miR-133b可能通过调控foxO1的表达影响小鼠B细胞发育

microRNAs(miRNAs)是一类具有转录后调控作用的非编码RNA,在发育、细胞增殖、凋亡及肿瘤发生等多种生理和病理过程中发挥重要作用.为全面了解小鼠B细胞中miRNAs的表达模式,利用流式细胞仪(FACS)分选处于不同发育时期的B细胞,采用TaqMan誖低密度芯片对其进行检测,筛选到pre-B阶段9个miRNAs表达量显著上调.将筛选出的miRNAs进行靶基因预测,并对预测靶基因进行功能聚类和通路分析,发现约4%的基因参与免疫系统过程,包括Bcl2、Kit等.选取foxO1与miR-19b、miR-142-3p、miR-106b、miR-182及miR-133b进行初步功能验证,双荧光素酶报告系统及Westernblot检测结果均显示,miR-133b可直接作用于foxO1 3′UTR从而降低foxO1的表达.结合人类和小鼠B细胞中foxO1的表达情况分析,其表达模式同miR-133b表达模式呈负相关,说明miR-133b可能参与了B细胞发育过程中foxO1的表达调控过程.     

新型microRNA—miR-34在肿瘤中的研究进展

miR-34是一类保守的、非编码miRNA。人类miR-34包括miR-34a、miR-34b和miR-34c等,在多种肿瘤中都呈现非正常表达。miR-34通过被p53激活,抑制E2F3、Bcl-2、c—myc、CDK4、CDK6、Cyclin D1以及Cyclin E2的表达,使肿瘤细胞停滞在G1期,抑制肿瘤细胞的生长,诱导肿瘤细胞凋亡,并通过E2F3、SIRT1与p53形成正反馈环路,不断增强其自身和p53的作用。本文就miR-34的研究进展进行综述。     

子宫蜕膜组织miR-29a、miR-155表达在小鼠流产中作用机制

[目的]探讨子宫蜕膜组织miR-29a、miR-155表达在小鼠流产过程中的作用及机制。[方法]采用DBA/2×CBA/J的Clark经典反复流产模型小鼠15只作为研究组,15只正常小鼠作为对照组,分别在妊娠15 d后摘取小鼠子宫,采用HE染色观察小鼠子宫蜕膜组织形态;PT-PCR、Western Blot等方式检测子宫蜕膜组织中miR-29a、miR-155的表达水平和MAPK家族蛋白表达水平。[结果]与正常小鼠相比,复发性流产小鼠的子宫脱膜组织细胞形态异常,细胞核数量明显减少;脱膜组织的miR-29a表达明显增加,miR-155表达显著减少;脱膜组织的P38、ERK1/2和JNK蛋白表达明显减少。[结论]复发性流产小鼠体内的miR-29a表达较正常小鼠上升,而miR-155表达下降,其主要通过抑制MAPK信号通路中的P38、ERK1/2和JNK蛋白表达来调节子宫脱膜组织病变,临床上可用于诊断复发性流产疾病。     

miR-29家族及其靶基因与恶性肿瘤关系的研究进展

微小RNA-29(microRNA-29,miR-29)家族成员包括miR-29a、miR-29b和miR-29c,是一类与器官纤维化密切相关的小分子RNA。近年研究发现,多种肿瘤组织中存在miR-29s的表达紊乱。miR-29家族不但具有抑癌作用,还有促癌作用,其有望成为肿瘤早期诊断、疗效检测或复发监测的重要新靶标。现就miR-29s及其靶基因在肿瘤细胞增殖、分化、凋亡、侵袭和转移中的作用及其研究进展进行综述。     

