathways as selectively enriched. A total of 55 lncRNAs, 50 miRNAs, and 10 mRNAs from this network were shown to be closely associated with overall survival in LGG. Finally, 59 miRNAs, 235 mRNAs, and 17 lncRNAs were used to develop a ceRNA network comprising 313 nodes and 1046 edges. This study helps expand our understanding of ceRNA networks and serves to clarify the underlying pathogenesis mechanism of LGG.

Molecular subtypes based on CNVs related gene signatures identify candidate prognostic biomarkers in lung adenocarcinoma

The classical factors for predicting prognosis currently cannot meet the developing requirements of individualized and accurate prognostic evaluation in lung adenocarcinoma (LUAD). With the rapid development of high-throughput DNA sequencing technologies, genomic changes have been discovered. These sequencing data provide unprecedented opportunities for identifying cancer molecular subtypes. In this article, we classified LUAD into two distinct molecular subtypes (Cluster 1 and Cluster 2) based on Copy Number Variations (CNVs) and mRNA expression data from the Cancer Genome Atlas (TCGA) based on non-negative matrix factorization. Patients in Cluster 1 had worse outcomes than that in Cluster 2. Molecular features in subtypes were assessed to explain this phenomenon by analyzing differential expression genes expression pattern, which involved in cellular processes and environmental information processing. Analysis of immune cell populations suggested different distributions of CD4+ T cells, CD8+ T cells, and dendritic cells in the two subtypes. Subsequently, two novel genes, TROAP and RASGRF1, were discovered to be prognostic biomarkers in TCGA, which were confirmed in GSE31210 and Tianjin Medical University Cancer Institute and Hospital LUAD cohorts. We further proved their crucial roles in cancers by vitro experiments. TROAP mediates tumor cell proliferation, cycle, invasion, and migration, not apoptosis. RASGRF1 has a significant effect on tumor microenvironment. In conclusion, our study provides a novel insight into molecular classification based on CNVs related genes in LUAD, which may contribute to identify new molecular subtypes and target genes.

Long non-coding RNA SUMO1P3 promotes tumour progression by regulating cell proliferation and invasion in glioma

Gliomas account for 50% of primary brain tumours in the central nervous system. Small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3), a newly identified long non-coding RNA (lncRNA), serves an oncogenic role in various types of cancer. The aim of the present study was to investigate the effect of SUMO1P3 on glioma progression. The results demonstrated that SUMO1P3 expression was upregulated in glioma tissues and cell lines. Furthermore, SUMO1P3 was associated with a poor overall survival of patients with glioma. The results of the in vitro cell proliferation and flow cytometry assays demonstrated that SUMO1P3-knockdown suppressed cell proliferation and cell cycle. The results of the wound healing and Transwell assays demonstrated that SUMO1P3-knockdown significantly repressed cell migration and invasion. In addition, SUMO1P3 promoted glioma by regulating the expression levels of β-catenin, cyclin-D1, N-cadherin and E-cadherin. Overall, the results of the present study suggested that SUMO1P3 may act as an oncogene by regulating cell proliferation, cell cycle, cell migration and invasion in glioma, and may represent a novel diagnostic biomarker and therapeutic target for glioma.

Effect of Ras-guanine nucleotide release factor 1-mediated H-Ras/ERK signaling pathway on glioma

OBJECTIVE

To investigate the function of Ras-guanine nucleotide release factor 1 (Ras-GRF1) in glioma through mediating H-Ras/ERK signaling pathway.

METHODS

Ras-GRF1, H-Ras, K-Ras and N-Ras expressions in glioma and normal brain tissues were detected via Immunohistochemistry. Glioma cells (U87 cells, U251 cells and primary human glioma cells) were transfected with Ras-GRF1 siRNA, H-Ras siRNA and/or Ras-GRF1 lentivirus activation particles. Then, the following aspects were evaluated: cell proliferation by MTT assay, clonogenic ability by the plate clone formation experiment, cell migration and invasion by Wound-healing and Transwell assays, and cell apoptosis by Annexin-V-FITC/PI staining. The protein expressions were measured by Western blotting. Subcutaneous and orthotopic mouse models of glioma were conducted to determine the role of Ras-GRF1 in glioma tumorigenesis.

RESULTS

Ras-GRF1, H-Ras, K-Ras and N-Ras expressions were upregulated in the glioma tissues, which were correlated with the WHO grade of glioma. Besides, Ras-GRF1 expression was positively related to H-Ras expression. Ras-GRF1 siRNA could reduce the expression of H-Ras and p-ERK/ERK in glioma cell. H-Ras siRNA inhibited the proliferation, clone formation, migration and invasion, and enhance the apoptosis of glioma cells, which, however, were reversed by Ras-GRF1 lentivirus activation particles. In vivo experiments also revealed that Ras-GRF1 shRNA reduced the volume and weight of the tumors in the nude mice, with down-regulations of H-Ras and p-ERK/ERK.

