Regulatory Effects Of microRNAs Research Articles

Expression of miR-210-3p in the aqueous humor of patients with age-related cataracts and its effect on human lens epithelial cell injury induced by hydrogen peroxide

Purpose: The regulatory effect of microRNA on diseases has been confirmed. This study aimed to evaluate the expression of microRNA-210-3p in age-related cataracts and assess the effect of abnormal miR-210-3p expressions on H2O2-induced SAR01/04 cells. Methods: Reverse-transcription quantitative polymerase chain reaction method was performed to assess the levels of miR-210-3p in aqueous humor samples. Receiver operating characteristic analysis was employed to assess the discrimination ability of miR-210-3p between patients with age-related cataracts and healthy people, and Pearson correlation analysis was used to identify the correlation between miR-210-3p and oxidative stress indices such as superoxide dismutase, glutathione peroxidase, malonaldehyde. Cell counting kit-8 assay and Transwell assay were used to estimate the biological function of H2O2-induced age-related cataract cell model. The levels of oxidative stress indices such as superoxide dismutase, glutathione peroxidase, and malonaldehyde were measured to evaluate the degree of oxidative stress damage in the age-related cataract cell model. The relationship between miR-210-3p and its target gene was verified by luciferase reporter gene analysis. Results: The miR-210-3p expression was elevated in the aqueous humor of patients with age-related cataracts. A high miR-210-3p expression showed a high diagnostic value for age-related cataracts and was significantly associated with the level of oxidative stress markers in patients with age-related cataracts. The inhibition of miR-210-3p can reverse oxidative stress stimulation and adverse effects on H2O2-induced cell function. Conclusions: The results suggested that miR-210-3p could promote cell viability, cell migration, and oxidative stress by targeting autophagy-related gene 7 in in vitro age-related cataract cell model.

Identification of novel factors that affect the onset of idiopathic chronic pancreatitis: The role for microRNA-323b-5p.

The c.194+2 T>C variant of serine protease inhibitor Kazal type 1 (SPINK1) is a known genetic risk factor found in Chinese patients with idiopathic chronic pancreatitis (ICP), but the early-onset mechanisms of ICP are still unclear. Complementary experimental approaches were used to pursue other potential pathologies in the present study. The serum level of SPINK1 of ICP patients in the Han population in China was detected and verified by an enzyme-linked immunosorbent assay. Next, differentially expressed proteins and microRNAs from plasma samples of early-onset and late-onset ICP patients were screened by proteomic analysis and microarray, respectively. Combined with these advanced methods, the data strongly suggest that the regulatory effects of microRNAs were involved in the early-onset mechanism of the ICP by in vitro experiments. There was no significant difference in the plasma SPINK1 expression between the early-onset ICP and the late-onset patients. However, the expression of plasma glutathione peroxidase (GPx3) in early-onset ICP patients was markedly lower than that in late-onset ICP patients, although the level of hsa-miR-323b-5p was lower in late-onset patients compared to the early-onset ICP group. In vitro experiments confirmed that hsa-miR-323b-5p could increase apoptosis in caerulein-treated pancreatic acinar cells and inhibit the expression of GPx3. The up-regulated hsa-miR-323b-5p might play a crucial role in the early-onset mechanisms of ICP by diminishing the antioxidant activity through the down-regulation of GPx3.

MicroRNA-146: Biomarker and Mediator of Cardiovascular Disease

Cardiovascular diseases (CVDs) are the prime cause of morbidity and mortality worldwide. Although noticeable progress has been made in the diagnosis, prognosis, and treatment, there is still a critical demand for new diagnostic biomarkers and novel therapeutic interventions to reduce this disease incidence. Many investigations have been conducted on the regulatory effects of microRNAs in cardiovascular diseases. miRNA circulating serum level changes are correlated with several CVDs. In addition, there is growing evidence representing the potential role of miRNAs as diagnostic biomarkers or potential therapeutic targets for CVD. Preliminary studies identified the prominent role of miR-146 in host defense, innate immunity, and different immunological diseases by regulating cytokine production and innate immunity modification in bacterial infections. However, more recently, it was also associated with CVD development. miR-146 has received much attention, with positive results in most studies. Research demonstrated the crucial role of this molecule in the pathogenesis of cardiac disease and related mechanisms. As a result, many potential applications of miR-146 are expected. In this paper, we provide an overview of recent studies highlighting the role of miR-146 in CVD, focusing on CAD (coronary artery disease), cardiomyopathy, and MI (myocardial infarction) in particular and discussing its current scientific state, and use a prognostic biomarker as a therapeutic agent for cardiovascular diseases.

