Stains
YAP1

Authors: Meenakshi Vij Gupta, M.D., Rohan Gupta, M.D. Ph.D. (see Authors page)

Revised: 18 January 2017, last major update January 2017

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: YAP1[title]
Cite this page: YAP1. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stainsyap1.html. Accessed October 20th, 2017.
Definition / general
  • Yes Associated Protein 1 (YAP1) is a protein that behaves as a transcriptional regulator by activating genes responsible for cell proliferation and suppressing those responsible for apoptosis
Clinical features
  • At low density, YAP1 is predominantly nuclear and is translocated to the cytoplasm at high density (antibody ab81183)
  • It is frequently overexpressed in mammary carcinoma, glioblastoma and squamous cell carcinoma; also pancreatic, oral, cervical, ovarian and lung cancer (Genes Dev 2009;23:2729)
Uses by pathologists
  • YAP1 is a potent oncogene located on 11q22 and is overexpressed in various cancers (Genes Dev 2009;23:2729)
  • YAP1 is basally inhibited in the Hippo signaling pathway, which controls organ size at the cellular level, ultimately promoting tumor suppression (Genes Dev 2009;23:2729)
  • It is also a Sonic hedgehog (Shh) target and markedly elevated in Shh driven medulloblastomas (Oncogene 2012;31:1923)
    • YAP1 accelerates tumor growth and promotes resistance to radiation therapy, allowing continued proliferation after radiation
    • YAP1 activity enables cells to enter mitosis by driving IGF2 expression and Akt activation
    • The YAP1 oncogene serves as a major target for the development of new cancer therapies (Cancer Res 2012;72:3424)
Case reports
  • 29 year old man with YAP1-TFE3 translocated epithelioid hemangioendothelioma arising in a groin lymph node (Virchows Arch 2015;466:473)
Microscopic (histologic) images

Images hosted on Pathout server:
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Contributed by Meenakshi Vij Gupta, M.D.



Images hosted on other servers:
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Medulloblastoma: YAP1 immunohistochemistry on formalin
fixed paraffin embedded tissue samples (Fig 4)