Role of MicroRNA-214 in Dishevelled1-Modulated β-catenin Signalling in Non-Small Cell Lung Cancer Progression

Background: The mortality of patients with non-small cell lung cancer (NSCLC) is rather high. This is largely because of the lack of specific targets and understanding of the molecular mechanism for early diagnosis. Dishevelled (Dvl) dysregulation leads to malignant progression. We confirmed that Dvl1 expression is associated with a poor prognosis of patients with NSCLC. However, how Dvl1 transmits signals through the Wnt/β-catenin pathway remains unknown. Methods: In this study, the expression levels of Dvl1 and β-catenin in resected NSCLC samples were immunohistochemically analysed. Dvl1 cDNA and small interfering RNA against β-catenin were transfected into NSCLC cells, and their effects on canonical Wnt signalling and biological behaviour of NSCLC cells were analysed. Using bioinformatics analyses, an interaction between microRNA (miR)-214 and β-catenin was identified; miR-214 expression was determined in NSCLC tissues using quantitative real-time polymerase chain reaction. An exogenous miR-214 (mimic) was used to analyse the biological behaviour of NSCLC cells and the effect of Dvl1 on canonical Wnt activation. Results: Dvl1 overexpression in NSCLC tissues as well as Dvl1 and β-catenin nuclear coexpression were significantly associated with poor prognosis of NSCLC (P < 0.05). Additionally, Dvl1 promoted Wnt/β-catenin signalling to enhance the malignant phenotype of NSCLC cells. Moreover, miR-214 directly targeted the 3' untranslated region of β-catenin to inhibit the activation of canonical Wnt signalling induced by Dvl1. Conclusions: Our results suggest that Dvl1 is a potential therapeutic target for NSCLC and that miR-214 plays an inhibitory role in Dvl1-mediated activation of Wnt/β-catenin signalling in NSCLC cells, which could affect NSCLC progression.

Circular RNA ITCH attenuates the progression of nasopharyngeal carcinoma by inducing PTEN upregulation via miR-214

BACKGROUND

Circular RNA itchy E3 ubiquitin protein ligase (circ-ITCH) has previously been reported to play a key role in carcinogenesis. Nevertheless, the role of circ-ITCH in nasopharyngeal carcinoma (NPC) remains to be explored.

METHODS

Gene expression analysis was performed using a quantitative real-time polymerase chain reaction, western blotting and immunohistochemistry. The role of circ-ITCH in NPC was explored using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, colony formation, transwell invasion, scratch healing and xenograft tumor assays. Furthermore, luciferase reporter assay was carried out to assess the interactions among circ-ITCH, microRNA-214 (miR-214) and phosphatase and tensin homolog (PTEN).

RESULTS

The levels of circ-ITCH and PTEN were decreased, whereas the level of miR-214 was increased in NPC tissues collected from 28 subjects compared to normal nasopharynx tissues collected from 15 subjects. Moreover, a negative correlation between circ-ITCH and miR-214 expression and a positive correlation between circ-ITCH and PTEN expression were observed in NPC tissues. Downregulation of circ-ITCH expression was also observed in NPC cell lines. In addition, upregulation of circ-ITCH markedly inhibited NPC cell proliferation, migration and invasion. Furthermore, circ-ITCH was confirmed to exert its function by sponging miR-214. PTEN was found to be a direct target gene of miR-214 and its expression was negatively correlated with miR-214 expression in NPC tissues. Moreover, our results showed that the circ-ITCH/miR-214 axis regulated NPC proliferation, migration and invasion through regulating the expression of PTEN. Upregulation of circ-ITCH or PTEN blocked miR-214-mediated promotion of NPC tumorigenesis in vitro. Additionally, upregulation of circ-ITCH also suppressed NPC tumorigenesis in vivo.

CONCLUSIONS

The present study demonstrated that circ-ITCH suppressed NPC tumorigenesis by upregulating PTEN expression through interacting with miR-214, thus proposing a novel mechanism for NPC inhibition.

Protective effects of dexmedetomidine on cerebral ischemia/reperfusion injury via the microRNA-214/ROCK1/NF-κB axis

BACKGROUND

Cerebral ischemia/reperfusion injury (CIRI) is a complication of surgical procedure associated with high mortality. The protective effect of dexmedetomidine (DEX) on CIRI has been explored in previous works, yet the underlying molecular mechanism remains unclear. Our study explored the protective effect of DEX and its regulatory mechanism on CIRI.

METHODS

A CIRI rat model was established using middle cerebral artery occlusion (MCAO). Neurological deficit scores for rats received MCAO modeling or DEX treatment were measured. Cerebral infarction area of rats was detected by TTC staining, while damage of neurons in hippocampal regions of rats was determined by hematoxylin-eosin (HE) staining. Apoptosis rate of neurons in hippocampal regions was examined by TUNEL staining. The dual-luciferase assay was performed to detect the binding of microRNA-214 (miR-214) to Rho-associated kinase 1 (ROCK1).

RESULTS

DEX treatment significantly reduced infarction area of MCAO rats and elevated miR-214 expression. Injection of miR-214 inhibitor attenuated the effect of DEX in MCAO rats by increasing the area of cerebral infarction in rats and apoptosis rate of hippocampal neurons. ROCK1 was targeted and negatively regulated by miR-214. The overexpression of ROCK1 led to activation of NF-κB to aggravate CIRI.

CONCLUSION

Therapeutic effects of DEX on CIRI was elicited by overexpressing miR-214 and impairing ROCK1 expression and NF-κB activation. Our finding might provide novel insights into the molecular mechanism of DEX in rats with CIRI.

Rs884225 polymorphism is associated with primary hypertension by compromising interaction between epithelial growth factor receptor (EGFR) and miR-214

Genetic variations in the 3′UTR of mRNAs as well as sequences of microRNAs (miRNAs) and long non‐coding RNAs (lncRNAs) can affect gene expression by interfering with the binding between them. In this study, we investigated the role of the following polymorphisms in the risk of hypertension: the 774T > C (rs17337023) polymorphism located in the EGFR 3’ untranslated region (3’UTR), the rs884225 polymorphism located in the sequence of miR‐214, and the single nucleotide polymorphisms (SNPs) rs325797437, rs344501106, rs81286029 and rs318656749 located in the promoter of lncRNA MEG3. Taqman genotyping assays and haplotype analysis tools were used to measure the MEG3 haplotypes and the rs17337023 and rs884225 polymorphisms genotypes. The relationship between MEG3, miR‐214 and EGFR was validated using computational analysis and luciferase assays. Unlike other polymorphisms, only patients grouped according to their rs884225 genotypes exhibited varied EGFR mRNA and protein levels, which indicated that the rs884225 genotype is associated with the expression of EGFR mRNA and protein levels. MiR‐214 was confirmed to bind to MEG3 and 3’UTR of EGFR by showing that the transfection of exogenous miR‐214 significantly down‐regulated the luciferase activity of A549 and H460 cells transfected with wild‐type MEG3 or wild‐type EGFR 3’ UTR. Additionally, MEG3 overexpression inhibited miR‐214 expression while elevating the EGFR mRNA and protein expressions. Meanwhile, MEG3 down‐regulation demonstrated an opposite result, thus establishing the MEG3/miR‐214/EGRF signalling pathway. Our study confirmed that the T > C substitution of rs884225 polymorphism located in miR‐214 binding site in the 3’UTR of EGFR is associated with increased risk of primary hypertension.

MicroRNA-214 enriched exosomes from human cerebral endothelial cells (hCEC) sensitize hepatocellular carcinoma to anti-cancer drugs

Hepatocellular carcinoma (HCC) is the most common primary liver tumor worldwide. Current medical therapy for HCC has limited efficacy. The present study tests the hypothesis that human cerebral endothelial cell-derived exosomes carrying elevated miR-214 (hCEC-Exo-214) can amplify the efficacy of anti-cancer drugs on HCC cells. Treatment of HepG2 and Hep3B cells with hCEC-Exo-214 in combination with anti-cancer agents, oxaliplatin or sorafenib, significantly reduced cancer cell viability and invasion compared with monotherapy with either drug. Additionally, the therapeutic effect of the combination therapy was detected in primary tumor cells derived from patients with HCC. The ability of hCEC-Exo-214 in sensitizing HCC cells to anti-cancer drugs was specific, in that combination therapy did not affect the viability and invasion of human liver epithelial cells and non-cancer primary cells. Furthermore, compared to monotherapy with oxaliplatin and sorafenib, hCEC-Exo-214 in combination with either drug substantially reduced protein levels of P-glycoprotein (P-gp) and splicing factor 3B subunit 3 (SF3B3) in HCC cells. P-gp and SF3B3 are among miR-214 target genes and are known to mediate drug resistance and cancer cell proliferation, respectively. In conclusion, the present in vitro study provides evidence that hCEC-Exo-214 significantly enhances the anti-tumor efficacy of oxaliplatin and sorafenib on HCC cells.

