miR-221/222与肿瘤发生发展关系的研究进展

微小RNA-221/222(miR-221/222)是一类与肿瘤发生密切相关的微小RNA,异常表达存在于机体多系统、多步骤、多位点肿瘤的分化发展进程中。miR-221/222通过靶向不同靶基因的信号转导途径发挥着抑癌基因或促癌基因的作用,有望成为恶性肿瘤的生物学标志物和新型治疗靶点。该文就miR-221/222与肿瘤发生发展关系的研究进展作一综述。     

子宫内膜癌组织微小RNA-373表达情况及其对子宫内膜癌细胞增殖、迁移的影响研究

背景微小RNA-373 (miRNA-373)在多种恶性肿瘤(如肝癌、肺癌)的发生发展过程中具有重要作用,但其在子宫内膜癌(EC)发生发展中的作用尚不完全清楚。目的探讨EC组织miRNA-373表达情况及其对EC细胞增殖、迁移的影响。方法选取2012年6月-2013年6月在邯郸市妇幼保健院行手术治疗的64例EC患者的EC组织作为试验组,另选取同期在邯郸市妇幼保健院行子宫切除术的30例良性子宫肌瘤患者的正常组织作为对照组。采用实时荧光定量聚合酶链反应(qRT-PCR)检测两组miRNA-373表达情况,绘制Kaplan-Meier生存曲线以分析不同miRNA-373表达情况EC患者术后5年预后;分别比较转染miRNA-373模拟物(miRNA-373 mimic)及其阴性对照物(mimic-NC)、miRNA-373抑制剂(miRNA-373 inhibitor)及其阴性对照物(inhibitor-NC)的HEC-1B细胞大型肿瘤抑制基因2 (LATS2)表达情况、转染96 h后吸光度值、迁移细胞数量;采用双荧光素酶报告基因系统验证miRNA-373与LATS2间的靶标关系。结果 (1)试验组miRNA-373相对表达量高于对照组(P<0.05)。根据miRNA-373相对表达量平均值将试验组患者分为低表达组(n=26)和高表达组(n=38),Kaplan-Meier生存曲线显示,高表达组患者术后5年累积生存率为52.6%,低于低表达组的84.6%(P<0.05)。(2)转染miRNA-373 mimic的HEC-1B细胞LATS2相对表达量低于转染mimic-NC的HEC-1B细胞(P<0.05);转染miRNA-373 inhibitor的HEC-1B细胞LATS2相对表达量高于转染inhibitor-NC的HEC-1B细胞(P<0.05)。转染96 h后,转染miRNA-373 mimic的HEC-1B细胞吸光度值高于转染mimic-NC的HEC-1B细胞(P<0.05);转染miRNA-373 inhibitor的HEC-1B细胞吸光度值低于转染inhibitor-NC的HEC-1B细胞(P<0.05)。转染miRNA-373 mimic的HEC-1B细胞中迁移细胞数量多于转染mimic-NC的HEC-1B细胞(P<0.05);转染miRNA-373 inhibitor的HEC-1B细胞中迁移细胞数量少于转染inhibitor-NC的HEC-1B细胞(P<0.05)。(3)双荧光素酶报告基因系统检测结果显示,LATS2含有miRNA-373的潜在结合位点。野生型LATS2中miRNA-373相对荧光强度低于空载对照(P<0.05);突变型LATS2中miRNA-373相对荧光强度与空载对照比较,差异无统计学意义(P>0.05)。结论 EC组织miRNA-373呈高表达,其可通过直接靶向调节LATS2的表达而促进EC细胞增殖、迁移,进而影响EC患者预后。     

Further results on H ∞ control for discrete‐time uncertain singular systems with interval time‐varying delays in state and input

This paper investigates the state feedback robust H _∞ control problem of a class of discrete‐time singular systems with norm‐bounded uncertainties and interval time‐varying delays in state and input. A new bounded real lemma for discrete‐time singular systems with a pair of time‐varying interval state delays is first investigated. Mathematical comparisons of the new bounded real lemma and two existing ones are presented. Then, on the basis of the bounded real lemma proposed here, a sufficient condition in the form of nonlinear matrix inequality, such that the considered state feedback robust H _∞ control problem is solvable, is given. In order to solve the nonlinear matrix inequality, a cone complementarity linearization algorithm is offered. Several numerical examples are presented to show the applicability of the proposed approach. Copyright © 2012 John Wiley & Sons, Ltd.     

MicroRNA-29与糖尿病及其并发症

小分子RNA(miR)是近年发现的一类广泛存在于动植物中的小分子非编码RNA,它通过抑制靶目标的转录或直接将其降解而发挥作用.miR-29是新近发现的与糖尿病及其并发症有密切关系的一类小分子RNA.研究发现,miR-29可直接参与糖尿病的基本病理生理过程,如参与胰岛素相关信号通路.同时也参与肾脏纤维化、视网膜神经元凋亡等过程,从而在糖尿病肾病、糖尿病视网膜病变等糖尿病并发症的发生中起重要作用.     