miR-29b对人子宫内膜癌RL95-2细胞凋亡的影响

为了探讨miR-29b对人子宫内膜癌(endometrial cancer, EC) RL95-2细胞凋亡的影响及机制,本研究将RL95-2细胞转染miR-29b mimics和miR-NC后,采用MTT法检测细胞活力;运用Annexin V-PI法检测细胞凋亡;采用Western blotting检测Caspase-3蛋白表达;使用流式细胞术检测ROS水平。研究结果显示:与miR-NC组比较,miR-29b mimics过表达miR-29b组在培养24 h和48 h后的RL95-2细胞活力显著降低(p0.05)。与miR-NC组比较,miR-29b mimics组的RL95-2细胞凋亡率显著增加(p0.05)。与miR-NC组比较,miR-29b mimics组的RL95-2细胞Cleaved caspase-3蛋白表达水平显著增加(p0.05)。此外,miR-29b mimics组的RL95-2细胞ROS水平明显低于miR-NC组(p0.05)。本研究的初步结论表明:miR-29b可能通过调控ROS水平促进人RL95-2细胞凋亡。     

miR-29家族通过AKT/mTOR信号通路抑制结肠癌MC38细胞的增殖、迁移和侵袭

结肠癌是最常见的恶性肿瘤之一,死亡人数仅次于肺癌。有研究发现miR-29家族成员(miR-29a、miR-29b和miR-29c)在结肠癌组织中的表达水平显著低于癌旁组织,但其对结肠癌的影响不明。为探讨miR-29家族对结肠癌的影响及作用机制,该研究在结肠癌细胞系MC38中分别转染miR-29a/b/c-3p mimics,利用qRT-PCR、CCK-8、EdU染色等实验确定miR-29家族成员可以显著降低MC38细胞的增殖能力(P<0.05);通过划痕实验和Transwell侵袭实验,明确miR-29家族成员可显著抑制MC38细胞的迁移和侵袭(P<0.05);最后利用信号通路活性分析、双荧光素酶报告分析等确定miR-29家族成员能够抑制AKT/mTOR信号通路的活性,并且与束蛋白结合蛋白1(Fascin actin-bundling protein 1,FSCN1)存在相互作用。上述结果表明,miR-29家族成员能够抑制AKT/mTOR信号通路活性,进而降低结肠癌细胞MC38增殖、迁移和侵袭的能力。     

miR-29b对TNF—α诱导的人脐静脉内皮细胞增殖与凋亡的影响

目的探索过表达miR-29b对TNF-α 诱导的人脐静脉内皮细胞（HUVECs）增殖与凋亡的影响及初步作用机制。方法MTT 法筛选TNF—α诱导HUVECs的最佳浓度和时间,建立细胞凋亡模型;MTY法筛选miR-29bmimic转染HUVECs的最佳转染时间和浓度：MTr法检测过表达miR-29b对TNF-α诱导HUVECs增殖活力的影响;Hoechst33342荧光染色检测过表达miR-29b对TNF—α诱导HUVECs凋亡的影响：Western印迹技术检测过表达miR-29b对Akt磷酸化水平、Bcl-2蛋白表达的影响。结果TNF—α诱导的HUVECs凋亡的最佳浓度为10ng／ml,最佳时间是48h;miR-29bmimics转染HUVECs的最佳浓度为50nmol/L,最佳作用时间是48h;过表达miR-29b能显著降低TNF-α诱导的HUVECs的增殖活力（P〈0．001）;Heochst33342荧光染色结果显示。miR-29b过表达能促进TNF-α诱导的HUVECs的凋亡（P〈0．05）;过表达miR-29b能显著下调Akt磷酸化（p-Akt）与Bcl-2蛋白的表达（P〈0．001）。结论过表达miR-29b可降低TNF-α诱导的HUVECs的增殖活力并促进其凋亡,其机制可能与下调Akt磷酸化、Bd-2蛋白的表达相关。     

