上皮-间质转化与乳腺癌转移

癌细胞的远处转移是肿瘤发展的最终形式，也是癌症患者死亡的最主要原因。尽管早期乳腺癌患者通过规范化治疗，5年生存率达到了目前的98％；但转移性乳腺癌患者的5年生存率较40年前相比，只是从20％提高到目前的26％，     

PAK5通过上皮-间质转化促进人乳腺癌细胞侵袭

目的:探讨p21活化激酶-5（p21-activated kinase 5,PAK5）蛋白对乳腺肿瘤细胞侵袭转移的作用机制。方法:观察PAK5过表达对乳腺癌细胞形态的影响,人乳腺肿瘤细胞MCF-7通过慢病毒感染稳定表达Flag-PAK5。然后提取感染细胞的总蛋白进行蛋白免疫印迹检测上皮-间质转化（EMT）标志物上皮-钙黏蛋白（E-cadherin）,纤维连接蛋白（Fibronectin）和波形蛋白（vimentin）的表达。最后通过Transwell实验检测过表达PAK5对乳腺癌细胞迁移和侵袭的影响。结果:过表达PAK5蛋白能够使细胞形态由鹅卵石样像梭形变化,下调E-cadherin蛋白,促进乳腺癌细胞迁移和侵袭。结论:PAK5可能参与调节乳腺肿瘤细胞发生上皮－间质转化,促进乳腺肿瘤侵袭转移的发生。     

尼古丁诱导肺癌细胞上皮间质转化促进其侵袭转移

背景与目的我们的前期研究发现尼古丁能诱导肺癌细胞上皮间质转化。本研究的目的是探讨尼古丁诱导的上皮间质转化（epithelial-mesenchymal transition, EMT）与肺癌侵袭之间的关系。方法应用不同浓度尼古丁处理肺腺癌A549细胞,应用Real-time PCR和Western blot方法检测EMT相关分子标志物E-钙粘蛋白（E-cadherin）和波形蛋白（Vimentin）mRNA和蛋白表达水平,应用免疫荧光技术检测β-链蛋白（β-catenin）蛋白表达位置的变化,应用划痕实验和Transwell小室侵袭实验检测尼古丁对肺癌细胞迁移侵袭能力的影响。结果尼古丁明显下调肺癌细胞株A549 E-cadherin mRNA和蛋白水平表达（P<0.01, P<0.01）,并具有浓度和时间依赖性;尼古丁明显上调肺癌细胞株A549 Vimentin mRNA和蛋白水平表达（P<0.01, P<0.01）;尼古丁诱导肺癌细胞株A549细胞β-catenin蛋白发生核转移;划痕实验和侵袭实验观察到尼古丁处理的肺癌细胞株A549细胞的迁移和侵袭能力明显增强（P<0.01, P<0.01）。结论尼古丁能够诱导肺癌细胞发生EMT,并且促进肺癌细胞株A549细胞的体外侵袭潜能。     

上皮—间质转化与肿瘤侵袭转移关系的研究进展

上皮-间质转化（EMT）是指上皮细胞在特定的生理和病理情况下转化成有迁移能力的间质细胞的现象。近年来研究发现EMT与肿瘤的侵袭转移密切相关。生长因子、转录因子、microRNA等都可以参与各种信号通路来诱导或调控细胞发生EMT。本文就EMT现象及其与肿瘤侵袭转移的关系进行综述。     

