"Persistent activation of the mammalian target of rapamycin signaling pathway in cutaneous squamous cell carcinomas in cats

SANZ RESSEL BL, ; MASSONE AR; BARBEITO CG

VETERINARY DERMATOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021 vol. 32 p. 675 - 680

0959-4493

Abstract5 Background - Cutaneous squamous cell carcinoma (CSCC) represents the most common6 malignant tumor of the feline skin. Emerging evidence suggests that the7 phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR)8 signaling pathway may represent a potential target for pharmacological intervention in9 human and canine CSCC.10 Hypothesis/Objectives - The present study aimed to explore the expression pattern and11 status of activation of relevant signaling proteins of the PI3K/Akt/mTOR signaling12 pathway in feline CSCC.Methods ? The expression of pEGFRTyr1068, pAktSer473, pS6Ser235/236 13 combined with Ki-67,14 and the tumor suppressor protein PTEN was evaluated by immunohistochemistry in 4515 samples of feline CSCC, using a tissue microarray.16 Results - The immunodetection using phosphospecific antibodies to detect the activated17 forms of signaling proteins showed that the PI3K/Akt/mTOR signaling pathway is18 frequently activated in feline CSCCs, and may be independent of the activation of EGFR.19 The results also showed that PTEN expression is not significantly altered in feline CSCCs.20 Conclusions and clinical importance - Our study shows that the persistent activation of21 the PI3K/Akt/mTOR signaling pathway represents a key event in feline CSCCs, pointing to22 this signaling pathway as a potential therapeutic target in feline patients with CSCC.