miR-29b Mimic Research Articles

Epigenetic Regulations of Genes Related to Lipid Metabolism by MicroRNA in Mice Fed High Fat Diet

BackgroundHigh fat diet impacts lipid metabolism by altering the transportation, oxidation, and storage of fatty acids. Lipoprotein lipase (LPL) plays a critical role in lipid metabolism by catalyzing triglyceride hydrolysis and lipoprotein uptake in multiple tissues. Previous study reported that miR‐29b negatively regulated LPL expression in mammary epithelial cells transfected with miR‐29b mimics. The present study investigated changes in LPL expression and epigenetic mechanisms by miR‐29 family in different tissues in mice fed a high fat diet.MethodFive‐week old male CBA mice were fed with either a control diet (Con group, 10% kcal from diet) or a high fat diet (HF group, 45% kcal from diet) ad libitum for 11 weeks.ResultsLPL mRNA was increased in adipose, muscle and colon in response to high fat diet. However, LPL mRNA expression decreased in the liver by high fat diet as well as hepatic lipase (HL). The results also showed the highest expression level of LPL mRNA in adipose tissue, followed by muscle, colon, and liver. Cpt1a mRNA, an important gene related to beta oxidation, was increased in adipose, muscle, colon, and liver in the HF group. Moreover, Cpt1a mRNA expression was the highest in liver followed by adipose, muscle, and colon. Meanwhile, high fat diet reduced the expression of miR‐29a, a predicted suppressor of LPL from miR‐29 family, in adipose tissue.ConclusionThe present results indicated that the triglyceride hydrolysis could be activated by high fat diet in other tissues than the liver and fatty acid transportation could be induced in mitochondria. Overall, LPL and Cpt1a mRNA changed differently in multiple tissue in response to high fat diet and is potentially post‐transcriptionally regulated by microRNA.Support or Funding InformationSource of research support (in a separate textbox): Campus Research Board of University of Illinois at Urbana‐Champaign and the USDA Cooperative State Research, Education and Extension Service, Hatch project numbers # ILLU‐698‐923 and ILLU‐698‐379This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Thrombin‐reduced miR‐27b attenuates platelet angiogenic activities in vitro via enhancing platelet synthesis of anti‐angiogenic thrombospondin‐1

Background Platelets can synthesize proteins upon activation. Platelets contain a number of microRNAs (miRNA) and a fully functional miRNA effector machinery. It is, however, unclear if platelet miRNAs can regulate protein synthesis of platelets, and whether the regulation may produce a physiological impact. Objectives To investigate if and how platelet miRNAs regulate de novo syntheses of angiogenic regulators and subsequently modulate platelet angiogenic activities. Methods and Results Microarray-based miRNA profiling showed that thrombin stimulation in vitro down- or up-regulated a number of platelet miRNAs, both in the total platelet miRNAs and in Ago2-associated miRNAs. Among those altered miRNAs, miR-27b was down-regulated in both the total and Ago2-immunoprecipitated miRNA profiles of platelets, which was confirmed by reverse transcription-quantitative PCR (RT-qPCR). Using western blotting assays, we showed that thrombin induced platelet de novo synthesis of thrombospondin-1, and that the level of thrombospondin-1 synthesis could reach a level of 3-5-fold higher than that before thrombin stimulation. With either the platelet precursor megakaryocyte cell line MEG-01 cells or mature platelets, we demonstrated that transfection of miR-27b mimic, but not the negative control of miRNA mimic, markedly reduced thrombospondin-1 protein levels. The latter subsequently enhanced platelet-dependent endothelial tube formation on matrigel. Conclusions Thrombin stimulation in vitro reduces platelet miR-27b levels that may markedly enhance thrombin-evoked platelet de novo synthesis of thrombospondin-1. Elevation of platelet miR-27b by transfection inhibits thrombospondin-1 synthesis, and subsequently enhances platelet pro-angiogenic activities. Hence, platelet activation-dependent reduction of miR-27b levels may represent a novel negative regulatory mechanism of platelet angiogenic activities.