The Regulatory Effects of MicroRNAs on Tumor Immunity.

MicroRNAs are endogenous noncoding small RNAs that posttranscriptionally regulate the expressions of their target genes. Accumulating research shows that miRNAs are crucial regulators of immune cell growth and antitumor immune response. Studies on miRNAs and tumors primarily focus on the tumor itself. At the same time, relatively few studies on the indirect regulatory effects of miRNAs in the development of tumors are achieved by affecting the immune system of tumor hosts and altering their immune responses. This review discusses the influence of miRNAs on the antitumor immune system.

[Regulatory effects of microRNAs on hepatic stellate cell activation and liver fibrogenesis].

Hepatic fibrogenesis (HF) is the common consequence of various chronic liver diseases (CLD) induced by a variety of pathogenic factors. The mechanism of HF involves the interactions within different types of liver cells, cytokines, chemokines, cell mediators and multiple signaling pathways in a way of networks. As a result, excessive production and deposition of extracellular matrix (ECM) mainly composed of type I and type III fibril forming collagen destroys the original morphology, structure and function of the liver. The activation of hepatic stellate cells (HSCs), the major scar forming cells in liver, plays a crucial role in hepatic fibrogenesis. MicroRNAs are a group of short, single stranded, non-coding RNAs that can inhibit mRNA expression at the transcriptional and post transcriptional levels. They can be loaded and transferred as cargos by exosomes, to regulate the function of nearby and distant receptive cells. The expressions of many microRNAs such as miR-21, miR-29, miR-708, miR-101, miR-455, miR-146, miR-193 change significantly in activated HSCs, which regulate the activation, fibrogenic function, proliferation, apoptosis and autophagy of HSCs via affecting target genes expression and signaling pathway molecules. They are important substances and regulatory mechanism that mediate the initiation and progression of HF.

Resveratrol Inhibits NLRP3 Inflammasome-Induced Pyroptosis and miR-155 Expression in Microglia Through Sirt1/AMPK Pathway.

Resveratrol is a natural polyphenolic compound with a wide range of biological activities such as antioxidant, anti-carcinogenic, anti-obesity, anti-aging, anti-inflammatory, immunomodulatory properties. Accumulating evidence suggests that resveratrol has pharmacological benefits in life-threatening diseases, including cardiovascular disease, cancer, diabetes, and neurodegenerative diseases. Resveratrol is widely known for its anti-inflammatory properties; however, signaling mechanisms of anti-inflammatory action are still elusive. Studies have illustrated that resveratrol can control different regulatory pathways by altering the expression and consequently regulatory effects of microRNAs. Our study aims to clarify the regulatory mechanisms of resveratrol in its anti-inflammatory features in the N9 microglial cell line. Our results demonstrated that resveratrol inhibits LPS- and ATP-activated NLRP3 inflammasome and protects microglial cells upon oxidative stress, proinflammatory cytokine production, and pyroptotic cell death resulting from inflammasome activation. Additionally, resveratrol inhibits nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and activates AMPK/Sirt1 pathways. Furthermore, our results indicated that resveratrol downregulated inflammasome-induced miR-155 expression. Then, inhibition of AMPK and Sirt1 pathways has significantly reversed protective effect of resveratrol on miR-155 expression. To sum up, our results suggest that resveratrol suppresses the NLRP3 inflammasome and miR-155 expression through AMPK and Sirt1 pathways in microglia.

