肝细胞生长因子诱导人肝癌细胞上皮间质转化

上皮间质转化(epithelial-mesenchymal transition,EMT)与肿瘤侵袭转移密切相关.虽然肝细胞生长因子(hepatocyte growth factor,HGF)已被证实为肿瘤EMT的主要诱导剂,但是HGF诱导肿瘤EMT发生的分子机制尚不完全清楚.本研究旨在探讨Snail在HGF诱导肝癌细胞上皮间质转化中的作用.用HGF处理肝癌Hep G2和Hep3B细胞,显微镜观察细胞形态变化,划痕试验及Transwell试验检测细胞迁移能力,Western印迹检测Met,AKT的磷酸化及蛋白质表达的变化,Western印迹与real-time RT-PCR检测上皮细胞表面标志E-Cadherin和间质细胞表面标志NCadherin、Fibronectin的表达变化,以及EMT相关转录因子的表达变化.经HGF处理的Hep G2、Hep3B细胞,Met和AKT的磷酸化水平显著增强;相差倒置显微镜下观察细胞形态向间质型细胞形态转化;细胞划痕和Transwell试验检测细胞的迁移能力较对照组显著增强;Real-time RT-PCR和Western印迹实验显示HGF的诱导能上调间质标记蛋白的表达及下调上皮型标志蛋白的表达.进一步发现,HGF能上调转录因子Snail的表达,干扰Snail能逆转HGF对Hep G2和Hep 3B细胞EMT发生的诱导作用.由此可见,HGF可能通过诱导Snail的表达促进肝癌细胞EMT的发生.这为阐明肝癌细胞侵袭转移机制,以及肝癌的防治提供新线索.     

肝星形细胞分泌的趋化因子CXCL1在肝癌转归中的作用

该文探讨了人肝星形细胞(hepatic stellate cells,HSC)对肝癌细胞(Hep G2、SMMC-7721)的迁移、侵袭能力和上皮–间质转化(epithelial-msenchymal transition,EMT)的影响及其机制。采用条件培养法培养肝癌细胞,利用细胞划痕和Transwell实验分析肝星形细胞对肝癌细胞的迁移和侵袭作用。Western blot分析肝星形细胞自身及其分泌到培养液中趋化因子CXCL1[chemokine(C-X-C motif)ligand 1]和肝癌细胞的CXCL1受体2—CXCR2(CXCL1 receptor 2)的表达量,以及条件培养下肝癌细胞中p-PI3K、p-AKT、p-GSK-3β和Snail的表达变化。激光共聚焦显微术和Western blot检测肝癌细胞上皮标志物E-cadherin、间质标志物N-cadherin和Vimentin的表达变化。结果显示,在HSC中大量表达并分泌趋化因子CXCL1,而肝癌细胞Hep G2、SMMC-7721中高表达CXCR2。肝癌细胞通过条件培养后,细胞形态改变,细胞黏附下降,细胞迁移和侵袭能力增强,上皮标志物E-cadherin蛋白表达下调、间质标志物N-cadherin蛋白和Vimentin蛋白表达上调,PI3K/AKT信号通路中的关键成员PI3K和AKT磷酸化水平上调,p-GSK-3β和转录因子Snail表达上调。在肝癌细胞条件培养下加入CXCR2受体的特异性抑制剂(SB265610)后,肝癌细胞上皮标志物E-cadherin蛋白表达上调、间质标志物N-cadherin蛋白和Vimentin蛋白表达下调,p-PI3K、p-AKT、p-GSK-3β和Snail的表达下调。以上结果说明,肝星形细胞可能通过CXCL1/CXCR2轴活化PI3K/AKT信号通路并最终促进肝癌细胞上皮–间质转化。     