Long non-coding RNA MEG3 silencing and microRNA-214 restoration elevate osteoprotegerin expression to ameliorate osteoporosis by limiting TXNIP

Studies have shown that long non-coding RNA (lncRNA) MEG3 plays a key role in osteoporosis (OP), but its regulatory mechanism is somewhat incompletely clear. Here, we intend to probe into the mechanism of MEG3 on OP development by modulating microRNA-214 (miR-214) and thioredoxin-interacting protein (TXNIP). Rat models of OP were established. MEG3, miR-214 and TXNIP mRNA expression in rat femoral tissues were detected, along with TXNIP, OPG and RANKL protein expression. BMD, BV/TV, Tb.N and Tb.Th in tissue samples were measured. Ca, P and ALP contents in rat serum were also determined. Primary osteoblasts were isolated and cultured. Viability, COL-I, COL-II and COL-Χ mRNA expression, PCNA, cyclin D1, OCN, RUNX2 and osteolix protein expresion, ALP content and activity, and mineralized nodule area of rat osteoblasts were further detected. Dual-luciferase reporter gene and RNA-pull down assays verified the targeting relationship between MEG3, miR-214 and TXNIP. MEG3 and TXNIP were up-regulated while miR-214 was down-regulated in femoral tissues of OP rats. MEG3 silencing and miR-214 overexpression increased BMD, BV/TV, Tb.N, Tb.Th, trabecular bone area, collagen area and OPG expression, and down-regulated RANKL of femoral tissues in OP rats. MEG3 silencing and miR-214 overexpression elevated Ca and P and reduced ALP in OP rat serum, elevated osteoblast viability, differentiation ability, COL-I and COL-Χ expression and ALP activity, and reduced COL-II expression of osteoblasts. MEG3 specifically bound to miR-214 to regulate TXNIP. MEG3 silencing and miR-214 overexpression promote proliferation and differentiation of osteoblasts in OP by down-regulating TXNIP, which further improves OP.

Exosomal Long Non-coding RNA HOTTIP Increases Resistance of Colorectal Cancer Cells to Mitomycin via Impairing MiR-214-Mediated Degradation of KPNA3

It has been reported that long non-coding RNA HOXA distal transcript antisense RNA (lncRNA HOTTIP) functions as a tumor promoter in colorectal cancer (CRC). Hence, we paid attention to exploring whether exosomes could carry lncRNA HOTTIP to affect the mitomycin resistance in CRC and to identify the underlying mechanisms. High expression of HOTTIP was detected in mitomycin-resistant CRC cells. Inhibition of HOTTIP reduced the mitomycin resistance. In the co-culture system of mitomycin-resistant cells or their derived exosomes with CRC cells, the HOTTIP was found to be transferred into the parental cells via extracellular vesicles (EVs) secreted from mitomycin-resistant cells and to contribute to the mitomycin resistance. Based on the bioinformatics databases, possible interaction network of HOTTIP, microRNA-214 (miR-214) and Karyopherin subunit alpha 3 (KPNA3) in CRC was predicted, which was further analyzed by dual-luciferase reporter, RNA binding protein immunoprecipitation and RNA pull-down assays. As HOTTIP down-regulated miR-214 to elevate the KPNA3 expression, HOTTIP enhanced the mitomycin resistance through impairing miR-214-dependent inhibition of KPNA3. Finally, HOTTIP was suggested as an independent factor predicting mitomycin response in patients with CRC. Those data together confirmed the promotive effects of EV-carried HOTTIP on the mitomycin resistance, while targeting HOTTIP might be a promising strategy overcoming drug resistance in CRC.

Disruption of microRNA-214 during general anaesthesia prevents brain injury and maintains mitochondrial fusion by promoting Mfn2 interaction with Pkm2

Duration of surgical general anaesthesia is associated with severe brain injury and neurological deficits. The specific mechanisms underlying post-general anaesthesia brain injury, however, still remain to be elucidated. Herein, we explore the role of microRNA-214 (miR-214) in the occurrence of brain injury after general anaesthesia and its underlying mechanism. Hippocampal tissues and neurons were isolated from rats exposed to 2% sevoflurane. TUNEL stains reflect hippocampal neuron apoptosis. Cultured hippocampal neurons stained with JC-1 and MitoTracker dyes were imaged by fluorescence microscope to visualize changes of mitochondrial membrane potential and mitochondrial fusion. Mitochondrial function was evaluated. Mitofusin 2 (Mfn2) binding to miR-214 or pyruvate kinase M2 (Pkm2) was confirmed by co-immunoprecipitation, immunofluorescence, dual luciferase reporter gene and RNA immunoprecipitation assays. After exposure to 2% sevoflurane, up-regulated miR-214 expression and impaired interaction between Mfn2 and Pkm2 were found in rat hippocampal tissues. Rats exposed to 2% sevoflurane also experienced neuronal injury, mitochondrial defects and deficits in the brain-derived neurotrophic factor (Bdnf) signalling. miR-214 was shown to target Mfn2 by impairing its binding with Pkm2. Inhibiting miR-214 expression using its specific inhibitor improved mitochondrial membrane potential, enhanced mitochondrial fusion, maintained mitochondrial function, restored interaction between Mfn2 and Pkm2, and activated the Bdnf signalling in cultured hippocampal neurons. Adenovirus infection of miR-214 inhibitor reduced neuron apoptosis and maintained mitochondrial function in the hippocampus of rats exposed to 2% sevoflurane. Taken together, the study demonstrates inhibition of miR-214 is cerebral protective against brain injury following general anaesthesia.

miR-214 Attenuates Aortic Valve Calcification by Regulating Osteogenic Differentiation of Valvular Interstitial Cells

Calcific aortic valve disease (CAVD) is a common heart valve disease in aging populations, and aberrant osteogenic differentiation of valvular interstitial cells (VICs) plays a critical role in the pathogenesis of ectopic ossification of the aortic valve. miR-214 has been validated to be involved in the osteogenesis process. Here, we aim to investigate the role and mechanism of miR-214 in CAVD progression. miR-214 expression was significantly downregulated in CAVD aortic valve leaflets, accompanied by upregulation of osteogenic markers. Overexpression of miR-214 suppressed osteogenic differentiation of VICs, while silencing the expression of miR-214 promoted this function. miR-214 directly targeted ATF4 and Sp7 to modulate osteoblastic differentiation of VICs, which was proved by dual luciferase reporter assay and rescue experiment. miR-214 knockout rats exhibited higher mean transvalvular velocity and gradient. The expression of osteogenic markers in aortic valve leaflets of miR-214 knockout rats was upregulated compared to that of the wild-type group. Taken together, our study showed that miR-214 inhibited aortic valve calcification via regulating osteogenic differentiation of VICs by directly targeting ATF4 and Sp7, indicating that miR-214 may act as a profound candidate of targeting therapy for CAVD.

SRF Potentiates Colon Cancer Metastasis and Progression in a microRNA-214/PTK6-Dependent Manner

Objective

Serum response factor (SRF), a sequence-specific transcription factor, is closely related to metastasis of gastric cancer, a digestive tract cancer. Herein, we probed the effect of SRF on metastasis and progression of colon cancer (CC), another digestive tract disorder, and the detailed mechanism.

Methods

Microarray analysis was conducted on tumor and adjacent tissues to filter differentially expressed miRNA, followed by RT-qPCR validation in CC cell lines. The transcription factor and the target gene of microRNA-214 (miR-214) were predicted, and their binding relationships were tested by luciferase reporter assays and ChIP assays. Subsequently, SRF and protein tyrosine kinase 6 (PTK6) expression in CC patients and cells was evaluated by RT-qPCR, while JAK2 and STAT3 expression in cells by Western blot analysis. To further explore functions of miR-214, PTK6 and SRF on CC, CC cells were delivered with si-PTK6, miR-214 mimic and/or SRF overexpression.

