MCPIP1 is a novel link between diabetogenic conditions and impaired insulin secretory capacity.

During diabetes development insulin production and glucose-stimulated insulin secretion (GSIS) are defective due to inflammation-related, yet not fully understood mechanisms. MCPIP1 (monocyte chemotactic protein-induced protein-1) is a strong regulator of inflammation, and acts predominantly as a specific RNase. The impact of MCPIP1 on insulin secretory capacity is unknown. We show that the expression of the ZC3H12A gene, which encodes MCPIP1, was induced by T1DM- and by T2DM-simulating conditions, with a stronger effect of cytokines. The number of MCPIP1-positive pancreatic islet-cells, including beta-cells, was significantly higher in diabetic compared to nondiabetic individuals. In the 3'UTR regions of mRNAs coding for Pdx1 (pancreatic and duodenal homeobox 1), FoxO1 (forkhead box protein O1), and of a novel regulator of insulin handling, Grp94 (glucose-regulated protein 94), MCPIP1-target structures were detected. Overexpression of the wild type MCPIP1wt, but not of the mutant MCPIP1D141N (lacking the RNase activity), decreased the expression of genes involved in insulin production and GSIS. Additionally INS1-E-MCPIP1wt cells exhibited a higher Ire1 (inositol-requiring enzyme 1) expression. MCPIP1wt overexpression blunted GSIS and glucose-mediated calcium influx with no deleterious effects on glucose uptake or glucokinase activity. We identify MCPIP1 as a new common link between diabetogenic conditions and beta-cell failure. MCPIP1 may serve as an interesting target for novel beta-cell protective approaches.

Identification of RNA-binding proteins that partner with Lin28a to regulate Dnmt3a expression.

Lin28 is an evolutionary conserved RNA-binding protein that plays important roles during embryonic development and tumorigenesis. It regulates gene expression through two different post-transcriptional mechanisms. The first one is based on the regulation of miRNA biogenesis, in particular that of the let-7 family, whose expression is suppressed by Lin28. Thus, loss of Lin28 leads to the upregulation of mRNAs that are targets of let-7 species. The second mechanism is based on the direct interaction of Lin28 with a large number of mRNAs, which results in the regulation of their translation. This second mechanism remains poorly understood. To address this issue, we purified high molecular weight complexes containing Lin28a in mouse embryonic stem cells (ESCs). Numerous proteins, co-purified with Lin28a, were identified by proteomic procedures and tested for their possible role in Lin28a-dependent regulation of the mRNA encoding DNA methyltransferase 3a (Dnmt3a). The results show that Lin28a activity is dependent on many proteins, including three helicases and four RNA-binding proteins. The suppression of four of these proteins, namely Ddx3x, Hnrnph1, Hnrnpu or Syncrip, interferes with the binding of Lin28a to the Dnmt3a mRNA, thus suggesting that they are part of an oligomeric ribonucleoprotein complex that is necessary for Lin28a activity.

Identification of 3' UTR motifs required for mRNA localization to myelin sheaths in vivo.

Myelin is a specialized membrane produced by oligodendrocytes that insulates and supports axons. Oligodendrocytes extend numerous cellular processes, as projections of the plasma membrane, and simultaneously wrap multiple layers of myelin membrane around target axons. Notably, myelin sheaths originating from the same oligodendrocyte are variable in size, suggesting local mechanisms regulate myelin sheath growth. Purified myelin contains ribosomes and hundreds of mRNAs, supporting a model that mRNA localization and local protein synthesis regulate sheath growth and maturation. However, the mechanisms by which mRNAs are selectively enriched in myelin sheaths are unclear. To investigate how mRNAs are targeted to myelin sheaths, we tested the hypothesis that transcripts are selected for myelin enrichment through consensus sequences in the 3' untranslated region (3' UTR). Using methods to visualize mRNA in living zebrafish larvae, we identified candidate 3' UTRs that were sufficient to localize mRNA to sheaths and enriched near growth zones of nascent membrane. We bioinformatically identified motifs common in 3' UTRs from 3 myelin-enriched transcripts and determined that these motifs are required and sufficient in a context-dependent manner for mRNA transport to myelin sheaths. Finally, we show that 1 motif is highly enriched in the myelin transcriptome, suggesting that this sequence is a global regulator of mRNA localization during developmental myelination.