CONCLUSION

Ras-GRF1 was upregulated in glioma tissues and correlated with its malignancy and prognosis. Silencing Ras-GRF1, through mediating H-Ras/ERK pathway, may suppress the growth and metastasis of glioma.

MiR-145-5p suppresses the proliferation, migration and invasion of gastric cancer epithelial cells via the ANGPT2/NOD_LIKE_RECEPTOR axis

Objective

This study aimed to investigate the relationship among miR-145-5p, ANGPT2 and the NOD_LIKE_RECEPTOR pathway, thereby revealing the molecular mechanism of these three factors underlying the proliferation, migration and invasion of gastric cancer (GC) epithelial cells.

Methods

qRT-PCR was carried out to detect the expression of miR-145-5p and ANGPT2 mRNA. Western blot was performed to test the protein levels of ANGPT2 as well as NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway. The targeting relationship between miR-145-5p and ANGPT2 was verified via a dual-luciferase reporter gene assay. The proliferation, migration and invasion of GC cells were detected through MTT and Transwell assays, respectively.

Results

The expression of miR-145-5p was significantly down-regulated in GC cells, while that of ANGPT2 was notably up-regulated. MiR-145-5p directly bound with the 3′-UTR of ANGPT2 mRNA, thereby targeting ANGPT2 after transcription. Overexpression of miR-145-5p inhibited the proliferation, migration and invasion of GC cells by suppressing ANGPT2. Moreover, low expression of ANGPT2 affected the protein levels of NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway, thus weakening the abilities of cell proliferation, migration and invasion.

Conclusions

MiR-145-5p plays an important role in GC epithelial cells, and it can affect cell proliferation, migration and invasion of GC cells by targeting ANGPT2 and regulating the NOD_LIKE_RECEPTOR pathway. Overall, our study further elucidates the molecular mechanism underlying the malignant progression of GC.

miR-137: A Novel Therapeutic Target for Human Glioma

MicroRNA (miR)-137 is highly expressed in the brain and plays a crucial role in the development and prognosis of glioma. In this review, we aim to summarize the latest findings regarding miR-137 in glioma cell apoptosis, proliferation, migration, invasion, angiogenesis, drug resistance, and cancer treatment. In addition, we focus on the identified miR-137 targets and pathways in the occurrence and development of glioma. Finally, future implications for the diagnostic and therapeutic potential of miR-137 in glioma were discussed.

MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis

The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.

MiR-29c-3p Suppresses the Migration, Invasion and Cell Cycle in Esophageal Carcinoma via CCNA2/p53 Axis

Objective

In the present study, we tried to describe the role of miR-29c-3p in esophageal carcinoma (EC) and the relationship of miR-29c-3p with CCNA2 as well as cell cycle, accordingly revealing the potential molecular mechanism across cell proliferation, migration and invasion.

Methods

Expression profiles of EC miRNAs and matched clinical data were accessed from TCGA database for differential and survival analyses. Bioinformatics databases were employed to predict the downstream targets of the potential miRNA, and enrichment analysis was performed on the miRNA and corresponding target gene using GSEA software. qRT-PCR was conducted to detect the expression levels of miR-29c-3p and CCNA2 mRNA in EC tissues and cells, and Western blot was performed for the examination of CCNA2, CDK1 and p53 protein levels. Subsequently, cells were harvested for MTT, Transwell as well as flow cytometry assays to examine cell viability, migration, invasion and cell cycle. Dual-luciferase reporter gene assay and RIP were carried out to further investigate and verify the targeted relationship between miR-29c-3p and CCNA2.

Results

MiR-29c-3p was shown to be significantly down-regulated in EC tissues and able to predict poor prognosis. CCNA2 was found to be a downstream target of miR-29c-3p and mainly enriched in cell cycle and p53 signaling pathway, whereas miR-29c-3p was remarkably activated in cell cycle. MiR-29c-3p overexpression inhibited cell proliferation, migration and invasion, as well as arrested cells in G0/G1 phase. As suggested by dual-luciferase reporter gene assay and RIP, CCNA2 was under the regulation of miR-29c-3p, and the negative correlation between the two genes was verified. Silencing CCNA2 could suppress cell proliferation, migration and invasion, as well as activate p53 pathway, even was seen to reverse the inhibitory effect of PFTβ on p53. Besides, in the presence of low miR-29c-3p, CCNA2 was up-regulated while p53 was simultaneously inhibited, resulting in the promotion of cell migration, invasion and cell cycle arrest.