乳腺癌MCF-7细胞通过TGF-β诱导的上皮-间质转化获得耐药北大核心CSCD

目的:通过研究高侵袭转移性乳腺癌细胞株MDA-MB-231和低侵袭转移性细胞株MCF-7中上皮-间质转化(epithelial-mesenchymal transition,EMT)和耐药的相关性,以探讨乳腺癌耐药的机制。方法:采用实时荧光定量PCR法检测MDA-MB-231和MCF-7细胞中EMT标志物E-钙黏蛋白(E-cadherin)、波形蛋白(vimentin)和纤黏蛋白(bronectin)以及转录因子Snail、Slug和锌指E-box同源结合框1(Zincnger E-box binding homeobox 1,ZEB1)mRNA的表达水平;划痕愈合实验和Transwell小室实验分别检测MDA-MB-231和MCF-7细胞的迁移和侵袭能力;CCK-8法检测MDA-MB-231和MCF-7细胞对化疗药物5-氟尿嘧啶、顺铂和紫杉醇的敏感性,并采用实时荧光定量PCR法检测耐药基因多重耐药相关蛋白1(multidrug resistance-associated protein 1,MDR1)和MDR相关蛋白1(MDR-associated protein,MRP1)mRNA的表达水平。用转化生长因子β(transforming growth factor-β,TGF-β)诱导MCF-7细胞发生EMT,或用靶向E-cadherin基因的E-cadherin-siRNA沉默EMT相关标志物E-cadherin的表达,再用CCK-8法检测MCF-7细胞对5-氟尿嘧啶敏感性的变化。结果:MDA-MB-231细胞中vimentin、fibronectin、Slug和ZEB1 mRNA的表达水平均高于MCF-7细胞(P值均<0.000 1),E-cadherin mRNA的表达水平明显低于MCF-7细胞(P=0.000 2),Snail mRNA的表达水平无明显差异。与MCF-7细胞相比,MDA-MB-231细胞的迁移和侵袭能力明显更强(P值均<0.000 1);5-氟尿嘧啶、顺铂和紫杉醇对MDAMB-231细胞的半数抑制浓度(half maximal inhibitory concentration,IC50)值明显高于MCF-7细胞(P值均<0.05);MDA-MB-231细胞中耐药相关基因MDR1和MRP1 mRNA表达水平明显更高(P值均<0.000 1)。TGF-β诱导MCF-7细胞发生EMT后,5-氟尿嘧啶对MCF-7细胞的IC50值明显上升(P<0.05);沉默E-cadherin表达后,MCF-7细胞对5-氟尿嘧啶的耐药性明显增强(P<0.05)。结论:乳腺癌中EMT和耐药存在相关性,诱导EMT发生可导致细胞耐药。     

上皮-间质转化与肺癌侵袭转移及耐药性的研究进展

侵袭转移和耐药是肺癌患者治疗失败的主要原因。最近研究表明,上皮-间质转化（EMT）在肺癌远处转移及化疗耐药的发生中扮演着非常重要的角色。因此,针对EMT的研究有助于肿瘤的预防和治疗。本文结合国内外最新报道,对EMT与肺癌侵袭转移及耐药性的研究进展作一综述。     

HER-2通过ZEB1促进乳腺癌细胞上皮间质转化

背景与目的：人类表皮生长因子受体2(human epidermal growth factor receptor-2,HER-2)是表皮生长因子受体家族中的一员,它参与细胞多个生物过程,如细胞增殖、侵袭和凋亡等。有研究表明,HER-2与细胞上皮间质转化(epithelial-mesenchymal transition,EMT)过程相关,但具体机制有待进一步探讨,本研究旨在探讨HER-2对EMT的调节机制。方法：用Transwell小室模拟细胞的迁徙侵袭能力;采用实时荧光定量聚合酶链反应(real-time lfuorescent quantitative polymerase chain reaction,RTFQ-PCR)检测目的基因的表达;用活性氧检测试剂盒检测细胞活性氧的水平。结果：Transwell小室模拟实验发现,HER-2过表达能促进乳腺癌细胞的侵袭转移;机制研究表明,HER-2能上调ZEB1,用siRNA降低ZEB1表达使HER-2过表达细胞的侵袭能力受损;此外,HER-2过表达乳腺癌细胞中活性氧水平较低。结论：HER-2可以上调ZEB1的表达而赋予乳腺癌细胞EMT相关特性,ZEB1可作为进一步研究HER-2与EMT调节关系的靶点。     

上皮-间质转化在非小细胞肺癌侵袭与转移中作用的研究进展

上皮-间质转化（Epithelial—mesenchymal transition,EMT）与恶性肿瘤的侵袭及转移有着密切的关系,是目前研究恶性肿瘤侵袭及转移的热点。有大量研究表明在多种恶性肿瘤如乳腺癌、卵巢癌和非小细胞肺癌的侵袭与转移过程中都有上皮-间质转化现象,并阐述上皮-间质转化的信号通路及其蛋白分子。本文对上皮-间质转化在非小细胞肺癌侵袭与转移的研究成果做一综述。     

上皮间质转化与肿瘤侵袭转移关系的研究进展

上皮间质转化(epithelial-mesenchymal transition,EMT)是指上皮细胞失去极性,失去与基底膜的连接等上皮表型,通过特定程序转化为具有间质表型的生物学过程,从而获得了较高的迁移与侵袭、抗凋亡和降解细胞外基质的能力,与肿瘤的侵袭转移密切相关。参与这一过程的细胞内信号转导途径主要有:TGF-β信号途径、PI3K/AKT途径、Notch信号通路、Wnt信号通路等。本文就EMT在肿瘤侵袭转移中的作用及其分子机制的研究作一综述。     