MiR-181b regulates autophagy in a model of Parkinson’s disease by targeting the PTEN/Akt/mTOR signaling pathway

ObjectiveParkinson’s disease (PD) is the second most common neurodegenerative disease. Recent studies have shown that dysregulation of microRNA plays an important role in PD, and defects in autophagy are also critically associated with mechanisms underlying PD. We aim to investigate the effect of miR-181b on autophagy, particularly the involvement of miR-181b in the regulation of the phosphatase and tensin homolog (PTEN)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway and neuronal autophagy in a 1-methyl-4- phenylpyridinium iodide(MPP+)-induced cellular model of Parkinson’s disease. Materials and methodsWe used MPP+ as a tool to construct the PD cell model, using miR-181b mimics or inhibitors to regulate the expression of miR-181b. PC12 cell viability was detected by MTT. The expression of miR-181b was determined by quantitative real-time PCR analysis. The expression of autophagy protein markers (LC3II) and PTEN/Akt/mTOR signaling proteins (PTEN, p-AKT,p-mTOR and p-p70S6K) were determined by Western blotting analysis. ResultsThe expression of miR-181b and autophagy-related proteins was gradually decreased with increasing MPP+ content. Overexpression of miR-181b significantly decreased the LC3II/GAPDH ratio and increased cell viability compared to the MPP+ treated group, whereas inhibition of miR-181b attenuated these effects. In addition, we observed that PTEN expression was reduced by miR-181b mimics and induced by its inhibitors in MPP+-treated PC12 cells. Additionally, the indicators of AKT/mTOR signaling, phosphorylated (active) AKT, mTOR and p70S6K were both increased by miR-181b mimics and decreased by its inhibitors. ConclusionsOur results suggest that miR-181b regulates autophagy by targeting the PTEN/Akt/mTOR signaling pathway, thereby affecting cell viability in PD.

Targeted delivery of microRNA 146b mimic to hepatocytes by lactosylated PDMAEMA nanoparticles for the treatment of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide, and precision therapeutic will be a benefit for the NAFLD regression. In this study, we observed low microRNA 146 b (miR-146 b) expression in NAFLD mice model induced by methionine–choline-deficient diet (MCD) compared with control group. Furthermore, miR-146b−/− mice induced MCD exhibited severe liver steatosis and hepatitis. A bio-distribution study showed that novel Lactosylated PDMAEMA nanoparticles effectively targeted hepatocytes Lac-PDMAEMA. We coupled miR-146b mimic with Lac-PDMAEMA and then were administrated to NAFLD mice model, which could obviously alleviate the hepatic steatosis. Lac-PDMAEMA effectively delivered miR-146b mimic to hepatocytes with a ∼8-fold upregulation of miR-146b mimic targeting MyD88 and IRAK1, and in turn suppressed the expression of PPARγ. Meanwhile, TNF-α and IL-6 mRNA levels were decreased after administration of Lac-PDMAEMA/miR-146b mimic. So, we made a conclusion that targeted delivering miR-146b mimic to the hepatocytes by, coupling Lac-PDMAEMA nanoparticles could effectively alleviate the hepatic steatosis in NAFLD mice, which maybe bring a new and effective way to intervene and therapy the NAFLD.

Label free quantitative proteomics reveals the role of miR-200b in androgen-independent prostate cancer cells

BackgroundOur previous studies indicated that miR-200b inhibits the growth of androgen-independent prostate cancer (AIPC) cells. In this study, we employed quantitative proteomics techniques to unravel the role of miR-200b in AIPC.MethodsmiR-200b was over-expressed or inhibited by transfection with miR-200b mimics or miR-200b inhibitor in PC3 cells. Total proteins were collected and the profiles of different groups were analyzed by label-free proteomics. PANTHER was applied to analyze biological processes, molecular functions and pathways of proteins regulated by miR-200b. miRBase was used to evaluate target genes of miR-200b in proteins regulated by miR-200b.ResultsThirteen proteins were up-regulated in miR-200b mimics/mimics NC (negative miRNA control) and 14 proteins were down-regulated; 67 proteins were up-regulated in miR-200b inhibitor/inhibitor NC and 98 proteins were down-regulated. There were seven proteins which were both down-regulated by miR-200b mimics and up-regulated by miR-200b inhibitor, TM4SF1, YAP1, PPP1R2, MARCKS, RTN4, GLIPR2 and SUCLG1. Among these, TM4SF1, YAP1, PPP1R2, MARCKS, RTN4 were predicted as target genes of miR-200b by miRBase, while GLIPR2 and SUCLG1 were not.ConclusionThis work identified several target genes of miR-200b by label free proteomics method, i.e., TM4SF1, YAP1, PPP1R2, MARCKS, RTN4, GLIPR2, and SUCLG1. The signaling pathways regulated by these proteins such as Hippo signaling may contribute to the phenotype resulting from miR-200b.