TGF-β_1通过PI3K/AKT/ARK5/Snail信号通路促进非小细胞肺癌SPC-A1细胞的上皮-间质转化

上皮-间质转化(EMT)在肿瘤侵袭转移发展进程中起着重要的作用.转化生长因子-β(TGF-β)已被证实为肿瘤EMT的主要诱导剂.然而,其分子机制仍有待深入研究.该研究旨在探讨TGF-β1促进非小细胞肺癌(NSCLC)细胞系SPC-A1上皮-间质转化过程中的分子机制.细胞的形态学检查结果显示,TGF-β1刺激SPC-A1细胞后细胞形态变成梭形.Transwell侵袭实验揭示,TGF-β1刺激后细胞侵袭能力明显增强.Western印迹结果证明,与未经TGF-β1刺激的SPC-A1细胞比较,EMT上皮标志物上皮-钙粘蛋白(E-cadherin)表达明显下调,而间质标志物波形蛋白(vimentin)明显上调,p-AKT、p-ARK5的表达也明显增强.此外,转录因子Snail在细胞核内的表达水平明显增强.TGF-β1和PI3K抑制剂LY294002同时刺激SPC-A1细胞后,p-AKT、p-ARK5较只加TGF-β1时表达明显降低,Snail在核内的表达水平也明显降低.结果提示,TGF-β1通过激活AKT、ARK5磷酸化,促进转录因子Snail入核,进而导致SPC-A1细胞EMT.     

miR-145通过下调PLCε抑制膀胱癌EMT和迁移及其机制研究

目的:探讨miR-145调控PLCε对膀胱癌细胞T24上皮间质转化(EMT)和迁移的影响及可能的分子机制。方法:(1)腺病毒感染T24细胞,划痕实验和Transwell检测细胞的迁移能力;RTPCR、Western blot分别检测PLCε及EMT相关分子的表达;为探究其分子机制,Western blot检测GSK-3β磷酸化(Ser9位点)和Snail的表达情况。(2)利用生物信息学技术预测可能调控PLCε的miRNA,结合文献报道的膀胱癌microRNA表达谱结果筛选出miR-145;转染miR-145 mimics至T24,q PCR检测miR-145、PLCε的表达,Western blot检测PLCε的表达。(3)转染miR-145 mimics,Western blot检测EMT相关分子及p-GSK-3β、Snail;划痕实验、Transwell检测过表达miR-145后细胞的迁移能力。结果:(1)干扰PLCε表达能显著抑制细胞的迁移,同时,使T24细胞中E-cadherin表达上调,N-cadherin和Vimentin表达下调;干扰PLCε后,GSK-3β磷酸化(Ser9位点)水平下降,Snail表达降低。(2)转染miR-145 mimics可使T24细胞中miR-145表达增高,且明显抑制T24细胞中PLCε的表达。(3)在T24中过表达miR-145,细胞迁移能力显著下降,EMT标志分子的表达情况与沉默PLCε结果一致。同时,与阴性对照组相比,转染miR-145 mimics组p-GSK-3β和Snail表达显著减少。结论:PLCε通过GSK-3β/Snail信号通路促进膀胱癌细胞T24发生EMT及迁移,miR-145可以逆转PLCε诱导膀胱癌EMT的发生,从而阻止膀胱癌细胞的迁移。     

TGF-β1对乳腺癌细胞系Snail表达的影响

目的通过TGF-β1诱导乳腺癌MCF-7发生上皮-间质转化(epithelial-mesenchymal transition,EMT)后检测锌指转录因子Snail表达的改变,探讨Snail在EMT及乳腺癌发生发展中的作用。方法常规培养乳腺癌细胞株MCF-7后,用TGF-β1诱导其发生EMT,用Transwell侵袭小室法进行细胞体外侵袭能力检测;用免疫组织化学方法及免疫荧光检测E-cadherin、Vi mentin、Snail的表达;用real ti me PCR检测E-cadherin、Vi mentin、Snail mRNA的表达。结果TGF-β1处理72h后的MCF-7细胞穿透能力明显增强。E-cadherin蛋白及mRNA表达减少,Vi mentin、Snail蛋白及mRNA表达增加。结论E-cadherin、Vi mentin是细胞发生EMT的重要生物学标志,Snail可能在转录水平上调控E-cadherin、Vi mentin蛋白的表达,Snail在EMT和乳腺癌的发生发展中起着重要的作用。     