Analysis of RBP Regulation and Co-regulation of mRNA 3' UTR Regions in a Luciferase Reporter System.

The luciferase reporter assay is a widely used tool to study the cis and trans factors controlling regulation of gene expression. In this assay, regulatory elements can be fused to the luciferase gene, and as a result effect protein output by changing rates of transcription, rates of translation, or mRNA stability. This protocol focuses on probing the function of RNA-binding proteins (RBPs) through their interactions with the 3' untranslated region (UTR), thus examining gene expression regulation on the mRNA level. Assessment of 3' UTR sequence requirements, as well as single and co-regulatory roles of RBPs in regulation of mRNAs will be discussed.

The G4 resolvase RHAU modulates mRNA translation and stability to sustain postnatal heart function and regeneration.

Post-transcriptional regulation of mRNA translation and stability is primarily achieved by RNA-binding proteins, which are of increasing importance for heart function. Furthermore, G-quadruplex (G4) and G4 resolvase activity are involved in a variety of biological processes. However, the role of G4 resolvase activity in heart function remains unknown. The present study aims to investigate the role of RNA helicase associated with adenylate- and uridylate-rich element (RHAU), an RNA-binding protein with G4 resolvase activity in postnatal heart function through deletion of Rhau in the cardiomyocytes of postnatal mice. RHAU-deficient mice displayed progressive pathological remodeling leading to heart failure and mortality and impaired neonatal heart regeneration. RHAU ablation reduced the protein levels but enhanced mRNA levels of Yap1 and Hexim1 that are important regulators for heart development and postnatal heart function. Furthermore, RHAU was found to associate with both the 5' and 3' UTRs of these genes to destabilize mRNA and enhance translation. Thus, we have demonstrated the important functions of RHAU in the dual regulation of mRNA translation and stability, which is vital for heart physiology.

Human urine-derived stem cells protect against renal ischemia/reperfusion injury in a rat model via exosomal miR-146a-5p which targets IRAK1.

Rationale: Ischemia/reperfusion injury (IRI) is a major cause of acute kidney injury (AKI) that is associated with high morbidity and mortality, and for which specific treatments are lacking. In this study, we investigated the protective effect of human urine-derived stem cells (USCs) and their exosomes against IRI-induced AKI to explore the potential of these cells as a new therapeutic strategy. Methods: USCs were derived from fresh human urine. Cell surface marker expression was analyzed by flow cytometry to determine the characteristics of the stem cells. Adult male Sprague-Dawley rats were used to generate a lethal renal IRI model. One dose of USCs (2×106 cells/ml) or exosomes (20 µg/1 ml) in the experimental groups or saline (1 ml) in the control group was administered intravenously immediately after blood reperfusion. Blood was drawn every other day for measurement of serum creatinine (sCr) and blood urea nitrogen (BUN) levels. The kidneys were harvested for RNA and protein extraction to examine the levels of apoptosis and tubule injury. In vitro, the hypoxia-reoxygenation (H/R) model in human kidney cortex/proximal tubule cells (HK2) was used to analyze the protective ability of USC-derived exosomes (USC-Exo). Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR), western blotting, superoxide dismutase activity, and malonaldehyde content analyses were used to evaluate oxidative stress in HK2 cells treated with USC-Exo after H/R. Exosomal microRNA sequencing techniques and bioinformatics analysis were used to search for enriched miRNAs in the exosomes and interacting genes. The interaction between miRNAs and the 3' untranslated region of the target gene was detected using a dual luciferase reporting system. The miRNA mimic and inhibitor were used to regulate the miRNA level in HK2 cells. Results: Treatment with USCs led to reductions in the levels of sCr, BUN, and renal tubular cell apoptosis; inhibited the infiltration of inflammatory cells; and protected renal function in the rat IRI model. Additionally, USC-derived exosomes protected against IRI-induced renal damage. miR-146a-5p was the most abundant miRNA in exosomes obtained from the conditioned medium (CM) of USCs. miR-146a-5p targeted and degraded the 3'UTR of interleukin-1 receptor-associated kinase 1 (IRAK1) mRNA, subsequently inhibited the activation of nuclear factor (NF)-κB signaling, and protected HK2 cells from H/R injury. USC transplantation also upregulated miR-146a-5p expression, downregulated IRAK1 expression and inhibited nuclear translocation of NF-κB p65 in the kidney of the rat IRI model. Conclusions: According to our experimental results, USCs could protect against renal IRI via exosomal miR-146a-5p, which could target the 3'UTR of IRAK1 and subsequently inhibit the activation of NF-κB signaling and infiltration of inflammatory cells to protect renal function. As a novel cell source, USCs represent a promising non-invasive approach for the treatment of IRI.

