Integrated Proteomic and Metabolomic Analyses Characterise Molecular Alterations Associated with JSRV-Induced OPA

Ovine pulmonary adenocarcinoma (OPA), caused by the exogenous Jaagsiekte sheep retrovirus (JSRV), shares several pathological and molecular features with human lung adenocarcinoma, providing an important model for comparative oncology. JSRV pathogenesis is mostly studied at the transcriptome level, with systematic proteomic and metabolomic studies remaining insufficient. Therefore, this study aimed to systematically characterise the molecular alterations associated with JSRV-induced OPA by integrating direct data-independent acquisition proteomics and untargeted metabolomics. We established an OPA model by infecting lambs with JSRV and performed multi-omics analyses on the lesion and control lung tissues (n = 3 per group for both proteomic and metabolomic analyses). In total, 1631 differentially expressed proteins and 748 differential metabolites were identified, and the two omics datasets exhibited highly coordinated variations. Integrated analyses suggested that adhesion remodelling (with downregulated LIMCH1), endoplasmic reticulum stress (with upregulated HYOU1), and metabolic and immune-related alterations (accompanied by elevated GFPT1 and PTGS2) represent major biological processes associated with JSRV infection. Western blot analysis confirmed the expression changes in these proteins. Overall, this study provides a multidimensional molecular landscape of OPA and expands current understanding of the molecular alterations associated with JSRV infection. These findings provide candidate pathways and molecular targets for future mechanistic studies and comparative investigations of lung adenocarcinoma.