Dissecting the interplay between deregulated signaling networks and aberrant YAP/TAZ activity in myxoid liposarcoma

剖析粘液样脂肪肉瘤中信号网络失调与异常 YAP/TAZ 活性之间的相互作用

• 批准号: 455323733
• 负责人: Professor Dr. Stefan Fröhling
• 金额: --
• 依托单位: Gerhard-Domagk-Institut für Pathologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/455323733?language=en
• 关键词: Dissecting; interplay; between; deregulated; signaling

Dissecting the interplay between deregulated signaling networks and aberrant YAP/TAZ activity in myxoid liposarcomaMyxoid liposarcoma (MLS) are malignant adipocytic tumors driven by the FUS-DDIT3 fusion gene encoding an aberrant transcription factor. The mechanisms whereby FUS-DDIT3 mediates sarcomagenesis are incompletely understood, and strategies to selectively target MLS cells remain elusive. We have previously shown that MLS cells are dependent on YAP, the central effector of the Hippo pathway, that FUS-DDIT3 promotes YAP expression and transcriptional activity, and that both proteins physically interact. Furthermore, we provided evidence of recurrent PI3K/AKT signaling pathway activation in MLS through mutations in PIK3CA, PTEN loss, or FUS-DDIT3-dependent transcriptional induction of a cell-autonomous IGF-II/IGF-IR feed-forward mechanism. Recent data from others documented physical interactions between the Hippo effectors YAP/TAZ and members of the epigenetic regulatory SWI/SNF complex, which modulate the formation YAP/TAZ-TEAD complexes. In addition, the FUS-DDIT3 protein itself was shown to associate with SWI/SNF subunits. The functional interplay between FUS-DDIT3, activated kinase signaling, the Hippo-YAP/TAZ cascade, and the SWI/SNF complex has not been investigated in MLS.The first part of the project will include immunohistochemical investigations and analyses of whole-exome/genome and RNA sequencing data in a large cohort of MLS tissues to identify informative patterns of YAP/TAZ, PI3K/AKT, and MEK/ERK activation.The second part will address regulatory dependencies between FUS-DDIT3, specific kinase pathways, and YAP/TAZ activation in vitro through (i) interrogation of kinase pathways known to be of relevance in MLS and (ii) an unbiased CRISPR interference screen to identify signaling intermediates specifically acting between kinases and phosphatases and the Hippo pathway.The third part will be dedicated to elucidating physical associations between FUS-DDIT3, YAP/TAZ, TEAD, and selected SWI/SNF complex proteins by systematic co-immunoprecipitation experiments, focusing on interactions that modulate YAP/TAZ signals in MLS.Employing a combined antibody-guided chromatin tagmentation sequencing and RNA sequencing approach, the fourth part will approach the transcriptional interplay between YAP/TAZ, FUS-DDIT3, and the SWI/SNF complex through identification of genomic loci/chromatin sites regulated in a specific/overlapping manner. Against this background, it will comparatively analyze the distribution of functional chromatin marks and gene expression profiles upon modulation of YAP/TAZ, FUS-DDIT3, and selected SWI/SNF complex members.The results of this project will contribute to the understanding of MLS biology and will lay the groundwork for the development of future molecularly targeted therapies.

粘液样脂肪肉瘤（MLS）是由编码异常转录因子的FUS-DDIT 3融合基因驱动的恶性脂肪细胞肿瘤。FUS-DDIT 3介导肉瘤发生的机制尚不完全清楚，选择性靶向MLS细胞的策略仍然难以捉摸。我们以前已经表明，MLS细胞依赖于雅普，海马通路的中央效应，FUS-DDIT 3促进雅普的表达和转录活性，这两种蛋白质物理相互作用。此外，我们提供了MLS中通过PIK 3CA突变、PTEN缺失或细胞自主IGF-II/IGF-IR前馈机制的FUS-DDIT 3依赖性转录诱导而反复发生的PI 3 K/AKT信号通路激活的证据。来自其他人的最新数据记录了Hippo效应物雅普/TAZ与表观遗传调节SWI/SNF复合物的成员之间的物理相互作用，其调节雅普/TAZ-TEAD复合物的形成。此外，FUS-DDIT 3蛋白本身被证明与SWI/SNF亚基相关。在MLS中，FUS-DDIT 3、活化的激酶信号传导、Hippo-雅普/TAZ级联和SWI/SNF复合物之间的功能相互作用尚未研究。该项目的第一部分将包括免疫组织化学研究和对大队列MLS组织中的全外显子组/基因组和RNA测序数据的分析，以鉴定雅普/TAZ、PI 3 K/AKT、和MEK/ERK激活。第二部分将解决FUS-DDIT 3，特异性激酶途径，和雅普/TAZ的体外激活，通过（i）已知与MLS相关的激酶途径的询问和（ii）一个无偏见的CRISPR干扰筛选，以确定特异性作用于激酶和磷酸酶与Hippo通路之间的信号传导中间体。第三部分将致力于阐明FUS-DDIT 3，雅普/TAZ，TEAD，第四部分采用抗体引导的染色质标签片段化测序和RNA测序相结合的方法，研究了MLS中雅普/TAZ、FUS-DDIT 3、以及通过识别以特定/重叠方式调节的基因组基因座/染色质位点来识别SWI/SNF复合物。在此背景下，本研究将比较分析雅普/TAZ、FUS-DDIT 3和SWI/SNF复合体成员调控下的功能染色质标记分布和基因表达谱，为进一步了解MLS生物学和分子靶向治疗奠定基础。