Human NMD ensues independently of stable ribosome stalling.

Nonsense-mediated mRNA decay (NMD) is a translation-dependent RNA degradation pathway that is important for the elimination of faulty, and the regulation of normal, mRNAs. The molecular details of the early steps in NMD are not fully understood but previous work suggests that NMD activation occurs as a consequence of ribosome stalling at the termination codon (TC). To test this hypothesis, we established an in vitro translation-coupled toeprinting assay based on lysates from human cells that allows monitoring of ribosome occupancy at the TC of reporter mRNAs. In contrast to the prevailing NMD model, our in vitro system reveals similar ribosomal occupancy at the stop codons of NMD-sensitive and NMD-insensitive reporter mRNAs. Moreover, ribosome profiling reveals a similar density of ribosomes at the TC of endogenous NMD-sensitive and NMD-insensitive mRNAs in vivo. Together, these data show that NMD activation is not accompanied by stable stalling of ribosomes at TCs.

Gene autoregulation by 3' UTR-derived bacterial small RNAs.

Negative feedback regulation, that is the ability of a gene to repress its own synthesis, is the most abundant regulatory motif known to biology. Frequently reported for transcriptional regulators, negative feedback control relies on binding of a transcription factor to its own promoter. Here, we report a novel mechanism for gene autoregulation in bacteria relying on small regulatory RNA (sRNA) and the major endoribonuclease, RNase E. TIER-seq analysis (transiently-inactivating-an-endoribonuclease-followed-by-RNA-seq) revealed ~25,000 RNase E-dependent cleavage sites in Vibrio cholerae, several of which resulted in the accumulation of stable sRNAs. Focusing on two examples, OppZ and CarZ, we discovered that these sRNAs are processed from the 3' untranslated region (3' UTR) of the oppABCDF and carAB operons, respectively, and base-pair with their own transcripts to inhibit translation. For OppZ, this process also triggers Rho-dependent transcription termination. Our data show that sRNAs from 3' UTRs serve as autoregulatory elements allowing negative feedback control at the post-transcriptional level.

MiR-92b-3p regulates oxygen and glucose deprivation-reperfusion-mediated apoptosis and inflammation by targeting TRAF3 in PC12 cells.

NEW FINDINGS: What is the central question of this study? MiR-92b-3p was found to be reduced in a rat model of middle cerebral artery occlusion: what are the functions of miR-92b-3p in oxygen and glucose deprivation-reperfusion (OGD/R)? What is the main finding and its importance? MiR-92b-3p abated apoptosis, mitochondrial dysfunction and inflammation caused by OGD/R via targeting TRAF3, suggesting that miR-92b-3p may serve as a potential therapeutic target in ischaemic stroke treatment. ABSTRACT: Stroke is the most common cause of human neurological disability. MiR-92b-3p has been shown to be decreased in a rat model of middle cerebral artery occlusion, but its effects in cerebral ischaemic insult are unknown. In this study, PC12 cells were exposed to oxygen and glucose deprivation-reperfusion (OGD/R) to establish cerebral ischaemic injury in vitro. Quantitative real time-PCR analysis demonstrated that OGD/R exposure led to down-regulation of miR-92b-3p and increased mRNA and protein levels of tumour necrosis factor receptor-associated factor 3 (TRAF3). Gain of miR-92b-3p expression facilitated cell survival; attenuated lactate dehydrogenase leakage, cell apoptosis, caspase 3 activity and cleaved-caspase 3 (c-caspase 3) expression; and decreased the Bax/Bcl-2 ratio. Furthermore, miR-92b-3p repressed mitochondrial membrane potential depolarization, reactive oxygen species production, cytochrome c protein expression, inflammatory cytokine production and the reduction of ATP content. MiR-92b-3p directly targeted the 3'-untranslated region of TRAF3 and decreased TRAF3 expression. Reinforced expression of TRAF3 partly abrogated the biological activity of miR-92b-3p during OGD/R. Hence, miR-92b-3p abated apoptosis, mitochondrial dysfunction and inflammatory responses induced by OGD/R by targeting TRAF3.

