TGF-β信号通路调控乳腺癌上皮-间质转化的研究进展

上皮-间质转化(epithelial-mesenchymal transition,EMT)是指具有极性的上皮细胞丧失极性,转化成具有迁移能力的间质细胞的过程。在乳腺癌中,EMT的发生促进原位癌向侵袭性癌发展,并与肿瘤细胞获得耐药性有关。参与调控细胞发生EMT的因素众多,涉及众多信号通路、转录因子及下游相关基因。其中,转化生长因子β(transforming growth factorβ,TGF-β)信号通路在乳腺癌EMT过程中起着重要的作用。本文综述了TGF-β信号通路在调控乳腺癌EMT的研究进展。     

上皮-间质转化在肺纤维化中的研究进展

肺纤维化是众多肺部疾病的最终表现结果,其形成过程十分复杂,发生的机制也尚未完全阐明。目前的研究发现,上皮-间质转化（epithelial-mesenchymal transition,EMT）是肺纤维化发病机制中的一个关键步骤。转化生长因子-β、Notch和Wingless-type信号通路是普遍认可的介导调控EMT的信号通路。微小核糖核酸及内质网应激等在EMT过程中发挥重要作用。充分认识EMT在肺纤维化发生发展中的作用,有助于寻找治疗肺纤维化的新方法和新药物。本文就近年来国内外学者对EMT在肺纤维化中的研究新进展进行综述。     

中药在TGF-β信号通路抑制肺纤维化中的 作用研究进展

肺纤维化是一种严重致死性疾病,其发病并非单一机制。上皮间质转化（EMT）是肺纤维化发生和发展的重要过程,在这个过程中TGF-β信号通路是其发展的重要机制。TGF-β信号通路分为Smads通路和non-Smads通路。目前中药在治疗肺纤维化方面具有显著作用已被证实,有关其治疗肺纤维化的机制也有大量研究。本文对中药在TGF-β信号通路中的抑制作用作一综述,以期为中药治疗肺纤维化的开发和利用提供参考。     

Wnt信号通路诱导肿瘤细胞上皮间质转化的研究进展

肿瘤细胞发生上皮间质转化(epithelial-mesenchymaltransition,EMT)从而具有侵袭转移的能力,是肿瘤发展的一个重要过程。既往研究发现Wnt信号通路调节控制着许多生命过程,也发现其是诱导EMT不可缺少的重要通路。通过对Wnt信号分子的调控,可以有效的阻断甚至逆转EMT。Wnt诱导EMT发生发展过程的研究,也为抗肿瘤新药开发提供了新思路,推动了药物的研发。该文旨在对近年Wnt信号通路诱导EMT的研究做一综述。     

缺氧诱导因子通过Notch信号通路对上皮间质转化调控作用的研究进展

缺氧诱导因子(HIFs)是肿瘤急慢性缺氧反应中的关键性蛋白成员,具有特殊的生物学功能。HIFs在包括肝细胞癌(HCC)在内的多种肿瘤中高表达,并能促进肿瘤细胞上皮间质转化(EMT)过程。HCC具有典型侵袭性生长特性,该特性与EMT密切相关。Notch信号通路是一种生物进化中高度保守的信号转导通路,参与细胞的EMT过程,在HIFs促进肿瘤的生长和迁移过程中扮演重要角色。HIFs可能直接或间接通过Notch信号通路在包括HCC在内的肿瘤细胞EMT过程中发挥效应。现对HIFs促进肿瘤细胞EMT,特别是对HCC EMT的调控作用及Notch信号通路在该过程的可能作用进行简要综述。     

Wnt/β-catenin信号通路抑制剂的抗肿瘤研究进展

Wnt信号通路广泛存在于多细胞真核生物中,并且高度保守,在胚胎发育过程中起到重要作用。大量研究表明,Wnt信号通路的异常激活与肿瘤的发生发展密切相关,其在多种恶性肿瘤的增殖、分化、凋亡、迁移、侵袭、上皮间质转化(Epithelial-mesenchymal transition, EMT)及肿瘤干细胞特性中发挥重要作用,因此开发靶向Wnt信号通路的抗肿瘤药物具有重要意义。目前,Wnt信号通路抑制剂的研究已取得一定进展。本文主要对近年来Wnt途径中关键成员Wnt/β-catenin信号通路的抑制剂在肿瘤治疗中的研究进展作一综述。     

