Prevalence of the Hippo Effectors YAP1/TAZ in Tumors of Soft Tissue and Bone

Sci Rep. 2019 Dec 23;9(1):19704. doi: 10.1038/s41598-019-56247-8.

Abstract

Tumors of soft tissue and bone represent a heterogeneous group of neoplasias characterized by a wide variety of genetic aberrations. Albeit knowledge on tumorigenesis in mesenchymal tumors is continuously increasing, specific insights on altered signaling pathways as a basis for molecularly targeted therapeutic strategies are still sparse. The aim of this study was to determine the involvement of YAP1/TAZ-mediated signals in tumors of soft tissue and bone. Expression levels of YAP1 and TAZ were analyzed by immunohistochemistry in a large cohort of 486 tumor specimens, comprising angiosarcomas (AS), Ewing sarcomas, leiomyosarcomas, malignant peripheral nerve sheath tumors (MPNST), solitary fibrous tumors, synovial sarcomas (SySa), well-differentiated/dedifferentiated/pleomorphic and myxoid liposarcomas (MLS). Moderate to strong nuclear staining of YAP1 and TAZ was detected in 53% and 33%, respectively. YAP1 nuclear expression was most prevalent in MPNST, SySa and MLS, whereas nuclear TAZ was predominately detected in AS, MLS and MPNST. In a set of sarcoma cell lines, immunoblotting confirmed nuclear localization of YAP1 and TAZ, corresponding to their transcriptionally active pool. Suppression of YAP1/TAZ-TEAD mediated transcriptional activity significantly impaired sarcoma cell viability in vitro and in vivo. Our findings identify nuclear YAP1 and TAZ positivity as a common feature in subsets of sarcomas of soft tissue and bone and provide evidence of YAP1/TAZ-TEAD signaling as a specific liability to be considered as a new target for therapeutic intervention. Nuclear YAP1/TAZ expression may represent a biomarker suited to identify patients that could benefit from YAP1/TAZ-TEAD directed therapeutic approaches within future clinical trials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Bone Neoplasms / metabolism*
  • Bone Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Chick Embryo
  • Hippo Signaling Pathway
  • Humans
  • Protein Serine-Threonine Kinases / metabolism*
  • Sarcoma / metabolism
  • Sarcoma / pathology
  • Soft Tissue Neoplasms / metabolism*
  • Soft Tissue Neoplasms / pathology
  • Trans-Activators / metabolism*
  • Transcription Factors / metabolism*
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins
  • Xenograft Model Antitumor Assays
  • YAP-Signaling Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Trans-Activators
  • Transcription Factors
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins
  • WWTR1 protein, human
  • YAP-Signaling Proteins
  • YAP1 protein, human
  • Protein Serine-Threonine Kinases