Conclusion

MiR-29c-3p plays a regulatory role in EC tumorigenesis and development. MiR-29c-3p can target CCNA2 to mediate p53 signaling pathway, finally attributing to the inhibition of cell proliferation, migration and invasion, and making cells arrest in G0/G1 phase.

The functions of microRNA-124 on bladder cancer

Background: To detect the expression of miR-124 in bladder cancer (BC) cell lines and tissue specimens and to analyze its association with the growth of the BC cells.

Methods: Quantitative real-time polymerase chain reaction (qPCR) was applied to examine the expression of miR-124 in BC cell lines and tissues. The function of miR-124 in modulating cell proliferation was assessed in BC cells with miRNA-124 overexpression; the cell viability was identified by Cell Count Kit-8; flow cytometry was employed to detect the cell cycle; the expressions of E2F3, cyclin-dependent kinase 4 (CDK4), Ki-67 and vascular endothelial growth factor (VEGF) were tested by qPCR and Western blot; angiogenesis experiment was performed to analysis changes in angiogenesis rate; and bioinformatics prediction and dual luciferase reporter system were employed to identify the target of miR-124.

Results: Survival curve data showed that the expression of MicroRNA-124 was positively correlated with survival. MicroRNA-124 expression was significantly decreased in BC cell lines and tissues. Bioinformatics prediction and dual luciferase reporter system verified CDK4 as a direct target of miR-124, which regulated the proliferation of BC cells by directly inhibiting CDK4. BC cells over-expressing miR-124 showed significantly inhibited cell viability, decreased angiogenesis rate, prevented cell proliferation and diminished the expression of E2F3, CDK4, Ki-67 and VEGF. All of these changes were reversed by over-expressing CDK4.

Conclusion: MicroRNA-124 suppressed the proliferation of CRC cells by directly targeting CDK4, which provides a target for improving the therapeutic effect of BC.

Luteolin suppresses tumor proliferation through inducing apoptosis and autophagy via MAPK activation in glioma

PURPOSE

Glioma is a malignant tumor that originates in the brain and spine and is difficult to be completely removed. Though glioma patients receive active treatment, the survival rate is still poor. Therefore, it is urgent to discover a new medicine to treat glioma patients in order to improve the survival rate. In this study, we explored the anticancer effect and the potential mechanism of luteolin on glioma in vitro.

MATERIALS AND METHODS

Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Fluorescent microscopy and flow cytometry analysis were used to determine the cellular apoptosis. Western blot analysis was performed to explore the changes in protein expression. Quantitative reverse transcription-PCR (qRT-PCR) analysis was utilized to evaluate the expression level of the tumor suppressor miR-124-3p.

RESULTS

CCK-8 assays indicated that luteolin significantly inhibited glioma cell proliferation in a time- and dose-dependent manner. Fluorescent microscopy and flow cytometry analysis confirmed that luteolin induced glioma cell apoptosis. Western blot analysis showed that luteolin induced cellular apoptosis in glioma cells via MAPK activation (JNK, ERK, and p38). Luteolin stimulated the death receptor (FADD) to regulate the apoptosis proteins (Caspase-8, Caspase-3, and PARP). Luteolin increased the expression levels of LC3B II/I and downregulated the level of p62 that promotes cell autophagy. Finally, qRT-PCR confirmed that luteolin upregulated the expression levels of miR-124-3p.

CONCLUSION

These findings illustrate that luteolin may be a potential drug for glioma treatment.

The long non-coding RNA SNHG14 inhibits cell proliferation and invasion and promotes apoptosis by sponging miR-92a-3p in glioma

Malignant glioma is one of the most common types of primary brain tumours. Long non-coding RNAs (lncRNAs) have recently emerged as a new class of therapeutic targets for many cancers. In this study, we aimed to explore the functional involvement of small nucleolar RNA host gene 14 (SNHG14) and its potential regulatory mechanism in glioma progression. SNHG14 was found to be downregulated in human glioma tissues and cell lines. SNHG14 significantly inhibited cell viability, reduced cell invasion, and induced apoptosis in glioma cell lines. Furthermore, a correlation analysis demonstrated that there was a negative correlation between SNHG14 expression and miR-92a-3p expression. Bioinformatics prediction and luciferase reporter assays demonstrated that miR-92a-3p could directly bind to SNHG14. miR-92a-3p was significantly upregulated in glioma and acted as an oncogene in glioma cells by inhibiting Bim. Moreover, mechanistic investigations showed that miR-92a-3p could reverse the tumour suppressive effects induced by SNHG14 in glioma, indicating that SNHG14 may act as an endogenous sponge that competes for binding to miR-92a-3p. Our results suggest that SNHG14 and miR-92a-3p may be promising molecular targets for glioma therapy.