Stem cells rescue cardiomyopathy induced by P. gingivalis-LPS via miR-181b.

Systemic inflammation induced by bacterial infection is one of several causative agents for cardiovascular disorders in patients with periodontal disease. Experimental results indicate that miRNAs play important roles in systemic inflammation induced by endotoxins. Further evidence states that stem cell based therapy shows potential in the treatment of inflammatory responses induced by sepsis. This study investigates if stem cells show protective effects on cardiomyocyte damage induced by porphyromonas gingivalis-LPS (Pg-LPS) through regulating miRNAs. H9c2 cardiomyoblasts and neonatal rat cardiomyocytes (NRCMs) were damaged using Pg-LPS in this study. Pg-LPS damaged H9c2 or NRCMs were then rescued using adipose-derived stem cells (ADSC). The experimental results reveal that Pg-LPS treatment is capable of inducing TLR4/NFκB axis activation, cell death signaling and IGF1R/PI3 K/Akt axis suppression. miR181b was downregulated in Pg-LPS damaged H9c2/NRCMs. All markers were improved in H9c2/NRCMs cocultured with ADSC. miR181b mimic and inhibitor confirmed that miR181b plays a central role in regulating the cardio protective effect on Pg-LPS damaged H9c2/NRCMs cocultured with ADSC. miR181b acts as potential therapeutic marker in cardiomyopathy induced by Pg-LPS. Transplantation of adipose-derived stem cells show potential in the treatment of cardiomyopathy induced by porphyromonas gingivalis endotoxin via regulation of miR181b.

MicroRNA-148b inhibits proliferation and the epithelial-mesenchymal transition and increases radiosensitivity in non-small cell lung carcinomas by regulating ROCK1.

Non-small cell lung cancer (NSCLC) accounts for ~80% of all types of lung cancer, which has the highest morbidity and mortality of all types of cancer worldwide. It is important to identify novel biomarkers and the molecular mechanism of NSCLC to improve current treatments of NSCLC. The present study aimed to investigate the effect of miR-148b expression on the proliferation, epithelial-mesenchymal transition (EMT) and radiosensitivity of NSCLC cells. It was demonstrated that miR-148b expression was significantly decreased in NSCLC tissues and cell lines. A549 cells were then transfected with a miR-148b mimic and a miR-148b inhibitor. Transfection with the miR-148b mimic decreased proliferation whereas transfection with the miR-148b inhibitor increased the proliferation of A549 cells. Additionally, the miR-148b mimic increased E-cadherin expression and decreased N-cadherin and vimentin expression. By contrast, transfection with the miR-148b inhibitor decreased E-cadherin expression and increased N-cadherin and vimentin expression. Irradiation-induced cell death was significantly promoted by the miR-148b mimic but inhibited by the miR-148b inhibitor. The miR-148b mimic significantly decreased the expression of Rho-associated protein kinase 1 (ROCK1) and it was demonstrated that overexpression of ROCK1 significantly inhibited the effects of miR-148b on cell proliferation, the EMT and irradiation-induced cell death. Therefore, the current study revealed that miR-148b inhibited NSCLC cell proliferation and the EMT, and increased the radiosensitivity of NSCLC cells by inhibiting ROCK1 expression. Therefore, miR-148b/ROCK1 signaling may be a novel therapeutic target to inhibit the growth of NSCLC cells and enhance the effects of radiotherapy to treat patients with NSCLC.

Inhibition of miR-29b suppresses MAPK signaling pathway through targeting SPRY1 in atherosclerosis

The treatment of atherosclerosis (AS), a severe condition associated with the pathogenesis of cardiovascular diseases (CVDs), is still not satisfactory worldwide. In this study, we aim to investigate whether protein sprout homologue 1 (SPRY1), a upstream mediator of MAPK signal pathway, is the target of miR-29b in vascular endothelium during the development of AS. ApoE−/− mice model was established, and an inverse correlation was noticed between level of miR-29b and SPRY1 expression in the aortic tissues. Meanwhile, the tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS) expression and NADPH oxidase activity were up-regulated in atherosclerotic tissues. In vitro experiments were carried out to investigate the roles of miR-29b in regulating the expression of SPRY1 in cultured human umbilical vein endothelial cells (HUVECs). We found that miR-29b mimic and antagomir could modulate the expression of SPRY1 protein in cultured HUVECs. However, the expression of SPRY1 mRNA showed no statistical difference when treating with miR-29b mimic or antagomir. These indicated that the modulation of SPRY1 induced by miR-29b was at the posttranslational level. Dural luciferase reporter assay was conducted to detect the potential interaction between miR-29b and the 3'UTR of SPRY1, which indicated that SPRY1 was a target of miR-29b. Besides, miR-29b antagomir induced decrease of TNF-α, ROS production and NADPH oxidase activity and down-regulated the expression of p-ERK and p-p38 in the presence of oxLDL. In conclusion, inhibition of miR-29b could attenuate AS by inhibiting the SPRY1/MAPK signaling pathway and inflammation in aorta. In future, treatment options based on miR-29b may be applicable for the treatment of AS.

