Long Non-coding RNA Maternally Expressed Gene 3 Research Articles

Prognostic significance of long non coding maternally expressed gene 3 in pediatric acute myeloid leukemia.

The purpose of this study was to evaluate the correlation of long non-coding RNA maternally expressed gene 3 (Lnc-MEG3) with disease features, treatment response, and survival in pediatric acute myeloid leukemia (AML) patients.Among 92 de novo pediatric AML patients (before treatment and after 1 course of induction) and 40 controls, bone marrow mononuclear cells were obtained. Then, Lnc-MEG3 expression was determined by reverse transcription quantitative polymerase chain reaction. After 1 course of standard induction therapy of pediatric AML patients, complete remission (CR) was assessed. Furthermore, event-free survival (EFS) and overall survival (OS) were determined according to follow-up data.Lnc-MEG3 was reduced in pediatric AML patients compared with controls. In pediatric AML patients, Lnc-MEG3 was correlated with French-American-Britain subtypes and lower Chinese Medical Association risk stratification, while it was not associated with cytogenetic features, FLT3-ITD mutation, CEBPA mutation, NPM1 mutation, WT1 mutation, or National Comprehensive Cancer Network risk stratification. After 1 course of treatment, Lnc-MEG3 exhibited an up-regulation trend. Furthermore, Lnc-MEG3 was of no difference before treatment between patients with and without CR, while elevated Lnc-MEG3 and change of Lnc-MEG3 after 1 course of treatment were associated with increased CR rate. Additionally, increased Lnc-MEG3 expression before treatment was associated with longer EFS but not OS, while enhanced Lnc-MEG3 expression after 1 course of treatment was correlated with both prolonged EFS and OS.Lnc-MEG3 may have clinical significance as a biomarker for assisting with disease management, treatment optimization, and prognosis improvement in pediatric AML patients.

Role of long non-coding RNA MEG3 in hyperglycose-induced neurocyte damage in rats: relationship with mitochondrion-dependent apoptosis

Objective To evaluate the role of long non-coding RNA maternally expressed gene 3 (MEG3) in hyperglycose-induced neurocyte damage and the relationship with mitochondrion-dependent apoptosis in rats. Methods Normally cultured PC12 cells were divided into 5 groups (n=18 each) using a random number table method: normal concentration of glucose control group (C group), normal concentration of glucose plus MEG3 group (C+ MEG3 group), high-concentration glucose group (HG group), high-concentration glucose plus MEG3 group(HG+ MEG3 group), and high-concentration glucose plus negative lentiviral vector (LV-NC) group (HG+ NC group). PC12 cells were cultured in DMEM medium with 25 mmol/L glucose in group C. PC12 cells were cultured in DMEM medium with 25 mmol/L glucose after being transfected with MEG3 lentiviral vector (LV-MEG3) in C+ MEG3 group.PC12 cells were cultured in DMEM medium with 250 mmol/L glucose in HG group.PC12 cells were incubated in DMEM medium containing 250 mmol/L glucose after being transfected with LV-MEG3 in HG+ MEG3 group.PC12 cells were incubated in DMEM medium containing 250 mmol/L glucose after being transfected with LV-NC in HG+ NC group.After the cells were cultured or incubated for 1 day, the cell viability was measured by CCK8 assay, the apoptosis rate and level of reactive oxygen species (ROS) were determined by flow cytometry, and the amount of lactic dehydrogenase (LDH) released was measured by DCFH-DA, the expression of Cyt c, caspase-3, caspase-9, Bcl-2, Bax and Apaf-1 was determined by Western blot, and the opening of mitochondrial permeability transition pore (mPTP) was determined by fluorescent method.Blc-2/Bax ratio was calculated. Results Compared with group C, the cell viability was significantly decreased, the amount of LDH released, ROS level and apoptosis rate were increased, the opening of mPTP was increased, and the expression of caspase-3, caspase-9, Cyt c, Bax, Bcl-2 and Apaf-1 was up-regulated in HG, HG+ MEG3 and HG+ NC groups, and Bcl-2/Bax ratio was increased in HG+ MEG3 group and decreased in HG and HG+ NC groups (P<0.05). Compared with HG group and HG+ NC group, the cell activity was significantly increased, the amount of LDH released, ROS level and apoptosis rate were decreased, the opening of mPTP was decreased, the expression of caspase-3, caspase-9, Cyt c, Bax, and Apaf-1 was down-regulated, the expression of Bcl-2 was up-regulated, and Bcl-2/Bax ratio was increased in HG+ MEG3 group (P<0.01). Conclusion MEG3 may be involved in the endogenous protective mechanism during hyperglycose-induced neurocyte damage by inhibiting mitochondrion-dependent apoptosis in rats. Key words: RNA, long noncoding; Diabetes mellitus; Neurons; Apoptosis

LncRNA MEG3 aggravates palmitate-induced insulin resistance by regulating miR-185-5p/Egr2 axis in hepatic cells.

Long non-coding RNA (LncRNA) has been reported to play an important role in type 2 diabetes (T2D). We investigated the role of LncRNA maternally expressed gene 3 (MEG3) and its potential interaction with miR-185-5p in palmitate-induced hepatocyte insulin resistance. High-fat diet (HFD) mice and insulin resistant hepatocyte were employed. Relative mRNA expressions of MEG3, miR-185-5p, and early growth response proteins-2 (Egr2) were measured by qRT-PCR. Western blot was performed to evaluate Egr2 protein expression levels. Glycogen contents and plasma insulin levels were tested by the corresponding assay. MEG3 and Egr2 were upregulated, but miR-185-5p was downregulated in palmitate-treated insulin resistance hepatocytes and HFD mice. MEG3 knockdown alleviated the influence of palmitate on insulin resistance in vitro and in vivo. miR-185-5p expression was upregulated upon MEG3 knockdown. Expression of Egr2 was positively correlated with MEG3 knockdown or overexpression, which could be negatively managed by abnormal expression of miR-185-5p. Our data demonstrated that LncRNA MEG3 aggravated palmitate-induced insulin resistance by regulating miR-185-5p/Egr2 axis, providing new insights into T2D therapeutic strategies.