微小RNA-10b在胃癌组织中的表达及其临床意义

目的 探讨胃癌组织和癌旁组织中微小RNA(miR)-10b的表达差异及其临床意义.方法 采用SYBR Green Ⅰ荧光定量聚合酶链反应(FQ-PCR)法检测78例胃癌患者手术切除癌组织及配对癌旁组织标本中miR-10b的表达水平.结果 miR-10b在胃癌组织中的相对表达水平(6.758±2.301)显著高于其在配对癌旁组织中的表达(8.516±1.870),差异有统计学意义(P＜0.01).胃癌组织中miR-10b的表达水平与临床TNM分期(P＜0.01)、肿瘤大小(P＜0.01)、淋巴结转移(P＜0.01)以及肿瘤浸润深度(P＜0.01)密切相关,而与年龄、性别、分化程度无明显相关(P＞0.05).结论 胃癌组织中miR-10b的高表达可能与胃癌的发生、发展、侵袭、转移相关.     

微小RNA-494过表达与RNA干扰抑制Survivin基因对前列腺癌移植瘤生长的比较

目的 比较过表达微小RNA (microRNA)-494与采用RNA干扰抑制前列腺癌PC-3细胞中Survivin基因的表达,对前列腺癌移植瘤生长的影响.方法 将过表达microRNA-494的腺病毒载体Ad-494及负载Survivin短发卡RNA (shRNA)腺病毒载体Ad-sur分别或联合感染PC-3细胞后,将相应PC-3细胞接种于裸鼠右前肢皮下,建立前列腺癌移植瘤模型.并以磷酸盐缓冲液(PBS)组及空载体组(Ad-GFP)作为对照.动态测量肿瘤体积.55 d后处死各组裸鼠,瘤体称重计算抑瘤率.Western blot检测肿瘤组织中Survivin表达变化.免疫组织化学测定Survivin、B淋巴细胞/白血病-2(bcl-2)、bcl-2相关X蛋白(bax)及半胱氨酰天冬氨酸特异性蛋白酶(Caspase)-3表达变化.结果 Ad-sur组、Ad-494组、Ad-sur+ Ad-494组裸鼠前列腺癌移植瘤的生长明显被抑制.第35天时即表现差异.其中Ad-sur+ Ad-494组瘤体积最小,为(40.69±0.69) mm3,Ad-sur、Ad-494组瘤体体积分别为(102.11±5.32) mm3、(99.03±3.50) mm3,3组肿瘤体积均明显小于PBS组(572.72±10.46) mm3、Ad-GFP组(544.85 ±10.28) mm3(P＜0.05).但Ad-sur组与Ad-494组间瘤体大小差异无统计学意义(P＞0.05).55 d后,Ad-sur、Ad-494、Ad-sur+ Ad-494组对移植瘤抑制率分别64.62％、65.98％、86.67％,Ad-sur+ Ad-494组具有抑瘤增效的相加作用(Q=0.99).同对照组比较,实验各组的Survivin基因均表达下降,差异有统计学意义(P＜0.05).其中,Ad-494组与Ad-sur组间差异无统计学意义(P＞0.05),Ad-sur+ Ad-494组较Ad-494、Ad-sur组更为显著;实验各组中的bax、Caspase-3表达上调,bcl-2表达下调,且Ad-sur+ Ad-494组效果优于Ad-sur、Ad-494组.结论 过表达microRNA-494与RNA干扰方法均可抑制前列腺癌裸鼠移植瘤Survivin基因表达,从而抑制移植瘤的生长,且两者联合效果更加显著.     

微小RNA-181b及其靶基因肝癌缺失基因-1在肝癌发生中的作用

目的 探讨微小RNA(miRNA,miR)-181b对肝癌缺失基因-1(DLC-1)的调控及其在肝癌发病中的作用.方法 通过实时荧光定量聚合酶链反应(FQ-PCR)和Western blot检测4份正常肝脏组织,17份癌旁组织、肝癌组织及肝癌SMMC7721细胞、胚肝LO2细胞中miR-181b和DLC-1的mRNA和蛋白质表达水平.应用miR-181b抑制剂下调肝癌细胞SMMC7721中miR-181b表达后,实时定量聚合酶链反应和Westem blot检测SMMC7721细胞中DLC-1表达水平的变化.结果 miR-181b在正常肝组织、癌旁组织和肝癌组织中的相对表达量分别为0.162 ±0.004、0.175±0.021和0.656±0.034,肝癌组织高于正常肝组织(P＜0.05).miR-181b在SMMC7721细胞中的表达较LO2细胞上调(0.723±0.042和0.262±0.037,P＜0.01).DLC-1 mRNA在正常肝组织、癌旁组织和肝癌组织中的相对表达量分别为0.392±0.094、0.187 ±0.043和0.081 ±0.012,肝癌组织低于正常肝组织(P＜0.05);DLC-1蛋白在正常肝组织、癌旁组织和肝癌组织中的相对表达量分别为0.423±0.026、0.214±0.029和0.112±0.021,差异有统计学意义(P＜0.01).miR-181b抑制剂转染SMMC7721细胞后,DLC-1蛋白在空白组、转染组和阴性对照组的相对表达量分别为0.132±0.027、0.379±0.019和0.125±0.015,转染组较其他两组明显升高(P＜0.05).结论 miR-181b在肝癌组织中表达上调,其抑制DLC-1的表达可能是肝癌发生的重要机制.     

