内皮素1过表达经Akt/PKB信号通路抑制大鼠肺细小动脉平滑肌细胞凋亡的体外研究

目的 探讨过表达内皮素1(ET-1)对体外培养的大鼠肺细小动脉平滑肌细胞(RPMC)凋亡的影响及其作用机制.方法 采用组织灌注法体外分离和培养原代RPMC,经免疫荧光法和电镜鉴定后,脂质体法瞬时转染ET-1基因,用流式细胞技术检测细胞周期和凋亡,免疫印迹法检测丝/苏氨酸蛋白激酶(Akt/PKB)的磷酸化水平和剪切的半胱天冬酶-3(Caspase-3)的表达.结果 成功分离和培养出原代RPMC,实时荧光定量逆转录-聚合酶链反应检测显示,RPMC中ETA受体mRNA表达水平明显高于ETB受体.瞬时转染ET-1基因48 h后,流式细胞仪结果显示,与空载相比,RPMC的凋亡明显下降.免疫印迹法检测显示,过表达ET-1后,Akt/PKB的磷酸化水平升高,剪切的Caspase-3的表达水平下降.结论 过表达ET-1可能主要通过ETA受体,并经Akt/PKB-Caspase-3信号通路抑制RPMC的凋亡,从而在肺动脉高压的血管重塑过程中发挥重要作用.     

天龙喘咳灵对转化生长因子-β1诱导的气道α-平滑肌肌动蛋白的影响及信号转导机制

目的观察中药天龙喘咳灵对转化生长因子-β1(TGF-β1)诱导的气道上皮下成纤维细胞(HPBFs)α-平滑肌肌动蛋白(α-SMA)表达的影响,探讨其可能的信号转导机制。方法2005—2006年,在广州市红十字会医院呼吸科于原代培养的HPBFs中,分别加入天龙喘咳灵合剂、天龙喘咳灵主要组分(淡附子、青天葵和法夏)的单味药预孵育2h,再加入TGF-β1(10μg/L)共孵育;刺激10min和30min,分别提取细胞总蛋白,Western免疫印迹方法检测磷酸化p38MAPK、ERK1/2和smad2的蛋白表达;刺激20h和72h,提取细胞总RNA及蛋白,检测α-SMA蛋白及mRNA的表达。结果天龙喘咳灵组和淡附子组α-SMA蛋白和mRNA的表达均较单纯TGF-β1刺激组减少(P<0·05),天龙喘咳灵组对α-SMA蛋白和mRNA表达量的抑制程度高于淡附子组;天龙喘咳灵组和淡附子组磷酸化ERK1/2的表达明显低于单纯TGF-β1刺激组,而青天葵和法夏两组与单纯TGF-β1组相似。各药物处理组对TGF-β1诱导的磷酸化p38和smad2的表达无明显影响。结论天龙喘咳灵抑制HPBFs的α-SMA表达,可能是通过降低TGF-β1诱导的ERK1/2磷酸化水平实现的,并且其中的组分淡附子可能起主要作用。     

FKN对外周血单个核细胞ERK1/2活化和TNF-α表达的影响及ERK1/2的临床作用

目的 探讨趋化因子(FKN)对单个核细胞细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)1/2和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)表达的影响及ERK1/2在其中的作用.方法 抗凝血用Ficoll密度梯度离心法分离外周血单个核细胞.将每份提取的单个核细胞分为3组:空白对照组、FKN组、FKN+PD98059(ERK特异性阻断剂)组;分别应用Western印迹法和酶联免疫法检测各组单个核细胞中磷酸化ERK1/2及TNF-α的表达水平.结果 FKN诱导组磷酸化的ERK1/2和TNF-α表达较空白组显著增多(P<0.05);PD98059组磷酸化的ERK1/2和TNF-α表达较FKN组显著减少(P<0.05).结论 FKN-CX3CR1可能通过增加单个核细胞磷酸化ERK1/2和TNF-α的表达而促进动脉粥样硬化的进展,FKN可能是通过ERK1/2途径诱导单个核细胞TNF-α的表达.     

