hsa-mir-520真核表达载体的构建及对E-钙粘蛋白表达的影响

目的 构建hsa-mir-520真核表达载体,并转染大肠癌细胞SW-480细胞,检测细胞中E-钙粘蛋白表达情况.方法 依据miRBase数据库中hsa-mir-520序列,设计并合成寡核苷酸片段,构建hsa-mir-520表达载体和对照载体.采用脂质体转染方法分别将mir-520表达载体、及对照质粒转染大肠癌细胞SW-480细胞株.采用酶切、测序检测载体构建;Western blot检测E-钙粘蛋白的表达.结果 酶切和测序表明hsa-mir-520真核表达载体构建成功.Western blot结果显示与转染对照质粒和未转染的细胞相比,转染了hsa-mir-520重组质粒的细胞中E-cadherin蛋白的表达明显增加(P<0.01),密度扫描半定量分析显示E-cadherin蛋白的表达增加了大约40%.结论 成功构建了hsa-mir-520和对照的真核表达载体,hsa-mir-520质粒转染大肠癌细胞SW-480后可增加E-钙粘蛋白的表达.     

Silencing of microRNA‐122 is an early event during hepatocarcinogenesis from non‐alcoholic steatohepatitis

Non‐alcoholic steatohepatitis (NASH) has emerged as a common cause of chronic liver disease and virus‐independent hepatocellular carcinoma (HCC) in patients with obesity, diabetes, and metabolic syndrome. To reveal the molecular mechanism underlying hepatocarcinogenesis from NASH, microRNA (miRNA) expression profiles were analyzed in STAM mice, a NASH‐HCC animal model. MicroRNA expression was also examined in 42 clinical samples of HCC tissue. Histopathological images of the liver of STAM mice at the ages of 6, 8, 12, and 18 weeks showed findings compatible with fatty liver, NASH, liver cirrhosis (LC), and HCC, respectively. Expression of miR‐122 in non‐tumor LC at the age of 18 weeks was significantly lower than that in LC at the age of 12 weeks. Expression of miR‐122 was further decreased in HCCs relative to non‐tumor LC at the age of 18 weeks. Expression of miR‐122 was also decreased in clinical samples of liver tissue showing macrovesicular steatosis and HCC, being consistent with the findings in the NASH model mice. DNA methylation analysis revealed that silencing of miR‐122 was not mediated by DNA hypermethylation of the promoter region. These results suggest that silencing of miR‐122 is an early event during hepatocarcinogenesis from NASH, and that miR‐122 could be a novel molecular marker for evaluating the risk of HCC in patients with NASH.     

Serum microRNA-1 and microRNA-122 are prognostic markers in patients with hepatocellular carcinoma

BackgroundThe identification of new biomarkers to predict the aggressiveness of hepatocellular carcinoma (HCC) and supplement the current set of prognosis and treatment algorithms is an important clinical need. Extracellular microRNAs (miRNAs) circulating in the blood are a new class of highly promising disease markers.AimHere we investigated the prognostic potential of miR-1 and miR-122 in sera from patients with HCC.MethodsRNA was extracted from 195 sera of HCC patients and 54 patients with liver cirrhosis, obtained at the time of study enrolment. miR-1 and miR-122 levels were correlated with overall survival (OS), Cancer of the Liver Italian Program (CLIP) score, Barcelona Clinic Liver Cancer stage, clinical chemistry parameters and tumor specific treatment.ResultsPatients with higher miR-1 and miR-122 serum levels showed longer OS than individuals with lower miR-1 and miR-122 serum concentrations (hazard ratio [HR] 0.440, 95% confidence interval [CI] 0.233–0.831, P = 0.011 for miR-1 and HR 0.493, 95% CI 0.254–0.956, P = 0.036 for miR-122, respectively). Serum miR-1 and miR-122 concentrations did not differ significantly between patients with HCC and liver cirrhosis. An age-, sex-, tumor stage and treatment-adjusted multivariate Cox regression analysis revealed that miR-1 serum levels (HR 0.451, 95% CI 0.228–0.856, P = 0.015) were independently associated with OS, whereas serum miR-122 was not. miR-1 serum levels showed no relevant correlation with clinical chemistry liver parameters, whereas serum miR-122 correlated with clinical chemistry parameters of hepatic necroinflammation, liver function and synthetic capacity.ConclusionOur data indicate that serum miR-1 is a new independent parameter of OS in HCC patients and may therefore improve the predictive value of classical HCC staging scores.     