缺氧诱导因子和Notch信号通路在上皮间质转化(EMT)疾病间的作用机制

缺氧诱导因子(Hypoxia-inducible fact,HIF)为缺氧、炎症、代谢适应和肿瘤进展之间的重要交汇点,同时也参与纤维化的进展过程。Notch信号通路是一个在进化过程中高度保守的信号通路,广泛参与细胞的增殖、分化及凋亡过程,在恶性肿瘤的侵袭与转移等过程中发挥着重要作用。缺氧诱导的上皮间质转化(Epithelial-mesenchymal transition,EMT)需要功能性的Notch信号转导驱动EMT的过程。近年研究表明,细胞缺氧反应并不是单独的反应,而是与信号机制相交,例如Notch信号传导,这是在控制干细胞维持和分化的大多数细胞类型中操作的关键调节信号传导机制。本文讨论了关于Notch信号通路与细胞缺氧反应之间的交集以及Notch信号和缺氧在EMT相关疾病中的作用机制。     

FOX家族介导的上皮间质转化在肿瘤转移中的研究进展

在肿瘤的侵袭转移进程中,上皮间质转化(epithelial mesenchymal transition,EMT)是其中一个重要的生物学过程。但由于EMT复杂的信号通路和未尽阐明的分子机制,治疗EMT仍然是世界性的难题。但多种研究也证实了EMT并非是不可逆转的过程。近年来对叉头框转录因子(FOX)基因家族在EMT中的研究,显示了其在肿瘤转移中具有重要的调控作用。该文综述了FOX基因家族介导的EMT过程在肿瘤多种生物学过程的研究,以期对EMT的信号网络有更好的了解,并为有效干预EMT提供新的依据。     

小檗碱通过TGF-β/Smad通路抑制TGF-β1诱导的人肝癌HepG2细胞上皮间质转化的研究

目的探讨小檗碱(berberine)对转化生长因子-β1(transforming growth factor-β1,TGF-β1)诱导的人肝癌HepG2细胞上皮间质转化(epithelial-mesenchymal transition,EMT)的作用及其机制。方法MTT法检测小檗碱对HepG2细胞增殖活性;采用10 ng·L-1 TGF-β1诱导HepG2细胞EMT模型形成,并加入小檗碱处理;克隆形成实验、细胞划痕和Transwell小室实验分别检测HepG2细胞的克隆形成能力、迁移和侵袭能力;免疫荧光法检测EMT间质标志物Vimentin的表达;Western blot法检测EMT标志物蛋白(E-cadherin、N-cadherin、Snail)、基质金属蛋白酶(MMP-2)、TGF-β/Smad通路蛋白(Smad2、p-Smad2、Smad3、p-Smad3)的表达。结果小檗碱呈浓度时间依赖性抑制HepG2细胞活性;与TGF-β1组比较,小檗碱可以明显抑制HepG2细胞的克隆形成能力、迁移和侵袭能力;并且小檗碱可以抑制TGF-β1上调的E-cadherin蛋白表达,和TGF-β1下调的N-cadherin、Vimentin、Snail、MMP-2、p-Smad2、p-Smad3蛋白表达。结论小檗碱可能通过抑制TGF-β/Smad信号通路,干预TGF-β1诱导HepG2细胞的EMT进程,抑制HepG2细胞的迁移和侵袭能力。     