New results on H∞ filtering for nonlinear large‐scale systems with interconnected time‐varying delays

This paper proposes a new design method of H_∞ filtering for nonlinear large‐scale systems with interconnected time‐varying delays. The interaction terms with interval time‐varying delays are bounded by nonlinear bounding functions including all states of the subsystems. A stable linear filter is designed to ensure that the filtering error system is exponentially stable with a prescribed convergence rate. By constructing a set of improved Lyapunov functions and using generalized Jensen inequality, new delay‐dependent conditions for designing H_∞ filter are obtained in terms of linear matrix inequalities. Finally, an example is provided to illustrate the effectiveness of the proposed result. Copyright © 2015 John Wiley & Sons, Ltd.     

Mechanism of Regulatory Effect of MicroRNA-206 on Connexin 43 in Distant Metastasis of Breast Cancer

Background:

MicroRNA-206 (miR-206) and connexin 43 (Cx43) are related with the distant metastasis of breast cancer. It remains unclear whether the regulatory effect of miR-206 on Cx43 is involved in metastasis of breast cancer.

Methods:

Using quantitative real-time polymerase chain reaction and Western blot, the expressions of miR-206 and Cx43 were determined in breast cancer tissues, hepatic and pulmonary metastasis (PM), and cell lines (MCF-10A, MCF-7, and MDA-MB-231). MCF-7/MDA-M-231 cells were transfected with lentivirus-shRNA vectors to enhance/inhibit miR-206, and then Cx43 expression was observed. Cell counting kit-8 assay and Transwell method were used to detect their changes in proliferation, migration, and invasion activity. The mutant plasmids of Cx43-3’ untranslated region (3’UTR) at position 478–484 and position 1609–1615 were constructed. Luciferase reporter assay was performed to observe the effects of miR-206 on luciferase expression of different mutant plasmids and to confirm the potential binding sites of Cx43.

Results:

Cx43 protein expression in hepatic and PM was significantly higher than that in the primary tumor, while no significant difference was showed in messenger RNA (mRNA) expression. MiR-206 mRNA expression in hepatic and PM was significantly lower than that in the primary tumor. Cx43 mRNA and protein levels, as well as cell proliferation, migration, and invasion capabilities, were all significantly improved in MDA-MB-231 cells after reducing miR-206 expression but decreased in MCF-7 cells after elevating miR-206 expression, which demonstrated a significantly negative correlation between miR-206 and Cx43 expression (P = 0.03). MiR-206 can drastically decrease Cx43 expression of MCF-7 cells but exerts no effects on Cx43 expression in 293 cells transfected with the Cx43 coding region but the lack of Cx43-3’UTR, suggesting that Cx43-3’UTR may be the key in Cx43 regulated by miR-206. Luciferase expression showed that the inhibition efficiency was reduced by 46.80% in position 478–484 mutant, 16.72% in position 1609–1615 mutant; the inhibition was totally disappeared in double mutant (P = 0.02).

Conclusions:

MiR-206 can regulate the expression of Cx43, the cytobiological activity, and the metastasis of breast cancer through binding to the two binding sites in Cx43-3’UTR: position 478–484 and position 1609–1615.     

miR-214和miR-181c在胃癌组织中的表达及预后价值

目的探讨微小RNA-214（miR-214）和miR-181c在胃癌组织中的表达水平及对预后的影响。 方法选取2014年1月至2015年1月于川北医学院附属医院收治的68例胃癌患者为研究对象,均接受手术治疗,出院后随访1~60个月。利用实时荧光定量PCR技术检测患者癌组织和癌旁组织miR-214、miR-181c相对表达量;利用Kaplan-Meier曲线进行生存分析;Cox多因素回归分析影响胃癌患者预后的独立危险因素。 结果胃癌组织中miR-214、miR-181c表达水平均明显低于癌旁组织,差异有统计学意义（P<0.05）。根据miR-214、miR-181c表达均值将患者分为高表达组和低表达组,miR-214、miR-181c表达水平与年龄、性别、淋巴结是否转移无关,与TNM分期、肿瘤分化程度有关（P<0.05）。患者总生存率为44.12%,miR-214低表达组和高表达组术后5年累积生存率分别为35.71%、57.69%,两组间比较差异有统计学意义（P=0.035）;miR-181c低表达组和高表达组术后5年累积生存率分别为35.55%、60.87%,差异有统计学意义（P=0.024）。Cox多因素回归分析结果显示,TNM分期高（HR=1.569,95% CI：1.029~2.391,P=0.036）、miR-214低表达（HR=1.643,95% CI：1.294~2.087,P<0.001）及miR-181c低表达（HR=1.327,95% CI：1.045~1.685,P=0.021）是影响胃癌患者预后的独立危险因素。 结论miR-214、miR-181c在胃癌组织中表达显著下调,与胃癌患者临床病理参数及不良预后有关,参与胃癌的发生发展过程。