TRPM3通过Wnt/β-catenin信号通路诱导上皮性卵巢癌细胞上皮间质转化的作用研究

目的:探讨瞬时受体电位离子通道3(Transient receptor potential melastatin 3,TRPM3)对卵巢癌侵袭转移和上皮细胞间质转化(Epithelial mesenchymal transition,EMT)的影响及其分子作用机制。方法:采用小干扰RNA沉默上皮性卵巢癌细胞株中HEY及SKOV3中TRPM3的表达,通过Transwell实验和划痕实验检测上皮性卵巢癌细胞的侵袭和迁移能力的变化,Western Blot检测EMT相关蛋白、Wnt/β-catenin通路相关蛋白的表达情况。结果:与对照组细胞相比,干扰组的上皮性卵巢癌细胞迁移和侵袭能力均明显减弱,EMT相关蛋白的上皮细胞标志分子E-cadherin的表达上调,间质细胞标志分子N-cadherin和EMT相关转录调控因子Snail的表达下调,Wnt/β-catenin通路相关蛋白CyclinD1、β-catenin的表达下调。结论:TRPM3可能通过激活Wnt/β-catenin通路促进卵巢癌细胞的上皮间质转化过程,进而增强其侵袭转移的能力。     

过表达Snail增强肺癌细胞A549的体外侵袭能力

用锌指转录因子Snail诱导肺癌细胞A549发生上皮细胞-间质转化(epithelial-mesenchymal transition,EMT),检测肺癌发生EMT后细胞侵袭能力的变化,为临床筛选分子靶向药物提供依据.构建pcDNA3.1-snail载体,用pcDNA3.1-snail及空pcDNA3.1载体转染肺癌A549细胞后,进行G418筛选;光镜观察培养后细胞形态学的改变、免疫细胞化学与免疫荧光检测细胞表达E-钙黏着蛋白(E-cadherin)、波形蛋白(vimentin)的改变,Western印迹检测细胞中E-钙黏着蛋白和波形蛋白的改变,Transwell侵袭小室法进行细胞体外侵袭能力检测.采用pcDNA3.1-snail转染细胞后,A549细胞变得细长,细胞融合度降低.免疫细胞化学、免疫荧光、Western印迹结果显示,E-钙黏着蛋白表达降低,波形蛋白表达升高;transwell侵袭小室法结果显示,过表达Snail的A549细胞穿透matrigel胶的细胞数明显增多.结果提示,Snail能有效诱导肺癌发生EMT,并且能增强肺癌的体外侵袭能力.     

Hsa_circ_0000745对肝癌细胞增殖、侵袭、迁移的作用及其机制

该文主要研究环状RNA hsacirc0000745对肝癌细胞的促肿瘤作用及其相关作用机制。首先,采用实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)方法检测不同肝癌细胞中环状RNA hsacirc0000745的表达;其次,利用siRNA干扰技术敲低HepG2细胞中的hsacirc0000745;然后,采用CCK-8和平板克隆实验检测细胞的增殖能力,用Transwell实验和划痕愈合实验检测肝癌细胞HepG2的侵袭及迁移能力,利用Western blot方法检测增殖、侵袭及迁移相关蛋白的表达。结果表明,干扰hsacirc0000745后,肝癌细胞的增殖及克隆形成能力降低(P<0.05),同时伴有增殖相关蛋白cyclin D1表达水平下降(P<0.001),细胞迁移和侵袭能力降低(P<0.05),上皮标志物E-Cadherin的表达水平上调(P<0.05),而间质标志物N-Cadherin和Vimentin的表达水平下调(P<0.05)。该研究结果表明,干扰hsacirc0000745显著抑制肝癌细胞的增殖、迁移、侵袭能力和上皮–间质转化(epithelial mesenchymal transition,EMT)。这为肝癌的诊断和治疗提供了新的潜在靶点和视角。     

