Relative Expression Levels Of miR-155 Research Articles

Expression of miR-155 in Serum Exosomes in Children with Epilepsy and Its Diagnostic Value

Objective This study was designed to analyze the expression of miR-155 in serum exosomes in children with epilepsy and to explore its diagnostic value. Methods From March 2020 to March 2021, 43 hospitalized children with epilepsy admitted to the Department of Neurology of the hospital were included, and another 43 gender- and age-matched healthy children were randomly selected as the healthy control group during the same period. Then fasting serum samples of the two groups were collected to extract the exosomes. The morphology of the exosomes was evaluated under a transmission electron microscope, and the expression of specific protein markers on the surface was detected by Western Blot. In addition, the relative expression of miR-155 in serum exosomes in children with epilepsy with different courses of the disease and different degrees of abnormal electroencephalography (EEG) was compared, and the area under the receiver operating characteristic (ROC) curve (ROC-AUC) was used to evaluate the diagnostic value of miR-155. Results A higher relative expression level of miR-155 in serum exosomes was obtained in the epilepsy group, as compared to the healthy control group (P<0.05), and the relative expression of miR-155 in serum exosomes in children with epilepsy was correlated with the course of the disease and the degree of abnormal EEG (both P<0.05). In addition, the expression of miR-155 in serum exosomes showed high diagnostic efficiency for epilepsy (AUC = 0.813, P<0.05). Conclusion The expression of miR-155 in serum exosomes in children with epilepsy is up-regulated, and its level is related to the course of the disease and the degree of abnormal EEG, so miR-155 in serum exosomes may be used as a biomarker for the diagnosis and assessment of the severity of epilepsy.

Value of MiR-155 in Prognostic Evaluation of Elderly Patients with Primary Immune Thrombocytopenia

To explore the value of has-microRNA-155 (miR-155) in peripheral blood mononuclear cells (PBMNC) in prognostic evaluation of elderly patients with primary immune thrombocytopenia (PITP). One hundred and thirty elderly PITP patients and 60 healthy volunteers in our hospital were selected. The relative expression level of miR-155 in PBMNC was detected by RT-PCR. Unconditional logistic multivariate regression analysis was used to analyze the relationship between miR-155 expression and prognosis of PITP patients, and Kaplan-Meier was further used to analyze the relationship between miR-155 and PITP recurrence. The relative expression level of miR-155 in PBMNC of elderly PITP patients was significantly higher than that in healthy volunteers, and increased significantly with the severity of the disease (P＜0.05). The overall effective rate of elderly PITP patients with miR-155 low-expression was significantly higher than that in the patients with miR-155 high-expression (96.92% vs 72.31%) by after treatment with glucocorticoid. Multivariate analysis showed that miR-155 was an independent risk factor for PITP patients. Elderly patients with high expression of miR-155 showed a higher risk of recurrence. miR-155 in PBMNC has a high accuracy for PITP diagnosis, and the elderly patients with high level of miR-155 show a poor prognosis and a higher risk of recurrence.

Association between cytokines and two circulating micro-RNAs and development of premature ventricular contractions-induced cardiomyopathy.

Objective(s):Recent progress in understanding the pathogenesis of premature ventricular contraction (PVC)-induced cardiomyopathy (PIC) has suggested a key role for inflammation. The aim of this study was to evaluate the expression of messenger RNAs (mRNAs) and the protein production of interleukin-6 (IL-6), IL-10, tumor necrosis factor alpha (TNF-α) and interferon-γ (IFN-γ) and two circulating micro-RNAs related to inflammation and cardiovascular disease; miR-155 and miR-146.Materials and Methods:The study population was comprised 25 patients with PIC and 25 patients with normal left ventricular ejection fraction despite frequent PVCs. TNF-α, IL-6, IL10, and IFN-γ levels were evaluated in peripheral blood mononuclear cells (PBMCs) by flow cytometry and their mRNAs were assessed by real time PCR. We analyzed circulating levels of these cytokines by enzyme linked immunosorbent assay (ELISA). Two circulating micro-RNAs, miR-155 and miR-146a, were also investigated.Results:The flow cytometry findings showed that the median fluorescence intensity (MFI) of antibodies reacted with the IL-6 and TNF-α were higher in PIC group than the control group (P-value<0.001). In ELISA, the levels of IL-6 (P-value<0.001) and TNF-α (P-value <0.001) and in RT-PCR the relative expression levels of IL-6 (P-value<0.001) and TNF-α (P-value<0.001) were significantly higher in the PIC group. The relative expression levels of miR-155 and miR-146a were not significantly different between 2 groups (P-value>0.05).Conclusion:In our patients with PIC, there was an elevation in the expression levels of IL-6 and TNF-α in PBMCs. This finding may provide further insights into the inflammatory pathways involved in PIC.