Role of the Outer Inflammatory Protein A/Cystine–Glutamate Transporter Pathway in Gastric Mucosal Injury Induced by Helicobacter pylori

INTRODUCTION:Helicobacter pylori infection is a major cause of gastrointestinal diseases. However, the pathogenesis of gastric mucosal injury by H. pylori remains unclear. Exogenous glutamate supplementation protects against gastric mucosal injury caused by H. pylori. Previously, we showed that aspirin-induced gastric injury is associated with reduction in glutamate release by inhibition of cystine–glutamate transporter (xCT) activity. We hypothesized that the xCT pathway is involved in H. pylori-induced gastric mucosal injury. In this study, we tested the activity of xCT and evaluated the regulatory effect of outer inflammatory protein (Oip) A on xCT in H. pylori-induced gastric mucosal injury.METHODS:In the H. pylori-infected mice and cell lines, the activity of xCT and the regulatory effect of microRNA on xCT were tested, and the effect of OipA from H. pylori on xCT activity was observed.RESULTS:The results of in vivo and in vitro experiments showed that H. pylori infection induced gastric mucosal injury. This was accompanied by a reduction in xCT activity, which was attenuated by exogenous glutamate treatment. Furthermore, the expression of miR-30b was upregulated, and miR-30b inhibitors significantly restored xCT activity and gastric mucosal injury caused by H. pylori infection. The OipA, a virulence protein from H. pylori, significantly upregulated the expression levels of miR-30b and inhibited xCT activity.DISCUSSION:OipA plays a significant role in H. pylori-induced gastric mucosal injury, and the effects are mediated by micro30b/xCT pathway.

MicroRNA let‑7d‑5p rescues ovarian cancer cell apoptosis and restores chemosensitivity by regulating the p53 signaling pathway via HMGA1.

Ovarian cancer (OC) is the gynecological malignancy type with the highest mortality rate in females. The regulatory effect of microRNAs(miRs) on their target genes serves a key role in tumor development. Therefore, in the present study, whether miR let‑7d‑5p targeting high mobility groupA1(HMGA1) regulated biological characteristics and chemosensitivity of OC cells by mediating the p53 signaling pathway was investigated. The let‑7d‑5p level was detected in OC tissues and adjacent normal tissues, followed by detection in OC cell lines SKOV3, A2780, OVCAR‑3 and CaOV3, and human normal ovarian epithelial cell line(IOSE‑80), in order to select the OC cell line for the following experiments. Subsequently, OC cells were treated with the let‑7d‑5p mimic, siHMGA1 and Tenovin‑1. The targeting association between let‑7d‑5p and HMGA1 was then examined, and the OC cell viability, migration, cycle and apoptosis were evaluated. Subsequently, the chemosensitivity of OC cells to cisplatin was verified. Finally, expression levels of let‑7d‑5p, HMGA1, p21, B‑cell lymphoma‑2(Bcl‑2)‑associatedX (Bax), p27, p53 wild‑type(p53wt), p53 mutated (p53mut), proliferating cell nuclear antigen(PCNA), cyclin‑dependent kinase2(CDK2), matrix metallopeptidase(MMP)2, MMP9 and Bcl‑2 were determined. As demonstrated in the results, let‑7d‑5p expression was low in OC tissues and had an increased reduction in the OVCAR‑3 cell line. HMGA1 was confirmed as a target of let‑7d‑5p, and its expression was also silenced by let‑7d‑5p. let‑7d‑5p repressed OC cell viability, migration, cell cycle progression and apoptosis, while it promoted the chemosensitivity of OC cells to cisplatin by targeting HMGA1. The expression of let‑7d‑5p, p21, Bax, p27 and p53wt was increased, while that of HMGA1, p53mut, PCNA, CDK2, MMP2, MMP9 and Bcl‑2 was reduced following cell transfection. The results in the present study provided evidence that let‑7d‑5p may suppress proliferation, and facilitate apoptosis and cisplatin chemosensitivity of OC cells by silencing HMGA1 via the p53 signaling pathway.

