上皮间质转化在肿瘤侵袭转移中的研究进展

上皮-间质转化（epithelial-mesenchymal transitions,EMT）是上皮细胞向间质细胞转化的现象,不仅参与胚胎发育和正常生理,还参与许多病理过程。同样EMT也参与肿瘤的发生与发展,尤其在促进肿瘤侵袭转移中发挥着重要作用。研究表明,肿瘤细胞借助EMT方式增强肿瘤细胞迁移和运动能力,促进肿瘤的侵袭与转移。在肿瘤侵袭转移历程中,关于EMT发生的分子调控机制研究已取得了良好的进展,但其详细机制仍然不是十分清楚。本文主要介绍生长因子、转录因子、miRNAs、甲基化及其他调控因子在肿瘤EMT中的调控功能,进一步综述EMT在肿瘤侵袭转移中的作用。     

间质-上皮转化在肿瘤转移中的作用

肿瘤转移是一个多步骤、多因素参与的复杂过程,是目前临床上绝大多数肿瘤患者的致死因素.上皮-间质转化(epithelial-mesenchymal transition, EMT)过程已被证实可促使肿瘤细胞发生转移.近年来许多研究表明,间质-上皮转化(mesenchymal-epithelial transition, MET)即EMT的逆过程,与肿瘤也密切相关,特别是肿瘤转移即形成继发性的肿瘤转移灶.深入研究肿瘤MET有望为肿瘤转移的预防和诊治提供新思路.     

TGF-β调节的EMT在肿瘤浸润、转移中作用的研究进展

恶性肿瘤的浸润转移是导致肿瘤患者死亡的主要原因,转化生长因子-β(transforming growth factor-β,TGF-β)调节的上皮间质转化(epithelial-mesenchymal transition,EMT)能使肿瘤上皮细胞转变为具有间质特性的细胞,肿瘤细胞由此获得侵袭性和迁移性,从原发灶中逸出,进而发生转移。因此,对TGF-β调节的EMT在肿瘤浸润转移中作用的深入研究能够为临床治疗肿瘤转移提供研究基础。将对TGF-β调节EMT的信号通路,及其在肿瘤浸润转移中的作用和干预研究进行综述。     

β-catenin和E-cadherin在肿瘤发展中的研究

肿瘤细胞的侵袭和转移是恶性肿瘤的主要特征之一,其间涉及多种机制,研究表明某些蛋白在肿瘤的转移过程中起着重要的作用,其中上皮钙粘蛋白（E-cadherin）β-连环蛋白（β-catenin）与肿瘤发生、发展及转移有密切关系的蛋白之一。本文就β-catenin和E-cadherin与肿瘤发展,转移关系的研究进展作一综述。     

肿瘤转移研究的现状与趋势

肿瘤转移是恶性肿瘤的主要特征,是引起癌症患者死亡的首要因素．肿瘤转移的发生涉及到肿瘤细胞及其所处的微环境中复杂的信号通路,这些信号通路的激活及相互作用介导了肿瘤的转移、侵袭和在血液/淋巴循环系统中存活,以及在转移靶部位的生长过程．肿瘤转移是一个复杂的、多因素调控的动态过程,对于肿瘤转移机制的研究将有助于深入了解转移过程,并可以鉴定到有意义的治疗靶标,为临床诊断和治疗奠定基础．     

调控肿瘤上皮–间质转化及肿瘤干细胞样特性的信号通路串话

上皮–间质转化（epithelial-mesenchymal transition,EMT）是上皮来源肿瘤细胞获得侵袭和转移能力的重要生物学过程。肿瘤干细胞样细胞（cancer stem-like cells,CSLCs）在肿瘤发生、侵袭、转移和复发中亦起着关键作用。近年发现,EMT与肿瘤干细胞样特性获得存在密切关联,二者通过TGF-β、Wnt/β-catenin、Notch、Hedgehog、FGF、PI3k/Akt等多种信号通路及通路间的信号串话而交互作用,共同影响着肿瘤发生、侵袭及转移,了解调控EMT/CSLCs关键信号分子的功能及相互作用对于肿瘤靶向治疗具有重要意义。     

EMT参与肿瘤侵袭转移的研究进展

在癌症类型中,上皮癌占绝大多数。从良性腺瘤过渡到恶性癌和转移期间,上皮肿瘤细胞获得去分化、迁移和入侵行为,同时上皮-间质转化（epithelial-mesenchymal transition EMT）伴随着显著的细胞形态学变化、细胞与细胞间及细胞与基质之间的粘附性丢失及重塑、并获得迁徙和侵袭能力。正如完全分化的上皮细胞转换成低分化、迁移和侵入性间质细胞,其涉及到一个高度的细胞可塑性、大量不同的基因和表观遗传学改变,因此EMT本身是一个多阶段的过程。该综述的目的是系统地总结EMT分子机制及EMT与肿瘤关系的最新进展。     