Expression of MiR-155 in Tissue of Patients with Diffuse Large B-Cell Lymphoma and Its Effect on Cell Biological Characteristics

To investigate the expression of miR-155 in patients with diffuse large B-cell lymphoma (DLBCL), and to explore the effect of transfection of miR-155 inhibitor on the biological characteristics of DLBCL cells. A total of 76 patients with DLBCL treated in our hospital were selected from April 2013 to December 2017. In the same time, 40 cases of lymph node reactive hyperplasia (LNRH) were selected as control group. DB cells were cultured and divided into miR-155 inhibitor, negative control and blank groups. The expressions of miR-155 in DLBCL, negative and blank control groups were detected by using real-time PCR, the cell proliferation was detected by MTT assay, the apoptosis was detected by flow cytometry, and the cell migration and invasion were detected by Transwell assay. The relative expression level of miR-155 in tissues of DLBCL patients was significantly higher than that in tissne of controls (1.93±0.16 vs 1.01±0.09) (t=33.991, P=0.000). The expression level of miR-155 increased (P＜0.05) in DLBCL patients with LDH level abnormarity, BCL-2+, MUM1+, Ki-67≥50%, non-GC type, Ann Arbor stage III-IV, extranodal lesion number≥2 and IPI score 3-5. The relative expression level of miR-155 in the miR-155 inhibitor group was lower than that in the negative control group and the blank group (P＜0.05). The absorbance (A) values at 24, 48, 72 and 96 h of culture in the miR-155 inhibitor group were lower than those in the negative control group and the blank group (P＜0.05), while the apoptotic rate was higher than that in the negative control group and the blank group (P＜0.05). Both the migrating cells and invading cell number in the miR-155 inhibitor group were lower than those in the negative control group and the blank group (P＜0.05). The miR-155 highly expresses in DLBCL tissue, which relates with tumor malignancy and invasion progression. The specific inhibition of miR-155 expression in DB cells can reduce cell proliferation, accelerate cell apoptosis, and inhibit cell migration and invasion.

Up-regulated expression of miR-155 in human colonic cancer.

The aim of this study is to investigate the expression of miR-155 in colonic cancer tissue and to assess the potential predictive value of miR-155 in colonic cancer patients. From March to September of 2011, we included 57 patients with primary colonic cancer who underwent curative surgical resection. Total RNAs were extracted from colonic cancer tissues and adjacent normal tissues. Then the expression of miR-155 in colonic cancer and paracancerous tissues was investigated using real time quantitative reverse transcription-polymerase chain reaction. And the relationship between miR-155 expression level and the clinical, pathological parameters of colonic cancer was analyzed. The relative expression level of miR-155 in colonic cancer tissues was significantly higher than that in paracancerous tissues and related to tumor-node-metastasis staging, tumor invasion, metastasis, and differentiation. The expression of miR-155 is up-regulated in colonic cancer tissues. MiR-155 may acts as proto-oncogenes involved in carcinogenesis, development, and invasion of colon cancer making it a potential target for gene therapy of colon cancer.

MiR-155 expression level changes might be associated with initial phases of breast cancer pathogenesis and lymph-node metastasis.

Breast carcinoma is heterogeneous disease. Understanding the process of invasion and metastasis and the selection of the therapy for patients with breast carcinomas still remains difficult. MicroRNAs are powerful gene expression regulators. Because of inconsistent findings, we have analyzed potential difference in miR-155 levels in three breast cancer groups. Our goals were to examine miR-155 expression levels in normal tissue, non-invasive and invasive breast carcinomas, and their association with standard clinical and pathological parameters and oncomiR-21, and to investigate the ability of miR-155 to separate invasive breast carcinomas with non-invasive component from pure invasive. In the group of 40 breast tissue samples, relative expression levels of miR-155 were examined with stem-loop quantitative real-time PCR using TaqMan technology. The significant difference among four examined groups of the breast tissue was detected (p = 0.001). In the group of pure invasive tumors, patients with positive nodal status had significantly higher miR-155 levels (p = 0.046). Our results suggest that miR-155 might be involved in breast cancer pathogenesis and in tumor spreading to the lymph nodes, and that it might be used as biomarker for additional stratification of patients with invasive breast carcinomas with non-invasive component.