IGF-1对Rh1肉瘤细胞PI3K/Akt/mTOR信号通路的影响

目的 探讨胰岛素样生长因子(IGF)1对Rh1肉瘤细胞生长活性和PI3 K/Akt/mTOR信号通路的背景变化.方法 常规细胞培养,用无血清培养基消除内源性因子影响27h,再用IGF-1(终浓度为10 ng/ml)刺激72 h,流式细胞仪检测细胞生长活性;另外Western印迹方法观察IGF-1刺激细胞5、10、20、30和60min后Akt(s473)、S6的动态变化.结果 与对照组相比,IGF-1可促进Rh1细胞存活.IGF-1刺激不同时间后S6磷酸化则随着时间的延长逐渐增强;IGF-1亦导致Akt(s473)位点的磷酸化,随时间的延长,磷酸化Akt在5min时达高峰,此后逐渐减弱.结论 Akt、S6等是PI3K/Akt/mTOR信号通路中的重要信号分子,对Rhl细胞而言,在IGF-1刺激下S6有逐渐增强的变化,Akt (s473)位点磷酸化则有减弱的动态变化.     

siRNA介导COX-2基因沉默对大肠癌LoVo细胞侵袭及上皮间质转化的影响

目的探讨靶向沉默环氧合酶-2(cyclooxygenase-2,COX-2)表达对大肠癌LoVo细胞侵袭能力及上皮间质转化的影响。方法在体外COX-2 siRNA转染大肠癌LoVo细胞,RT-PCR及免疫印迹法验证转染后COX-2 mRNA及蛋白表达,Transwell小室法检测细胞侵袭能力的改变;免疫印迹法检测EMT标志物(E-cadherin、Vimentin、Fibronectin)、ERK/MAPK和PI3K/Akt通路相关蛋白(Akt、p-Akt、p-GSK-3β、ERK、p-ERK)及MMP-9表达的变化情况。结果 COX-2 siRNA转染大肠癌LoVo细胞后,COX-2 mRNA及蛋白表达下调,同时细胞侵袭能力降低;上皮标记物E-cadherin表达上调,同时间叶标记物Vimentin和Fibronectin表达下调;细胞总的ERK、Akt蛋白表达水平无明显改变,而p-ERK、p-Akt表达降低,同时,Akt下游效应蛋白p-GSK-3β表达也下调; MMP-9表达下调。结论 COX-2 siRNA转染有效抑制了大肠癌LoVo细胞COX-2表达,并可能通过阻滞细胞ERK/MAPK和PI3K/Akt通路,进而抑制EMT,下调MMP-9表达,降低细胞侵袭能力。     

α-烯醇化酶在内皮素-1诱导的肥大心肌细胞中的表达和调控通路

目的 观察内皮素-1(ET-1)诱导的心肌细胞肥大模型中细胞外信号调节激酶(ERK1/2)、磷酸化细胞外信号调节激酶(p-ERK1/2)、低氧诱导因子(HIF-1α),α-烯醇化酶(α-enolase)蛋白表达情况,探讨肥大心肌细胞α-enolase高表达的调控机制. 方法 建立ET-1诱导的心肌细胞肥大模型,从细胞表面积、细胞蛋白合成速率和肌原纤维的重排3方面进行验证;将原代培养心肌细胞随机分为4组:(1)对照组;(2)PD98059干预组;(3)ET-1刺激组;(4)PD98059+ET-1刺激组.免疫印迹方法 检测ERK1/2、p-ERK1/2、HIF-1α、α-enolase的蛋白表达. 结果 ET-1刺激后心肌细胞表面积为(1350.7±107.5)μm2,较对照组(896.1±70.2)μm2增加(P<0.05);ET-1刺激后心肌细胞[3H]亮氨酸掺入量较对照组增加[分别为(1387.9±14.8)dpm和(787.7±10.2)dpm,P<0.013;肌原纤维染色可见ET-1刺激屙心肌细胞肌原纤维排列较对照组紧密、染色浓,表明ET-1能诱导心肌细胞肥大.ERK1/2抑制剂PD98059预处理的心肌细胞在ET-1刺激后细胞表面积和细胞的[3H]亮氨酸掺入量均较ET-1刺激组减少[细胞表面积分别为(907.0±92.5)μm2和(1350.7±107.5)μm2,P<0.05;[3H]亮氨酸掺入量:(841.5±10.5)dpm和(1387.9±14.8)dpm,P<0.05].ET-1刺激后心肌细胞有p-ERK1/2表达,其抑制剂PD98059在抑制ERK1/2活化的同时也部分抑制了HIF-1α、α-enolase蛋白的表达. 结论 ERK1/2的活化与ET-1诱导的细胞肥大关系密切,在ET-1促心肌细胞肥大过程中,从MAPK/ERK1/2至HlF-1α及α-enolase这条信号通路町能参与α-enolase高表达的调控.     

