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21.
抑癌因子miRNA-7(miR-7)在肿瘤组织发生中表达下降,但机制未明。最近发现环状RNA-7(ciRS-7)具有miR-7海绵样吸附作用,从而抑制miR-7的功能,该发现为探索miR-7在肿瘤中表达降低的原因开辟了新的途径。目前认为ciRS-7/miR-7轴不仅具有重要的生物学作用,同时参与机体多种疾病的发生发展。笔者就ciRS-7/miR-7轴调控肿瘤生长转移的研究进展进行综述。  相似文献   
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背景:mi RNA通过调节特异靶基因的表达,在疾病的发展及预后中起着重要作用。目的:探索mi RNA-21在宫颈癌Hela细胞中对TLR4基因的调控关系。方法:通过miR NA靶基因预测网站寻找可能与miR NA-21相互作用的靶基因,利用已构建的携带pri-mi RNA-21基因重组腺病毒载体,包装并大量扩增病毒感染Hela细胞,检测荧光蛋白的表达水平,提取感染48 h蛋白,通过Western印迹检测TLR4蛋白表达。从蛋白水平验证在Hela细胞中mi RNA-21与靶基因TLR4的靶向调控关系。结果与结论:100 MOI的重组腺病毒p Ad/pri-miR NA-21、p Ad/neg可以成功感染Hela细胞。生物信息学方法显示mi RNA-21和TLR4存在可能的结合位点。发现感染pA d/pri-miR NA-21组与对照组pA d/neg及空白组相比,TLR4蛋白的表达量明显降低。证实了mi RNA-21可以负调节靶基因TLR4的表达。  相似文献   
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目的 检测microRNA-181a(miR-181a)在急性淋巴细胞白血病(ALL)患儿中的表达水平,并研究其在ALL细胞株CCRF-CEM细胞及耐药株CEM-C1细胞中的功能.方法 采用实时荧光定量PCR方法检测ALL患儿骨髓样本、ALL细胞株CCRF-CEM细胞及其耐药株CEM-C1细胞中miR-181a的表达水平.采用电穿孔转染的方法抑制耐药株CEM-C1细胞并上调非耐药株CCRF-CEM细胞中miR-181a的表达,予不同浓度梯度(终浓度分别为0.01、0.1、1、10、100、1 000 ng/ml)喜树碱处理后,采用CCK-8法观察各浓度梯度喜树碱处理后细胞的存活情况,绘制细胞增殖抑制曲线并计算半数抑制浓度(IC50).结果 初诊-复发组患儿初诊及复发骨髓样本miR-181a相对表达水平(4.84±2.71及6.53±2.20)均高于对照组(1.41±0.53)(P=0.017、0.001),初诊-完全缓解组患儿初诊骨髓样本miR-181a水平(7.58±2.50)较对照组明显升高(P=0.000),而完全缓解后miR-181a水平下降至1.35±0.35,与对照组比较差异无统计学意义(P=0.863).CEM-C1细胞miR-181a相对表达水平(-4.39±0.08)较CCRF-CEM细胞(-2.32±0.03)明显升高(P=0.000).转染miR-181a抑制剂CEM-C1细胞较转染阴性对照组增殖抑制率明显升高(P<0.05),IC50分别为30.61、2 255.00 ng/ml,耐药指数(RI) =73.67.miR-181a过表达CCRF-CEM细胞较阴性对照组增殖抑制率明显降低(P<0.05),IC50分别为126.60、1.34 ng/ml,RI=94.26.结论 ALL患儿骨髓及CEM-C1细胞中miR-181a异常高表达,抑制CEM-C1细胞中miR-181a的表达可明显增加CEM-C1细胞的药物敏感性,在CCRF-CEM细胞中上凋miR-181a的表达能明显增加CCRF-CEM细胞的耐药性.  相似文献   
24.
microRNA(miRNA)是一类普遍存在的小分子RNA,通常在转录后水平抑制靶基因的表达。 miRNA参与了多种疾病的基因调控并与糖尿病病程的发展有关。糖尿病是最常见的内分泌代谢疾病,糖尿病前期是指一种异常的血糖状态,特征为糖耐量减低和(或)空腹血糖受损。糖尿病前期在最终进展为显性2型糖尿病之前,可以持续相当长的时间,目前关于循环miRNA在2型糖尿病及糖尿病前期中的作用仍需大量研究证实。  相似文献   
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As a mechanical and exogenous stimulus, exercise training induces cardiac physiological hypertrophy, and the cardiac structure is changed slowly, steadily and coordinately. Simultaneously, energy metabolism and function of the cardiac muscle are also improved. These are positive adaptations in the heart when experiencing endurance exercise training. Recently, angiotensin Ⅱ type 1 (AT1) receptor, autophagy and miRNAs are all considered as important regulators to cardiac hypertrophy induced by exercise training at different molecular levels. Fully understanding the relations and the important role of AT1 receptor, autophagy and miRNAs in cardiac physiological hypertrophy will further enrich the signaling pathway of cardiac hypertrophy induced by exercise training.  相似文献   
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MicroRNA polymorphisms may be associated with carcinogenesis or immunopathogenesis of infection. We evaluated whether the mircoRNA-604 (miR-604) polymorphism can affect the persistence of hepatitis B virus (HBV) infection, and the development to hepatocellular carcinoma (HCC) in patients with chronic HBV infection. A total of 1,439 subjects, who have either past or present HBV infection, were enrolled and divided into four groups (spontaneous recovery, chronic HBV carrier without cirrhosis, liver cirrhosis and HCC). We genotyped the precursor miR-604 genome region polymorphism. The CC genotype of miR-604 rs2368392 was most frequently observed and T allele frequency was 0.326 in all study subjects. The HBV persistence after infection was higher in those subjects with miR-604 T allele (P=0.05 in a co-dominant and dominant model), which implied that the patients with miR-604 T allele may have a higher risk for HBV chronicity. In contrast, there was a higher rate of the miR-604 T allele in the chronic carrier without HCC patients, compared to those of the HCC patients (P=0.03 in a co-dominant model, P=0.02 in a recessive model). The T allele at miR-604 rs2368392 may be a risk allele for the chronicity of HBV infection, but may be a protective allele for the progression to HCC in chronic HBV carriers.

Graphical Abstract

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30.
Gastric cancer is the fourth most common cancer in the world and the second leading cause of cancerrelated death.More than 80%of diagnoses occur at the middle to late stage of the disease,highlighting an urgent need for novel biomarkers detectable at earlier stages.Recently,aberrantly expressed microRNAs(miRNAs)have received a great deal of attention as potential sensitive and accurate biomarkers for cancer diagnosis and prognosis.This review summarizes the current knowledge about potential miRNA biomarkers for gastric cancer that have been reported in the publicly available literature between 2008 and 2013.Available evidence indicates that aberrantly expressed miRNAs in gastric cancer correlate with tumorigenesis,tumor proliferation,distant metastasis and invasion.Furthermore,tissue and cancer types can be classified using miRNA expression profiles and next-generation sequencing.As miRNAs in plasma/serum are well protected from RNases,they remain stable under harsh conditions.Thus,potential functions of these circulating miRNAs can be deduced and may implicate their diagnostic value in cancer detection.Circulating miRNAs,as well as tissue miRNAs,may allow for the detection of gastric cancer at an early stage,prediction of prognosis,and monitoring of recurrence and/or lymph node metastasis.Taken together,the data suggest that the participation of miRNAs in biomarker development will enhance the sensitivity and specificity of diagnostic and prognostic tests for gastric cancer.  相似文献   
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