MicroRNA-155 modulates the proliferation of vascular smooth muscle cells by targeting endothelial nitric oxide synthase

A variety of microRNAs (miRNAs) have been reported to be significantly be involved in the regulation of vascular smooth muscle cell (VSMC) proliferation, which is an essential process for the formation of atherosclerotic plaque. The objective of the present study was to explore the role of microRNA-155 (miR-155) in the regulation of VSMC growth and migration. A total of 12 atherosclerotic plaque samples and 9 control samples were collected, and the expression levels of miR-155/endothelial nitric oxide synthase (eNOS) were determined in those samples by RT-qPCR and western blot analysis. The results revealed that the relative expression levels of miR-155 in the atherosclerotic plaque samples were significantly upregulated compared with those in the normal control samples. We further found eNOS to be an effective target of miR-155 in the VSMCs by luciferase assay, which was confirmed by the observation that VSMCs transfected with miR-155 mimics exhibited a significantly lower protein expression level of eNOS. We also demonstrated that the exogenous overexpression of miR-155 significantly enhanced cell proliferation by inhibiting apoptosis in human aortic SMCs (HASMCs), and it also promoted the migratory ability of the cells. In conclusion, our data demonstrate that miR-155 is significantly upregulated in atherosclerotic plaque, functioning to accelerate the proliferation and migration of VSMCs by targeting eNOS.

Changes of expression of miR-155 in colitis-associated colonic carcinogenesis

To investigate the changes of miR-155 and its target genes in colitis-associated carcinogenesis. Colitis-associated colon cancer was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in C57BL/6 mice. Mice of three different stages during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment and a DSS only group representing chronic inflammation without cancer were set up as well. Colon tissue was collected and expression of miR-155 in the colon tissues was measured by real-time fluorescent quantitative PCR. TargetScan and PicTar were used to predict potential target genes of miR-155, which were then preliminarily screened with our gene expression microarray database of AOM-DSS mouse model. Regular PCR was used to confirm the changes of the expression of these potential target genes in AOM-DSS mouse model. Colitis-associated colon cancer was effectively induced by azoxymethane and dextran sulfate sodium in C57BL/6 mice. Histological examination revealed that the evolution process was sequentially from normal, mild dysplasia, moderate dysplasia, and severe dysplasia to adenocarcinoma in the AOM-DSS mouse model. The level of miR-155 was gradually elevated with the formation of colitis-associated colon cancer. There was no significant difference between the levels of miR-155 expression in the DSS group (0.005 6 ± 0.003 7) and control group (0.012 0 ± 0.005 1) (P > 0.05), but the level of miR-155 in the AD3 group (0.054 4 ± 0.027 0) was significantly higher than that of the DSS group (0.005 6 ± 0.003 7)(P < 0.01). No significant change of miR-155 expression was found in the DSS only group. The relative expression levels of miR-155 in the control group, DSS only group and AD3 group were 0.012 0 ± 0.005 1, 0.005 6 ± 0.003 7, 0.054 4 ± 0.027 0, respectively. Data analysis with the gene expression microarray showed that Tle4, Kcna1, Itk, Bcorl1, Cacna1c, Rspo2 and Foxo3 were potential target genes of miR-155 in the AOM-DSS mouse model. Changes of Kcna1 and Cacna1c in the AOM-DSS mouse model were validated to be consistent with the changes obtained with the gene expression microarray. The up-regulation of miR-155 is related to colitis-associated carcinogenesis, but is irrelevant to chronic inflammation in the mouse model.

Effects of microRNA-155 on the growth of human lung cancer cell line 95D in vitro

背景与目的近年来的研究发现miRNAs（microRNAs）家族成员miR-155与肺癌的发生相关，然而具体机制不明。本研究拟探讨上调miR-155表达对人肺癌95D细胞体外生长的影响及其可能的作用机制，为后续深入研究miR-155在肺癌发生、发展中的作用提供新的实验依据。方法人肺癌95D细胞分为空白对照组、miR-155阴性对照组和miR-155转染组，分别作加入转染试剂、转染miR-155阴性对照和转染miR-155处理。Real-time PCR特异性探针法检测转染后95D细胞中miR-155的表达水平；应用MTT法检测miR-155对95D细胞增殖的抑制作用；流式细胞术检测95D细胞周期的分布；Western blot检测95D细胞SOS1蛋白的表达变化。结果Real-time PCR结果显示，与对照组相比，转染组95D细胞miR-155的表达水平明显增加（P < 0.05）；镜下可见转染miR-155的95D细胞生长减缓，形态发生改变；MT结果表明miR-155转染后，95D细胞增殖受到抑制，转染组和对照组存在明显差异（P < 0.05）；流式细胞术分析显示，与对照组相比，转染miR-155的95D细胞周期发生改变，G0/G1期细胞明显增多，而S期则明显减少（P < 0.05）；Western blot结果显示转染组95D细胞SOS1蛋白的表达明显降低（P < 0.05）。结论miR-155能明显抑制人肺癌95D细胞的体外生长，这可能与miR-155下调SOS1表达及诱导95D细胞G0/G1期阻滞相关。