AZD8055抑制胆管癌细胞HuCCT1的迁移及EMT进程的机制研究

目的探讨哺乳动物雷帕霉素靶蛋白(mTOR)双重抑制剂AZD8055在抑制人胆管癌细胞HuCCT1的迁移及EMT进程中的作用及分子机制。方法 MTT法与平板克隆形成实验检测AZD8055对胆管癌细胞增殖的影响;划痕愈合实验和Transwell小室迁移实验检测AZD8055对HuCCT1细胞迁移能力的影响;Western blot法检测EMT标志相关蛋白、Akt/mTOR信号通路蛋白及DEK蛋白的表达;利用STITCH、GeneMANIA数据库,分析AZD8055、DEK、Akt信号通路相互作用关系;在DEK基因沉默后,检测胆管癌细胞增殖活力、迁移能力及Akt/mTOR信号通路相关蛋白表达水平的变化。结果 AZD8055可抑制胆管癌细胞的增殖及迁移能力,同时抑制Akt/mTOR信号通路相关蛋白、DEK蛋白表达及EMT的进程;沉默DEK基因可明显抑制胆管癌细胞增殖及迁移能力,并降低Akt、S6、4EBP1蛋白的磷酸化水平。结论 AZD8055抑制HuCCT1细胞的迁移及EMT进程,其机制与下调DEK,抑制Akt/mTOR信号通路有关。     

The interplay between TGF-β/SMAD and BMP/SMAD signaling pathways in the epithelial mesenchymal transition of A549 cells induced by silica

The epithelial–mesenchymal transition (EMT) is a phenotype transdifferentiation of epithelial into mesenchymal cells and contributes to pulmonary fibrotic disease. SMAD-dependent pathway has been reported to play a key role in the multiple fibrotic diseases. We hypothesized that TGF-β/SMAD signaling could cross-interact with BMP/SMAD signaling pathways in silica-induced EMT in A549 cells. We investigated that the ability of silica-induced EMT in A549 cells, and this process was significantly inhibited by SB431542 through up-regulation of Vimentin, α-SMA and collagen type I expression and down-regulation of E-cadherin expression. Whereas BMP/SMAD inhibition using LDN193189 enhanced EMT. In addition, we also demonstrated that SB431542 could enhance BMP/SMAD signaling pathways in silica-induced EMT and vice versa. Therefore, our study provides evidence that the TGF-β/SMAD pathway was a crucial regulator in silica-induced EMT and that SB431542 could prevent the EMT. More importantly, we have identified that the interplay of TGF-β/SMAD and BMP/SMAD pathways in silica-induced EMT in A549 cells.     

上皮-间充质转化对肝纤维化作用的研究进展

上皮-间充质转化在许多生理和病理过程中都具有重要作用,近年研究证明,肝纤维化过程中同样存在上皮-间充质转化现象.本文综合国内外研究成果,阐述发生上皮-间充质转化的肝源细胞(肝细胞、胆管上皮细胞、肝祖细胞、肝星状细胞)以及肝纤维化发生发展过程中上皮-间充质转化涉及的信号通路及调节机制,并探讨了以上皮-间充质转化为靶标的抗肝纤维治疗策略的可行性及研究进展.     

PTPL1 suppresses lung cancer cell migration via inhibiting TGF-β1-induced activation of p38 MAPK and Smad 2/3 pathways and EMT

Epithelial-mesenchymal transition (EMT) enables dissemination of neoplastic cells and onset of distal metastasis of primary tumors. However, the regulatory mechanisms of EMT by microenvironmental factors such as transforming growth factor-β (TGF-β) remain largely unresolved. Protein tyrosine phosphatase L1 (PTPL1) is a non-receptor protein tyrosine phosphatase that plays a suppressive role in tumorigenesis of diverse tissues. In this study we investigated the role of PTPL1/PTPN13 in metastasis of lung cancer and the signaling pathways regulated by PTPL1 in terms of EMT of non-small cell lung cancer (NSCLC) cells. We showed that the expression of PTPL1 was significantly downregulated in cancerous tissues of 23 patients with NSCLC compared with adjacent normal tissues. PTPL1 expression was positively correlated with overall survival of NSCLC patients. Then we treated A549 cells in vitro with TGF-β1 (10 ng/mL) and assessed EMT. We found that knockdown of PTPL1 enhanced the migration and invasion capabilities of A549 cells, through enhancing TGF-β1-induced EMT. In nude mice bearing A549 cell xenografts, knockdown of PTPL1 significantly promoted homing of cells and formation of tumor loci in the lungs. We further revealed that PTPL1 suppressed TGF-β-induced EMT by counteracting the activation of canonical Smad2/3 and non-canonical p38 MAPK signaling pathways. Using immunoprecipitation assay we demonstrated that PTPL1 could bind to p38 MAPK, suggesting that p38 MAPK might be a direct substrate of PTPL1. In conclusion, these results unravel novel mechanisms underlying the regulation of TGF-β signaling pathway, and have implications for prognostic assessment and targeted therapy of metastatic lung cancer.     