Inhibition of MiRNA-125b Decreases Cerebral Ischemia/Reperfusion Injury by Targeting CK2α/NADPH Oxidase Signaling

Background/Aims: Cerebral ischemia-reperfusion (I/R) injury involves multiple independently fatal terminal pathways. CK2α/NADPH oxidase is an important signaling pathway associated with ischemia-reperfusion injury, and miR-125b can regulate oxidative stress-related injury. In this study, we investigated whether the effect of miR-125b in rat brain I/R injury occurs through its modulation of the CK2α/NADPH oxidase pathway. Methods: Rats were subjected to 2 h of cerebral ischemia followed by 24 h of reperfusion to establish an I/R injury model. Neurological deficit was evaluated using a five-point score. Infarct volume was evaluated with 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and RT-PCR was used to detect expressions of miR125b and CK2α. We then examined the association between miR-125b expression and the CK2α/NADPH oxidative signaling pathway in a PC-12 cell oxygen-glucose deprivation and reoxygenation (OGD/R) injury model. Transfection with miR-125b mimics, an miR-125b inhibitor, and luciferase reporter gene plasmid was accomplished using commercial kits. In these cells, Western blots were used to detect the levels of expression of CK2α, cleaved caspase-3, NOX2, and NOX4. RT-PCR was used to detect the expressions of CK2α, miR125b, NOX2, and NOX4. We evaluated Lactate Dehydrogenase (LDH) level, NADPH oxidase activity, and caspase-3 activity using commercial kits. Mitochondrial reactive oxygen species (ROS) were measured by fluorescence microscopy. For both PC-12 cells and rat brains, histological analyses were conducted to observe morphological changes, and apoptosis was measured using a commercial kit. Results: I/R rats exhibited an increase in neurological deficit score, infarct volume, and cellular apoptosis, along with miR-125b elevation and CK2α downregulation. OGD/R treatment increased PC-12 cells’ injuries, cellular apoptosis, and ROS levels. These changes were associated with miR-125b elevation, CK2α downregulation and activations of NOX2 and NOX4, mimicking our in vivo findings. All of these effects were reversed by the inhibition of miR-125b, confirming a strong correlation between miR-125b activity and the CK2α/NADPH oxidase signaling pathway. Conclusions: Based on these observations, we conclude that inhibition of miR-125b protects the rat brain from I/R injury by regulating the CK2α/NADPH oxidative signaling pathway.

32 MicroRNA-29b Improves the Quality and Developmental Potential of Blastocysts Derived from Somatic Cell Nuclear Transfer in Cattle

MicroRNAs (miRNAs) are small non-coding RNAs with important roles in diverse cellular processes. miR-29b plays a crucial role during somatic cell reprogramming. However, studies of the function of miR-29b in embryogenesis are limited. The aim of the current study was to explore the effects of miR-29b on the developmental competence of bovine somatic cell nuclear transfer (SCNT) embryos as well as the underlying mechanisms of action. The expression level of miR-29b was lower in bovine SCNT embryos at the pronuclear, 8-cell, and blastocyst stages compared with IVF embryos (P < 0.05). To determine the function of miR-29b in the bovine SCNT embryo, we microinjected a miR-29b mimic and inhibitor into bovine SCNT zygotes. The results showed that miR-29b significantly decreased the expression of Dnmts (Dnmt3a/3b and Dnmt1) in bovine SCNT embryos (P < 0.05). We further investigated SCNT embryo developmental competence and found that miR-29b overexpression during bovine SCNT embryonic development does not improve developmental potency (P > 0.05) but down-regulation inhibits developmental potency (P < 0.05). Although miR-29b overexpression does not improve the developmental potency of bovine SCNT embryos, the quality of bovine SCNT embryos at the blastocyst stage improved significantly (P < 0.05). The expression of pluripotency factors (OCT4 and SOX2) and cellular proliferation rate were significantly higher in blastocysts from the miR-29b overexpression group than the control and down-regulation groups (P < 0.05). In addition, outgrowth potential in blastocysts after miR-29b overexpression was also significantly greater in the miR-29b overexpression group than in the control and down-regulation groups (P < 0.05). Taken together, these results demonstrated that miR-29b plays an important role in bovine SCNT embryo development.

