Potential Value of YAP Staining in Rhabdomyosarcoma.

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DOI: 10.1369/0022155418766515; PMCID: PMC6071181


Rhabdomyosarcoma (RMS) is a common malignancy of soft tissue, subclassified as alveolar (ARMS), pleomorphic (PRMS), spindle cell/sclerosing (SRMS), and embryonal (ERMS) types. The Yes-associated protein (YAP) is a member of the Hippo pathway and a transcriptional regulator that controls cell proliferation. We have studied the immunohistochemical expression of YAP in different RMSs, arranged in tissue microarray (TMA) and whole slide formats. Pertinent clinical data including patient age, gender, tumor location, and clinical stage were collected. Out of 96 TMA cases, 30 cases (31%) were pleomorphic, 27 (28%) were embryonal, 24 (25%) alveolar, and 15 (16%) spindle cell. Positive nuclear YAP staining was seen in the PRMS (17/30, 56.7%), SRMS (7/15, 46.7%), ERMS (19/27 or 70%), and less in ARMS (37.5%). YAP nuclear staining was significantly more prevalent in ERMS than ARMS ( p=0.02). Of the 41 whole slide cases, nuclear staining was detected in all ARMS but was restricted in distribution to <30% of the cells, in contrast to ERMS and SRMS, which had diffuse or >30% staining. These results highlight the role of YAP in RMS tumorigenesis, a fact that can be useful in engineering targeted therapy. Restricted nuclear YAP staining (<30% of cells) may be of value in the diagnosis of ARMS.

Journal Title

The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society





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MeSH Keywords

Adaptor Proteins, Signal Transducing; Adolescent; Adult; Aged; Aged, 80 and over; Carcinogenesis; Cell Nucleus; Child; Child, Preschool; Female; Humans; Immunohistochemistry; Infant; Male; Middle Aged; Neoplasm Staging; Phosphoproteins; Rhabdomyosarcoma; Staining and Labeling; Tissue Array Analysis; Transcription Factors; Young Adult


Hippo; IHC; YAP; rhabdomyosarcoma; tissue microarray

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