Table of Contents
Definition / general | Clinical features | Uses by pathologists | Case reports | Microscopic (histologic) imagesCite this page: Gupta, M.V., Gupta, R. YAP1. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsyap1.html. Accessed April 18th, 2021.
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)