PO.TB03.05 · 肿瘤生物学
一条新的mTORC2信号通路定义了尿路上皮癌中的促转移侵袭伪足网络
A novel mTORC2 signaling pathway defines the pro-metastatic invadopodia network in urothelial carcinoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：尿路上皮癌（UC）是膀胱癌最常见的类型，仍是全球癌症相关死亡的主要原因之一。UC的结局主要由肿瘤的分期和分级决定，高度侵袭性和转移性肿瘤的治疗结局显著降低。尽管研究持续进行，界定UC中这一行为的机制仍知之甚少。我们实验室已鉴定出哺乳动物雷帕霉素靶蛋白复合物2（mTORC2）为UC侵袭行为的关键调控因子，并发现mTORC2活性增加与更高的UC分期之间存在关联。
方法：使用基因集富集分析（GSEA）和磷酸化蛋白质组学分析进行基因和蛋白分析。使用免疫组化和多重免疫荧光（mIF）实验确定侵袭伪足内蛋白的表达和共定位。使用RNA沉默和抑制剂应用进行通路组分的靶向，并使用明胶降解实验、transwell侵袭和细胞迁移评估来测定功能输出。
结果：我们的研究发现，mTORC2可通过推测的mTOR磷酸化与侵袭伪足支架蛋白TKS5alpha相互作用。此外，mTORC2和TKS5alpha似乎在细胞内以及肿瘤的侵袭边缘共定位。沉默mTORC2或TKS5alpha中的任一者，在细胞侵袭和基质降解方面产生相似的表型。对癌症基因组图谱UC队列的分析显示，高TKS5alpha表达与生存降低相关，且GSEA分析显示PI3K/AKT/mTOR信号在高TKS5alpha表达的肿瘤中显著富集。这些发现提示，mTORC2可能通过侵袭伪足形成、并通过一条包含TKS5alpha的新的、可作用的信号级联来促进促侵袭和促转移活性。
小结：我们的研究支持mTORC2在驱动UC侵袭和转移中的关键作用，这一点通过体外和人膀胱癌样本分析得到证实。本研究引入了一条此前未被认识的、涉及mTORC2和TKS5alpha在UC侵袭伪足形成和转移中的信号轴。这些研究结果有望定义UC侵袭伪足中的一条新信号轴，从而拓宽我们对膀胱癌机制的理解。
查看英文原文 English abstract
Background Urothelial carcinoma (UC), the most common form of bladder cancer, remains a leading cause of cancer-related mortality worldwide. UC outcomes are driven primarily by stage and grade of the tumor, with highlyinvasive and metastatic tumors showing significantly reduced treatment outcomes. Despite ongoing research,mechanisms that define this behavior in UC remain poorly understood. Our laboratory has identifiedmammalian target of rapamycin complex 2 (mTORC2) as a key regulator of invasive behavior in UC and anassociation between increased mTORC2 activity and higher UC stage.
Methods Gene and protein analyses were performed using Gene Set Enrichment Analysis (GSEA) andphosphoproteomic profiling. Immunohistochemistry and multi-Immunol fluorescence (mIF) assays were used todetermine expression and co-localization of proteins within invadopodia. Targeting of pathway componentswas performed using RNA silencing and inhibitor application, with functional outputs assayed using gelatindegradation assay, transwell invasion, and cell migration assessments.
Results Our study identified that mTORC2 can interact with TKS5alpha, an invadopodial scaffold protein, through putativemTOR phosphorylation. Furthermore, mTORC2 and TKS5alpha appear co-localize within cells and to the invasiveedge of tumors. Silencing of either mTORC2 or TKS5alpha results in similar phenotypes in cell invasion and matrixdegradation. Analysis of the Cancer Genome Atlas UC cohort showed high TKS5alpha expression was associatedwith reduced survival, and GSEA analysis showed PI3K/AKT/mTOR signaling was significantly enriched intumors with high TKS5alpha expression. These findings suggest that mTORC2 may promote pro-invasive andpro-metastatic activities through invadopodia formation and via a novel, and actionable, signaling cascade thatincludes TKS5alpha.
Summary Our studies support a critical role for mTORC2 in driving invasion and metastasis in UC, as demonstrated byboth in vitro and human bladder cancer sample analysis. The study introduces a previously unrecognizedsignaling axis involving mTORC2 and TKS5alpha in invadopodia formation and metastasis in UC. The results fromthese studies have the potential to define a novel signaling axis in UC invadopodia that broadens ourmechanistic understanding of bladder
利益披露 Disclosure
D. E. Hansel, None.