上皮间质转化与肿瘤侵袭转移关系的研究进展

上皮间质转化（epithelial-mesenchymal transition,EMT）是指上皮细胞失去极性,失去与基底膜的连接等上皮表型,通过特定程序转化为具有间质表型的生物学过程,从而获得了较高的迁移与侵袭、抗凋亡和降解细胞外基质的能力,与肿瘤的侵袭转移密切相关。参与这一过程的细胞内信号转导途径主要有：TGF-β信号途径、PI3K/AKT途径、Notch信号通路、Wnt信号通路等。本文就EMT在肿瘤侵袭转移中的作用及其分子机制的研究作一综述。     

BMP4 通过诱导EMT 促进肝癌迁移侵袭*

目的:检测BMP 4 在肝癌中的表达并探讨BMP 4 在诱导肝癌EMT 中的作用,进而研究其对肝癌细胞迁移侵袭能力的影响。方法:采用免疫组织化学方法检测肝癌组织中BMP 4 的表达,分析其与肝癌临床病理资料之间的关系。将BMP 4 表达质粒转染至肝癌细胞系HepG2 中,诱导BMP 4 外源性过表达。观察BMP 4 转染前、后HepG2 的细胞形态学改变;Westernblot检测转染前、后HepG2 中BMP 4、EMT 相关蛋白（E-cadherin、Vimentin）表达变化情况;划痕和侵袭实验检测BMP 4 对细胞迁移侵袭能力的影响。结果:BMP 4 与患者的年龄、病理分级、临床分期、不良预后密切相关。BMP 4 过表达后HepG2 呈现典型的EMT 形态学改变,E-cadherin 表达下调、Vimentin 表达上调、细胞的迁移侵袭能力显著增强。结论:BMP 4 与肝癌临床病理资料密切相关,并可能通过诱导EMT 促进肝癌细胞的迁移侵袭能力。      

miR-1297 通过下调TET3 促进乳腺癌MCF-7 细胞的恶性生物学行为

[摘要] 目的：探讨miR-1297 对乳腺癌细胞恶性生物学行为的调控作用及其潜在机制。方法：选用2016 年5 月至2018 年5月乐山市人民医院甲乳外科手术切除的20 例乳腺癌组织和癌旁组织标本以及乳腺癌细胞系MCF-7、SW626、HCC1937 和人乳腺上皮细胞MCF-10A,用qPCR检测乳腺癌组织和细胞系中miR-1297 的表达水平。实验分为对照组、miR-1297 inhibitor 组、TET甲基胞嘧啶双加氧酶3（TET3）过表达组及同时过表达TET3 和miR-1297 组,用CCK-8、Transwell 实验检测MCF-7 细胞的增殖、迁移和侵袭能力,用WB检测MCF-7 细胞中TET3 和EMT相关蛋白（E-cadherin、N-cadherin 和vimentin）的表达水平。用双荧光素酶报告基因验证miR-1297 与TET3 的靶向关系。结果：miR-1297 在乳腺癌组织和细胞系中均高表达（P<0.01 或P<0.05）。敲降miR-1297 后,MCF-7 细胞的增殖、迁移、侵袭和EMT均明显受到抑制（P<0.05 或P<0.01）。转染pcDNA3.1-TET3 后,MCF-7 细胞TET3的表达水平显著上调（P<0.05）;同时过表达TET3 和miR-1297 能够逆转MCF-7 细胞中TET3 的表达水平及TET3 对MCF-7 细胞增殖、迁移、侵袭和EMT的抑制作用。双荧光素酶报告基因结果显示,miR-1297 靶向结合TET3 的3'' UTR,miR-1297 靶向下调TET3 从而促进MCF-7 细胞的恶性生物学行为。结论：miR-1297 在乳腺癌组织和细胞中高表达,其通过靶向下调TET3 的表达水平促进MCF-7 细胞增殖、迁移、侵袭和EMT等恶性生物学行为。     