Results

miR-214 expressed poorly in CC tissues and cell lines, which related to advanced TNM staging and survival. miR-214 mimic inhibited proliferation, migration, invasion, xenograft tumor growth and metastasis of CC cells. SRF, overexpressed in CC samples and cells, suppressed the transcription of miR-214. Meanwhile, SRF upregulation counteracted the inhibitory role of miR-214 mimic in CC cell growth. miR-214 negatively regulated PTK6 expression to impair the JAK2/STAT3 pathway activation, thereby halting CC cell proliferation, migration, invasion, xenograft tumor growth and metastasis.

Conclusion

Altogether, miR-214 may perform as a tumor suppressor in CC, and the SRF/miR-214/PTK6/JAK2/STAT3 axis could be applied as a biomarker and potential therapeutic target.

Serum TSGF and miR-214 levels in patients with hepatocellular carcinoma and their predictive value for the curative effect of transcatheter arterial chemoembolization

BACKGROUND

The purpose of this study is to evaluate the expression of tumor-specific growth factor (TSGF) and microRNA-214 (miR-214) in the serum of patients with primary hepatocellular carcinoma (PHC) and their predictive values for the curative effect of transcatheter arterial chemoembolization (TACE).

METHODS

A retrospective analysis of the clinical data of 87 PHC patients were treated with TACE. According to the curative effect 1 month after TACE, PHC patients were divided into disease control group (n=56) and disease progression group (n=31). The expression levels of TSGF and miR-214 were detected by qRT-PCR before or after treatment with TACE in disease control group and disease progression group. The predictive value of TSGF and miR-214 for the efficacy of TACE were evaluated by the receiver operating characteristic (ROC) curve. The Kaplan-Meier survival curve was drawn according to the critical value of ROC. The effect of pretreatment levels of TSGF and miR-214 was analyzed on the three-year survival rate of patients.

RESULTS

After TACE treatment, the mRNA expressive of serum TSGF were increased in progression group, while the levels of miR-214 were decreased compared with control group (P<0.05). Importantly, at one month after TACE treatment, the levels of TSGF were decreased in control group and progression group, while the expression of miR-214 was increased compared with in both groups before TACE treatment(P<0.05). The result of ROC analysis showed that for predicting the curative effect of TACE, the levels of TSGF and miR-214 expression were (181.32, 0.63) (0.849 and 0.807) and (0.759-0.938, 0.707-0.907) in the cutoff values, AUCs and 95% confidence intervals, respectively. The result of Kaplan-Meier analysis showed that the 3-year survival rate of the low TSGF group was up-regulated than that of the high TSGF group [65.12% (31/44) vs. 30.23% (13/43); χ2=5.014; P=0.025]. The 3-year survival rate of the miR-214 high expression group was up-regulated than that of the miR-214 low expression group [61.70% (29/47) vs. 30.00% (12/40); χ2=6.928; P=0.008].

CONCLUSIONS

Serum TSGF and miR-214 could be used as potential biomarkers for PHC diagnosis and prognosis.

MicroRNA-214 modulates the senescence of vascular smooth muscle cells in carotid artery stenosis

Background

MicroRNAs control gene expression by post-transcriptional inhibition. Dysregulation of the expressions of miR-199a/214 cluster has been linked to cardiovascular diseases. This study aimed at identifying potential microRNAs related to vascular senescence.

Methods

Seven candidate microRNAs (miR-19a, −20a, −26b, −106b, − 126, − 214, and − 374) related to cell proliferation were tested for their expressions under CoCl₂-induced hypoxia in vascular smooth muscle cells (VSMCs). After identification of miR-214 as the candidate microRNA, telomere integrity impairment and cell cycle arrest were examined in VSMCs by using miR-214 mimic, AntagomiR, and negative controls. To investigate the clinical significance of miR-214 in vascular diseases, its plasma level from patients with carotid artery stenosis (CAS) was assessed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).

Results

CoCl₂ treatment for 48 h suppressed cell proliferation and angiogenesis as well as enhanced cell senescence in VSMCs. Besides, miR-214 level was elevated in both intracellular and exosome samples of VSMCs after CoCl₂ treatment. Manipulating miR-214 in VSMCs demonstrated that miR-214 not only inhibited angiogenic and proliferative capacities but also promoted senescence through the suppression of quaking. Additionally, circulating miR-214 level was upregulated in CAS patients with high low-density lipoprotein cholesterol (LDL-C) value.

Conclusion

Our findings suggested that miR-214 plays a role in the modulation of VSMC angiogenesis, proliferation, and senescence with its plasma level being increased in CAS patients with elevated LDL-C value, implying that it may be a vascular senescence marker and a potential therapeutic target for vascular diseases.

Transcription factor YY1 inhibits the expression of THY1 to promote interstitial pulmonary fibrosis by activating the HSF1/miR-214 axis

Interstitial pulmonary fibrosis (IPF) is a progressive disease of diverse etiology manifesting with proliferation of lung fibroblasts and accumulation of extracellular matrix deposition in pulmonary interstitium. Recent studies show aberrant expression of mRNAs and microRNAs (miRNAs) in human embryonic pulmonary fibroblasts (HEPFs). In this study, we investigated effects of the YY1/HSF1/miR-214/THY1 axis on the functions of HEPFs and IPF. Loss- and gain-of-function tests were conducted to identify roles of YY1, HSF1, miR-214, and THY1 in IPF. As determined by RT-qPCR or western blot assay, silencing YY1 down-regulated HSF1 expression and attenuated the expression of pro-proliferative and fibrosis markers in HEPFs. Meanwhile, viability of HEPFs was impeded by YY1 knockdown. The binding relationship between miR-214 and THY1 was verified using dual-luciferase reporter assay. In HEPFs, down-regulation of HSF1 reduced miR-214 expression to repress proliferation and fibrogenic transformation of HEPFs, while inhibition of miR-214 expression could restrain the fibrogenic transformation property of HEPFs by up-regulating THY1. Subsequently, IPF model in mice was induced by bleomycin treatment. These animal experiments validated the protective effects of YY1 knockdown against IPF-induced lung pathological manifestations, which could be reversed by THY1 knockdown. Our study demonstrates the important involvement of YY1/HSF1/miR-214/THY1 axis in the development of IPF.

Long Noncoding RNA FENDRR Exhibits Antifibrotic Activity in Pulmonary Fibrosis

Abnormal activation of lung fibroblasts contributes to the initiation and progression of idiopathic pulmonary fibrosis (IPF). The objective of the present study was to investigate the role of fetal-lethal noncoding developmental regulatory RNA (FENDRR) in the activation of lung fibroblasts. Dysregulated long noncoding RNAs in IPF lungs were identified by next-generation sequencing analysis from the two online datasets. FENDRR expression in lung tissues from patients with IPF and mice with bleomycin-induced pulmonary fibrosis was determined by quantitative real-time PCR. IRP1 (iron-responsive element-binding protein 1), a protein partner of FENDRR, was identified by RNA pulldown-coupled mass spectrometric analysis and confirmed by RNA immunoprecipitation. The interaction region between FENDRR and IRP1 was determined by cross-linking immunoprecipitation. The in vivo role of FENDRR in pulmonary fibrosis was studied using adenovirus-mediated gene transfer in mice. The expression of FENDRR was downregulated in fibrotic human and mouse lungs as well as in primary lung fibroblasts isolated from bleomycin-treated mice. TGF-β1 (transforming growth factor-β1)-SMAD3 signaling inhibited FENDRR expression in lung fibroblasts. FENDRR was preferentially localized in the cytoplasm of adult lung fibroblasts and bound IRP1, suggesting its role in iron metabolism. FENDRR reduced pulmonary fibrosis by inhibiting fibroblast activation by reducing iron concentration and acting as a competing endogenous RNA of the profibrotic microRNA-214. Adenovirus-mediated FENDRR gene transfer in the mouse lung attenuated bleomycin-induced lung fibrosis and improved lung function. Our data suggest that FENDRR is an antifibrotic long noncoding RNA and a potential therapeutic target for pulmonary fibrosis.