上皮间质转化在肝纤维化中的作用及相关信号通路研究进展

上皮间质转化是指有极性的上皮细胞失去其上皮特征并逐渐转化为具有迁徙和侵袭能力的间充质细胞的过程,其中2型上皮间质转化与肝纤维化密切相关,故近年来上皮间质转化成为肝纤维化及其靶向药物研究的热点。综述上皮间质转化在肝纤维化中的作用及相关信号通路的研究进展,以期为肝纤维化及其靶向药物的研究提供参考。     

The therapeutic potential of targeting the epithelial–mesenchymal transition in cancer

Introduction: The process of epithelial-to-mesenchymal transition (EMT) has long been advocated as a process during tumor progression and the acquisition of metastatic potential of human cancers. EMT has also been linked with resistance to cancer therapies.

Areas covered: Basic research has provided evidence connecting EMT to increased invasion, angiogenesis and metastasis of cancer cells. A number of signaling pathways such as notch, wnt, hedgehog and PI3K-AKT, and various other individual factors therein, have been intricately connected to the onset of EMT. Here, we provide latest updates on the evidences that further highlight an association between various signaling pathways and EMT, with a focus on therapeutic targets that may have the potential to reverse EMT.

Expert opinion: Our understanding of EMT and its underlying causes is rapidly evolving and a number of putative targets have been identified. It is crucial, now than ever before, to design novel translational and clinical studies for the benefit of advanced stage cancer patients with metastatic disease.     

TGFB2 serves as a link between epithelial-mesenchymal transition and tumor mutation burden in gastric cancer

Immune checkpoint blockade (ICB) has been a major breakthrough in various cancers including gastric cancer (GC), yet the clinical outcomes remain poor. Currently, epithelial-mesenchymal transition (EMT) has been reported to be associated with tumor mutational burden (TMB), which can cause lack of response to ICB. However, the underlying mechanism remains unknown. Members of the transforming growth factor β (TGFB) family are regarded as the main mediators of EMT, yet how TGFB2 drives EMT in GC is not fully understood. In this study, we found that overexpression of TGFB2 was correlated with poor prognosis in TGCA-STAD and four GEO GC datasets. Gene set enrichment analysis revealed that the EMT pathway was significantly enriched in the high TGFB2 expression group, whilst the TMB-related pathways including mismatch repair, base excision repair, and DNA replication were strongly enriched in the low expression group. Furthermore, EMT score analysis, WGCNA and functional analysis showed that TGFB2 was co-expressed with neurite-related pathways that might drive EMT. Also, CIBERSORT analysis revealed that tumor-infiltrating immune cells like T follicular helper cells might participate in the process of TGFB2 affecting TMB levels in GC. Moreover, in other various cancers, TGFB2 was also negatively correlated with TMB levels as well as ICB response. Overall, these results revealed that TGFB2 could play a vital role in linking EMT and TMB in GC, suggesting that TGFB2 may be a predictive therapeutic target for GC.     

Genes associated with epithelial-mesenchymal transition: possible therapeutic targets in ductal pancreatic adenocarcinoma?

