lncRNA MEG3 modified epithelial-mesenchymal transition of ovarian cancer cells by sponging miR-219a-5p and regulating EGFR

This study was aimed to verify whether there existed any associations between long noncoding RNA MEG3/miR-219a-5p/EGFR axis and the development of ovarian cancer (OC). As a whole, we gathered 317 pairs of OC tissues and surgical marginal normal tissues and simultaneously acquired four OC cell lines (ie, A2780, Caov-3, OVCAR-3, and SKOV-3) and human normal ovarian surface epithelial cell line. Moreover, pcDNA3.1-MEG3, si-MEG3, miR-219a-5p mimic, miR-219a-5p inhibitor, pcDNA3.1-EGFR, and si-EGFR were, respectively, transfected into the OC cells, and their impacts on viability, proliferation, apoptosis, invasion, and migration of OC cells were assessed via conduction of MTT assay, colony formation assay, flow cytometry assay, transwell assay, and scratch assay. Ultimately, dual-luciferase reporter gene assay was performed to testify the targeted relationships among maternally expressed gene 3 (MEG3), miR-219a-5p, and estimated glomerular filtration rate (EGFR). It was indicated that underexpressed MEG3 and miR-219a-5p were significantly associated with unfavorable prognosis of patients with OC when compared with overexpressed MEG3 and miR-219a-5p (P < .05). In addition, the OC cells transfected with si-MEG3 or miR-219a-5p inhibitor exhibited stronger viability, proliferation, invasion, and migration than untreated cells (P < .05). Correspondingly, the apoptotic percentage of OC cells was reduced observably under treatments of si-MEG3 and miR-219a-5p inhibitor (P < .05). Moreover, MEG3 exerted modulatory effects on the expression of miR-219a-5p (P < .05), and there was a sponging relationship between them (P < .05). Finally, EGFR expression was modified by both MEG3 and miR-219a-5p significantly (P < .05), and raising EGFR expression could changeover the impacts of MEG3 and miR-219a-5p on the above-mentioned activity of OC cells (P < .05). Conclusively, MEG3 could serve as a promising biomarker for diagnosis and treatment of OC, considering its involvement with OC etiology via regulation of miR-219a-5p/EGFR axis.     

RELA/NEAT1/miR-302a-3p/RELA feedback loop modulates pancreatic ductal adenocarcinoma cell proliferation and migration

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging malignancy due to distant metastasis. RELA, a major component of the NF-κB pathway, could serve as an oncogene through activating proliferation or migration-related gene expression, including NEAT1, a well-known oncogenic long noncoding RNA. In the current study, the expression and function of RELA and NEAT1 in PDAC were examined. The potential upstream regulatory microRNAs of RELA were screened and verified for their correlation with RELA and NEAT1. The expression and function of the selected miR-302a-3p were evaluated. RELA and NEAT1 expression were upregulated in PDAC tissues, particularly in PDAC tissues with lymph node metastasis, and their expression correlated with clinical parameters. RELA overexpression promoted PDAC cell proliferation and migration, which could be partially attenuated by the NEAT1 knockdown. By binding to RELA, miR-302a-3p inhibited RELA expression, as well as PDAC cell proliferation and migration. RELA downstream NEAT1 expression was negatively regulated by miR-302a-3p; the suppressive effect of NEAT1 knockdown on PDAC cell proliferation and migration was partially attenuated by miR-302a-3p inhibition. Moreover, through direct binding, the expression of miR-302a-3p was also negatively regulated by NEAT1. The expression of miR-302a-3p was downregulated and negatively correlated with RELA or NEAT1 in tissue samples, indicating that rescuing miR-302a-3p expression may inhibit PDAC cell proliferation and migration through RELA/NEAT1. In summary, RELA, NEAT1, and miR-302a-3p form a feedback loop in PDAC to modulate PDAC cell proliferation and migration.     