MiR-29b expression is associated with a dexmedetomidine-mediated protective effect against oxygen-glucose deprivation-induced injury to SK-N-SH cells in vitro.

Ischemic cerebral stroke is a leading cause of death and long-term disability world-wide. Neuronal injury following cerebral ischemia initiates a complex series of signaling cascades that lead to neuronal cell death. MicroRNA 29b (miR-29b) has reported involvement in the pathogenic process of ischemic brain injury. Dexmedetomidine (Dex) is a highly selective α2 adrenergic receptor stimulant that exerts a protective effect on brain tissue. To determine whether Dex might directly influence miR-29b expression after an ischemic injury, human neuroblastoma SK-N-SH cells were subjected to oxygen-glucose deprivation (OGD) for the purpose of creating a neuronal injury model that mimics the effects of brain ischemia in vitro. Next, the association of miR-29b with the protective effect of Dex against ischemic brain injury was studied through the enhancement or inhibition of miR-29b expression by transfection with an miR-29b mimic or inhibitor. We demonstrated that Dex treatment could reduce miR-29b expression, increase cell viability, and inhibit cell apoptosis in the OGD-induced neuronal injury model in vitro. Furthermore, down-regulation of miR-29b expression produced effects on OGD-induced neuronal injuries that were similar to those produced by Dex treatment. Moreover, up-regulation of miR-29b reversed the protective effect of Dex treatment against OGD-induced neuronal injury. Therefore, down-regulation of miR-29b expression might play a role in anti-apoptotic signaling similar to that played by Dex. Elucidation of the role played by miR-29b in ischemia, and identification of a definite association between Dex and miR-29b may lead to the development of new strategies for treating ischemic brain injuries.

MiR-200b downregulates CFTR during hypoxia in human lung epithelial cells

BackgroundHypoxic conditions induce the expression of hypoxia-inducible factors (HIFs) that allow cells to adapt to the changing conditions and alter the expression of a number of genes including the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR is a low abundance mRNA in airway epithelial cells even during normoxic conditions, but during hypoxia its mRNA expression decreases even further.MethodsIn the current studies, we examined the kinetics of hypoxia-induced changes in CFTR mRNA and protein levels in two human airway epithelial cell lines, Calu-3 and 16HBE14o-, and in normal primary bronchial epithelial cells. Our goal was to examine the posttranscriptional modifications that affected CFTR expression during hypoxia. We utilized in silico predictive protocols to establish potential miRNAs that could potentially regulate CFTR message stability and identified miR-200b as a candidate molecule.ResultsAnalysis of each of the epithelial cell types during prolonged hypoxia revealed that CFTR expression decreased after 12 h during a time when miR-200b was continuously upregulated. Furthermore, manipulation of the miRNA levels during normoxia and hypoxia using miR-200b mimics and antagomirs decreased and increased CFTR mRNA levels, respectively, and thus established that miR-200b downregulates CFTR message levels during hypoxic conditions.ConclusionThe data suggest that miR-200b may be a suitable target for modulating CFTR levels in vivo.

MiR-125b Increases Nasopharyngeal Carcinoma Radioresistance by Targeting A20/NF-κB Signaling Pathway.

Radioresistance poses a major challenge in nasopharyngeal carcinoma (NPC) treatment, but little is known about how miRNA regulates this phenomenon. In this study, we investigated the function and mechanism of miR-125b in NPC radioresistance, one of upregulated miRNAs in the radioresistant NPC cells identified by our previous microarray analysis. We observed that miR-125b was frequently upregulated in the radioresistant NPCs, and its increment was significantly correlated with NPC radioresistance, and was an independent predictor for poor patient survival. In vitro radioresponse assays showed that miR-125b inhibitor decreased, whereas miR-125b mimic increased NPC cell radioresistance. In a mouse model, therapeutic administration of miR-125b antagomir dramatically sensitized NPC xenografts to irradiation. Mechanistically, we confirmed that A20 was a direct target of miR-125b and found that miR-125b regulated NPC cell radioresponse by targeting A20/NF-κB signaling. With a combination of loss-of-function and gain-of-function approaches, we further showed that A20 overexpression decreased while A20 knockdown increased NPC cell radioresistance both in vitro and in vivo Moreover, A20 was significantly downregulated while p-p65 (RelA) significantly upregulated in the radioresistant NPCs relative to radiosensitive NPCs, and miR-125b expression level was negatively associated with A20 expression level, whereas positively associated with p-p65 (RelA) level. Our data demonstrate that miR-125b and A20 are critical regulators of NPC radioresponse, and high miR-125b expression enhances NPC radioresistance through targeting A20 and then activating the NF-κB signaling pathway, highlighting the therapeutic potential of the miR-125b/A20/NF-κB axis in clinical NPC radiosensitization. Mol Cancer Ther; 16(10); 2094-106. ©2017 AACR.