Role of microRNAs in the resistance of colorectal�cancer to chemoradiotherapy (Review)

Colorectal cancer (CRC) is among the main tumor-related causes of death worldwide. The fact that the majority of the patients develop resistance to chemoradiotherapy (CRT) is a major obstacle for the treatment of CRC. In order to develop more effective treatment strategies, it is crucial to elucidate the mechanisms underlying the development of resistance to CRT. Several studies have recently indicated the regulatory effects of microRNAs (miRNAs) in response to antitumor agents. For example, miR-34a attenuates the chemoresistance of colon cancer to 5-FU by inhibiting E2F3 and SIRT1. The miR-34a mimic MRX34 is the first synthetic miRNA to have been entered into clinical trials. miR-21 prevents tumor cell stemness, invasion and drug resistance, which are required for the development of CRC. These findings suggest that miRNAs represent a focus in the research of novel cancer treatments aimed at sensitizing cancer cells to chemotherapeutic drugs. The aim of the present study was to review the functions of miRNAs and investigate the roles of miRNAs in CRC radioresistance or chemoresistance. Furthermore, the potential of including miRNAs in therapeutic strategies and using them as molecular biomarkers for predicting radiosensitivity and chemosensitivity was discussed.

An alternative microRNA-mediated post-transcriptional regulation of GADD45A by p53 in human non-small-cell lung cancer cells

GADD45A (growth arrest and DNA damage inducible alpha), a stress response gene induced by genotoxic and nongenotoxic stresses, is implicated in various key processes, including the control of cell cycle checkpoints and DNA repair. The expression of GADD45A is directly regulated by numerous transcription factors, with p53 being the most representative. Moreover, post-transcriptional regulation also plays a role in GADD45A expression. However, little is known about the regulatory effects of microRNAs (miRNAs) on GADD45A expression. As a potential tumour suppressor, miR-138 has pleiotropic biological functions in various cancers. We have previously reported p53-mediated activation of miR-138 in human non-small-cell lung cancer (NSCLC) cells. In this study, we found that miR-138 specifically targeted AGO2, which affects the stability and maturation of miR-130b. Decreased expression of miR-130b promoted the expression of GADD45A and resulted in the G2/M phase arrest and proliferation inhibition in human NSCLC cells. Our results suggested that p53 could alternatively upregulate GADD45A in human NSCLC cells through a post-transcriptional pathway in which miR-138 is involved.

Evidence for the relationship between the regulatory effects of microRNAs and attack robustness of biological networks

It has been previously suggested that microRNAs (miRNAs) have a tendency to regulate the important components of biological networks. The goal of the present study was to systematically test if one can establish a relationship between miRNA targets and the important components of biological networks (including human protein-protein interaction network, signaling network and metabolic network). For this analysis, we have studied the attack robustness of these networks. It has been previously shown that deletion of network vertices in descending order of their importance (e.g., in decreasing order of vertex degrees) can affect the network structure much more considerably. In the current study, we introduced three miRNA-based measures of importance: “miRNA count” (i.e., the number of miRNAs that regulate a given network component); average adjacent miRNA count, “AAmiC” (i.e., the average number of miRNAs regulating the targeted components adjacent to a given component); and total adjacent miRNA count, “TAmiC” (i.e., the total number of miRNAs regulating the targeted components adjacent to a given component). Our results suggest that “miRNA count” is only marginally capable of locating the important components of the networks, while TAmiC was the most relevant measure. By comparing TAmiC with the classical centrality measures (which are solely based on the network structure) when simultaneously removing vertices, we show that this measure is correlated to degree and betweenness centrality measures, while its performance is generally better than that of closeness and eigenvector centrality measures. The results of this study suggest that TAmiC which represents a measure based on both network structure and biological knowledge, can successfully determine the important network components indicating that miRNA regulation and network robustness are related.

The effect of microRNA-101 on biological behaviord of human prostate cancer cell line PC-3 by targeting enhancer of zeste homolog 2