敲减心磷脂酰基转移酶1对肝细胞脂肪变和氧化应激的影响及其机制

目的探讨心磷脂酰基转移酶1(ALCAT1)对脂肪肝细胞模型中肝细胞脂肪变和氧化应激的影响及其作用机制。方法以游离脂肪酸(FFA;亚油酸和棕榈酸混合物)诱导建立脂肪肝细胞模型,采用实时荧光定量PCR和蛋白质印迹法检测ALCAT1在脂肪肝细胞模型中的表达情况。构建空载小干扰RNA(siRNA)质粒和ALCAT1 siRNA质粒。以空载siRNA质粒转染人正常肝细胞(L-02细胞)24 h,然后与FFA共培养24 h,设立脂肪肝细胞模型组;以ALCAT1 siRNA质粒转染L-02细胞24 h,然后与FFA共培养24 h,设立ALCAT1干预组;以常规培养基培养的L-02细胞作为空白对照组。在透射电子显微镜下观察各组的脂滴沉积、线粒体形态,采用蛋白质印迹法测定自噬体标志物微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)、酵母ATG6同源物(Beclin1)和哺乳动物雷帕霉素靶蛋白(mTOR)信号通路关键蛋白mTOR和磷酸化丝氨酸/苏氨酸激酶(AKT)的表达水平,采用ELISA法测定氧化应激产物丙二醛、4-羟基壬烯醛(4-HNE)、活性氧和炎症因子IL-6、TNF-α的表达。采用独立样本t检验进行统计学...     

Syndecan 4促进心肌细胞生理性肥大研究

目的:研究syndecan 4(Synd4)在心肌细胞生理性肥大中的作用及其机制。方法:将大鼠心肌细胞分为对照腺病毒组(Ad-lacz组),Synd4腺病毒转染组(Ad-synd4组),腺病毒+胰岛素样生长因子组(Ad-lacz+IGF组)和腺病毒+异丙肾上腺素组(Ad-lacz+ISO组),通过α-SMA染色观察细胞形态,S~(35)-半胱氨酸摄取试验检测蛋白质合成,real-time PCR检测胚胎基因和能量代谢相关基因表达,免疫印迹法测定caspase-3的表达。并在Ad-synd4转染的细胞中分别加入PKC阻滞剂Calphostin C和PI3K阻滞剂LY294002,α-SMA染色观察细胞形态,免疫印迹法测定Akt、p-Akt、PPARα的表达。结果:与IGF作用后相似,Synd4过表达可使细胞面积增大2倍,蛋白质合成增加50%,脂肪酸代谢相关基因PPARα和m CPT-1的mRNA表达明显上调(P0.05),caspase-3蛋白的表达无变化。Calphostin C和LY294002均可抑制Synd4诱导的心肌细胞肥大和p-Akt、PPARα等蛋白的表达(P0.05),但Calphostin C的作用更加明显。结论:Synd4可促进心肌细胞生理性肥大,其可能的作用机制是通过PKCα提高Akt磷酸化水平而实现的。     

内皮素-1诱导大鼠肾小管上皮细胞转分化的可能机制

目的:探讨内皮素-1(ET-1)是否可诱导大鼠肾小管上皮细胞转分化(TEMT)及可能的分子机制.方法:体外培养大鼠肾小管上皮细胞(NRK52E)并进行分组;倒置显微镜观察细胞的形态变化;Western印迹法检测细胞E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-SMA)、p38丝裂原活化蛋白激酶(p38MAPK)及磷酸化-p38MAPK(p-p38MAPK)蛋白的表达;逆转录-聚合酶链反应(RT-PCR)法检测细胞E-cadherin及α-SMA mRNA的表达. 结果:ET-1可诱导细胞由鹅卵石样变为梭形,下调E-cadherin表达,上调α-SMA、p38 MAPK及p-p38MAPK表达,增强p38MAPK活性(P＜0.05),而内皮素A受体拮抗剂BQ123能明显抑制这些变化(P＜0.05).p38MAPK特异性抑制剂SB203580可抑制ET-1诱导的细胞梭形性变,ET-1诱导的E-cadherin、α-SMA及p-p38MAPK表达改变及p38MAPK活性改变(P＜0.05),但对p38MAPK表达无明显影响(P＞0.05). 结论:ET-1可能通过激活肾小管上皮细胞p38 MAPK通路,下调E-cadherin的表达,同时上调d-SMA的表达,从而诱导肾小管上皮细胞转分化.     