Interfering histone deacetylase 4 inhibits the proliferation of vascular smooth muscle cells via regulating MEG3/miR-125a-5p/IRF1

In this study, we investigated the role ofhistone deacetylase 4 (HDAC4) and MEG3/miR-125a-5p/interferonregulatoryfactor 1 (IRF1) on vascular smooth muscle cell (VSMCs)proliferation. Platelet derived growth factor (PDGF)-BB was used toinduce the proliferation and migration of VSMCs. The expressionsof MEG3, miR-125a-5p, HDAC4 and IRF1in VSMCs were detectedby qRT-PCR and western blot, respectively. ChIP assay was usedto determine the relationship between MEG3 and HDAC4. Doubleluciferase reporter assay was used to test the regulation betweenmiR-125-5p and IRF1. Results showed that PDGF-BB decreasedthe expression of MEG3 and IRF1, while increased the expressionof miR-125a-5p and HDAC4. In addition, HDAC4 knockdowninhibited the proliferation and migration of VSMCs via upregulatingMEG3 and downregulating miR-125a-5p. MiR-125a-5p inhibitorcould repress the proliferation and migration of VSMCs andalleviate intimal hyperplasia (IH) by directly upregulating IRF1expression. These results suggested that HDAC4 interferenceinhibited PDGF-BB-induced VSMCs proliferation via regulatingMEG3/miR-125a-5p/IRF1 axis, and then alleviated IH.     

PGC-1 promotes insulin resistance in liver through PPAR-alpha-dependent induction of TRB-3

Insulin resistance is a major hallmark in the development of type 2 diabetes, which is characterized by an impaired ability of insulin to inhibit glucose output from the liver and to promote glucose uptake in muscle. The nuclear hormone receptor coactivator PGC-1 (peroxisome proliferator-activated (PPAR)-gamma coactivator-1) has been implicated in the onset of type 2 diabetes. Hepatic PGC-1 expression is elevated in mouse models of this disease, where it promotes constitutive activation of gluconeogenesis and fatty acid oxidation through its association with the nuclear hormone receptors HNF-4 and PPAR-alpha, respectively. Here we show that PGC-1-deficient mice, generated by adenoviral delivery of PGC-1 RNA interference (RNAi) to the liver, experience fasting hypoglycemia. Hepatic insulin sensitivity was enhanced in PGC-1-deficient mice, reflecting in part the reduced expression of the mammalian tribbles homolog TRB-3, a fasting-inducible inhibitor of the serine-threonine kinase Akt/PKB (ref. 6). We show here that, in the liver, TRB-3 is a target for PPAR-alpha. Knockdown of hepatic TRB-3 expression improved glucose tolerance, whereas hepatic overexpression of TRB-3 reversed the insulin-sensitive phenotype of PGC-1-deficient mice. These results indicate a link between nuclear hormone receptor and insulin signaling pathways, and suggest a potential role for TRB-3 inhibitors in the treatment of type 2 diabetes.     

Long non-coding RNA MEG3 regulates CSE-induced apoptosis and inflammation via regulating miR-218 in 16HBE cells

Chronic obstructive pulmonary disease (COPD) is a prevalent disease worldwide, mainly caused by cigarette smoking. Maternally expressed gene 3 (MEG3) functions as the lncRNA and is upregulated in COPD patients and human bronchial epithelial cells after fine particulate matter (PM2.5) treatment. However, the molecular mechanism of MEG3 in COPD remains unknown. The expression of MEG3 and miR-218 in COPD tissues and cigarette smoke extract (CSE)-treated 16HBE cells was detected by RT-qPCR. The effects of MEG3 and miR-218 on proliferation and apoptosis in (CSE)-treated 16HBE cells were analyzed by CCK-8 and flow cytometry assay, respectively. The protein levels of inflammatory cytokines (IL-1β IL-6 and TNF-α) were detected in 16HBE cells by ELISA. MEG3 and miR-218 binding interaction was predicted by LncBase Predicted v.2 and further confirmed by dual luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. MEG3 was upregulated in COPD tissues and inversely related to FEV1%. MEG3 was upregulated in (CSE)-treated 16HBE cells, and knockdown of MEG3 mitigated CSE-repressed proliferation and CSE-triggered apoptosis or inflammation. MiR-218 was demonstrated as a target miRNA of MEG3. MiR-218 was downregulated in COPD tissues and (CSE)-treated or MEG3 overexpressed 16HBE cells. MiR-218 overexpression attenuated CSE-blocked proliferation and CSE-induced apoptosis or inflammation. Deficiency of MEG3 counteracted CSE-blocked proliferation CSE-induced apoptotic rate and inflammatory cytokine (IL-1β IL-6 and TNF-α) levels, while introduction of anti-miR-218 reversed these effects. MEG3 regulated CSE-inhibited proliferation and CSE-induced apoptosis or inflammation by targeting miR-218, providing a possible therapeutic target for treatment of CSE-induced COPD.     