Sphingosine 1-phosphate/microRNA-1249-5p/MCP-1 axis is involved in macrophage-associated inflammation in fatty liver injury in mice.

Monocyte chemotactic protein-1 (MCP-1) is one of the most representative inflammatory cytokines, and has been proved to be markedly increased in injured liver and sphingosine 1-phosphate (S1P)-treated macrophages. However, microRNAs (miRNAs) targeting MCP-1 and the role of miRNA/MCP-1 axis in S1P-mediated liver inflammation remain largely unknown. Here, we demonstrate that MCP-1 expression is increased in the liver and isolated liver macrophages of MCDHF mice. Moreover, there is a positive correlation between the hepatic levels of S1P and MCP-1. We then predict miRNAs targeting MCP-1 by bioinformatics analysis and select miRNA-1249-5p (miR-1249-5p) from the intersection of TargetScan database and downregulated miRNAs in the injured liver. S1P significantly upregulates the expression of MCP-1 and decreases miR-1249-5p expression in macrophages. MiR-1249-5p directly targets 3'-UTR of MCP-1 and negatively regulates its expression in S1P-treated macrophages. Administration of miR-1249-5p agomir decreases hepatic MCP-1 levels and attenuates liver inflammation in MCDHF mice. Protein-protein interaction network by STRING displays that S1P system is closely associated with MCP-1/CCR2 axis in the network of inflammation. In conclusion, we characterize the vital role of miR-1249-5p in negatively regulating MCP-1 expression in vitro and in vivo, which may open new perspectives for pharmacological treatment of liver disease.

A tale of non-canonical tails: gene regulation by post-transcriptional RNA tailing.

RNA tailing, or the addition of non-templated nucleotides to the 3' end of RNA, is the most frequent and conserved type of RNA modification. The addition of tails and their composition reflect RNA maturation stages and have important roles in determining the fate of the modified RNAs. Apart from canonical poly(A) polymerases, which add poly(A) tails to mRNAs in a transcription-coupled manner, a family of terminal nucleotidyltransferases (TENTs), including terminal uridylyltransferases (TUTs), modify RNAs post-transcriptionally to control RNA stability and activity. The human genome encodes 11 different TENTs with distinct substrate specificity, intracellular localization and tissue distribution. In this Review, we discuss recent advances in our understanding of non-canonical RNA tails, with a focus on the functions of human TENTs, which include uridylation, mixed tailing and post-transcriptional polyadenylation of mRNAs, microRNAs and other types of non-coding RNA.

MicroRNA­103 modulates tumor progression by targeting KLF7 in non­small cell lung cancer.

Numerous studies have identified that microRNAs (miRs) play a crucial role in the tumorigenesis of non­small cell lung cancer (NSCLC). However, to the best of our knowledge, the physiological function of miR­103 in NSCLC is not fully understood. Experiments in the present study revealed that miR­103 expression was increased in NSCLC cell lines. In addition, a series of methods, including MTT, colony formation, 5­ethynyl­2'­deoxyuridine, Transwell, wound healing, flow cytometric, reverse transcription­quantitative PCR and western blot assays, were performed, which revealed that overexpression of miR­103 enhanced cell growth, migration, invasion and epithelial­mesenchymal transition (EMT), and suppressed apoptosis of A549 and H1299 cells. Additionally, a dual­luciferase reporter assay indicated that miR­103 directly targets the 3'­untranslated region of Kruppel­like factor 7 (KLF7), and KLF7 expression was negatively regulated by miR­103 expression. Furthermore, the present findings demonstrated that miR­103 promoted EMT via regulating the Wnt/ß­catenin signaling pathway in NSCLC. Collectively, the current results demonstrated that miR­103 serves a tumorigenesis role in NSCLC development by targeting KLF7, at least partly via the Wnt/ß­catenin signaling pathway. Consequently, these findings indicated that miR­103/KLF7/Wnt/ß­catenin may provide a novel insight into underlying biomarkers for improving the diagnosis and treatment of NSCLC.

miR-324-5p promotes adipocyte differentiation and lipid droplet accumulation by targeting Krueppel-like factor 3 (KLF3).