白细胞介素10基因转染对大鼠心肌梗死后心室纤维化重构的影响

目的探讨白细胞介素10(IL-10)基因转染对大鼠急性心肌梗死(AMI)后心室纤维化重构的影响及其可能的信号转导通路。方法实验大鼠共18只,随机分为假手术组、心肌梗死(MI)-2型腺相关病毒(AAV2)组(MI-AAV2)组和MI-AAV2-IL-10转染组,每组6只。结扎大鼠左冠状动脉前降支建立AMI动物模型,应用AAV2携带IL-10基因转染心肌组织。免疫组织化学测定心肌α平滑肌肌动蛋白(α-SMA)、心肌胶原蛋白Ⅰ、Ⅲ型(Ⅰ型胶原和Ⅲ型胶原)的表达。Western blot法检测梗死、边缘和远隔区心肌磷酸化细胞外信号调节激酶(ERK1/2)和p38蛋白的表达。结果MI-AAV2-IL-10组检测到外源性IL-10 mRNA和蛋白的有效表达。免疫组织化学结果显示MI-AAV2-IL-10组较MI-AAV2组心肌α-SMA表达降低54.5%(P<0.01)。Ⅰ、Ⅲ型胶原表达分别下降了45.4%和27.4%(P<0.01),Ⅰ/Ⅲ型胶原比值下降24.6%(P<0.05)。Western blot结果显示MI-AAV2-IL-10组较MI-AAV2组心肌各部位磷酸化ERK1/2和P38蛋白的表达均下调。结论IL-10基因转染可改善大鼠AMI后心室纤维化,可能是通过影响ERK1/2和P38 MAPKs激酶通路发挥作用。     

Chronic treatment with PDGF-BB and endothelin-1 synergistically induces vascular hyperplasia and loss of contractility in organ-cultured rat tail artery

ObjectiveIn this study, we examined the synergistic effects of the two potent pathogenic factors, platelet-derived growth factor-BB (PDGF-BB) and endothelin-1 (ET-1) to induce vascular hyperplasia using ex vivo organ-culture system.Methods and resultsIn organ-cultured rat tail arteries, concomitant treatment with 100 ng/ml PDGF-BB and 300 nM ET-1 for 4 days induced medial hyperplasia with increased smooth muscle cell proliferation. Concomitant treatment with PDGF-BB (10–300 nM) and ET-1 (30 nM–1 μM) dose-dependently suppressed contractile responses to high K⁺ and norepinephrine. This dyscontractility was accompanied by decreased α-actin protein expression. In all series of experiments, concomitant treatment with PDGF-BB and ET-1 exhibited stronger effects than sole treatment with PDGF-BB (100 ng/ml) or ET-1 (300 nM). Western blot analysis revealed that concomitant treatment with PDGF-BB and ET-1 synergistically phosphorylated extracellular signal-regulated kinase 1 and 2 (ERK1/2), Akt, and a downstream target of mammalian target of rapamycin (mTOR), p70 ribosomal S6 kinase in cultured artery. Consistently, a MAPK/ERK kinase (MEK) inhibitor, PD98059 (30 μM), a phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, and an mTOR inhibitor, rapamycin (30 nM), partially restored PDGF-BB and ET-1-induced hyperplastic changes.ConclusionsWe evidenced for the first time at tissue level that PDGF-BB and ET-1 synergistically accelerate vascular smooth muscle hyperplastic changes and lose its contractility, at least partially through ERK1/2, Akt, and mTOR activation.     

