The expression of Mirc1/Mir17–92 cluster in sputum samples correlates with pulmonary exacerbations in cystic fibrosis patients

Introduction

Cystic fibrosis (CF) is a multi-organ disorder characterized by chronic sino-pulmonary infections and inflammation. Many patients with CF suffer from repeated pulmonary exacerbations that are predictors of worsened long-term morbidity and mortality. There are no reliable markers that associate with the onset or progression of an exacerbation or pulmonary deterioration. Previously, we found that the Mirc1/Mir17–92a cluster which is comprised of 6 microRNAs (Mirs) is highly expressed in CF mice and negatively regulates autophagy which in turn improves CF transmembrane conductance regulator (CFTR) function. Therefore, here we sought to examine the expression of individual Mirs within the Mirc1/Mir17–92 cluster in human cells and biological fluids and determine their role as biomarkers of pulmonary exacerbations and response to treatment.

A urinary microRNA (miR) signature for diagnosis of bladder cancer

Introduction

Bladder cancer (BC) is diagnosed by cystoscopy, which is invasive, costly and causes considerable patient discomfort. MicroRNAs (miR) are dysregulated in BC and may serve as non-invasive urine markers for primary diagnostics and monitoring. The purpose of this study was to identify a urinary miR signature that predicts the presence of BC.

Predisposition to treatment response in major depressive episode: A peripheral blood gene coexpression network analysis

Antidepressant efficacy is insufficient, unpredictable and poorly understood in major depressive episode (MDE). Gene expression studies allow for the identification of significantly dysregulated genes but can limit the exploration of biological pathways. In the present study, we proposed a gene coexpression analysis to investigate biological pathways associated with treatment response predisposition and their regulation by microRNAs (miRNAs) in peripheral blood samples of MDE and healthy control subjects. We used a discovery cohort that included 34 MDE patients that were given 12-week treatment with citalopram and 33 healthy controls. Two replication cohorts with similar design were also analyzed. Expression-based gene network was built to define clusters of highly correlated sets of genes, called modules. Association between each module’s first principal component of the expression data and clinical improvement was tested in the three cohorts. We conducted gene ontology analysis and miRNA prediction based on the module gene list. Nine of the 59 modules from the gene coexpression network were associated with clinical improvement. The association was partially replicated in other cohorts. Gene ontology analysis demonstrated that 4 modules were associated with cytokine production, acute inflammatory response or IL-8 functions. Finally, we found 414 miRNAs that may regulate one or several modules associated with clinical improvement. By contrast, only 12 miRNAs were predicted to specifically regulate modules unrelated to clinical improvement. Our gene coexpression analysis underlines the importance of inflammation-related pathways and the involvement of a large miRNA program as biological processes predisposing associated with antidepressant response.     

微小RNA与肿瘤耐药

 【摘要】　微小RNA （miRNA）是近年来在真核生物中发现的、在转录后水平负调控基因表达的一类长约22个核苷酸的非编码小分子RNA。miRNA生物学效应广泛,与细胞生长、凋亡、新陈代谢和信号转导等密切相关。已报道miRNA在各种肿瘤中表达失常,可能发挥着癌基因和抑癌基因的双重作用,同时越来越多的研究表明miRNA在调节肿瘤细胞对抗肿瘤药物耐药方面发挥着重要作用。系统深入地研究miRNA在肿瘤耐药中的机制,将为发展基于miRNA逆转肿瘤耐药的治疗策略提供重要的依据。     