Objective To investigate the regulatory effect of microRNA (miR)-101 on the biological features of human prostate cancer cell line PC-3 by targeting enhancer of zeste homolog 2 (EZH2).Methods The expression of miR-101 and EZH2 in prostate cancer cell lines (PC-3,and LNCaP) and normal prostate epithelial RWPE-1 cell line was detected by real-time quantitative polymerase chain reaction (Real-time PCR) and Western blotting respectively.Dual luciferase reporter gene assay was employed to determine if miR-101 could target EZH2 through binding to 3' untranslated region (3 '-UTR) of EZH2 mRNA.PC-3 cells were transfected with synthetic miR-101 mimic.Methyl thiazol tetrazolium (MTT) assays were used to measure the proliferation of the PC-3 cells.Flow cytometry was used to analyze the cell cycle distribution.Annexin V/propidium iodide (PI) double staining was used to measure cell apoptosis.The wound scrape assays were used to measure the cell motility.Transwell invasion assays were used to analyze the invasiveness in vitro.Results The expression levels of miR-101 in PC-3 and LNCaP cell lines were lower than in the RWPE-1 cell line,while the expression levels of EZH2 mRNA and protein were higher.There was a negative correlation between the expression of miR-101 and EZH2 (P ＜ 0.05).Dual luciferase reporter gene assay confirmed EZH2 was one of regulatory genes by miR-101.After miR-101 mimic was transfected into prostate cancer PC-3 cells,the expression of miR-101 was up-regulated (P ＜ 0.05),and that of EZH2 mRNA and protein was down-regulated significantly (P ＜ 0.05).The growth rate in miR-101 group was lower significantly than that in two control groups at 48,72 and 96 h after transfeetion (P ＜ 0.05).Flow eytometry analysis showed there was G0/G1 phase arrest in miR-101 group compared to two control groups (P ＜ 0.05).Cell apoptosis rate in transfected experimental group with miR-101 mimics (miR-101 group),blank control group and negative control group at 48 h after transfection was (9.84 ± 0.83) ％,(2.53 ± 0.36) ％ and (2.71 ± 0.42) ％ respectively.The apoptosis rate in miR-101 group was higher than two control groups (P ＜ 0.01).Scarification test demonstrated that the migration of cells in miR-101 group was more slowly than two control groups (P ＜ 0.01).Transwell test showed that the number of PC-3 cells penetrating the Matrigel gel in miR-101 group was significantly less than two control groups (P ＜ 0.01).Conclusion EZH2 may be one of target genes of miR-101 that plays a negative regulatory role.The upregulation of miR-101 can lead to the lower expression of EZH2 in PC3 cells,suggesting miR-101 exerts significantly inhibitory effect on prostate cancer. Key words: Prostate cancer;  MicroRNA-101 ;  Enhancer of zeste homolog 2

Biological characteristics of colon cancer stem cells: recent progress

Colon cancer stem cells(CCSCs)play key roles in tumor initiation,proliferation,metastasis,and chemoresistance.Currently a large number of reports focused on markers of CCSCs,with relative less reporting on CCSCs biological characteristics:proliferation,metastasis,and chemoresistance.This paper reviewed the current research on the biological behavior of CCSCs,with special attention paid on the regulatory effects of microRNAs on CCSCs,hoping to provide reference for improving the diagnosis and treatment of colon cancer.

The CML-Microvesicles Are Enriched with Mirnas Regulating MAPK Signaling Pathway.