Epithelial to mesenchymal transition (EMT) is a biological process that allows well-differentiated, polarized epithelial cells to undergo a conversion to motile, unpolarized mesenchymal cells. EMT plays crucial roles during implantation, embryogenesis, and organ development (Type 1 EMT), is associated with tissue regeneration and organ fibrosis (Type 2 EMT), and involved in cancer invasion, metastasis, and drug resistance (Type 3 EMT). Since aggressiveness and drug resistance are hallmarks of ductal pancreatic cancer, significant effort has been undertaken in recent years to elucidate molecular EMT mechanisms in this dismal malignancy. This represents a formidable challenge for several reasons: EMT is a dynamic process, both with regard to spatial and temporal heterogeneity. Moreover, EMT is induced and regulated by a complex network of traditional signaling pathways and new players like microRNAs. Interestingly, similar molecular characteristics link EMT-type cells also to the concept of cancer stem cells. This review tries to integrate the current knowledge regarding EMT and pancreatic cancer; furthermore to outline not only the perspective on novel EMT-associated therapeutic targets, but also on overcoming drug resistance by interfering with EMT.     

PRR16/Largen Induces Epithelial-Mesenchymal Transition through the Interaction with ABI2 Leading to the Activation of ABL1 Kinase

Advanced or metastatic breast cancer affects multiple organs and is a leading cause of cancer-related death. Cancer metastasis is associated with epithelial-mesenchymal metastasis (EMT). However, the specific signals that induce and regulate EMT in carcinoma cells remain unclear. PRR16/Largen is a cell size regulator that is independent of mTOR and Hippo signalling pathways. However, little is known about the role PRR16 plays in the EMT process. We found that the expression of PRR16 was increased in mesenchymal breast cancer cell lines. PRR16 overexpression induced EMT in MCF7 breast cancer cells and enhances migration and invasion. To determine how PRR16 induces EMT, the binding proteins for PRR16 were screened, revealing that PRR16 binds to Abl interactor 2 (ABI2). We then investigated whether ABI2 is involved in EMT. Gene silencing of ABI2 induces EMT, leading to enhanced migration and invasion. ABI2 is a gene that codes for a protein that interacts with ABL proto-oncogene 1 (ABL1) kinase. Therefore, we investigated whether the change in ABI2 expression affected the activation of ABL1 kinase. The knockdown of ABI2 and PRR16 overexpression increased the phosphorylation of Y412 in ABL1 kinase. Our results suggest that PRR16 may be involved in EMT by binding to ABI2 and interfering with its inhibition of ABL1 kinase. This indicates that ABL1 kinase inhibitors may be potential therapeutic agents for the treatment of PRR16-related breast cancer.     

Transglutaminase 2: A multi-tasking protein in the complex circuitry of inflammation and cancer

Metastasis of primary tumors to distant sites and their inherent or acquired resistance to currently available therapies pose major clinical challenge to the successful treatment of cancer. The identification of tumor-coded genes and how they contribute to the progression of cancer is required to improve patient outcomes. Recently, cells that have undergone the epithelial-mesenchymal transition (EMT), which share characteristics with cancer stem cells (CSC) have been implicated to play a role in drug resistance and metastasis of several types of cancer. In this review, we discuss the relationship among transglutaminase 2 (TG2), the EMT, and CSCs in inflammation and cancer. TG2 is a structurally and functionally complex protein implicated in such diverse processes as tissue fibrosis, wound healing, apoptosis, neurodegenerative disorders, celiac disease, atherosclerosis and cancer. Depending on the cellular context, TG2 can either promote or inhibit cell death. Increased expression of TG2 in several types of cancer cells has been associated with increased cell invasiveness, cell survival and decreased survival of patients with cancer. Down-regulation of TG2 by small interfering RNA (siRNA) or its inhibition by small molecule inhibitors has been shown to significantly enhances the therapeutic efficacy of anticancer drugs and inhibit metastatic spread. In addition, TG2-regulated pathways are involved in promoting or protecting normal and tumor cells from death-induced signaling. We discuss the contribution of TG2-regulated pathways to the development of drug resistance and progression to metastatic disease and the therapeutic potential of TG2 for treating advanced-stage cancer.