EMT参与肿瘤侵袭转移的研究进展

在癌症类型中,上皮癌占绝大多数。从良性腺瘤过渡到恶性癌和转移期间,上皮肿瘤细胞获得去分化、迁移和入侵行为,同时上皮-间质转化(epithelial-mesenchymal transition EMT)伴随着显著的细胞形态学变化、细胞与细胞间及细胞与基质之间的粘附性丢失及重塑、并获得迁徙和侵袭能力。正如完全分化的上皮细胞转换成低分化、迁移和侵入性间质细胞,其涉及到一个高度的细胞可塑性、大量不同的基因和表观遗传学改变,因此EMT本身是一个多阶段的过程。该综述的目的是系统地总结EMT分子机制及EMT与肿瘤关系的最新进展。     

miR-155、EMT与肿瘤侵袭转移的研究进展

肿瘤细胞发生上皮间质转化(EMT)是其获得侵袭和转移能力的关键环节之一,而miR-155是EMT的重要调节因子,它通过靶向调节参与这一过程的关键蛋白因子的表达而发挥作用。miR-155的上述功能具有组织和细胞特异性,即在不同的肿瘤组织细胞中它具有促进或抑制侵袭和转移的能力,其功能的发挥取决于其作用靶点的生物学特征。就miR-155与EMT以及肿瘤侵袭转移关系的研究进展作一综述。     

肿瘤微环境中上皮–间质转化与肿瘤干细胞的调控

肿瘤微环境是一个复杂的组织样结构,具有丰富的表型和功能异质性。不同浓度的趋化因子、细胞因子与组成肿瘤微环境的细胞间相互作用,可激活上皮–间质转化(epithelial-mesenchymal transition,EMT)相关的信号通路及控制肿瘤干细胞(cancer stem cells,CSCs)的生成。EMT的异常激活会促进肿瘤细胞的可塑性,赋予上皮细胞间充质特性,并与癌细胞获得侵袭性的特征密切相关。CSCs是一类具有高致瘤潜能的细胞群,其能很容易地适应周围环境的变化,与肿瘤内其他细胞相比具有较强的抗药性。该文对肿瘤微环境中EMT与CSC的作用机制及相关信号通路的研究进展进行综述。     

The tumor microenvironment: An irreplaceable element of tumor budding and epithelial-mesenchymal transition-mediated cancer metastasis

Tumor budding occurs at the invasive front of cancer; the tumor cells involved have metastatic and stemness features, indicating a poor prognosis. Tumor budding is partly responsible for cancer metastasis, and its initiation is based on the epithelial-mesenchymal transition (EMT) process. The EMT process involves the conversion of epithelial cells into migratory and invasive cells, and is a profound event in tumorigenesis. The EMT, associated with the formation of cancer stem cells (CSCs) and resistance to therapy, results from a combination of gene mutation, epigenetic regulation, and microenvironmental control. Tumor budding can be taken to represent the EMT in vivo. The EMT process is under the influence of the tumor microenvironment as well as tumor cells themselves. Here, we demonstrate that the tumor microenvironment dominates EMT development and impacts cancer metastasis, as well as promotes CSC formation and mediates drug resistance. In this review, we mainly discuss components of the microenvironment, such as the extracellular matrix (ECM), inflammatory cytokines, metabolic products, and hypoxia, that are involved in and impact on the acquisition of tumor-cell motility and dissemination, the EMT, metastatic tumor-cell formation, tumor budding and CSCs, and cancer metastasis, including subsequent chemo-resistance. From our point of view, the tumor microenvironment now constitutes a promising target for cancer therapy.     

MiRNA调控非小细胞肺癌转移的研究进展

微小RNA是内源性的非编码小RNA分子,通过与靶mRNA的结合在转录后水平调控基因的表达,从而参与众多生命活动的调控。NSCLC是严重威胁人类健康的恶性肿瘤,侵袭转移是其主要特征,也是其治疗失败和死亡的主要原因。miRNA可以通过促进上皮-间质转化、金属基质蛋白酶表达,以及血管生成来促进NSCLC转移,而且miRNA在调节肺癌干细胞特性中也发挥着重要作用。转移相关的miRNA已成为肺癌靶向治疗的新靶点。     

Long non-coding RNAs: How to regulate the metastasis of non–small-cell lung cancer

Non–small-cell lung cancer (NSCLC) has become the most lethal human cancer because of the high rate of metastasis. Hence, clarifying the molecular mechanism underlying NSCLC metastasis is very important to improve the prognosis of patients with NSCLC. Long non-coding RNAs (LncRNAs) are a class of RNA molecules longer than 200 nucleotides, which can participate in diverse biological processes. About 18% of human LncRNAs were recently found to be associated with tumours. Many studies indicated that aberrant expression of LncRNAs played key roles in the progression and metastasis of NSCLC. According to the function in tumours, LncRNAs can be divided into two classes: oncogenic LncRNAs and tumour-suppressor LncRNAs. In this review, we summarized the main molecular mechanism of LncRNAs regulating NSCLC metastasis, including three aspects: (a) LncRNAs interact with miRNAs as ceRNAs; (b) LncRNAs bind with target proteins; and (c) LncRNAs participate in the transduction of different signal pathways. Then, LncRNAs can exert their function to regulate the metastasis of NSCLC through influencing the progression of epithelial-mesenchymal transition ( EMT) and the properties of cancer stem cell (CSC). But, it is necessary to do some further research to demonstrate the LncRNAs particular regulatory mechanism of inhibiting the metastasis of NSCLC and explore new drugs targeting LncRNAs.     

Regulation of breast cancer tumorigenesis and metastasis by miRNAs

miRNAs are a family of 17- to 23-nucleotide noncoding small RNAs that primarily function as gene expression fine regulators. A number of studies have shown that miRNAs play an important role in breast tumorigenesis, metastasis, proliferation and differentiation of breast cancer stem cells. This short review summarizes the progression of miRNA-mediated breast tumorigenesis and metastasis through various signaling pathways associated with drug resistance.     

Honokiol Suppresses Renal Cancer Cells’ Metastasis via Dual-Blocking Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties through Modulating miR-141/ZEB2 Signaling

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells’ metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that honokiol could up-regulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.