Equine Genital Squamous Cell Carcinoma Associated with EcPV2 Infection: RANKL Pathway Correlated to Inflammation and Wnt Signaling Activation.

Equine genital squamous cell carcinomas (egSCCs) are among the most common equine tumors after sarcoids, severely impairing animal health and welfare. papillomavirus type 2 (EcPV2) infection is often related to these tumors. The aim of this study was to clarify the molecular mechanisms behind egSCCs associated with EcPV2 infection, investigating receptor activator of nuclear factor-kappa B ligand (RANKL) signaling in NF-kB pathway, together with the Wnt and IL17 signaling pathways. We analyzed the innate immune response through gene expression evaluation of key cytokines and transcription factors. Moreover, Ki67 index was assessed with immunohistochemistry. EcPV2- DNA was checked, and viral presence was confirmed in 21 positive out to 23 cases (91%). Oncogene expression was confirmed in 14 cases (60.8%) for and in 8 (34.7%) for . , nuclear factor kappa-light-chain-enhancer of activated B cells ()-, , interleukin , , , , , , , , and lymphoid enhancer binding factor 1 showed a significant upregulation in tumor samples compared to healthy tissues. Our results describe an inflammatory environment characterized by the activation of RANKL/RANK and IL17 with the relative downstream pathways, and a positive modulation of inflammatory cytokines genes such as and . Moreover, the increase of , , and gene expression suggests an activation of both canonical and non-canonical Wnt signaling pathway that could be critical for carcinogenesis and tumor progression.