CDKL2 promotes epithelial-mesenchymal transition and breast cancer progression

The epithelial–mesenchymal transition (EMT) confers mesenchymal properties on epithelial cells and has been closely associated with the acquisition of aggressive traits by epithelial cancer cells. To identify novel regulators of EMT, we carried out cDNA screens that covered 500 human kinases. Subsequent characterization of candidate kinases led us to uncover cyclin-dependent kinase-like 2 (CDKL2) as a novel potent promoter for EMT and breast cancer progression. CDKL2-expressing human mammary gland epithelial cells displayed enhanced mesenchymal traits and stem cell-like phenotypes, which was acquired through activating a ZEB1/E-cadherin/β-catenin positive feedback loop and regulating CD44 mRNA alternative splicing to promote conversion of CD24^high cells to CD44^high cells. Furthermore, CDKL2 enhanced primary tumor formation and metastasis in a breast cancer xenograft model. Notably, CDKL2 is expressed significantly higher in mesenchymal human breast cancer cell lines than in epithelial lines, and its over-expression/amplification in human breast cancers is associated with shorter disease-free survival. Taken together, our study uncovered a major role for CDKL2 in promoting EMT and breast cancer progression.     

MicroRNAs:regulators of cancer metastasis and epithelial-mesenchymal transition (EMT)

Tumor metastasis is the main cause of death in patients with solid tumors. The epithelial-mesenchymal transition(EMT) process, in which epithelial cells are converted into mesenchymal cells, is frequently activated during cancer invasion and metastasis. MicroRNAs(miRNAs) are small, non-coding RNAs that provide widespread expressional control by repressing mRNA translation and inducing mRNA degradation. The fundamental roles of miRNAs in tumor growth and metastasis have been increasingly well recognized. A growing number of miRNAs are reported to regulate tumor invasion/metastasis through EMT-related and/or non-EMT–related mechanisms. In this review, we discuss the functional role and molecular mechanism of miRNAs in regulating cancer metastasis and EMT.     

The roles of microRNAs and epithelial-mesenchymal transition in colorectal cancer metastasis

Colorectal cancer (CRC) is the second most common cause of cancer death worldwide. Distant metastasis is the major cause of death in patients with CRC. During progression to metastasis in which maligna...     

Harmine suppresses breast cancer cell migration and invasion by regulating TAZ-mediated epithelial-mesenchymal transition

Breast cancer is a highly lethal disease due to cancer metastasis. Harmine (HM), a β-carboline alkaloid, is present in various medicinal plants. Our previous study demonstrated that HM suppresses cell proliferation and migration by regulating TAZ in breast cancer cells and accelerates apoptosis. Epithelial-mesenchymal transition (EMT) plays an important role in the development of breast cancer by inducing the characteristics of cancer stem cells, cancer metastasis and recurrence. Overexpression of TAZ was shown to mediate EMT in breast cancer cells. We aimed to investigate whether HM inhibits EMT and metastasis of breast cancer cells by targeting TAZ. In this study, the cells treated with HM or with downregulated expression of TAZ showed an increase in epithelial markers and decrease in mesenchymal markers in breast cancer cells. Consistently, the breast cancer cells treated with HM or with downregulated expression of TAZ showed suppressed migration and proliferation. Moreover, TAZ overexpression reversed EMT and metastasis induced by HM in breast cancer cells. Thus, HM suppresses EMT and metastasis and invasion by targeting TAZ in breast cancer cells. HM can be used as an anticancer drug for breast cancer treatment and chemoprevention.     

Cullin3 promotes breast cancer cells metastasis and epithelial-mesenchymal transition by targeting BRMS1 for degradation

Metastasis is the leading cause of death in breast cancer (BC) patients. However, until now, the mechanisms of BC metastasis remain elusive. Cullin3 is a highly conserved Cullin family member present in the genomes of all eukaryotes, which has been proposed as an oncogene in many types of tumors; however, its role and underlying mechanisms in BC remain unclear. Here we show that Cullin3 is elevated in BC and its expression level is positively correlated with metastasis. Overexpression of Cullin3 in BC cells increased proliferation, epithelial-mesenchymal transition, migration and invasion in vitro, and enhanced tumorigenic and metastatic capacities in vivo. In contrast, silencing Cullin3 in aggressive and invasive BC cells inhibited these processes. Mechanistically, we found Cullin3 exerts its function through promoting BRMS1 protein degradation, which was associated with EMT, migration and invasion. BRMS1 overexpression blocked Cullin3-driven EMT, and metastasis. Our results, for the first time, portray a pivotal role of Cullin3 in stimulating metastatic behaviors of BC cells. Targeting Cullin3 may thus be a useful strategy to impede BC cell invasion and metastasis.