文章通讯作者是美国科学院院士,世界有名的Whitehead研究所创始人之一的RobertA.Weinberg博士。他的研究方向为人类肿瘤的遗传学基础,其中*广为人知的是他的实验室发现了**个人类癌基因Ras和**个人类抑癌基因Rb。他的一系列杰出研究工作已经成为肿瘤研究领域乃至整个医学生物学领域的重要里程碑。
EMT是指上皮细胞在形态学上发生向成纤维细胞或间充质细胞表型的转变并获得迁移的能力。EMT是胚胎早期发育和器官生成过程中的一个极其重要的基本过程,它使在特殊部位产生的上皮细胞从上皮组织分离并迁移到其他位置,是正常发育、伤口**以及恶性上皮肿瘤发生的基础。过去的研究表明无论是在正常发育还是在肿瘤发生过程中,微环境各种刺激可通过多种不同信号途径诱导上皮细胞发生上皮间质转化。然而一直以来科学家们对于诱导EMT以及维持*终细胞状态的信号机制却并不是十分清楚。
在这篇文章中,Weinberg领导的研究小组证实TGF-β、经典及非经典Wnt三条信号通路协同作用诱导激活细胞EMT程序,之后以自分泌的方式维持*终的间质细胞状态。研究人员证实在上皮细胞中下调内源的自分泌信号抑制因子可诱导细胞启动EMT程序。与之相反,当他们在细胞中添加相关信号通路抑制剂时,发现自分泌信号破坏可导致原代乳腺上皮细胞迁移及自我更新受到抑制,并降低了转化衍生物诱导的肿瘤形成及转移。
这些研究结果揭示了启动EMT及维持*终细胞状态相关的信号机制,从而为预防肿瘤发生及转移提供了新的靶点。
此外不久前,Weinberg在Cell杂志上发表了一篇综述性文章中,简述了*近10年肿瘤学中的热点和进展,包括细胞自噬、肿瘤干细胞、肿瘤微环境等等,并且总结了肿瘤细胞十大特征,这十个特征分别是:自给自足生长信号(Self-Sufficiencyin Growth Signals);抗生长信号的不敏感(Insensitivity to AntigrowthSignals);抵抗细胞死亡(Resisting Cell Death);潜力无限的复制能力(LimitlessReplicative Potential);持续的血管生成(SustainedAngiogenesis);组织浸润和转移(Tissue Invasion andMetastasis);避免**摧毁(Avoiding Immune Destruction);促进肿瘤的炎症(TumorPromotion Inflammation); 细胞能量异常(Deregulating CellularEnergetics);基因组不稳定和突变(Genome Instability and Mutation)。
推荐原文摘要:
Paracrine and Autocrine Signals Induce and Maintain Mesenchymaland Stem Cell States in the Breast
The epithelial-mesenchymal transition (EMT) has been associatedwith the acquisition of motility, invasiveness, and self-renewaltraits. During both normal development and tumor pathogenesis, thischange in cell phenotype is induced by contextual signals thatepithelial cells receive from their microenvironment. The signalsthat are responsible for inducing an EMT and maintaining theresulting cellular state have been unclear. We describe threesignaling pathways, involving transforming growth factor (TGF)-βand canonical and noncanonical Wnt signaling, that collaborate toinduce activation of the EMT program and thereafter function in anautocrine fashion to maintain the resulting mesenchymal state.Downregulation of endogenously synthesized inhibitors of autocrinesignals in epithelial cells enables the induction of the EMTprogram. Conversely, disruption of autocrine signaling by addedinhibitors of these pathways inhibits migration and self-renewal inprimary mammary epithelial cells and reduces tumorigenicity andmetastasis by their transformed derivatives.