Epithelial–mesenchymal transition in an EcPV2‐positive vulvar squamous cell carcinoma of a mare

Abstract

AbstractBackgroundVulvar squamous cell carcinoma (VSCC) has been recently associated with Equus caballus papillomavirus type 2 (EcPV2) infection. Still, few reports concerning this disease are present in the literature.ObjectiveTo describe a case of naturally occurring EcPV2‐induced VSCC, by investigating tumour ability in undergoing the epithelial‐to‐mesenchymal transition (EMT).Study designCase report.MethodsA 13‐year‐old Haflinger mare was referred for a rapidly growing vulvar mass. After surgical excision, the mass was submitted to histopathology and molecular analysis. Histopathological diagnosis was consistent with a VSCC. Real‐time qPCR, real‐time reverse transcriptase (RT)‐qPCR and RNAscope were carried out to detect EcPV2 infection and to evaluate E6/E7 oncogenes expression. To highlight the EMT, immunohistochemistry (IHC) was performed. Expression of EMT‐related and innate immunity‐related genes was investigated through RT‐qPCR.ResultsReal‐time qPCR, RT‐qPCR and RNAscope confirmed EcPV2 DNA presence and expression of EcPV2 oncoproteins (E6 and E7) within the neoplastic vulvar lesion. IHC highlighted a cadherin switch together with the expression of the EMT‐related transcription factor HIF1α. With RT‐qPCR, significantly increased gene expression of EBI3 (45.0 ± 1.62, p < 0.01), CDH2 (2445.3 ± 0.39, p < 0.001), CXCL8 (288.7 ± 0.40, p < 0.001) and decreased gene expression of CDH1 (0.3 ± 0.57, p < 0.05), IL12A (0.04 ± 1.06, p < 0.01) and IL17 (0.2 ± 0.64, p < 0.05) were detected.Main limitationsLack of ability to generalise and danger of over‐interpretation.ConclusionThe results obtained were suggestive of an EMT event occurring within the neoplastic lesion.