MicroRNA‐26b‐5p Regulates Bone Marrow Mesenchymal Stem Cell Differentiation to Pericytes via Targeting Platelet‐Derived Growth Factor Receptor‐β and Interacting with Long non‐Coding RNA Maternally Expressed Gene 3 in Liver Fibrosis and Angiogenesis

Background/AimsPericytes are important regulators of vascular morphogenesis and function in multiple biological processes, including liver fibrosis, which is closely associated with angiogenesis. However, the origin and functional role of pericytes during liver fibrosis have not been deciphered yet.MethodsMice received irradiation and transplantation of EGFP‐labeled bone marrow (BM) mesenchymal stem cells (BMSCs), which obtained from EGFP transgenic mice and had been sorted and purified by immunomagnetic cell sorting with anti‐CD146 microbeads. Four weeks later, the BM was reconstructed and the chimera mice with EGFP‐labeled BMSCs were fed with methionine‐choline‐deficient and high fat (MCDHF) diet to build liver injury model. Expression of pericyte markers or fibrosis markers was characterized by qRT‐PCR, Western blot, immunofluerescent staining and microarray analysis. Biotin‐avidin pull‐down and lucifer reporter assay were performed to validate the binding of microRNA (miR)‐26b‐5p and its target platelet‐derived growth factor receptor beta (PDGFR‐β). GO, KEGG and Reactome enrichment analysis was conducted to clarify the function of differentially expressed genes.ResultsIncreased expression of pericyte markers (e.g. PDGFR‐β, neural glial antigen 2, regulator of G protein signaling 5) was detected in MCDHF mice with a positive correlation with fibrosis markers (e.g. TGF‐β1, α‐smooth muscle actin, procollagen α1(I) and (III)). Numerous PDGFR‐β+ pericytes was found in the fibrotic liver not only around mature vessels but also around nascent vessels, and a significant proportion (72.5%) of pericytes in mouse fibrotic liver derived from BMSCs. BMSCs differentiated into pericytes under TGF‐β1 treatment in vitro. Long non‐coding RNA maternally expressed gene 3 (LncMEG3), which had been focused on its effects on angiogenesis recently, positively regulated PDGFR‐β expression during BMSC differentiation to pericytes. Bioinformatics analysis from three databases (miRanda, TargetScan, and RNA22v2) suggested that miR‐26b‐5p was predicted to target PDGFR‐β. MiR‐26b‐5p negatively regulated BMSC differentiation to pericytes via directly targeting PDGFR‐β in cultured BMSCs. GO, KEGG and Reactome enrichment analysis revealed that miR‐26b‐5p overexpression affected a list of genes associated with cell differentiation, angiogenesis and extracellular matrix. LncMEG3 acted as a molecular sponge of miR‐26b‐5p thus contributed to the de‐repression of miRNA target PDGFR‐β. MiR‐26b‐5p agomir blocked BMSC differentiation to pericytes and attenuates liver fibrosis and angiogenesis in vivo.ConclusionmiR‐26b‐5p regulates BMSC differentiation to pericytes via targeting PDGFR‐β and interacting with lncMEG3, which may represent an effective therapeutic strategy for liver fibrosis.Support or Funding InformationThis work was supported by grants from the National Natural and Science Foundation of China (81430013, 81500465) and the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20150502)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Long non-coding RNA maternally expressed gene 3 expression in non-small cell lung cancer and its role in proliferation and migration

Objective To evaluate the maternally expressed gene 3 (MEG3) expression in non-small cellu luang cancer and its role proliferation and migration. Methods Fourty eight paties diagnosed of non-small cell lung cancer were included in this study. The MEG3 expression of the cancer tissue and normal lung tissue for the 48 cases were tested by real-time quantitative polymerase chain reaction (Real-time PCR) assay. The lung cancer cell line of A549 and H460 were transfected with long non-coding RNA MEG3 over expression plasmid (Pc-DNA3.1-MEG3). After transfection of Pc-DNA3.1-MEG3, the ablity of prolifieration and migration were tested by methyl thiazol tetrazolium (MTT) and wound assay. The associated protein fore prolifieration and migration were tested by Western blotting assay. Results Compared with normal lung tissue, 25 (52.08%) cancer tissue were showed low expression of MEG3 with statistical difference (P<0.05); The expression of MEG3 were 0.48±0.04, 0.62±0.05 and 10.36±1.78, 11.66±2.01 in A549 AND H460 lung cancer cell line for transfection of pcDNA3.1 and pcDNA3.1-MEG3 with statistical difference (P<0.05); The proliferation and migration ability was significant decreased after transfection of pcDNA3.1-MEG3 for A549 and H460 lung cancer cells (P<0.05). And the cyclin D1 protein expression was significant inhibit after transfection of pcDNA3.1-MEG3 (P<0.05). Conclusion MEG3 was relative low expressed in non-small cell lung cancer (NSCLC) and it inhibits proliferation and migration through inbibiting Cyclin D1 expression. Key words: Non-samll cell lung cancer; Long non-coding RNA; Maternally expressed gene 3; Proliferation; Migration