MiR-26b regulates invasion and migration of lung cancer cells through targeting hENT1 depending on RhoA/ROCK-1 pathway

To investigate the effect of miR-26b on the invasion and migration of lung cancer cell and to explore its mechanism. Methods: qPCR was used to detect the expression of miR-26b in lung cancer. Luciferase reporter gene was used to detect interaction between miR-26b and hENT1. Transwell assay was used to detect invasion ability after treatment of miR-26b mimics. Scratch assay was used to detect migration ability after treatment of miR-26b mimics. The expressions of hENT1, ROCK-1 and RhoA were detected by Western blot. The changes of cytoskeleton after miR-26b mimics treatment with phalloidin were observed. The effect of miR-26b mimics on the tumor size and volume of lung cancer was determined by subcutaneous tumor formation in nude mice. Results: MiR-26b expression was significantly reduced in lung cancer. With the progress of lung cancer, the expression of miR-26b was reduced. With the progress in differentiation of lung cancer, the expression of miR-26b was decreased. Decrease of miR-26b was associated with lung cancer lymph node metastasis. HENT1 was the direct target of miR-26b; miR-26b regulated the invasion and migration ability of human lung carcinoma A549 cells. MiR-26b regulated the expression of hENT1, ROCK-1 and RhoA. After the treatment with miR-26b mimics, the F-actin staining was significantly reduced, whereas the formation of wrinkles and the formation of pseudopodia were significantly reduced. Subcutaneous tumor formation in nude mice showed that miR-26b mimics treatment significantly reduced the tumor size and mass. Conclusion: MiR-26b plays a role in tumor suppression in lung cancer. miR-26b can regulate the invasion and migration ability of lung carcinoma A549 cells by targeting hENT1 depending on the RhoA/ROCK-1 pathway.

MiR-27b augments bone marrow progenitor cell survival via suppressing the mitochondrial apoptotic pathway in Type 2 diabetes.

Bone marrow-derived progenitor cells (BMPCs) are potential candidates for autologous cell therapy in tissue repair and regeneration because of their high angiogenic potential. However, increased progenitor cell apoptosis in diabetes directly limits their success in the clinic. MicroRNAs are endogenous noncoding RNAs that regulate gene expression at the posttranscriptional level, but their roles in BMPC-mediated angiogenesis are incompletely understood. In the present study, we tested the hypothesis that the proangiogenic miR-27b inhibits BMPC apoptosis in Type 2 diabetes. Bone marrow-derived EPCs from adult male Type 2 diabetic db/db mice and their normal littermates db/+ mice were used. MiR-27b expression (real-time PCR) in EPCs was decreased after 24 h of exposure to methylglyoxal (MGO) or oxidized low-density lipoprotein but not high glucose, advanced glycation end products, the reactive oxygen species generator LY83583, or H2O2 The increase in BMPC apoptosis in the diabetic mice was rescued following transfection with a miR-27b mimic, and the increased apoptosis induced by MGO was also rescued by the miR-27b mimic. p53 protein expression and the Bax/Bcl-2 ratio in EPCs (Western blot analyses) were significantly higher in db/db mice, both of which were suppressed by miR-27b. Furthermore, mitochondrial respiration, as measured by oxygen consumption rate, was enhanced by miR-27b in diabetic BMPCs, with concomitant decrease of mitochondrial Bax/Bcl-2 ratio. The 3' UTR binding assays revealed that both Bax, and its activator RUNX1, were direct targets of miR-27b, suggesting that miR-27b inhibits Bax expression in both direct and indirect manners. miR-27b prevents EPC apoptosis in Type 2 diabetic mice, at least in part, by suppressing p53 and the Bax/Bcl-2 ratio. These findings may provide a mechanistic basis for rescuing BMPC dysfunction in diabetes for successful autologous cell therapy.