MicroRNA-29b过表达慢病毒载体的构建及其生物学特性的研究

目的:构建针对小鼠microRNA-29b过表达的慢病毒载体,研究其在小鼠神经元GT1-7细胞系中的生物学特性。方法:化学合成两条寡聚核苷酸单链,通过搭桥互补延伸成DNA双链,形成miR-29b的前体结构,将酶切后的慢病毒载体FUGW通过同源重组的方法与miR-29b的前体结构进行连接,构建相应microRNA-29b过表达慢病毒载体,并包装成病毒颗粒后转染小鼠神经元细胞系GT1-7,通过博来霉素药物筛选获得稳转株,RT-PCR检测相关基因在mRNA转录水平上表达量情况。结果:测序图谱证实重组慢病毒表达质粒f-F-miR-29b构建成功,GT1-7细胞稳转株中,miR-29b的表达量与对照组相比提高了约28倍,其靶基因DCX,Vdac1,Pten的表达量有所抑制,性发育相关基因LH-β,kiss-1,Inshulin,IGF-I,GPR54,GnRH,leptin-R没有明显变化。结论:利用慢病毒筛选的方法,成功在小鼠神经元GT1-7细胞中获得microRNA-29b过表达稳转株,为以后microRNA-29b的生物学特性的研究奠定了基础。     

血浆miR-106b、miR-146a表达水平与癫痫患儿脑电图参数、Th17细胞和凋亡分子的相关性分析

摘要 目的：分析血浆miR-106b、miR-146a表达特点及其与脑电图参数、辅助性T细胞17（Th17）和凋亡分子的相关性以及诊断癫痫的价值。方法：选择2018年1月至2020年10月我院收治的癫痫患儿75例作为癫痫组,检测受试者血浆miR-106b、miR-146a表达,外周血Th17细胞占比、血清B细胞淋巴瘤/白血病-1（Bcl-1）、BCL2-Associated X蛋白（Bax）、Survivin、半胱氨酸天冬酰胺酶（Caspase-3）水平和脑电图参数α、β、 δ、θ波功率。分析miR-106b、miR-146a与Th17细胞占比、Bcl-1、Bax、Survivin、Caspase-3以及α、β、 δ、θ波功率的相关性,受试者工作特征（ROC）曲线分析miR-106b、miR-146a诊断癫痫的价值。结果：癫痫组血浆miR-106b、miR-146a表达、Th17细胞占比、Bax、Caspase-3水平高于对照组（P＜0.05）,α波功率、θ波功率、Bcl-1、Survivin水平低于对照组（P＜0.05）。miR-106b、miR-146a表达与Th17细胞占比、Bax、Caspase-3呈正相关（P＜0.05）,与α波功率、θ波功率、Bcl-1、Survivin呈负相关（P＜0.05）。联合miR-106b和miR-146a诊断癫痫的曲线下面积（AUC）为0.975,高于单独miR-106b和miR-146a诊断的0.884、0.835。结论：癫痫患儿血浆miR-146a、miR-106b表达增高,miR-146a、miR-106b高表达与脑电图异常、Th17细胞功能障碍以及神经细胞凋亡有关,miR-146a、miR-106b有望成为癫痫诊断的新生物学标志物。     

MiR-15b促进急性早幼粒细胞白血病细胞分化并抑制增殖

该文探讨了miR-15b在全反式维甲酸(all-trans retinoic acid, ATRA)治疗急性早幼粒细胞白血病(acute promyelocytic leukemia, APL)过程中发挥的作用。采用实时荧光定量PCR检测miR-15b的表达;流式细胞术检测细胞的分化情况; CCK-8实验检测细胞增殖;双荧光素酶报告实验检测miR-15b与CCNE1 3′UTR端的结合能力; Western blot检测下游靶基因CCNE1的表达。结果显示,ATRA促进miR-15b的表达;过表达miR-15b增强了ATRA对APL细胞的分化作用,而抑制miR-15b表达后则出现相反结果; miR-15b抑制了APL细胞的增殖能力;双荧光素酶报告实验显示miR-15b与CCNE1的3′UTR端结合; Western blot显示mi R-15b可以抑制下游靶基因CCNE1的表达。这些结果表明, miR-15b通过抑制CCNE1的表达促进APL细胞分化,抑制细胞增殖。     