MicroRNA-122 Promotes Proliferation,Invasion and Migration of Renal Cell Carcinoma Cells Through the PI3K/Akt Signaling Pathway

Objective: MicroRNAs (miRNAs) are a small class of non-coding, single-stranded RNAs with a criticalrole in genesis and maintenance of renal cancer mainly through binding to 3’-untranslated regions (3’UTR) oftarget mRNAs, which causes a block of translation and/or mRNA degradation. The aim of the present studywas to investigate the potential effects of miR-122 in human renal cell carcinomas. Methods: The expressionlevel of miR-122 was quantified by qRT-PCR. MTT, colony formation, invasion and migration assays were usedto explore the potential functions of miR-122 in human renal cell carcinoma cells. Results: Cellular growth,invasion and migration in two A498 and 786-O cells were significantly increased after miR-122 transfection.Further experiments demonstrated that overexpression of miR-122 resulted in the increase of phospho-Akt(Ser473) and phospho-mTOR (Ser2448), then activation of mTOR targets, p70S6K and 4E-BP1. Conclusions:The up-regulation of miR-122 may play an important role in the progress of renal cancer through activatingPI3K/Akt signal pathway and could be a potential molecular target for anti-cancer therapeutics.     

mi R-122 negatively correlates with liver fibrosis as detected by histology and FibroScan

AIM: To investigate whether expression of selected mi RNAs obtained from fibrotic liver biopsies correlate with fibrosis stage.METHODS: Altogether, 52 patients were enrolled in the study representing various etiologic backgrounds of fibrosis: 24 cases with chronic hepatitis infections(types B, C), 19 with autoimmune liver diseases(autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, overlapping syndrome cases), and 9 of mixed etiology(alcoholic and nonalcoholic steatosis, cryptogenic cases). Severity of fibrosis was determined by both histologic staging using the METAVIR scoring system and noninvasive transient elastography. Following RNAisolation, expression levels of mi R-21, mi R-122, mi R-214, mi R-221, mi R-222, and mi R-224 were determined using Taq Man Micro RNA Assays applying mi R-140 as the reference. Selection of mi RNAs was based on their characteristic up- or downregulation observed in hepatocellular carcinoma. Relative expression of mi RNAs was correlated with fibrosis stage and liver stiffness(LS) value measured by transient elastography, as well as with serum alanine aminotransferase(ALT) level.RESULTS: The expression of individual mi RNAs showed deregulated patterns in stages F1-F4 as compared with stage F0, but only the reduced level of mi R-122 in stage F4 was statistically significant(P 0.04). When analyzing mi RNA expression in relation to fibrosis, levels of mi R-122 and mi R-221 showed negative correlations with fibrosis stage, and mi R-122 was found to correlate negatively and mi R-224 positively with LS values(all P 0.05). ALT levels displayed a positive correlation with mi R-21(P 0.04). Negative correlations were observed in the fibrosis samples of mixed etiology between mi R-122 and fibrosis stage and LS values(P 0.05), and in the samples of chronic viral hepatitis, between mi R-221 and fibrosis stage(P 0.01), whereas mi R-21 showed positive correlation with ALT values in the samples of autoimmune liver diseases(P 0.03). The results also revealed a strong correlation between fibrosis stage and LS values(P 0.01) when etiology of fibrosis was not taken into account.CONCLUSION: Reduced expression of mi R-122 in advanced fibrosis and its correlation with fibrosis stage and LS values seem to be characteristic of hepatic fibrosis of various etiologies.     

实时荧光定量RT-PCR检测肝癌组织中miR-122a及miR-224的表达

目的 运用实时荧光定量RT-PCR方法分析miR-122与miR-224两种miRNAs在原发性肝细胞癌(HCC)中的表达,探讨以miRNAs为靶点在早期肝癌中的临床诊断意义.方法 采用基于2(-△△ACT)的实时荧光定量RT-PCR法对35例肝癌组织及癌旁组织的miR-122a及miR-224进行了定量分析,结果经由Noahernblot验证.结果 与正常组织相比,在所有的被检肝癌组织中,均发现了miR-122a有不同程度的表达下调(P<0.01),而上述肝癌组织中的miR-224的定量结果显示该miRNA表达显著增加(P<0.001).结论 HCC组织中存在上述两种miRNAs表达水平的改变.实时荧光定量RT-PCR法为早期、准确的在临床上检测肝组织癌变提供了新的思路.     