下咽癌放疗抵抗细胞放疗抗性与上皮–间质转化的关系

该文探讨了下咽鳞癌放疗抵抗细胞FaduRR发生放疗抵抗与上皮间质转化(epithelial-mesenchymal transition,EMT)的关系及可能的机制。课题组前期成功构建了放疗抵抗细胞株FaduRR。平板克隆形成实验、CCK8实验检测放疗抵抗性,流式细胞术检测细胞凋亡、细胞划痕和Transwell侵袭迁移实验检测迁移侵袭能力,Western blot和qRT-PCR实验检测蛋白和mRNA的表达。与亲本细胞Fadu相比,FaduRR细胞的放疗敏感性明显降低,X线照射后第4天的存活率明显增高、细胞凋亡率降低、细胞形态呈现上皮间质化的改变、细胞迁移侵袭能力增强、E-cadherin的蛋白和mRNA表达水平显著下调,而N-cadherin、Vimentin、p-Akt、p-GSK-3β、Snail的蛋白和mRNA表达水平显著上调,但Akt和GSK-3β的表达无明显变化。以上结果提示,下咽鳞癌放疗抵抗细胞株FaduRR发生了EMT改变,其机制可能与Akt/GSK-3β/Snail信号通路的激活有关。     

Snail真核表达载体的构建及功能鉴定

目的:构建Snail的慢病毒真核表达载体,并研究Snail在肿瘤发生和发展过程中对上皮-间质转化(EMT)的影响。方法:以乳腺文库为模板,PCR扩增Snail的全长编码序列,将其克隆到p CDH表达载体上,构建成p CDH-Snail真核表达载体,转染293T细胞,Western印迹检测p CDH载体介导的Snail的表达;与包装质粒共转染293T细胞,包装病毒后感染ZR75-1细胞,经嘌呤霉素筛选2周,得到稳定表达Snail的ZR75-1细胞株,检测ZR75-1细胞对EMT的影响,同时用倒置荧光显微镜观察ZR75-1稳定细胞株中上皮钙粘蛋白分布的变化。结果:Bam HⅠ、XbaⅠ双酶切及测序证实得到p CDH-Snail表达载体,Western印迹表明Snail在293T细胞内得到成功;经嘌呤霉素筛选,获得稳定表达Snail的ZR75-1细胞株;在倒置荧光显微镜下观察,ZR75-1稳定细胞株中的上皮钙粘蛋白绿色荧光明显减弱。结论:构建了p CDH-Snail的慢病毒真核表达载体,建立了稳定表达Snail的ZR75-1细胞,为进一步研究Snail在EMT过程中的机制奠定了基础。     

Hepatic stellate cell promoted hepatoma cell invasion via the HGF/c-Met signaling pathway regulated by p53

The biological behaviors of hepatocellular carcinoma (HCC) are complex mainly due to heterogeneity of progressive genetic and epigenetic mutations as well as tumor environment. Hepatocyte growth factor (HGF)/c-Met signaling pathway is regarded to be a prototypical example for stromal-epithelial interactions during developmental morphogenesis, wound healing, organ regeneration and cancer progression. And p53 plays as an important regulator of Met-dependent cell motility and invasion. Present study showed that 2 HCC cell lines, Hep3B and HepG2, displayed different invasive capacity when treated with HGF which was secreted by hepatic stellate cells (HSCs). We found that HGF promoted Hep3B cells invasion and migration as well as epithelial-mesenchymal transition (EMT) occurrence because Hep3B was p53 deficient, which leaded to the c-Met over-expression. Then we found that HGF/c-Met promoted Hep3B cells invasion and migration by upregulating Snail expression. In conclusion, HGF/c-Met signaling is enhanced by loss of p53 expression, resulting in increased ability of invasion and migration by upregulating the expression of Snail.     