Epigenetic deregulation of miR-29a and miR-1256 by isoflavone contributes to the inhibition of prostate cancer cell growth and invasion

The epigenetic regulation of genes has long been recognized as one of the causes of prostate cancer (PCa) development and progression. Recent studies have shown that a number of microRNAs (miRNAs) are also epigenetically regulated in different types of cancers including PCa. In this study, we found that the DNA sequence of the promoters of miR-29a and miR-1256 are partly methylated in PCa cells, which leads to their lower expression both in PCa cells and in human tumor tissues compared with normal epithelial cells and normal human prostate tissues. By real-time PCR, Western Blot analysis and miRNA mimic and 3′-UTR-Luc transfection, we found that TRIM68 is a direct target of miR-29a and miR-1256 and that the downregulation of miR-29a and miR-1256 in PCa cells leads to increased expression of TRIM68 and PGK-1 in PCa cells and in human tumor tissue specimens. Interestingly, we found that a natural agent, isoflavone, could demethylate the methylation sites in the promoter sequence of miR-29a and miR-1256, leading to the upregulation of miR-29a and miR-1256 expression. The increased levels of miR-29a and miR-1256 by isoflavone treatment resulted in decreased expression of TRIM68 and PGK-1, which is mechanistically linked with inhibition of PCa cell growth and invasion. The selective demethylation activity of isoflavone on miR-29a and miR-1256 leading to the suppression of TRIM68 and PGK-1 expression is an important biological effect of isoflavone, suggesting that isoflavone could be a useful non-toxic demethylating agent for the prevention of PCa development and progression.     

Epigenetic deregulation of miR-29a and miR-1256 by isoflavone contributes to the inhibition of prostate cancer cell growth and invasion

The epigenetic regulation of genes has long been recognized as one of the causes of prostate cancer (PCa) development and progression. Recent studies have shown that a number of microRNAs (miRNAs) are also epigenetically regulated in different types of cancers including PCa. In this study, we found that the DNA sequence of the promoters of miR-29a and miR-1256 are partly methylated in PCa cells, which leads to their lower expression both in PCa cells and in human tumor tissues compared with normal epithelial cells and normal human prostate tissues. By real-time PCR, Western Blot analysis and miRNA mimic and 3′-UTR-Luc transfection, we found that TRIM68 is a direct target of miR-29a and miR-1256 and that the downregulation of miR-29a and miR-1256 in PCa cells leads to increased expression of TRIM68 and PGK-1 in PCa cells and in human tumor tissue specimens. Interestingly, we found that a natural agent, isoflavone, could demethylate the methylation sites in the promoter sequence of miR-29a and miR-1256, leading to the upregulation of miR-29a and miR-1256 expression. The increased levels of miR-29a and miR-1256 by isoflavone treatment resulted in decreased expression of TRIM68 and PGK-1, which is mechanistically linked with inhibition of PCa cell growth and invasion. The selective demethylation activity of isoflavone on miR-29a and miR-1256 leading to the suppression of TRIM68 and PGK-1 expression is an important biological effect of isoflavone, suggesting that isoflavone could be a useful non-toxic demethylating agent for the prevention of PCa development and progression.     