叶下珠复方Ⅱ号对肝星状细胞增殖和miR-122/KLF6表达的影响

目的观察叶下珠复方Ⅱ号对肝星状细胞(HSC-T6)增殖及miR-122/KLF6表达的影响,探讨其抗肝纤维化的作用机制。方法体外培养HSC-T6细胞,分为空白对照组、叶下珠复方Ⅱ号高剂量组(120 g/L)和低剂量组(60 g/L),采用四甲基偶氮唑盐(MTT)法检测药物对HSC-T6细胞增殖的影响,实时荧光定量PCR法检测药物处理后HSC-T6细胞miR-122、KLF6和TGF-β1 m RNA表达的改变,Western blot法检测KLF6蛋白表达的变化。结果叶下珠复方Ⅱ号处理HSC-T6细胞后,叶下珠复方Ⅱ号高、低剂量组对HSC-T6细胞增殖均有明显的抑制作用。叶下珠复方Ⅱ号高、低剂量组HSC-T6细胞的miR-122表达增加,尤以高剂量组作用显著,与空白对照组比较,差异有统计学意义(P<0.01)。叶下珠复方Ⅱ号高、低剂量组KLF6 m RNA和蛋白表达均显著减少,TGF-β1 m RNA的表达明显抑制,与空白对照组比较,差异均有统计学意义(P<0.01),并呈明显的剂量-效应关系。结论叶下珠复方Ⅱ号能显著抑制HSC-T6细胞增殖,其作用机制与提高miR-122的表达、抑制其靶基因KLF6的m RNA和蛋白质表达有关。     

MicroRNA 122促进吉西他滨对体外非小细胞肺癌细胞系A549的杀伤作用

目的 探讨microRNA 122（miRNA122）对细胞毒性化疗药吉西他滨对体外杀伤非小细胞肺癌细胞株的影响.方法 利用脂质体转染miRNA122的表达载体;CCK-8测定系列浓度梯度吉西他滨检测对非小细胞肺癌细胞株A549的抑制率,计算IC50值;平板克隆实验检测吉西他滨对A549细胞杀伤的影响;流式细胞仪-Annexin/PI双染实验检测吉西他滨诱导A549细胞凋亡率.结果 吉西他滨对A549细胞具有明显地体外杀伤作用,其IC50值为（78.65±5.25）nmol/L,转染miRNA122能够上调吉西他滨的活性,其IC50值为（10.26±1.18）nmol/L;流式细胞术结果显示：A549细胞凋亡率诱导转染空载体组为26.24％±1.94％,诱导转染miRNA122组为63.30％±3.96％.miRNA122能够显著上调吉西他滨诱导A549细胞凋亡率.RT-PCR和蛋白印迹实验表明,转染miRNA122能够显著上调A549细胞内miRNA122的表达水平,降低miRNA122靶基因和调控基因的表达水平.结论 miRNA122能够上调吉西他滨对非小细胞肺癌细胞系A549的体外杀伤作用.     

启动子区甲基化对miRNA-122表达及肝癌细胞增殖和凋亡的影响

目的 探讨DNA甲基化对肝特异性miRNA-122表达调控以及肝癌细胞增殖和凋亡的影响.方法 甲基化测序检测肝细胞中miRNA-122启动子区的甲基化状态.实时定量PCR检测肝细胞中miRNA 122表达水平.流式细胞仪与CCK8检测去甲基化对肝癌细胞增殖和凋亡的影响.结果 与人原代正常肝细胞[(21.9±11.4)％]比较,Huh7、HepG2、QSG-7701细胞系miRNA-122启动子区的甲基化程度[分别为(87.6±9.3)％、(89.0±14.3)％、(69.5±11.5)％],均明显升高(P=0.000),尤其以Huh7、HepG2两种癌细胞系升高最为明显.与人原代正常肝细胞[(2.83×104±3746)]比较,三种细胞系miRNA-122的表达明显下降,其中以Huh7和HepG2两种癌细胞系降低最明显(P=0.007).与空白对照比较,在10 μmol/L的5氮杂-2′-脱氧胞苷作用下,Huh7和HepG2两种癌细胞系甲基化程度明显降低(P=0.038,0.025);而其miRNA-122表达明显升高(P=0.008,0.003).与空白对照组比较,Huh7细胞与HepG2细胞经去甲基化处理后细胞的凋亡均明显增加(P=0.001,0.027).结论 肝特异性miRNA-122的表达受DNA甲基化的明显调控,且与肝癌细胞的凋亡密切相关.miRNA122的甲基化调控可能参与了肝癌的发生和发展.