MicroRNA-200b inhibits pituitary tumor cell proliferation and invasion by targeting PKCα.

The present study aimed to investigate the expression of miR-200b and protein kinase Cα (PKCα) in pituitary tumors and to determine whether miR-200b may inhibit proliferation and invasion of pituitary tumor cells. The regulation of PKCα expression was targeted in order to find novel targets for the treatment of pituitary tumors. In total, 53 pituitary tumor tissue samples were collected; these included 28 cases of invasive pituitary tumors and 25 cases of non-invasive tumors, in addition to 5 normal pituitaries. The expression level of miR-200b in the pituitary tumor tissue was detected by quantitative polymerase chain reaction (qPCR) and the expression of PKCα protein was detected by immunohistochemistry. A PKCα 3'untranslated region (UTR) luciferase vector was constructed and a dual luciferase reporter gene assay was employed in order to examine the effect of miR-200b on the PKCα 3'UTR luciferase activity. AtT-20 cells were transfected with miR-200b mimics, PKCα siRNA and miR-200b mimics + PKCα, and the changes in cellular proliferation, invasion and apoptosis were observed via MTT, Transwell assay and flow cytometric analysis. Furthermore, PKCα mRNA expression was determined by qPCR, and Western blotting was performed to detect the expression of PKCα protein. miR-200b revealed downregulation in invasive pituitary tumor tissue, and the expression level was significantly down-regulated compared with normal and non-invasive pituitary tumor tissue (P<0.01). In addition, the positive rate of PKCα protein expression in invasive pituitary tumor tissues was significantly higher than in normal and non-invasive tissues (P<0.01). PKCα protein levels are inversely correlated with miR-200b levels in invasive pituitary tumor tissues (r=-0.436, P=0.021). The dual luciferase reporter gene assay revealed that miR-200b could specifically bind to the 3'UTR of PKCα and significantly inhibit the luciferase activity by 39% (P<0.01). Upregulation of miR-200b or downregulation of PKCα could suppress cell proliferation and invasion, and increase apoptosis of AtT-20 cells. It was revealed that PKCα siRNA could suppress both proliferation and invasion of AtT-20 cells and partially simulate the function of miR-200b. Expression of PKCα mRNA and protein decreased significantly in AtT-20 cells overexpressing miR-200b. Additionally, miR-200b was significantly down-regulated in invasive pituitary tumor tissue and inversely correlated with PKCα protein levels. In conclusion, miR-200b inhibited proliferation and invasiveness and promoted the apoptosis of pituitary tumor cells by targeting PKCα. The observations of the present study indicate that miR-200b and PKCα may serve as promising therapeutic targets for invasive pituitary tumors.

MicroRNA-148b suppresses proliferation, migration, and invasion of nasopharyngeal carcinoma cells by targeting metastasis-associated gene 2.

PurposeMicroRNAs (miRNAs) play important roles in tumorigenesis and metastasis by regulating genes expression. MiRNA-148b (miR-148b) had been reported to inhibit tumor progression in some kinds of cancers, but the functions of miR-148b in nasopharyngeal carcinoma (NPC) remain largely unknown. The aim of this study was to investigate the functional role of miR-148b in NPC.MethodsExpression of miR-148b in NPC tissues and cell lines was detected by quantitative reverse transcription polymerase chain reaction. MiR-148b was overexpressed in CNE2 and C666-1 cells by miR-148b mimic transfection. The effects of miR-148b on cell proliferation, migration, and invasion were determined by colony formation assays, cell viability assays, and transwell assays. The target gene of miR-148b was investigated by luciferase assays, and the rescue experiment was performed.ResultsMiR-148b was downregulated in NPC tissues and cell lines. Ectopic miR-148b expression significantly inhibited proliferation, migration, and invasion of CNE2 and C666-1 cells. We identified that metastasis-associated gene 2 (MTA2) is a direct target of miR-148b. Rescue experiment demonstrated that the tumor-suppressive effects of miR-148b on C666-1 cell were partly reversed by restoration of MTA2 expression. Moreover, miR-148b expression was negatively related to mRNA level of MTA2 in NPC tissues.ConclusionOur findings elucidate that miR-148b negatively regulates the growth, migration, and invasion of NPC cells, at least in part, by targeting MTA2. The present study indicates that miR-148b is a potential therapeutic agent for NPC.