LncRNA MEG3 regulates breast cancer proliferation and apoptosis through miR-141-3p/RBMS3 axis

Maternally expressed 3 (MEG3) and RNA binding motif single stranded interacting protein 3 (RBMS3) are abnormally expressed in breast cancer susceptibility genes (BRCA), but the mechanism of the two in breast cancer (BC) is unclear. By performing in vivo and in vitro experiments, we found that MEG3 and RBMS3 were low-expressed, negatively correlated with high-expressed miR-141-3p, were positively correlated with each other in BC. MEG3 targeted miR-141-3p, and miR-141-3p targeted RBMS3. MEG3, which was mainly distributed in BC cytoplasm, could down-regulate miR-141-3p and up-regulate RBMS3, and reverse effect of miR-141-3p on related gene expressions and on promoting cancer development. Overexpressed MEG3 inhibited growth of xenografts, promoted cell apoptosis via regulating apoptosis related factors, and up-regulated RBMS3 expression but down-regulated miR-141-3p. The findings of this study showed that MEG3 inhibited proliferation and promoted apoptosis of BC cells through the miR-141-3p/RBMS3 axis, and MEG3 inhibited growth of xenografts through miR-141-3p.     

microRNA-199a-3p,DNMT3A,and aberrant DNA methylation in testicular cancer

It was previously demonstrated that miR-199a was downregulated in testicular germ cell tumor (TGCT), probably due to hypermethylation of its promoter. Further study found that re-expression of miR-199a in testicular cancer cells (NT2) led to suppression of cell growth, cancer migration, invasion and metastasis. More detailed analyses showed that these properties of miR-199a could be assigned to miR-199a-5p, one of its two derivatives. The biological role of the other derivative, miR-199a-3p in TGCT, remains largely uncharacterized. In this report, we identified DNA (cytosine-5)-methyltransferase 3A (DNMT3A), the de novo methyltransferase, as a direct target of miR-199a-3p using a 3′-UTR reporter assay. Transient expression of miR-199a-3p in NT2 cells led to decrease, while knocking down of miR-199a-3p in a normal human testicular cell line (HT) led to elevation, of DNMT3A2 (DNMT3A gene isoform 2) mRNA and protein levels. In clinical samples, DNMT3A2 was significantly overexpressed in malignant testicular tumor, and the expression of DNMT3A2 was inversely correlated with the expression of miR-199a-3p. However, DNMT3A did not affect miR-199a expression in NT2 cells. Further characterization of miR-199a-3p revealed that it negatively regulated DNA methylation, partly through targeting DNMT3A. Overexpression of miR-199a-3p restored the expression of APC and MGMT tumor-suppressor genes in NT2 cells by affecting DNA methylation of their promoter regions. Our studies demonstrated the deregulation of miR-199a-3p expression in TGCT may provide novel mechanistic insights into TGCT carcinogenesis and suggested a potentially therapeutic use of synthetic miR-199a-3p oligonucleotides as effective hypomethylating compounds in the treatment of TGCT.     