Abstract 2786Leukemia-cell-derived microvesicles (MVs) act as vehicles for exchange of genetic information between leukemia and nomal cells, engendering a favorable microenvironment for leukemia development. Within the leukemia mass, all cell types may contribute to MV shedding, but specific contributions to tumor progression have yet to be established. MVs contain microRNAs that could be transferred to target cells inducing epigenetic changes. MicroRNAs are short non-coding regulatory RNAs that control gene expression and play an important role in cancer development and progression. However, little is known about the role of miRNAs in chronic myeloid leukemia (CML)-derived MVs. Given the attributes of MVs and microRNAs in leukemia progression, we therefore aimed to investigate a possible regulatory effect of microRNAs upon MVs as a mean to uncover molecular events involved in promotion of leukemogenesis by MVs.Hnece, we determined the miRNA expression profiles of CML-derived MVs and their parental cells using Agilent miRNA microarray analysis. The six miRNAs obtained by microarray profiling were validated using real-time PCR. The potential targets of the differentially expressed microRNAs were predicted using computational searches. Bioinformatic analyses of the predicted target genes were done for further research.We identified 104 microRNAs aberrantly expressed in both CML-derived MVs and their parental cells, indicating that CML-derived MVs miRNA is the mini version of the parental cells. Target gene-related pathway analyses showed that majority of the 104 microRNAs involved in the signaling pathways associated with leukemia, especially the mitogen-activated protein kinase (MAPK) signaling pathways. We found 34 microRNAs targeted 44 genes of the MAKP pathway, suggesting that the MAPK signaling pathway may commonly function together.By further conducting microRNA gene network analysis, we found that the miR-15a/b, miR-16, miR-17and miR-30 families are likely to play key roles in the regulation of MAPK pathways. The figure showed microRNA-gene interaction networks related to the pathway. The has-miR-30 family (except for hsa-miR-30a hsa-miR-30d) showed that the most target mRNAs, with degrees from 6 to 9, while hsa-miR-17, hsa-miR-16 and hsa-miR-15a/b occupy an important position in the MAPK pathway. The seven microRNAs might play an important role in the pathogenesis of CML.The MAPK pathway is a common point of convergence of many different mitogenic and anti-apoptotic signal transduction pathways in hematopoietic, as well as epithelial, cancer cells and can now be clinically targeted by highly selective small molecule inhibitors. Such deregulation of MAPK pathways contributes to BCR-ABL leukemogenesis, and their targeting with selective inhibitors provides an approach to enhance anti-leukemic responses and/or overcome leukemic cell resistance in CML. A large body of evidence has established that RAS/MAPK signaling contribute to the survival of BCR-ABL positive cells under imatinib selection pressure. It is evident that release of microRNAs from the lumen of MVs can induce activation of specific signal transduction cascades and influence the physiologic state of recipient cells. So the MVs derived from leukemia cells may weaken or enhance the expression of mRNA involved in MAPK pathway in recipient cells, and come to remodel the leukemia niche.In conclusion, we first demonstrated that CML-MVs were enriched with expression changes of distinct sets of miRNAs regulating MAPK sinaling pathway. MAPK sinaling pathway were active in CML-MVs and may commonly function together. We believe that this new correlation among MVs, microRNAs and MAPK pathway can be exploited to both better understand leukemia progression and also suggest novel therapies for leukemias. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

STAT signalling in malignant mesothelioma: Is there a regulatory effect of microRNAs?

PURPOSE: STAT1 and STAT3 are dysregulated in human malignant mesothelioma (MM), an aggressive cancer, with poor knowledge about predictive factors of outcome. Asbestos exposure is the main cause. Since microRNAs (miRNAs) are known to regulate the expression of target mRNAs, the aim of the study was to quantify selected miRNAs in MM which are thought to be involved in the STAT signalling pathway to gain more insight into a possible regulatory mechanism. PATIENTS: RNA was obtained from 35 formalin-fixed and paraffin-embedded tumour tissue samples. MATERIAL AND METHODS: MiRNAs were selected via in silico target prediction tools. Quantitative real-time PCR was used to assess the expression levels of the miRNAs. The reference gene RNU6B was used for normalization. An immunohistochemical (IHC) staining with 5 antibodies was performed on tissue microarray sections to correlate it with the results of the miRNA detection. RESULTS: MiR-106a (targeting STAT3) expression was increased in 63% of cases. MiR-155, miR-19a and miR-30d* (targeting SOCS1, SOCS1 and STAT1, respectively) were downregulated in all cases. Due to very low expression levels, miR-196a*, miR-608 and miR-765 (targeting SOCS6, PIAS1, and SOCS3, respectively) were not detected. Positive IHC staining was achieved for STAT1, pSTAT1(Ser727), STAT3 and PIAS1. STAT1 was higher expressed than STAT3; SOCS1 was not detected by IHC. CONCLUSION: An inverse correlation was found for pSTAT1 and miR-30d* (p = 0.014) and this miRNA may interact with STAT1 (p = 0.062). STAT3 is not affected by miR-106a (p = 0.53) although this miRNA is expected to play an important role in MM.

MRNA expression profiles show differential regulatory effects of microRNAs between estrogen receptor-positive and estrogen receptor-negative breast cancer

Most microRNAs have a stronger inhibitory effect in estrogen receptor-negative than in estrogen receptor-positive breast cancers