miRNAs, a kind of noncoding small RNA, play a significant role in adipose differentiation. In this study, we explored the effect of miR-324-5p in adipose differentiation, and found that miR-324-5p could promote adipocytes differentiation and increase body weight in mice. We overexpressed miR-324-5p during adipocytes differentiation, by oil red O and bodipy staining found that lipid accumulation was increased, and the expression level of adipogenic related genes were significantly increased. And the opposite experimental results were obtained after inhibiting miR-324-5p. In vivo, we injected miR-324-5p agomiR in obese mice and found that body weight, adipocyte area, and adipogenic-related gene expression level were significantly increased but lipolytic genes were decreased. To further explore the mechanism of miR-324-5p regulation in lipid accumulation, we constructed Krueppel-like factor 3 (KLF3) 3'-untranslated region luciferase reporter vector and KLF3 pcDNA 3.1 overexpression vector, and found that miR-324-5p was able to directly target KLF3. Overall, in this study we found that miR-324-5p could promote mice preadipoytes differentiation and increase mice fat accumulation by targeting KLF3.

miR­106b­5p modulates acute pulmonary embolism via NOR1 in pulmonary artery smooth muscle cells.

Acute pulmonary embolism (APE) is a common cause of acute cardiovascular failure and has a high morbidity and mortality rate. Inhibiting the excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) is a potential treatment strategy following an APE. Various microRNAs (miRNAs/miRs) have been shown to regulate cell proliferation, apoptosis and other physiological processes. However, the specific mechanisms underlying the action of multiple miRNAs are still not understood in APE. In the present study, the role of miR­106b­5p on APE was demonstrated in platelet­derived growth factor (PDGF)­induced PASMCs in vitro and in an APE­mouse model in vivo. The results showed that miR­106b­5p expression was downregulated in PDGF­induced PASMCs and APE mice, and NOR1 levels were upregulated. Proliferating cell nuclear antigen (PCNA) expression levels in cells and proliferation of PASMCs proliferation and migration were reduced following treatment with miR­106b­5p agomiR, and increased following treatment with miR­106b­5p antagomiR. miR­106b­5p targeted the 3' untranslated region of NOR­1 mRNA and reduced NOR1 expression. NOR1 overexpression reversed the effects of miR­106­5p on PDGF­induced PASMCs. The functional roles of miR­106b­5p in PDGF­induced PASMCs and an APE mouse­model, and the underlying molecular mechanisms were evaluated. AgomiR­106b­5p improved APE­induced mortality and pulmonary vascular proliferation in mice. These data suggest that miR­106­5p is a novel regulator of proliferation of PASMCs and of pulmonary vascular remodeling through PDGF­induced PASMCs in an APE mouse model via targeting NOR1. These results expand the understanding of the pathogenesis underlying APE and highlight potential novel therapeutic targets.

Analysis of the nucleocytoplasmic shuttling RNA-binding protein HNRNPU using optimized HITS-CLIP method.

RNA-binding proteins (RBPs) control many types of post-transcriptional regulation, including mRNA splicing, mRNA stability, and translational efficiency, by directly binding to their target RNAs and their mutation and dysfunction are often associated with several human neurological diseases and tumorigenesis. Crosslinking immunoprecipitation (CLIP), coupled with high-throughput sequencing (HITS-CLIP), is a powerful technique for investigating the molecular mechanisms underlying disease pathogenesis by comprehensive identification of RBP target sequences at the transcriptome level. However, HITS-CLIP protocol is still required for some optimization due to experimental complication, low efficiency and time-consuming, whose library has to be generated from very small amounts of RNAs. Here we improved a more efficient, rapid, and reproducible CLIP method by optimizing BrdU-CLIP. Our protocol produced a 10-fold greater yield of pre-amplified CLIP library, which resulted in a low duplicate rate of CLIP-tag reads because the number of PCR cycles required for library amplification was reduced. Variance of the yields was also reduced, and the experimental period was shortened by 2 days. Using this, we validated IL-6 expression by a nuclear RBP, HNRNPU, which directly binds the 3'-UTR of IL-6 mRNA in HeLa cells. Importantly, this interaction was only observed in the cytoplasmic fraction, suggesting a role of cytoplasmic HNRNPU in mRNA stability control. This optimized method enables us to accurately identify target genes and provides a snapshot of the protein-RNA interactions of nucleocytoplasmic shuttling RBPs.