Expression of microRNA-214 and galectin-3 in peripheral blood of patients with chronic heart failure and its clinical significance

Expression of microRNA (miR)-214 and galectin-3 (Gal-3) in peripheral blood of patients with chronic heart failure (CHF) and its clinical significance were investigated. A total of 50 cases of CHF patients, diagnosed and treated in Shanghai Xuhui Central Hospital from January 2017 to March 2018, were the study group and 30 healthy subjects who underwent physical examination during the same period were the control group. Concentration of serum Gal-3 was detected by ELISA and the expression of miR-214 in serum was detected by RT-qPCR. The expression of miR-214 and Gal-3 in the peripheral blood of CHF patients were analyzed. The diagnostic and predictive values of efficacy were analyzed by ROC curve analysis, and the correlation between miR-214 and Gal-3 was analyzed by Pearson's correlation analysis. The serum expression levels of miR-214 and Gal-3 in the observation group were significantly higher than those in the control group, with statistically significant difference (P<0.05). Pearson's correlation analysis revealed that the expression levels of miR-214 and Gal-3 were positively correlated in the peripheral blood of CHF patients (r=0.712, P<0.05). The area under curve (AUC) of miR-214 and Gal-3 for CHF diagnosis was 0.916 and 0.852, respectively (P<0.05). The AUC for predicting the efficacy of miR-214 and Gal-3 was 0.874 and 0.897, respectively (P<0.05). In conclusion, it is speculated that miR-214 and Gal-3 are involved in the occurrence and development of CHF, which is of guiding significance for the clinical diagnosis and monitoring of CHF.

microRNA-214 Prevents Traits of Cutaneous Squamous Cell Carcinoma via VEGFA and Bcl-2

BACKGROUND

Dysregulation of microRNA-214 (miR-214) has been indicated in different tumors. The function of miR-214 in cutaneous squamous cell carcinoma (CSCC) is yet to be deciphered. The current study aimed to investigate the specific mechanism underpinning CSCC development with the involvement of miR-214 and its putative targets.

METHODS

Microarray analysis of CSCC and adjacent tissues was carried out to filter the most significant downregulated miRNA. Survival analysis of patients was subsequently implemented, followed by miRNA expression determination in CSCC cells. Gain-of-function assays were performed to evaluate its function on cellular level. The targets of the determined miRNA were predicted and their expression in CSCC and adjacent tissues was evaluated. The targeting relationship was analyzed by dual-luciferase assays. Finally, rescue experiments were conducted.

RESULTS

miR-214 was reduced in CSCC tissues and cells, and the survival of patients harboring overexpression of miR-214 was higher. miR-214 restoration increased CSCC cell apoptosis, while decreased proliferative, invasive and migratory activities. miR-214 interacted with vascular endothelial growth factor A (VEGFA) and B-cell CLL/lymphoma 2 (Bcl-2). VEGFA and Bcl-2, overexpressed in CSCC tissues and cells, were negatively correlated with miR-214. Moreover, VEGFA and Bcl-2 overexpression reversed the anti-tumor phenotypes of miR-214 on CSCC cells. miR-214 disrupted the Wnt/β-catenin pathway through VEGFA and Bcl-2 in the CSCC cells.

CONCLUSION

Our data demonstrates that miR-214 exerts a suppressing role in CSCC. The discovery of novel targets such as miR-214 and VEGFA/Bcl-2 may facilitate the development of therapeutic options.

Oridonin relieves hypoxia-evoked apoptosis and autophagy via modulating microRNA-214 in H9c2 cells

Oridonin (Orid) has been diffusely applied to remedy dissimilar cancers. Howbeit, the influence of Orid in ischemic heart disease (IHD) remains imprecise. The current study uncovered the functions of Orid in hypoxia-caused apoptosis and autophagy in H9c2 cells. H9c2 cells received hypoxia and Orid manipulation, cell viability, apoptosis, apoptosis-interrelated factors and autophagy-correlative factors were appraised. After the extraordinary vectors transfections, the impacts of miR-214 inhibition on hypoxia-triggered apoptosis and autophagy were investigated. Further, dual luciferase reporter assay was enforced for ascertaining the pertinence between miR-214 and PTEN. PI3K/AKT/mTOR pathway was finally determined using western blot. We found that, Orid significantly alleviated hypoxia-induced apoptosis and autophagy through regulation their associated proteins in H9c2 cells. Up-regulation of miR-214 was found in hypoxia and Orid co-managed cells, meanwhile, repression of miR-214 obviously annulled the modulatory functions of Orid in hypoxia-evoked apoptosis and autophagy. Additionally, PTEN was forecasted to be a firsthand target of miR-214. Besides, we observed that Orid evoked PI3K/AKT/mTOR activation through elevation of miR-214 in hypoxia-managed H9c2 cells. In conclusion, the amusing results corroborated that Orid relieved hypoxia-caused apoptosis and autophagy via adjusting PI3K/AKT/mTOR pathway through enhancement of miR-214 in H9c2 cells.

Puerarin attenuates hypoxia-resulted damages in neural stem cells by up-regulating microRNA-214

Puerarin has been reported to be useful in protection against hypoxia-induced injury. In our current study, we attempted to explore the protective effects of puerarin against hypoxia-caused damages in neural stem cells (NSCs). Additionally, the relative molecular underpinning studies preliminarily proceeded. NSCs were pre-incubated with puerarin before the hypoxic stimulus. MicroRNA-214 (miR-214) inhibitor was transfected into NSCs. Subsequently, the viability of NSCs was assessed by CCK-8 assay. Flow cytometry was employed to detect apoptotic cells after staining. qRT-PCR was performed to quantify miR-214. Western blot was applied for analyzing the expression of apoptosis-relative proteins and regulators. We found that puerarin alleviated hypoxia-induced apoptosis and maintained cell viability. Hypoxia-evoked up-regulation of miR-214 was further enhanced by puerarin. By contrast, miR-214-deficient NSCs showed the reduction in cell viability and the facilitation in apoptosis progress after pre-treatment with puerarin and stimulation in a hypoxia circumstance. Additionally, puerarin restored the phosphorylation of relative regulators, which was originally blunted by hypoxia. However, puerarin did not evidently restore the phosphorylation for response to hypoxia in miR-214-silenced NSCs. In conclusion, puerarin might be applied as a novel agent to ameliorate hypoxia-evoked damages in NSCs. Molecularly, miR-214 might be implicated in the protective roles of puerarin.

Downregulation of microRNA-214 improves therapeutic potential of allogeneic bone marrow-derived mesenchymal stem cell by targeting PIM-1 in rats with acute liver failure

Acute liver failure (ALF) is a disease resulted from diverse etiology, which generally leads to a rapid degenerated hepatic function. However, transplantation bone marrow-derived mesenchymal stem cells (BMSCs) transplantation has been suggested to relieve ALF. Interestingly, microRNA-214 (miR-214) could potentially regulate differentiation and migration of BMSCs. The present study aims to inquire whether miR-214 affects therapeutic potential of BMSCs transplantation by targeting PIM-1 in ALF. 120 male Wistar rats were induced as ALF model rats and transplanted with BMSCs post-alteration of miR-214 or PIM-1 expression. Further experiments were performed to detect biochemical index (alanine aminotransferase [ALT], aspartate transaminase [AST], total bilirubin [TBiL]), and expression of miR-214, PIM-1, hepatocyte growth factor (HGF), caspase 3, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) in rat serum. Apart from the above detection, apoptosis of hepatocytes and Ki67 protein expression in hepatic tissues of rats were additionally assessed. After BMSCs transplantation with miR-214 inhibition, a decreased expression of ALT, AST, and TBiL yet an increased expression of HGF was shown, coupled with a decline in the expression of caspase 3, TNF-α, and IL-10. Meanwhile, alleviated hepatic injury and decreased apoptotic index of hepatic cells were observed and the positive rate of Ki67 protein expression was significantly increased. Moreover, miR-214 and caspase 3, TNF-α, and IL-10 decreased notably, while PIM-1 was upregulated in response to miR-214 inhibition. Strikingly, the inhibition of PIM-1 reversed effects triggered by miR-214 inhibition. These findings indicated that downregulation of miR-214 improves therapeutic potential of BMSCs transplantation by upregulating PIM-1 for ALF.