长非编码 RNA ILF3-AS1 通过调控 miR-130a-3p/PTEN轴抑制宫颈癌细胞的增殖

ILF3反义 RNA 1(ILF3 antisense RNA 1,ILF3-AS1)是一条定位于染色体 19p13.2的lncRNA,它是白介素增强子结合因子3(interleukin enhancer binding factor 3,ILF3)的反义 RNA.ILF3-AS1在多种肿瘤发生发展中发挥关键作用,但其...     

PGE2 induces apoptosis of hepatic stellate cells and attenuates liver fibrosis in mice by downregulating miR-23a-5p and miR-28a-5p

MicroRNAs (miRNAs), small noncoding RNAs modulating messenger RNA (mRNA) and protein expression, have emerged as key regulatory molecules in chronic liver diseases, whose end stage is hepatic fibrosis, a major global health burden. Pharmacological strategies for prevention or treatment of hepatic fibrosis are still limited, what makes it necessary to establish a better understanding of the molecular mechanisms underlying its pathogenesis. In this context, we have recently shown that cyclooxygenase-2 (COX-2) expression in hepatocytes restricts activation of hepatic stellate cells (HSCs), a pivotal event in the initiation and progression of hepatic fibrosis. Here, we evaluated the role of COX-2 in the regulation of a specific set of miRNAs on a mouse model of CCl₄ and bile duct ligation (BDL)-induced liver fibrosis. Our results provide evidence that COX-2 represses miR-23a-5p and miR-28-5p expression in HSC. The decrease of miR-23a-5p and miR-28-5p expression promotes protection against fibrosis by decreasing the levels of pro-fibrogenic markers α-SMA and COL1A1 and increasing apoptosis of HSC. Moreover, we demonstrate that serum levels of miR-28-5p are decreased in patients with chronic liver disease. These results suggest a protective effect exerted by COX-2-derived prostanoids in the process of hepatofibrogenesis.     

miRNA expression profiling uncovers a role of miR-302b-3p in regulating skin fibroblasts senescence

Numbers of emerging evidence suggest that variable microRNA (miRNA) expression facilitates the aging process. In this study, we distinguished aberrant miRNA expression in aged skin and explored the biological functions and potential mechanism of upregulated miR-302b-3p. At first, miRNA microarray analysis was examined to explore miRNA expression profiling in the skin of aging mice model by D -galactose (d -gal) injection. We identified 29 aberrant miRNAs in aged mice skin. Next, KEGG enrichment analysis was conducted with DIANA-miPath v3.0, which was revealed that enrichment pathways involved in such processes as extracellular matrix-receptor interaction, MAPK signaling pathway, and mammalian target of rapamycin (mTOR) signaling pathway. The target genes of deregulated miRNAs were predicted from four bioinformatic algorithms (miRDB, Targetscan, miRwalk, and Tarbase). The interaction network of miRNAs and their targets were visualized using Cytoscape software. As a result, we found that some hub genes (including JNK2, AKT1/2/3, PAK7, TRPS1, BCL2L11, and IKZF2) were targeted by 12 potential miRNAs (including miR-302b-3p, miR-291a-5p, miR-139-3p, miR-467c-3p, miR-186-3p, etc.). Subsequently, we identified five upregulated miRNA via quantitative polymerase chain reaction and all of them were confirmed increased significantly in aged skin tissues compared with young control tissues. Among them, high expression of miR-302b-3p was verified in both aged skin tissues and senescence fibroblasts. Furthermore, miR-302b-3p mimic accelerated skin fibroblast senescence and suppressed the longevity-associated gene Sirtuin 1(Sirt1) expression, whereas miR-302b-3p inhibitor could delay skin fibroblast senescence and contribute Sirt1 expression. In addition, we demonstrated that c-Jun N-terminal kinase 2(JNK2) is a direct target of miR-302b-3p by a luciferase reporter assay. An inverse correlation was verified in fibroblasts between miR-302b-3p and JNK2. Most importantly, siRNA JNK2 confirmed that low expression of JNK2 could accelerate fibroblasts senescence. In conclusion, our results indicated that overexpressed miR-302b-3p plays an important biological role in accelerating skin aging process via directly targeting JNK2 gene.