MicroRNA-24-3p Targets Notch and Other Vascular Morphogens to Regulate Post-ischemic Microvascular Responses in Limb Muscles.

MicroRNAs (miRs) regulate complex processes, including angiogenesis, by targeting multiple mRNAs. miR-24-3p-3p directly represses eNOS, GATA2, and PAK4 in endothelial cells (ECs), thus inhibiting angiogenesis during development and in the infarcted heart. miR-24-3p is widely expressed in cardiovascular cells, suggesting that it could additionally regulate angiogenesis by acting on vascular mural cells. Here, we have investigated: 1) new miR-24-3p targets; 2) the expression and the function of miR-24-3p in human vascular ECs; 3) the impact of miR-24-3p inhibition in the angiogenesis reparative response to limb ischemia in mice. Using bioinformatics target prediction platforms and 3'-UTR luciferase assays, we newly identified Notch1 and its Delta-like ligand 1 (Dll1) to be directly targeted by miR-24-3p. miR-24-3p was expressed in human ECs and pericytes cultured under normal conditions. Exposure to hypoxia increased miR-24-3p in ECs but not in pericytes. Transfection with a miR-24-3p precursor (pre-miR-24-3p) increased miR-24-3p expression in ECs, reducing the cell survival, proliferation, and angiogenic capacity. Opposite effects were caused by miR-24-3p inhibition. The anti-angiogenic action of miR-24-3p overexpression could be prevented by simultaneous adenovirus (Ad)-mediated delivery of constitutively active Notch intracellular domain (NICD) into cultured ECs. We next demonstrated that reduced Notch signalling contributes to the anti-angiogenic effect of miR-24-3p in vitro. In a mouse unilateral limb ischemia model, local miR-24-3p inhibition (by adenovirus-mediated miR-24-3p decoy delivery) restored endothelial Notch signalling and increased capillary density. However, the new vessels appeared disorganised and twisted, worsening post-ischemic blood perfusion recovery. To better understand the underpinning mechanisms, we widened the search for miR-24-3p target genes, identifying several contributors to vascular morphogenesis, such as several members of the Wingless (Wnt) signalling pathway, ß-catenin signalling components, and VE-cadherin, which synergise to regulate angiogenesis, pericytes recruitment to neoformed capillaries, maturation, and stabilization of newly formed vessels. Among those, we next focussed on ß-catenin to demonstrate that miR-24-3p inhibition reduces ß-catenin expression in hypoxic ECs, which is accompanied by reduced adhesion of pericytes to ECs. In summary, miR-24-3p differentially targets several angiogenesis modulators and contributes to autonomous and non-autonomous EC crosstalk. In ischemic limbs, miR-24-3p inhibition increases the production of dysfunctional microvessels, impairing perfusion. Caution should be observed in therapeutic targeting of miR-24-3p.

rs1016860 of BCL2 3'UTR associates with hsa-miR-629-5p binding potential in breast cancer and gastric cancer in Isfahan population.

INTRODUCTION: Breast cancer is caused by the interaction of inherited and environmental risk factors. Also, gastric cancer is the second fatal carcinoma. B-cell leukemia/lymphoma 2 gene family plays a crucial role in carcinogenesis by inhibiting the apoptosis process. MATERIALS AND METHODS: In this study, 129 patients with breast cancer and 132 controls as well as 136 patients with gastric cancer and 50 controls were enrolled. We used Real time PCR to determine the genotype of the samples. Finally, we analyzed the diagram based on high temperature melting curve diagram using the MICPCR software, followed by bioinformatics prediction of rs1016860 functions. RESULTS: rs1016860 of BCL2 gene with CC, CT, and TT genotypes were observed in this region. The association of Estrogen receptor and Progesterone receptor, cancer stage and grade of cancer in the patients with genotypes was significant in breast cancer. The association of the status of primary tumor in the patients with genotypes is significant in gastric cancer (Chi-Square p < 0.05 and p = 0.000 did not follow the Hardy-Weinberg equilibrium). DISCUSSION: It was predicted that the TT genotype could be dangerous in breast cancer and gastric cancer; it is expected via bioinformatics that this SNP could lead to signaling pathways of cancer progression, by altering the binding potential of miR-629-5p to BCL2 3'UTR.

Short Direct Repeats in the 3' Untranslated Region Are Involved in Subgenomic Flaviviral RNA Production.