Role of miR-214 in regulation of β-catenin and the malignant phenotype of melanoma

Wnt/β-catenin signaling plays an important role in melanocyte biology, especially in the early stages of melanocyte transformation and melanomagenesis. β-catenin, encoded by the gene CTNNB1, is an intracellular signal transducer of Wnt signaling and activates transcription of genes important for cell proliferation and survival. Wnt/β-catenin signaling is frequently activated in melanoma through oncogenic mutations of β-catenin and elevated β-catenin levels are positively correlated with melanoma aggressiveness. Molecular mechanisms that regulate β-catenin expression in melanoma are not fully understood. MicroRNA-214 is known to function as a tumor suppressor by targeting β-catenin in several types of cancer cells. Here, we investigated the regulation of β-catenin by miR-214 and its role in melanoma. We show that β-catenin mRNA levels are negatively correlated with miR-214 in melanoma. However, overexpression of miR-214 paradoxically increased β-catenin protein levels and promoted malignant properties of melanoma cells including resistance to mitogen-activated protein kinase inhibitors (MAPKi). RNA-seq analysis revealed that melanoma cells predominantly express a β-catenin mRNA isoform lacking miR-214 target site. Using matched miRNA and mRNA-seq and bioinformatics analysis, we identified novel miR-214 targets, ankyrin repeat domain 6 (ANKRD6) and C-terminal binding protein 1 (CTBP1), that are involved in negative regulation of Wnt signaling. Overexpression of miR-214 or knockdown of the novel miR-214 targets, ANKRD6 or CTBP1, increased melanoma cell proliferation, migration, and decreased sensitivity to MAPKi. Our data suggest that in melanoma cells β-catenin is not regulated by miR-214 and the functions of miR-214 in melanoma are mediated partly by regulating proteins involved in attenuation of Wnt/β-catenin signaling.

Cardiomyocytes capture stem cell-derived, anti-apoptotic microRNA-214 via clathrin-mediated endocytosis in acute myocardial infarction

Extracellular vesicles (EVs) have emerged as key mediators of intercellular communication that have the potential to improve cardiac function when used in cell-based therapy. However, the means by which cardiomyocytes respond to EVs remains unclear. Here, we sought to clarify the role of exosomes in improving cardiac function by investigating the effect of cardiomyocyte endocytosis of exosomes from mesenchymal stem cells on acute myocardial infarction (MI). Exposing cardiomyocytes to the culture supernatant of adipose-derived regenerative cells (ADRCs) prevented cardiomyocyte cell damage under hypoxia in vitro. In vivo, the injection of ADRCs into the heart simultaneous with coronary artery ligation decreased overall cardiac infarct area and prevented cardiac rupture after acute MI. Quantitative RT-PCR-based analysis of the expression of 35 known anti-apoptotic and secreted microRNAs (miRNAs) in ADRCs revealed that ADRCs express several of these miRNAs, among which miR-214 was the most abundant. Of note, miR-214 silencing in ADRCs significantly impaired the anti-apoptotic effects of the ADRC treatment on cardiomyocytes in vitro and in vivo To examine cardiomyocyte endocytosis of exosomes, we cultured the cardiomyocytes with ADRC-derived exosomes labeled with the fluorescent dye PKH67 and found that hypoxic culture conditions increased the levels of the labeled exosomes in cardiomyocytes. Chlorpromazine, an inhibitor of clathrin-mediated endocytosis, significantly suppressed the ADRC-induced decrease of hypoxia-damaged cardiomyocytes and also decreased hypoxia-induced cardiomyocyte capture of both labeled EVs and extracellular miR-214 secreted from ADRCs. Our results indicate that clathrin-mediated endocytosis in cardiomyocytes plays a critical role in their uptake of circulating, exosome-associated miRNAs that inhibit apoptosis.

MicroRNA-214 contributes to regulation of necroptosis via targeting ATF4 in diabetes-associated periodontitis

Diabetes and periodontal diseases have a mutual promoting relationship that induces severe tissue damage and cell death. The potential roles of microRNAs (miRNAs) and the type of cell death involved in diabetes-associated periodontitis are obscure. The gingival tissues of patients were obtained and MC3T3-E1 cells were costimulated with high glucose and lipopolysaccharide (LPS). Osseous morphometric analysis was evaluated with micro-CT, and histological characteristics were measured by hematoxylin/eosin and immunohistochemical staining. Cytokine secretion was confirmed by enzyme-linked immunosorbent assay, and reactive oxygen species (ROS) was measured using a DCFH-DA probe kit. Gene expression was measured by real-time quantitative reverse transcription PCR (qRT-PCR), and protein expression was assessed by Western blot and immunofluorescence analysis. The miR-214 level, receptor-interacting serine-threonine protein (RIP) 1, RIP3, and phospho-mixed lineage kinase domain-like (p-MLKL) protein expression were elevated in the inflamed gingival tissues of diabetes-associated periodontitis patients, with activating transcription factor 4 (ATF4) expression showing the opposite effect. The high glucose (22 mM) could not induce significant increase of RIP1, RIP3, and p-MLKL; however, the high glucose and LPS (500-1000 ng/mL) cotreatment resulted in increase in the number of RIP1, RIP3, and p-MLKL in MC3T3-E1 cells. NAC (ROS inhibitor) inhibited RIP1, RIP3, and increased ATF4; however, necrostatin-1 (Nec-1) (RIP1 inhibitor) specifically inhibited the protein expression of RIP1 and RIP3 and had no influence on ATF4. The use of antagomir-214 suppressed the expression of miR-214, RIP1, RIP3, and p-MLKL, but increased ATF4 protein level in glucose and LPS-induced cells. ATF4 knockdown by ATF4 small interfering RNA offset the effect of antagomir-214. RIP1- and RIP3-dependent necroptosis was confirmed in the inflamed gingival tissues of diabetes-associated periodontitis patients and high glucose- and LPS- cotreated cells. It was suggested that miR-214-targeted ATF4 participated in the regulation of necroptosis in vivo and in vitro.

miRNA-214 suppresses oxidative stress in diabetic nephropathy via the ROS/Akt/mTOR signaling pathway and uncoupling protein 2

In the present study, the function of microRNA (miR)-214 on diabetic nephropathy (DN) and diabetes of proximal tubular cells was investigated. Reverse transcription-quantitative polymerase chain reaction was used measure the expression of miR-214 in rats with DN and ELISA was performed to measure oxidative stress and ROS levels. Results indicated that miR-214 expression in the peripheral blood was significantly decreased in rats with DN. The in vitro model of DN indicated that miR-214 upregulation significantly decreased oxidative stress and reactive oxygen species (ROS) levels, but significantly increased uncoupling protein 2 (UCP2), phosphorylated (p)-Akt and p-mammalian target of rapamycin (mTOR) protein expression levels. The administration of genipin, a UCP2 inhibitor, significantly attenuated the effects of miR-214 upregulation on oxidative stress in the in vitro DN model by regulating ROS, Akt and mTOR protein expression levels. Notably, Akt inhibitor suppressed p-Akt protein expression and attenuated the effects of miR-214 upregulation on oxidative stress in the in vitro DN model. Collectively, these data suggest that miR-214 regulates diabetes through a ROS/Akt/mTOR signaling pathway by UCP2 in proximal tubular cells.

Downregulation of miRNA-214 in cancer-associated fibroblasts contributes to migration and invasion of gastric cancer cells through targeting FGF9 and inducing EMT

Background

Cancer-associated fibroblasts (CAFs), one of the principal constituents of the tumor microenvironment, have a pivotal role in tumor progression. Dysregulation of microRNAs (miRNAs) in CAFs contributes to the tumor-promoting ability of CAFs. However, the mechanism underlying the involvement of miRNAs in CAFs of gastric cancer (GC) is not fully understood. This study aimed to explore the effects of miRNA-214 in CAFs on GC migration and invasion.

Methods

The primary CAFs and corresponding normal fibroblasts (NFs) were isolated. Cell counting kit-8, EdU cell proliferation staining and Transwell assays were used to determine the role of miRNA-214 in GC progression. Real-time polymerase chain reaction, Western blot analysis, and dual-luciferase reporter assay were performed to verify the target genes of miRNA-214. Immunofluorescence and Western blot analysis were applied to detect the expression of epithelial–mesenchymal transition (EMT) markers. Immunohistochemistry and in situ hybridization were implemented to analyze the fibroblast growth factor 9 (FGF9) and miRNA-214 expression in human GC tissues, respectively. Finally, to assess its prognostic relevance, Kaplan–Meier survival analysis was conducted.