MicroRNA-137 regulates hypoxia-induced retinal ganglion cell apoptosis through Notch1

The apoptosis of retinal ganglion cells (RGCs) is a hallmark of several optic neuropathies. MicroRNAs (miRNAs) are recently identified regulators of various biological processes. However, the role of miRNAs in regulating RGC apoptosis remains largely unknown. We herein aimed to demonstrate that miR-137 acts as a hypoxia-responsive gene in RGCs that is downregulated under hypoxic conditions. It was observed that overexpression of miR-137 markedly aggravated hypoxia-induced cell apoptosis, whereas inhibition of miR-137 effectively protected RGCs against hypoxia-induced apoptosis. Hypoxia induced Notch1 expression and signaling activation, while blocking Notch signaling significantly aggravated hypoxia-induced cell apoptosis. Further data revealed that the pro-survival Akt signaling pathway was involved in miR-137-Notch signaling pathway-mediated RGC protection. Knockdown of Notch significantly reversed the effect of anti‑miR-137 on RGC protection and Akt signaling activation. In addition, blocking Akt signaling also significantly abrogated the protective effect of anti-miR-137 on hypoxia-induced cell injury. Overall, the results of the present study demonstrated that miR-137 targets Notch1 expression, revealing a novel link between miR-137 and Notch signaling, and suggesting that a miR-137/Notch1 axis may serve as a potential molecular target for the treatment of hypoxia-induced retinal diseases.

Upregulation of the long non-coding RNA SNHG1 predicts poor prognosis, promotes cell proliferation and invasion, and reduces apoptosis in glioma

Long non-coding RNAs (lncRNAs), which are non-coding RNAs with a length above 200 nucleotides, have emerged as novel and important gene expression modulators in carcinogenesis. Recent evidence indicates that the lncRNA small nucleolar RNA host gene 1 (SNHG1) functions as an oncogene in several types of human cancers. However, its function in the development of glioma remains unknown. The aim of this research was to investigate the clinical aspects and biological mechanisms of SNHG1 in glioma. SNHG1 expression was measured in glioma tissues and cell lines by quantitative real-time PCR (qRT-PCR). The association between SNHG1 expression in tissues and clinicopathological characteristics and prognosis in glioma patients was also explored. Gain-of-function and loss-of-function studies using SNHG1 cDNA and siRNA, respectively, were used to investigate the role of SNHG1 in cell proliferation, invasion and apoptosis in glioma. SNHG1 was highly expressed in glioma tissues, and its upregulation was closely related to old age. Kaplan-Meier analysis showed that high expression of SNHG1 was significantly associated with poor overall survival (OS). Functionally, ectopic expression of SNHG1 enhanced cell proliferation and cell invasion and reduced cell apoptosis in vitro, while SNHG1 knockdown reversed these effects. Taken together, our findings indicate that SNHG1 functions as an oncogene in glioma and may serve as a novel therapeutic target in future treatments.

MicroRNA-137 represses FBI-1 to inhibit proliferation and in vitro invasion and migration of hepatocellular carcinoma cells

The pro-oncogene factor that binds to inducer of short transcripts-1 (FBI-1), which is encoded by ZBTB7A gene and belongs to POK (POZ/BTB and KrÜppel) protein family, has been shown to enhance hepatocellular carcinoma (HCC) cells proliferation and multi-drug resistance (MDR) process. However, the possibility that FBI-1 is a therapeutic target for further HCC treatment remains poorly determined. In the current study, two microRNA (miRNA) target prediction programs (TargetScan and MiRanda) were used to identify miR-137 as a potential regulator of FBI-1. Our results showed that expression of miR-137 was downregulated, while FBI-1 was upregulated in clinical HCC specimens, compared with paired non-tumor specimens. Overexpression of miR-137 via adenoviral vector inhibited the proliferation and anchorage-independent growth of HCC cells, HepG2 and MHCC-97H. Our data also showed that miR-137 repressed endogenous expression level of FBI-1, as well as Notch-1 and Survivin. MiR-137 also inhibited in vitro invasion and migration of HCC cells and attenuated their epithelial-mesenchymal transition (EMT) process. Moreover, miR-137 suppressed the growth rate of HepG2 cells in nude mice model. Overexpression of miR-137 via its adenoviral vector enhanced the sensitivity of HepG2 cells to anti-tumor drugs and attenuated the MDR process of a resistance cell line HepG2/adriamycin (ADR). Thus, FBI-1 downregulation mediated by miR-137 overexpression may be a potential strategy for HCC treatment.