Deficiency in AMP-activated protein kinase exaggerates high fat diet-induced cardiac hypertrophy and contractile dysfunction

AMPK, a metabolic sensor, protects against ischemic injury and cardiac hypertrophy although its role in obesity is unclear. This study was designed to examine the impact of AMPK deficiency on cardiac dysfunction following high fat feeding. Adult WT and transgenic mice overexpressing a kinase dead (KD) α2 isoform (K45R mutation) of AMPK were fed a low or high fat diet for 20 weeks. DEXA was used to confirm adiposity. Wheat germ agglutinin immunostaining was used to evaluate myocardial histology. Myocardial function was evaluated using echocardiography and edge-detection. AMPK activity was analyzed using fluorescence polarization assays. [1-¹⁴C] oleate was used to determine fatty acid oxidation. Expression of AMPK, α1, α2, ACC, Akt, the Glut-4 translocation mediator Akt substrate of 160KD (AS160), mTOR, total and membrane Glut-4 was evaluated using Western blot. AMPK activity was decreased in KD mice regardless of diet regimen. High fat diet led to obesity, glucose intolerance and cardiac hypertrophy with accentuated glucose intolerance, dampened fatty acid oxidation and cardiac hypertrophy in KD mice. High fat feeding triggered lower fractional shortening, increased LV mass, left ventricular end diastolic/systolic diameter, decreased PS, ± dL/dt, prolonged TR₉₀ and intracellular Ca²⁺ mishandling with a more pronounced effect in KD mice. High fat diet and AMPK KD lessened AMPKα2 isoform activity and ACC phosphorylation. AMPK deficiency unveiled or accentuated high fat diet-induced decrease in phosphorylation of Akt and AS160, membrane fraction of Glut-4 and mTOR expression (a greater mTOR phosphorylation). Taken together, these data suggest that AMPK deficiency exacerbates obesity-induced cardiac hypertrophy and contractile dysfunction, possibly associated with AS160 and mTOR signaling.     

Requirement of activation of the extracellular signal-regulated kinase cascade in myocardial cell hypertrophy

The signal transduction mechanisms mediating hypertrophic responses in myocardial cells (MCs) remain uncertain. We investigated the role of the extracellular signal-regulated kinase (ERK) cascade in myocardial cell hypertrophy by the strategy of using the adenovirus-mediated overexpression of mitogen-activated protein kinase (MAPK)/ERK kinase (MEK), which is the upstream activator of ERK. We generated recombinant adenoviruses expressing constitutively active MEK1 (MEK1 EE) and dominant negative MEK1 (MEK1 DN). Overexpression of MEK1 EE in MCs activated ERK1/2 and subsequently induced atrial natriuretic peptide (ANP) mRNA expression. In addition, MEK1 EE overexpression resulted in an increase in cell size and sarcomeric reorganization. In contrast, overexpression of MEK1 DN in MCs inhibited endothelin-1 (ET-1)-, phenylephrine (PE)-, leukemia inhibitory factor (LIF)-, isoproterenol (ISP)-, and mechanical stretch-induced ERK activation and ANP mRNA expression. MEK1 DN overexpression inhibited ET-1-, PE-, LIF-, and ISP-induced increases in cell size and sarcomeric reorganization. Consistent with the observed effects on cellular morphology, overexpression of MEK1 EE resulted in an increase in amino acid incorporation, while overexpression of MEK1 DN inhibited ET-1-, PE-, LIF-, ISP-, and mechanical stretch-induced increases in amino acid incorporation. These results indicate that the ERK cascade plays an important role in the signaling pathway leading to the development of myocardial cell hypertrophy.     

Akt和胞外信号调节激酶通路间的信号交流对内质网应激条件下肝癌细胞周期的调控

目的 研究内质网应激介导的磷脂酰肌醇3激酶(PI3K)/Akt和丝裂原活化蛋白激酶(MEK)/胞外信号调节激酶(ERK)途径间的信号交流及其对内质网应激条件下肝癌细胞周期的调控作用.方法 采用PI3K抑制剂LY294002、Akt激活型突变载体myr-Akt和MEK抑制剂U0126分别阻断或激活内质网应激介导的Akt和ERK活化,并利用Western blot和流式细胞技术分析内质网应激条件下PI3K/Akt和MEK/ERK途径间的信号交流及其对肝癌细胞株SMMC-7721、Hep3B和HepG2细胞周期的调控作用.数据处理采用Sperman等级相关分析,P＜0.05为差异有统计学意义.结果 阻断PI3K/Akt明显促进内质网应激介导的MEK/ERK活化,而过度激活PI3K/Akt则抑制内质网应激介导的MEK/ERK活化.阻断MEK/ERK对内质网应激介导的PI3K/Akt活化无影响.持续活化的Akt突变载体myr-Akt和MEK抑制剂U0126均明显抑制了内质网应激诱导的压力细胞G0/G1期阻滞.结论 PI3K/Akt和MEK/ERK信号途径在内质网应激肝癌细胞中存在信号交流,该信号交流对细胞周期起重要调控作用.     