Results

MiRNA-214 was significantly downregulated in CAFs of GC compared with NFs. The upregulation of miRNA-214 in CAFs inhibited GC cell migration and invasion in vitro but failed to affect proliferation. Moreover, GC cells cultured with conditioned medium from CAFs transfected with miR-214 mimic showed increased expression of E-cadherin and decreased expression of Vimentin, N-cadherin and Snail, indicating the suppression of EMT of GC cells. Furthermore, FGF9 was proved to be a direct target gene of miR-214. The expression of FGF9 was higher in CAFs than that in tumor cells not only in primary tumor but also in lymph node metastatic sites (30.0% vs 11.9%, P < 0.01 and 32.1% vs 12.3%, P < 0.01, respectively). Abnormal expression of FGF9 in CAFs of lymph node metastatic sites was significantly associated with poor prognosis in patients with GC (P < 0.05).

Conclusions

This study showed that miR-214 inhibited the tumor-promoting effect of CAFs on GC through targeting FGF9 in CAFs and regulating the EMT process in GC cells, suggesting miRNA-214/FGF9 in CAFs as a potential target for therapeutic approaches in GC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0995-9) contains supplementary material, which is available to authorized users.

Increased serum levels of miR-214 in patients with PCa with bone metastasis may serve as a potential biomarker by targeting PTEN

MicroRNAs (miRNAs/miRs) are identified to serve key functions in the progression of various tumors. miR-214 is aberrantly expressed in various types of cancer. In the present study, the function of miR-214 and its feasibility as a potential non-invasive biomarker for patients with prostate cancer (PCa) in a hyperplasia group and a control group were investigated. First, RNA was isolated from the serum of 75 patients with PCa with bone metastasis, 65 patients with PCa with no bone metastasis and 70 healthy controls. The level of miR-214 expression was significantly upregulated in the serum of the bone metastasis group compared with the healthy control and non-bone metastasis groups. Expression levels of alkaline phosphatase (ALP), bone sialoprotein (BSP), collagen type I pyridine crosslinking peptide (ICTP) were also evaluated. The results indicated that serum levels of BSP, ALP and ICTP were increased in the bone metastasis group compared with that in the non-bone metastasis group, hyperplasia group and the control group (P<0.05). The expression level of miR-214 is positively associated with poorly differentiated tumors in patients with PCa with a Gleason score >7 (P<0.05). Western blot analysis demonstrated that phosphatase and tensin homolog (PTEN) was a target gene of miR-214. Additionally, silencing of PTEN significantly increased the invasive ability of PC3 cells even when miR-214 expression was inhibited. In summary, serum miR-214 expression may serve as a potential novel non-invasive biomarker for PCa screening through targeting PTEN.

MicroRNA-214 promotes the proliferation, migration and invasion of gastric cancer MKN28 cells by suppressing the expression of Dact2

The present study examined the expression of Dapper, antagonist of β-catenin 2 (Dact2) and microRNA (miR)-214 in gastric cancer at tissue and cellular levels, and to understand their biological roles. A total of 42 gastric cancer patients were enrolled in the present study. Bioinformatics tool was used to predict the miR molecule that potentially regulates Dact2 expression. To measure the expression of miR-214 and Dact2, reverse transcription-quantitative polymerase chain reaction was employed. Mixed gastric adenocarcinoma type MKN28 cells were transfected with negative control (NC), miR-214 mimics or inhibitor. The CCK-8 assay was used to investigate the proliferation of mixed gastric adenocarcinoma type MKN28 cells. To study migration and invasion abilities of mixed gastric adenocarcinoma type MKN28 cells, the Transwell assay was performed. To determine the expression of Dact2 protein, western blotting was conducted and the rescue assay was utilized to study the biological roles of miR-214 and Dact2 in mixed gastric adenocarcinoma type MKN28 cells. To test whether Dact2 is a direct target of miR-214, the dual luciferase reporter assay was performed. Results indicated that the expression of miR-214 was elevated, but expression of Dact2 mRNA was decreased in gastric cancer tissues, which was closely correlated with the invasion, metastasis, occurrence and development of gastric cancer. Notably, miR-214 promoted the proliferation of mixed gastric adenocarcinoma type MKN28 cells in vitro, whereas but Dact2 inhibited the proliferation of these cells. Downregulation of miR-214 expression or upregulation of Dact2 expression inhibited the migration and invasion of mixed gastric adenocarcinoma type MKN28 cells. Furthermore, miR-214 regulated the expression of Dact2 protein and its downstream β-catenin protein in mixed gastric adenocarcinoma type MKN28 cells. Dact2 reversed the effect of miR-214 on the proliferation, migration and invasion of mixed gastric adenocarcinoma type MKN28 cells. In addition, miR-214 directly targeted the 3'-UTR seeding region of Dact2 mRNA to regulate its expression. The present study demonstrated that expression of miR-214 was upregulated in gastric cancer tissues, and positively correlated with lymphatic metastasis and clinical staging. In addition, expression of Dact2 was downregulated in gastric cancer tissues and negatively correlated with lymphatic metastasis and clinical staging. Notably, the present findings suggest that miR-214 promoted the proliferation, migration and invasion of mixed gastric adenocarcinoma type MKN28 cells by suppressing the expression of Dact2.

microRNA-214 suppresses the growth of cervical cancer cells by targeting EZH2

A number of studies have revealed the significance of microRNAs (miRs) in tumorigenesis. Cervical cancer (CC) is one of the most malignant cancer types and is associated with a poor overall survival rate. A previous study demonstrated a critical role of miR-214 in the development of multiple cancer types, but its role in CC remains elusive. In the current study, miR-214 was observed to be downregulated in CC tissues compared with the adjacent non-cancerous tissue. Overexpression of miR-214 reduced the proliferation of CC cells, whereas inhibiting its expression resulted in enhanced proliferation. Furthermore, Enhancer of zeste homolog 2 (EZH2) was demonstrated to be a direct target of miR-214 in CC. An MTT assay demonstrated that upregulating miR-214 expression or knocking down the expression of EZH2 impaired the proliferation of a CC cell line. Low expression of miR-214 was positively associated with tumor differentiation (P=0.037) and tumor stage (P=0.012). Notably, low expression of miR-214 predicted poor prognosis of patients with CC. Consequently, the results of the current study demonstrated that miR-214 functions as a tumor suppressor in CC and may be regarded as a potential therapeutic target in CC.

Decreased expression of microRNA-214 contributes to imatinib mesylate resistance of chronic myeloid leukemia patients by upregulating ABCB1 gene expression

The aim of the present study was to determine the expression of adenosine triphosphate binding cassette subfamily B member 1 (ABCB1) gene and its protein P-glycoprotein (PGP) in bone marrow mononuclear cells from chronic myeloid leukemia (CML) patients with imatinib mesylate (IM) resistance, or IM-resistant CML K562 cells. In addition, the molecular mechanism of action of microRNA (miR)-214 on ABCB1 in IM resistance was investigated. A total of 26 CML patients with IM resistance were included in the present study. In addition, 31 CML patients who did not have IM resistance were included as the control group. Bone marrow was collected from all subjects. The K562R cell line, which is a K562 cell line with IM resistance, was used for cellular studies. Reverse transcription-quantitative polymerase chain reaction was used to determine the expression of ABCB1 mRNA and miR-214 in cells. Western blotting was employed to determine the expression of PGP. Dual luciferase reporter assay was carried out to identify interactions between ABCB1 mRNA and miR-214. MTT assay was used to determine the survival rate of cells. ABCB1 mRNA and PGP expression was upregulated in bone marrow mononuclear cells from CML patients with IM resistance. K562R cells had higher ABCB1 and PGP expression than K562 cells, potentially due to their different sensitivity to IM. Expression miR-214 was decreased in bone marrow mononuclear cells from patients with IM resistance and K562R cells. Notably, miR-214 was able to bind with the 3′-untranslated region, seed region of ABCB1 mRNA to regulate its expression. In addition, elevated expression of miR-214 restored IM sensitivity to K562R cells potentially by affecting ABCB1 expression. The present study demonstrated that upregulated expression of ABCB1 mRNA and PGP in bone marrow mononuclear cells from CML patients with IM resistance may be associated with the downregulation of miR-214. In addition, miR-214 may participate in the IM resistance of CML patients by regulating ABCB1 expression.