MicroRNA-137 suppresses tongue squamous carcinoma cell proliferation, migration and invasion

OBJECTIVES

Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral malignancy. Increasing evidence has shown that miRNAs play key roles in many biological processes such as cell development, invasion, proliferation, differentiation, metabolism, apoptosis and migration.

MATERIALS AND METHODS

qRT-PCR analysis was performed to measure miR-137 expression. CCK-8 analysis, cell colony formation, wound-healing analysis and invasion were performed to detect resultant cell functions. The direct target of miR-137 was labelled and measured by luciferase assay and Western blotting.

RESULTS

We demonstrated that expression of miR-137 was downregulated in TSCC tissues compared to matched normal ones. miR-137 expression was downregulated in TSCC lines (SCC4, SCC1, UM1 and Cal27) compared to the immortalized NOK16B cell line and normal oral keratinocytes in culture (NHOK). In addition, we have shown that miR-137 expression was epigenetically regulated in TSCCs. Overexpression of miR-137 suppressed TSCC proliferation and colony formation. Ectopic expression of miR-137 promoted expression of the epithelial biomarker, E-cadherin, and inhibited the mesenchymal biomarker, N-cadherin, as well as vimentin and Snail expression, indicating that miR-137 suppressed TSCC epithelial-mesenchymal transition (EMT). We also showed that ectopic expression of miR-137 inhibited TSCC invasion and migration. In addition, we identified SP1 as a direct target gene of miR-137 in SCC1 cells. SP1 overexpression rescued inhibitory effects exerted by miR-137 on cell proliferation and EMT.

CONCLUSIONS

These results indicate that miR-137 acted as a tumour suppressor in TSCC by targeting SP1.

MicroRNA-19b-3p Modulates Japanese Encephalitis Virus-Mediated Inflammation via Targeting RNF11

Japanese encephalitis virus (JEV) can invade the central nervous system and consequently induce neuroinflammation, which is characterized by profound neuronal cell damage accompanied by astrogliosis and microgliosis. Albeit microRNAs (miRNAs) have emerged as major regulatory noncoding RNAs with profound effects on inflammatory response, it is unknown how astrocytic miRNAs regulate JEV-induced inflammation. Here, we found the involvement of miR-19b-3p in regulating the JEV-induced inflammatory responsein vitroandin vivo The data demonstrated that miR-19b-3p is upregulated in cultured cells and mouse brain tissues during JEV infection. Overexpression of miR-19b-3p led to increased production of inflammatory cytokines, including tumor necrosis factor alpha, interleukin-6, interleukin-1β, and chemokine (C-C motif) ligand 5, after JEV infection, whereas knockdown of miR-19b-3p had completely opposite effects. Mechanistically, miR-19b-3p modulated the JEV-induced inflammatory response via targeting ring finger protein 11, a negative regulator of nuclear factor kappa B signaling. We also found that inhibition of ring finger protein 11 by miR-19b-3p resulted in accumulation of nuclear factor kappa B in the nucleus, which in turn led to higher production of inflammatory cytokines.In vivosilencing of miR-19b-3p by a specific antagomir reinvigorates the expression level of RNF11, which in turn reduces the production of inflammatory cytokines, abrogates gliosis and neuronal cell death, and eventually improves the survival rate in the mouse model. Collectively, our results demonstrate that miR-19b-3p positively regulates the JEV-induced inflammatory response. Thus, miR-19b-3p targeting may constitute a thought-provoking approach to rein in JEV-induced inflammation.

IMPORTANCE

Japanese encephalitis virus (JEV) is one of the major causes of acute encephalitis in humans worldwide. The pathological features of JEV-induced encephalitis are inflammatory reactions and neurological diseases resulting from glia activation. MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression posttranscriptionally. Accumulating data indicate that miRNAs regulate a variety of cellular processes, including the host inflammatory response under pathological conditions. Recently, a few studies demonstrated the role of miRNAs in a JEV-induced inflammatory response in microglia; however, their role in an astrocyte-derived inflammatory response is largely unknown. The present study reveals that miR-19b-3p targets ring finger protein 11 in glia and promotes inflammatory cytokine production by enhancing nuclear factor kappa B activity in these cells. Moreover, administration of an miR-19b-3p-specific antagomir in JEV-infected mice reduces neuroinflammation and lethality. These findings suggest a new insight into the molecular mechanism of the JEV-induced inflammatory response and provide a possible therapeutic entry point for treating viral encephalitis.