LncRNA CCAT1 Promotes Glioma Tumorigenesis by Sponging miR-181b.

Colon cancer-associated transcript 1 (CCAT1), a long non-coding RNA (lncRNA), is upregulated and has a vital role in the pathogenesis of numerous cancers. Recently, its high expression was found in glioma tissues. miR-181b is downregulated in glioma and acts as a tumor suppressor. However, the exact mechanism of CCAT1 action in the regulation of glioma development remains unknown. CCAT1 and miR-181b expression was firstly examined in glioma tissue samples by real-time PCR. An RNA interference approach was used to downregulate CCAT1 expression and we analyzed the underlying mechanism of CCAT1 by using bioinformatics analysis, CCK-8 assay, Transwell assay, flow cytometry, luciferase assay, RNA immunoprecipitation, real-time PCR, Western blot, and xenograft models. CCAT1 expression was significantly increased, while miR-181b decreased, in glioma tissues. Interestingly, miR-181b expression was negatively correlated with the CCAT1 level in glioma samples. Knockdown of CCAT1 notably suppressed proliferation, migration and the epithelial-mesenchymal transition (EMT) process, and promoted the apoptosis of U87 and LN229 glioma cells, which could be enhanced by transfection with miR-181b mimic while it was abolished by anti-miR-181b. Additionally, we found that CCAT1 may act as a competing endogenous RNA (ceRNA) for miR-181b, regulating the de-repression of FGFR3 and PDGFRα. In conclusion, CCAT1 promotes glioma tumorigenesis by sponging miR-181b, leading to the de-repression of its endogenous targets FGFR3 and PDGFRα, which provides a potential therapeutic target for glioma treatment. J. Cell. Biochem. 118: 4548-4557, 2017. © 2017 Wiley Periodicals, Inc.

MicroRNA-125b targeted STAT3 to inhibit laryngeal squamous cell carcinoma cell growth and motility

A majority of studies have indicated that microRNA-125b (miR-125b) is aberrantly expressed in various types of cancer. However, there are no studies on the expression and function of miR-125b in human laryngeal squamous cell carcinoma (LSCC). In the present study, miR-125b expression in LSCC sample tissues, corresponding adjacent non-neoplastic tissues, LSCC cell lines and a normal human keratinocyte cell line was measured using the reverse transcription-quantitative polymerase chain reaction. Following transfection with miR-125b mimics, the Cell Counting Kit-8, cell migration, cell invasion, western blotting and dual-luciferase reporter assays were performed on LSCC cell lines. According to the results, miR-125b was observed to be significantly downregulated in LSCC, and its expression was significantly associated with clinical stage and alcohol history. miR-125b was also observed to decrease cell growth, migration and invasion in LSCC cells by directly targeting signal transducer and activator of transcription 3. The results of the present study suggested that miR-125b may be a potential treatment target of LSCC in the future.

MicroRNA-15b promotes proliferation and invasion of non‑small cell lung carcinoma cells by directly targeting TIMP2.

MicroRNA-15b (miR-15b) plays an important role in tumor development and progression. miR-15b functions differently in various types of malignant tumors. However, the expression pattern and role of miR-15b in non-small cell lung cancer (NSCLC) have not been elucidated. In the present study, we investigated the effect of miR-15b on the occurrence and development of lung cancer and the underlying mechanism. Lung cancer cell lines A549 and LTEP-a-2 were transfected with miR-15b inhibitor or mimic, respectively. Real-time PCR revealed that the expression level of miR-15b was significantly higher in human NSCLC tissues and NSCLC cells, than that of normal tissues and cells, respectively (P<0.05). Moreover, the effect of miR-15b on A549 and LTEP-a-2 cell viability, cell cycle, migration and invasion was further evaluated. Experiments indicated that miR‑15b knockdown inhibited the viability, cell cycle, migration and invasion in A549 cells, while upregulation of miR-15b exhibited the opposite effect. Tissue inhibitor of metallopeptidases2 (TIMP2) protein and mRNA levels were downregulated after miR-15b overexpression in A549 and LTEP-a-2 cells, respectively. The dual-luciferase reporter gene assay implied that TIMP2 is a direct target gene of miR-15b. Our results indicate that high expression of miR-15b is associated with NSCLC and suggest that miR-15b expression may be a novel biomarker for predicting clinical outcomes in NSCLC patients. The inhibition of miR-15b may even provide helpful therapeutic strategies for the treatment of NSCLC.