MicroRNA-214 protects against hypoxia/reoxygenation induced cell damage and myocardial ischemia/reperfusion injury via suppression of PTEN and Bim1 expression

BACKGROUND

Myocardial apoptosis plays an important role in myocardial ischemia/reperfusion (I/R) injury. Activation of PI3K/Akt signaling protects the myocardium from I/R injury. This study investigated the role of miR-214 in hypoxia/reoxygenation (H/R)-induced cell damage in vitro and myocardial I/R injury in vivo.

METHODS AND RESULTS

H9C2 cardiomyoblasts were transfected with lentivirus expressing miR-214 (LmiR-214) or lentivirus expressing scrambled miR-control (LmiR-control) respectively, to establish cell lines of LmiR-214 and LmiR-control. The cells were subjected to hypoxia for 4 h followed by reoxygenation for 24 h. Transfection of LmiR-214 suppresses PTEN expression, significantly increases the levels of Akt phosphorylation, markedly attenuates LDH release, and enhances the viability of the cells subjected to H/R. In vivo transfection of mouse hearts with LmiR-214 significantly attenuates I/R induced cardiac dysfunction and reduces I/R-induced myocardial infarct size. LmiR-214 transfection significantly attenuates I/R-induced myocardial apoptosis and caspase-3/7 and caspase-8 activity. Increased expression of miR-214 by transfection of LmiR-214 suppresses PTEN expression, increases the levels of phosphorylated Akt, represses Bim1 expression and induces Bad phosphorylation in the myocardium. In addition, in vitro data shows transfection of miR-214 mimics to H9C2 cells suppresses the expression and translocation of Bim1 from cytosol to mitochondria and induces Bad phosphorylation.

CONCLUSIONS

Our in vitro and in vivo data suggests that miR-214 protects cells from H/R induced damage and attenuates I/R induced myocardial injury. The mechanisms involve activation of PI3K/Akt signaling by targeting PTEN expression, induction of Bad phosphorylation, and suppression of Bim1 expression, resulting in decreases in I/R-induced myocardial apoptosis.

miR-214 activates TP53 but suppresses the expression of RELA, CTNNB1, and STAT3 in human cervical and colorectal cancer cells

High Mobility Group AT-hook 1 (HMGA1) was identified as a target of miR-214 in human cervical and colorectal cancers (CaCx and CRC) in a previous study. While the expression of miR-214 remains suppressed, HMGA1 behaves as a potent oncogene and plays crucial roles in several aberrant signalling pathways by interacting with intermediates like RELA, CTNNB1, STAT3, and TP53 in CaCx and CRC. Hypothetically, miR-214 should be able to regulate the stabilization of some of these intermediates through the regulation of HMGA1. This was assessed by ectopically expressing miR-214 or complementarily, by inhibiting the expression of HMGA1. In promoter luciferase assays, miR-214 inhibited NF-κB and Wnt activities but elevated TP53 activity in cancer cells. Further, miR-214 suppressed the expression of HMGA1, RELA, CTNNB1, and STAT3 while elevating TP53 levels, similar to when small interfering RNA (siRNA) against HMGA1 was used, as revealed by Western blotting. It is suggested that poor expression of miR-214, commonly reported in CaCx and CRC tissues, may not only result in the sustained expression of HMGA1 but also that of RELA, CTNNB1, and STAT3, and a congruent suppression of TP53 during cancer initiation/progression. These several states are, however, reversed when miR-214 is reintroduced and could explain the tumour suppressive functions observed in earlier studies. Further studies are, however, required to reveal how microRNA-mediated regulation of HMGA1 expression may affect individual signalling pathways in CaCx and CRC. Current results reveal that miR-214 is not only able to regulate the expression of its direct target, HMGA1, but also that of a few signalling intermediates like TP53, RELA, CTNNB1, and STAT3, with which HMGA1 interacts. These intermediates play crucial roles in signalling pathways commonly deregulated in human CaCx and CRC. Hence, it is proposed that miR-214 might act as a tumour suppressor by regulating several aberrant signalling pathways through HMGA1. This knowledge has the potential to help design novel therapeutic strategies in CaCx and CRC.

miR-214 targets the PTEN-mediated PI3K/Akt signaling pathway and regulates cell proliferation and apoptosis in ovarian cancer

The present study aimed to investigate the potential role of microRNA (miR)-214 in targeting the phosphatase and tensin homolog (PTEN)-mediated phosphoinositide 3-kinase (PI3K)/Akt signaling pathway in ovarian cancer (OC). The target gene of miR-214 was determined by luciferase reporter gene assay and was indicated to be PTEN. Human SK-OV-3 cells were transfected with a miR-214 inhibitor and a miR-214 mimic, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect relative expression of miR-214. The MTT assay was performed to detect cell viability following transfection. Cell cycle and apoptosis were assessed by staining with propidium iodide (PI) and double staining with Annexin V/PI, respectively. The expression levels of PTEN and PI3K/Akt signaling pathway-associated proteins were detected by western blot analysis. The expression of miR-214 in tumor tissues and normal tissues was detected by RT-qPCR, and PTEN expression was detected by immunohistochemistry. SK-OV-3 cells transfected with a miR-214 inhibitor showed significantly inhibited cell viability and proliferation, and markedly increased apoptotic rate. SK-OV-3 cells transfected with miR-214 mimic showed significantly increased viability and proliferation, and markedly decreased apoptotic rate. The cells transfected with a miR-214 inhibitor exhibited significantly upregulated PTEN expression and significantly downregulated phosphatidylinositol (3,4,5)-trisphosphate (PIP3), phosphorylated (p)-Akt and p-glycogen synthase kinase (GSK)-3β expression. The cells transfected with miR-214 mimic exhibited significantly downregulated PTEN expression and significantly upregulated PIP3, p-Akt and p-GSK-3β expressions. The OC tissues exhibited an increased expression of miR-214 and a reduced positive rate of PTEN expression compared with adjacent normal tissues. miR-214 may activate the PI3K/Akt signaling pathway by downregulating the targeted PTEN, which may promote OC cell proliferation and inhibit apoptosis.

Abnormal alterations of miR-1 and miR-214 are associated with clinicopathological features and prognosis of patients with PDAC

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignant disease with a poor prognosis. PDAC is known to be difficult to diagnose at an early stage and to exhibit poor recurrence-free prognosis, but there is also a lack of effective treatment and limited knowledge of its biological characteristics. Therefore, there is an urgent requirement for an improved understanding of the cellular or molecular properties associated with PDAC, and to explore novel avenues for the diagnosis and treatment of this disease. In the present study, the microRNA (miRNA/miR) profiles of sera and tumor samples from patients with PDAC and healthy controls were investigated by miRNA microarray, and the potential role of miR-1 expression in PDAC was determined. A total of 43 patients attending the clinic diagnosed with PDAC at Changzhi City People's Hospital were invited to participate. Blood and surgical tumor samples were obtained for analysis by miRNA microarray and the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The surgical tumor tissue was additionally used to determine miRNAs status by in situ hybridization (ISH). The results of microarray revealed that: i) 27 miRNAs in the sera and 23 miRNAs in the tumor tissues obtained from patients with PDAC were different compared with their matched controls; ii) miR-1, miR-10b and miR-214 were significantly altered in the PDAC group, either in the sera or tumor tissue samples. Results from the RT-qPCR, which detected the levels of miRNAs in patients with PDAC, confirmed those obtained from the miRNA microarray. In particular, the results of the present study revealed that decreased miR-1 and increased miR-214 in the PDAC tissues were associated with the clinicopathological features and survival rates of patients with PDAC. The results of the present study indicated that miRNAs serve an important role in PDAC carcinogenic progression and supplied useful markers, including miR-1, miR-214 and miR-10b, for determining PDAC prognosis using noninvasive methods.