Suppression of type I collagen production by microRNA-29b in cultured human stellate cells

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression through imperfect base pairing with the 3′ untranslated region (3′UTR) of target mRNA. We studied the regulation of alpha 1 (I) collagen (Col1A1) expression by miRNAs in human stellate cells, which are involved in liver fibrogenesis. Among miR-29b, -143, and -218, whose expressions were altered in response to transforming growth factor-β1 or interferon-α stimulation, miR-29b was the most effective suppressor of type I collagen at the mRNA and protein level via its direct binding to Col1A1 3′UTR. miR-29b also had an effect on SP1 expression. These results suggested that miR-29b is involved in the regulation of type I collagen expression by interferon-α in hepatic stellate cells. It is anticipated that miR-29b will be used for the regulation of stellate cell activation and lead to antifibrotic therapy.     

miR-30b,Down-Regulated in Gastric Cancer,Promotes Apoptosis and Suppresses Tumor Growth by Targeting Plasminogen Activator Inhibitor-1

Background

Gastric cancer is one of the most common malignant diseases worldwide. Emerging evidence has shown that microRNAs (miRNAs) are associated with tumor development and progression. Our previous studies have revealed that H. pylori infection was able to induce the altered expression of miR-30b in gastric epithelial cells. However, little is known about the potential role of miR-30b in gastric cancer.

Methods

We analyzed the expression of miR-30b in gastric cancer cell lines and human gastric cancer tissues. We examined the effect of miR-30b mimics on the apoptosis of gastric cancer cells in vitro by flow cytometry (FCM) and caspase-3/7 activity assays. Nude mouse xenograft model was used to determine whether miR-30b is involved in tumorigenesis of gastric cancer. The target of miR-30b was identified by bioinformatics analysis, luciferase assay and Western blot. Finally, we performed the correlation analysis between miR-30b and its target expression in gastric cancer.

Results

miR-30b was significantly down-regulated in gastric cancer cells and human gastric cancer tissues. Enforced expression of miR-30b promoted the apoptosis of gastric cancer cells in vitro, and miR-30b could significantly inhibit tumorigenicity of gastric cancer by increasing the apoptosis proportion of cancer cells in vivo. Moreover, plasminogen activator inhibitor-1 (PAI-1) was identified as the potential target of miR-30b, and miR-30b level was inversely correlated with PAI-1 expression in gastric cancer. In addition, silencing of PAI-1 was able to phenocopy the effect of miR-30b overexpression on apoptosis regulation of cancer cells, and overexpression of PAI-1 could suppressed the effect of promoting cell apoptosis by miR-30b, indicating PAI-1 is potentially involved in miR-30b-induced apoptosis on cancer cells.

Conclusion

miR-30b may function as a novel tumor suppressor gene in gastric cancer by targeting PAI-1 and regulating the apoptosis of cancer cells. miR-30b could serve as a potential biomarker and therapeutic target against gastric cancer.     

miR-29a/b Enhances Cell Migration and Invasion in Nasopharyngeal Carcinoma Progression by Regulating SPARC and COL3A1 Gene Expression

Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with a genetic predisposition, Epstein-Barr virus infection and chromosomal abnormalities. Recently, several miRNAs have been shown to target specific mRNAs to regulate NPC development and progression. However, the involvement of miRNAs in processes leading to NPC migration and invasion remains to be elucidated. We predicted that miR-29a/b are associated with dysregulated genes controlling NPC through an integrated interaction network of miRNAs and genes. miR-29a/b over-expression in NPC cell lines had no significant effect on proliferation, whereas miR-29b mildly increased the percentage of cells in the G1 phase with a concomitant decrease in the percentage of cells in S phase. Furthermore, we demonstrated that miR-29a/b might be responsible for increasing S18 cell migration and invasion, and only COL3A1 was identified as a direct target of miR-29b despite the fact that both SPARC and COL3A1 were inhibited by miR-29a/b over-expression. Meanwhile, SPARC proteins were increased in metastatic NPC tissue and are involved in NPC progression. Unexpectedly, we identified that miRNA-29b expression was elevated in the serum of NPC patients with a high risk of metastasis. The 5-year actuarial overall survival rates in NPC patients with high serum miR-29b expression was significantly shorter than those with low serum miR-29b expression; therefore, serum miR-29b expression could be a promising prognostic marker.     

MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl₄-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.