Mosquito-borne flaviviruses consist of a positive-sense genome RNA flanked by the untranslated regions (UTRs). There is a panel of highly complex RNA structures in the UTRs with critical functions. For instance, Xrn1-resistant RNAs (xrRNAs) halt Xrn1 digestion, leading to the production of subgenomic flaviviral RNA (sfRNA). Conserved short direct repeats (DRs), also known as conserved sequences (CS) and repeated conserved sequences (RCS), have been identified as being among the RNA elements locating downstream of xrRNAs, but their biological function remains unknown. In this study, we revealed that the specific DRs are involved in the production of specific sfRNAs in both mammalian and mosquito cells. Biochemical assays and structural remodeling demonstrate that the base pairings in the stem of these DRs control sfRNA formation by maintaining the binding affinity of the corresponding xrRNAs to Xrn1. On the basis of these findings, we propose that DRs functions like a bracket holding the Xrn1-xrRNA complex for sfRNA formation.IMPORTANCE Flaviviruses include many important human pathogens. The production of subgenomic flaviviral RNAs (sfRNAs) is important for viral pathogenicity as a common feature of flaviviruses. sfRNAs are formed through the incomplete degradation of viral genomic RNA by the cytoplasmic 5'-3' exoribonuclease Xrn1 halted at the Xrn1-resistant RNA (xrRNA) structures within the 3'-UTR. The 3'-UTRs of the flavivirus genome also contain distinct short direct repeats (DRs), such as RCS3, CS3, RCS2, and CS2. However, the biological functions of these ancient primary DR sequences remain largely unknown. Here, we found that DR sequences are involved in sfRNA formation and viral virulence and provide novel targets for the rational design of live attenuated flavivirus vaccine.

Reduction of miR-212 contributes to pituitary adenoma cell invasion via targeting c-Met.

The current study aimed to evaluate the expression and role of miR-212 in the progression of pituitary adenoma (PA), thereby providing a theoretical basis and potential therapy methods for PA patients. Our data showed that miR-212 levels were significantly reduced in PA tissues than normal pituitary tissues. However, no significant difference was identified in the serum of PA patients and healthy control. In addition, the expression of miR-212 in invasive PA was significantly lower than that in noninvasive and normal pituitary tissues. Moreover, the level of miR-212 was decreased with the increase of tumor invasion. Meanwhile, the expression of miR-212 in giant adenomas was significantly lower than that in macroadenomas and microadenomas. Furthermore, inhibition of miR-212 significantly enhanced the proliferation and invasive capacity of GH3 cells. Dual luciferase reporter assay and western blot analysis confirmed that c-Met was a target gene of miR-212. More importantly, upregulation of c-Met significantly prompted PA cell proliferation mainly as a result of the enhanced level of phosphorylation of AKT. This effect could be abolished when c-Met was silenced in GH3 cells. In summary, reduced miR-212 expression in PA contributed to abnormal cancer cell proliferation and invasion mainly by targeting c-Met.

MiR-126 inhibits cell migration and invasion by targeting ADAM9 in oral squamous cell carcinoma.

OBJECTIVE: Oral squamous cell carcinoma (OSCC), the most frequent head and neck cancer, has a high potential for metastasis. MiR-126 plays an important role in the tumorigenesis of many tumors; however, there were little studies in OSCC. The purpose of our study was to explore how miR-126 and ADAM9 worked on migration and invasion in OSCC. PATIENTS AND METHODS: The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was applied to detect the mRNA level of miR-126 and ADAM9. The transwell assay was utilized to calculate the migratory and invasive capacities in the OSCC cells. The luciferase report assay was utilized to verify that ADAM9 was a direct target of miR-126. RESULTS: MicroR-126 was downregulated in OSCC tissues and cell lines SCC25 and HSC3. ADAM9 was predicted to be a direct target of miR-126 and was upregulated in the OSCC cells. In addition, miR-126 suppressed the migratory and invasive ability via mediating the expression of ADAM9 by directly targeting its mRNA 3'-noncoding region (UTR), whose partial functions was reversed by ADAM9. CONCLUSIONS: MiR-126 inhibited the migratory and invasive capacities of OSCC by directly targeting the 3'-UTR of ADAM9 mRNA. It is suggested that miR-126/ADAM9 axis may play an essential role in inhibiting the abilities of migration and invasion in oral squamous cell carcinoma cells.