Combined treatment with zingerone and its novel derivative synergistically inhibits TGF-β1 induced epithelial-mesenchymal transition,migration and invasion of human hepatocellular carcinoma cells

The epithelial–mesenchymal transition (EMT) is an important cellular process during which polarized epithelial cells become motile mesenchymal cells, which promote cancer metastasis. Ginger, the rhizome of Zingiber officinale, is extensively used in cooking worldwide and also as a traditional medicinal herb with antioxidant, anti-inflammatory and anticancer properties. Several pungent compounds have been identified in ginger, including zingerone, which has anticancer potential. However, the role of zingerone in EMT is unclear. We investigated the synergistic effect of zingerone and its derivative on EMT. Transforming growth factor-beta 1 (TGF-β1) induces the EMT to promote hepatocellular carcinoma metastasis, including migration and invasion. To understand the repressive role of the combination of zingerone and its derivative (ZD 2) in hepatocellular carcinoma metastasis, we investigated the potential use of each compound of ginger, such as zingerone, ZD 2 and 6-shogaol, or the mixture of zingerone and ZD 2 (ZD 2-1) as inhibitors of TGF-β1 induced EMT development in SNU182 hepatocellular carcinoma cells in vitro. We show that ZD 2-1, but not zingerone, ZD 2 and 6-shogaol significantly increased expression of the epithelial marker E-cadherin and repressed Snail upregulation and expression of the mesenchymal marker N-cadherin during initiation of the TGF-β1 induced EMT. In addition, ZD 2-1 inhibited the TGF-β1 induced increase in cell migration and invasion of SNU182 hepatocellular carcinoma cells. Furthermore, ZD 2-1 significantly inhibited TGF-β1 regulated matrix metalloproteinase-2/9 and activation of Smad2/3. We also found that ZD 2-1 inhibited nuclear translocation of NF-κB, activation of p42/44 MAPK/AP1 signaling pathway in the TGF-β1 induced EMT. Our findings provide new evidence that combined treatment with ZD 2, novel zingerone derivative, and zingerone synergistically suppresses hepatocellular carcinoma metastasis in vitro by inhibiting the TGF-β1 induced EMT.     

Celastrol inhibits TGF-β1-induced epithelial–mesenchymal transition by inhibiting Snail and regulating E-cadherin expression

The epithelial–mesenchymal transition (EMT) is a pivotal event in the invasive and metastatic potentials of cancer progression. Celastrol inhibits the proliferation of a variety of tumor cells including leukemia, glioma, prostate, and breast cancer; however, the possible role of celastrol in the EMT is unclear. We investigated the effect of celastrol on the EMT. Transforming growth factor-beta 1 (TGF-β1) induced EMT-like morphologic changes and upregulation of Snail expression. The downregulation of E-cadherin expression and upregulation of Snail in Madin–Darby Canine Kidney (MDCK) and A549 cell lines show that TGF-β1-mediated the EMT in epithelial cells; however, celastrol markedly inhibited TGF-β1-induced morphologic changes, Snail upregulation, and E-cadherin expression. Migration and invasion assays revealed that celastrol completely inhibited TGF-β1-mediated cellular migration in both cell lines. These findings indicate that celastrol downregulates Snail expression, thereby inhibiting TGF-β1-induced EMT in MDCK and A549 cells. Thus, our findings provide new evidence that celastrol suppresses lung cancer invasion and migration by inhibiting TGF-β1-induced EMT.     

Linoleic acid induces an EMT-like process in mammary epithelial cells MCF10A

Epidemiological studies and animal models suggest an association between high levels of dietary fat intake and an increased risk of developing breast cancer. Epithelial-mesenchymal-transition (EMT) is a process, by which epithelial cells are transdifferentiated to a mesenchymal state, and it has been implicated in cancer progression, including invasion and metastasis. Linoleic acid (LA) induces proliferation and invasion in breast cancer cells. However, the role of LA on the EMT process in human mammary epithelial cells remains to be studied. In the present study, we demonstrate that LA induces a transient down-regulation of E-cadherin expression, accompanied with an increase of Snail1, Snail2, Twist1, Twist2 and Sip1 expressions. Furthermore, LA induces FAK and NFκB activation, MMP-2 and -9 secretions, migration and invasion. In summary, our findings demonstrate, for the first time, that LA promotes an EMT-like process in MCF10A human mammary epithelial cells.