实时荧光定量PCR方法检测石蜡包埋组织microRNA表达的方法探讨

目的:探讨从石蜡包埋组织中运用实时荧光定量PCR(RQ-PCR)方法检测microRNA表达的可靠性和敏感性。方法:选取2005年至2010年从石河子大学医学院第一附属医院、新疆伊犁哈萨克族自治州友谊医院收集的97例福尔马林固定、石蜡包埋食管癌组织样本,提取组织总RNA,RT-PCR逆转录为cDNA,实时荧光定量PCR法检测microRNA表达。结果:97例食管癌组织样本中,RNA提取成功90例,7例失败,运用实时荧光定量PCR成功检测了83例microRNA表达,7例检测不准确。RNA提取成功率明显高于失败率,实时荧光定量PCR检出的定量准确例数高于定量不准确例数,P<0.05,差异具有统计学意义。结论:实时荧光定量PCR(RQ-PCR)方法是检测石蜡包埋组织中microRNA表达的一种有效方法。     

Tolerance versus immune response — MicroRNAs as important elements in the regulation of the HLA-G gene expression

HLA-G is a class Ib HLA which has gained much attention due to its multiple functions on the immune system. HLA-G exerts several immunomodulatory effects, being beneficially implicated in embryo implantation and fetal survival but, conversely, being potentially detrimental in tumors and viral infections. Such a two-edged sword behavior suggest that HLA-G expression is under tight regulation. However, to date, little is known about the regulation of this gene and previous works have been unable to well correlate HLA-G regulation at the mRNA level with the polymorphic variants at the genomic level. Here we present the hypothesis that an element, which was until now neglected, might play a role in HLA-G expression regulation: MicroRNAs might participate in the regulation of the HLA-G gene expression through a putative microRNA binding site at its 3′ UTR region. Inside the 20 nt region of this microRNA binding site lies a C/G polymorphism, which was shown to be responsible for differential microRNA binding affinity and translation suppression. The role of microRNA binding on the regulation of HLA-G gene expression (and therefore on tolerance versus immune response) can be easily tested through relatively simple steps: Confirming the expression of those three complementary microRNAs in human cells which express HLA-G, followed by examination of the correlation between HLA-G mRNA and protein production controlling for HLA-G genotypes and microRNA levels; finally, selective inhibition of microRNA activity with anti-sense oligos restoring HLA-G production would access microRNA influence on HLA-G expression which, if confirmed, might help in the development of strategies to the management of several conditions in which HLA-G is involved, including pregnancy complications, transplantation, and cancer.     

The tumor-promoting activity of 2-acetylaminofluorene is associated with disruption of the p53 signaling pathway and the balance between apoptosis and cell proliferation

The aromatic amine 2-acetylaminofluore (2-AAF) is a powerful complete genotoxic rat liver carcinogen that induces tumors without any additional interventions. While the tumor-initiating genotoxic activity of 2-AAF is well established, its tumor-promotion activity is far less understood. It is believed that the tumor-promoting property of 2-AAF is associated with selective enhancement of cell replication and sustained suppression of apoptosis in initiated cells. In the present study, we investigated the underlying mechanisms of tumor-promoting events induced by 2-AAF-exposure. Male Sprague-Dawley rats were fed NIH-31 diet containing 0.02% of 2-AAF for 12 and 24 weeks, and the expression pattern of genes associated with the p53-signaling pathway and microRNA genes was determined in the livers of control and 2-AAF-fed rats. The results indicate that the tumor-promoting property of 2-AAF during hepatocarcinogenesis is associated predominantly with the up-regulation of anti-apoptotic growth-related genes and down-regulation of expression of pro-apoptotic genes. This disrupts the balance between cell proliferation and apoptosis, which leads to consequential unrestricted cell proliferation, especially of initiated cells. Also, the long-term-administration of 2-AAF resulted in disruption of regulatory miR-34a-p53 feed-back loop that mediates apoptosis. This was evidenced by an increased expression of miR-34a in response to genotoxic effects of 2-AAF in the absence of p53 up-regulation, and loss of regulatory control of mir-34a on SIRT1 function. Additionally, the livers of 2-AAF-exposed rats were characterized by the substantial deregulation of expression of miR-18, miR-21, miR-182, and miR-200 family, microRNAs involved in control of apoptosis/cell proliferation and cell-cell contact pathways, two major pathways disrupted during the promotion stage of hepatocarcinogenesis.