title: YAP immunoreactivity is directly related to pilomatrixoma size and proliferation rate.
abstract: Organ size regulation is a highly coordinated process involving complex mechanisms. Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif, also known as WWTR1 (TAZ) have recently been linked to organ size determination and cell proliferation. Pilomatrixoma (PM) is a benign tumor of the adnexal appendages with a certain degree of differentiation toward the matrix of the hair follicle. PM presents as a dermal nodule that usually ranges from 0.5 to 2 cm, rarely exceeding 3 cm. We recently observed a case of unusual "giant" (6.5 cm) PM. Our hypothesis was that YAP and TAZ could be related to PM growth. We analyzed YAP and TAZ immunohistochemical expression in the giant and in ten usual size PMs in relation with tumor size and proliferation rate. YAP nuclear expression was remarkably higher in the giant PM in comparison with usual size PMs and statistically correlated, in a direct manner, with size and proliferation rate of PMs. Contrariwise, TAZ nuclear expression seemed stochastic. Our findings suggest that YAP could play a role in PM growth.
authors.affiliation: Department of Medicine (DIMED), Surgical Pathology and Cytopathology Unit, University of Padua, Via Aristide Gabelli, 61, 35121, Padua, PD, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Cappellesso
authors.forename: Alberto
authors.initials: A
authors.lastname: Bellan
authors.forename: Deborah
authors.initials: D
authors.lastname: Saraggi
authors.forename: Roberto
authors.initials: R
authors.lastname: Salmaso
authors.forename: Laura
authors.initials: L
authors.lastname: Ventura
authors.forename: Ambrogio
authors.initials: A
authors.lastname: Fassina
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006201:Hair Diseases / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010750:Phosphoproteins / Q000378:metabolism*; D018296:Pilomatrixoma / Q000378:metabolism / Q000473:pathology*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*; D015534:Trans-Activators; D014157:Transcription Factors; D000091364:Transcriptional Coactivator with PDZ-Binding Motif Proteins; D000091102:YAP-Signaling Proteins; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D015534:Trans-Activators; D014157:Transcription Factors; D000091364:Transcriptional Coactivator with PDZ-Binding Motif Proteins; C551991:WWTR1 protein, human; D000091102:YAP-Signaling Proteins; C088374:YAP1 protein, human