Dual actions of the Galpha(q) agonist Pasteurella multocida toxin to promote cardiomyocyte hypertrophy and enhance apoptosis susceptibility

Previous attempts to delineate the consequences of Galpha (q) activation in cardiomyocytes relied largely on molecular strategies in cultures or transgenic mice. Modest levels of wild-type Galpha(q) overexpression induce stable cardiac hypertrophy, whereas intense Galpha(q) stimulation induces cardiomyocyte apoptosis. The precise mechanism(s) whereby traditional targets of Galpha (q) subunits that induce hypertrophy also trigger cardiomyocyte apoptosis is not obvious and is explored with recombinant Pasteurella multocida toxin (rPMT, a Galpha(q) agonist). Cells cultured with rPMT display cardiomyocyte enlargement, sarcomeric organization, and increased atrial natriuretic factor expression in association with activation of phospholipase C, novel protein kinase C (PKC) isoforms, extracellular signal-regulated protein kinase (ERK), and (to a lesser extent) JNK/p38-MAPK. rPMT stimulates the ERK cascade via epidermal growth factor (EGF) receptor transactivation in cardiac fibroblasts, but EGF receptor transactivation plays no role in ERK activation in cardiomyocytes. Surprisingly, rPMT (or novel PKC isoform activation by PMA) decreases basal Akt phosphorylation; rPMT prevents Akt phosphorylation by EGF or IGF-1 and functionally augments cardiomyocyte apoptosis in response to H2O2. These results identify a Galpha(q)-PKC pathway that represses basal Akt phosphorylation and impairs Akt stimulation by survival factors. Because inhibition of Akt enhances cardiomyocyte susceptibility to apoptosis, this pathway is predicted to contribute to the transition from hypertrophy to cardiac decompensation and could be targeted for therapy in heart failure.     

Periostin过表达诱导人胃癌细胞化疗耐药性的机制研究

背景：前期研究发现periostin过表达可增强人胃癌细胞株SGC-7901对顺铂和5-氟尿嘧啶（5-Fu）诱导的细胞凋亡的抵抗能力。目的：探讨periostin过表达诱导人胃癌细胞化疗耐药性的可能机制。方法：Periostin稳转组和空载体稳转组SGC-7901细胞分别以5μmol／L顺铂或10μmol／L5-Fu处理24h或不予化疗药物处理,其中periostin稳转组在化疗药物处理前可接受或不接受Akt特异性抑制剂MK-2206（1μmol／L）预处理30min。以蛋白质印迹法检测各组细胞的总Akt、磷酸化Akt（p-Akt）、p53蛋白表达,流式细胞术检测细胞凋亡。结果：periostin稳转组SGC．7901细胞Akt磷酸化水平明显高于空载体稳转组,两组间总Akt无明显差异。在经顺铂或5-Fu处理的各组SGC．7901细胞中,periostin稳转组p53蛋白表达和细胞凋亡率明显低于空载体稳转组,而MK-2206预处理可在一定程度上逆转periostin对p53表达的抑制作用及其诱导的凋亡保护效应。结论：通过激活Akt通路抑制p53表达可能是periostin过表达诱导人胃癌细胞化疗耐药性的机制之一,有望作为胃癌治疗的潜在靶点。     

沉默RET基因表达对甲状腺髓样癌细胞增殖的影响

目的 研究沉默RET基因表达对人甲状腺髓样癌(medullary thyroid carcinoma,MTC)细胞系TT细胞增殖的影响及其机制.方法 将含RET的双链DNA克隆入pSileneerTM 3.1-H1 neo真核载体,构建pSilencer-ret重组质粒,以脂质体转染高表达RET的TT细胞.实时定量PCR和Western印迹法检测RET mRNA和蛋白的表达,以及细胞外信号调节激酶(ERK)的磷酸化水平,CCK-8法测定细胞增殖.结果 质粒测序证实重组质粒构建成功,转染后能明显抑制TT细胞RET mRNA和蛋白的表达,抑制细胞的增殖(P＜0.05),ERK磷酸化水平降低62.4%.结论 构建的pSilencer-ret重组质粒能有效地降低人MTC细胞RET的表达,抑制细胞增殖,与其降低ERK通路的信号转导有关,为MTC的基因治疗提供新策略.