Elucidating the mechanism of miRNA-214 in the regulation of gingival carcinoma

The aim of the present study was to evaluate the expression levels of microRNA (miRNA)-214 in tumor tissue, blood and saliva of patients with gingival carcinoma, and to investigate the mechanisms underlying the infiltration and invasion of gingival carcinoma. Between January 2013 and March 2015, blood and saliva samples, gingival carcinoma tumor specimens and peritumoral tumor tissues were harvested from 56 patients with gingival carcinoma. Blood and saliva samples were also harvested from 33 control patients without gingival carcinoma. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to detect miRNA-214 and protein tyrosine phosphatase gene (PTEN) mRNA levels. Western blotting and ELISA were performed to detect PTEN protein levels. The results of RT-qPCR demonstrated that the expression of PTEN mRNA in tumor tissues, blood and saliva of patients with gingival carcinoma were significantly decreased compared with that of the control group (P<0.05). These findings were consistent were consistent with the results of PTEN protein expression detected via western blotting and ELISA in these samples (P<0.05). Conversely, the expression levels of miRNA-214 in these samples were significantly increased (P<0.05) in patients with gingival carcinoma compared with the control group. The decreased expression of PTEN may be associated with the expression of miRNA-214. miRNA-214 may regulate infiltration and invasion of gingival carcinoma via PTEN. These results suggest that miRNA-214 may be used as a marker of gingival carcinoma.

Inducible microRNA-214 contributes to the suppression of NF-κB-mediated inflammatory response via targeting myd88 gene in fish

Upon recognition of bacterial pathogens by pattern recognition receptors, cells are activated to produce pro-inflammatory cytokines and type I IFN by multiple signaling pathways. Every step of the process must be precisely regulated to prevent dysregulation. MicroRNAs (miRNAs) have been shown to be important regulators with profound effects on inflammatory response. Nevertheless, the miRNA-mediated regulatory mechanism remains unclear in fish species. Here, we addressed the role of miiuy croaker miR-214 in the bacteria triggered inflammatory response. miR-214 could significantly be up-regulated by Vibro harveyi and LPS stimulation. Up-regulating miR-214 subsequently inhibits the production of inflammatory cytokines by targeting myd88 to avoid excessive inflammation. Moreover, the negative regulatory mechanism of miR-214 has been demonstrated to be via the myd88-mediated NF-κB pathway. This is the first to focus on miR-214 acting as the negative regulator involved in the bacteria-triggered inflammatory response and thus may provide knowledge on the host-cell regulator responses to microbial infection.

Murine MicroRNA-214 regulates intracellular adhesion molecule (ICAM1) gene expression in genital Chlamydia muridarum infection

The hallmark of chlamydial infection is the development of upper genital pathology in the form of hydrosalpinx and oviduct and/or tubal dilatation. Although molecular events leading to genital tissue presentation and cellular architectural remodelling are unclear, early-stage host immune responses are believed to contribute to these long-term sequelae. Recently, we reported the contribution of selected infection-associated microRNAs (miRs) in the generation of host immunity at early-stage infection (day 6 after intravaginal Chlamydia muridarum challenge in C57BL/6 mice). In this report, we describe the contribution of an infection-associated microRNA, i.e. miR-214, to host immunity. Chlamydia muridarum infection in the C57BL/6 mouse genital tract significantly down-regulated miR-214 while up-regulating intracellular adhesion molecule 1 (ICAM1) gene expression. These in vivo observations were confirmed by establishing direct regulation of ICAM-1 by miR-214 in ex vivo genital cell cultures in the presence of miR-214 mimic and inhibitor. Because, ICAM-1 contributes to recruitment of neutrophils following infection, we also demonstrated that alteration of ICAM1 by miR-214 in interleukin-17A-deficient (IL-17A(-/-) ) mice correlated with reduction of neutrophils infiltrating genital tissue at day 6 after challenge. Additionally, these early-stage events resulted in significantly decreased genital pathology in IL-17A(-/-) mice compared with C57BL/6 mice. This report provides evidence for early-stage regulation of ICAM1 by microRNAs, resulting in reduction of genital pathology associated with chlamydial infection.

Differential expression of microRNAs in dorsal root ganglia after sciatic nerve injury

This study investigated the possible involvement of microRNAs in the regulation of genes that participate in peripheral neural regeneration. A microRNA microarray analysis was conducted and 23 microRNAs were identified whose expression was significantly changed in rat dorsal root ganglia after sciatic nerve transection. The expression of one of the downregulated microRNAs, microRNA-214, was validated using quantitative reverse transcriptase-PCR. MicroRNA-214 was predicted to target the 3'-untranslated region of Slit-Robo GTPase-activating protein 3. In situ hybridization verified that microRNA-214 was located in the cytoplasm of dorsal root ganglia primary neurons and was downregulated following sciatic nerve transection. Moreover, a combination of in situ hybridization and immunohistochemistry revealed that microRNA-214 and Slit-Robo GTPase-activating protein 3 were co-localized in dorsal root ganglion primary neurons. Western blot analysis suggested that Slit-Robo GTPase-activating protein 3 was upregulated in dorsal root ganglion neurons after sciatic nerve transection. These data demonstrate that microRNA-214 is located and differentially expressed in dorsal root ganglion primary neurons and may participate in regulating the gene expression of Slit-Robo GTPase-activating protein 3 after sciatic nerve transection.

Upregulated expression of microRNA-214 is linked to tumor progression and adverse prognosis in pediatric osteosarcoma

BACKGROUND

MicroRNA-214 (miR-214) expression has been demonstrated to be dysregulated in human malignancies and to play various roles in tumor progression. While previous study of miRNA expression profiling found that it was one of the most upregulated miRNAs in osteosarcoma signature, the potential role of miR-214 in osteosarcomas has been unclear. Therefore, the aim of this study was to investigate association of miR-214 expression with clinicopathologic features and prognosis in pediatric patients with osteosarcoma.

PROCEDURE

Quantitative real-time reverse transcriptase-polymerase chain reaction analysis was performed to detect expression levels of miR-214 in cancerous and noncancerous bone tissues from 92 children treated for primary osteosarcomas. Then, the clinical significance of miR-214 dysregulation in pediatric osteosarcomas was also determined.

RESULTS

Compared with noncancerous bone tissues, the expression levels of miR-214 were significantly upregulated in osteosarcoma tissues (P < 0.001). High miR-214 expression occurred more frequently in osteosarcoma tissues with large tumor size (P = 0.01), positive metastasis (P = 0.001) and poor response to pre-operative chemotherapy (P = 0.006). Moreover, high miR-214 expression was significantly associated with both shorter overall (P < 0.001) and progression-free survival (PFS; P = 0.001). Multivariate analysis by the Cox proportional hazard model further confirmed that high miR-214 expression was an independent prognostic factor of unfavorable survival in pediatric osteosarcoma (for overall survival: P = 0.008; for PFS: P = 0.01).

CONCLUSION

Our data offer evidence that upregulated expression of miR-214 may be linked to tumor progression and adverse prognosis in pediatric osteosarcoma. Further investigation in prospective studies would appear warranted.

MiR-214 promotes the alcohol-induced oxidative stress via down-regulation of glutathione reductase and cytochrome P450 oxidoreductase in liver cells

BACKGROUND

The involvement of oxidative stress in the pathophysiological process of alcohol-induced liver injury has been studied for decades. However, the role of microRNAs (miRNAs) targeting to oxidative stress genes in the pathogenesis of alcohol-induced liver injury has not yet been determined. The aim of this study was to identify the targeting of miR-214 to both glutathione reductase (GSR) and cytochrome P450 oxidoreductase (POR) genes and elucidate their impact on alcohol-induced oxidative stress in liver cells.

METHODS

The miR-214 expression vector and reporter vectors of GSR and POR 3'-UTR were constructed. Human hepatoma cell (Bel7402), human embryonic kidney 293 cell (HEK293), and rat normal hepatocyte (BRL) were transfected and stimulated with ethanol (EtOH). Wistar rats were fed with EtOH for 4 weeks. The GSR and POR protein levels were detected by Western blot, and their activities were measured using the spectrophotometric method. The miR-214 expression was detected by real-time PCR. The index of oxidative stress including the total antioxidant capacity (T-AOC) and malondialdehyde (MDA) level was detected by commercial kits.

RESULTS

miR-214 bound specifically to the GSR and POR 3'-UTR and repressed the expressions and activities of both GSR and POR. EtOH up-regulated the miR-214 expression, down-regulated the GSR and POR protein levels and activities, and induced the oxidative stress in human and rat liver cells. EtOH-fed Wistar rats further confirmed that alcohol up-regulates the miR-214 expression in liver and repressed both GSR and POR in vivo.

CONCLUSIONS

These findings demonstrated a new mechanism by which the alcohol repressed the GSR and POR expression via up-regulation of miR-214 and in turn induced oxidative stress in liver cells.