Altered microRNA profiles and associated pathways in canine mammary adenocarcinoma

Canine mammary tumors (CMTs) are common in female dogs and represent a key model for studying human breast cancer (BC). Among the various subtypes of CMT, adenocarcinoma of the mammary gland (AMG) is one of the most prevalent and aggressive. In this study, we analyzed the expression of 84 microRNAs (miRNAs) in AMG and healthy mammary tissues using qRT-PCR. MiRNA profiling in canine AMG tissue revealed upregulation of miR-101, miR-106b, miR-143, miR-15a, miR-205, and miR-93, and downregulation of let-7c, miR-10b, miR-191, and miR-26a. Pathway enrichment linked these deregulated miRNAs to key oncogenic networks, particularly PI3K/AKT/mTOR, Wnt/β-catenin, and EMT regulation, demonstrating conserved molecular mechanisms shared with human BC and highlighting their potential as biomarkers in CMTs. These findings provide insights into the molecular mechanisms of CMT adenocarcinoma and suggest the potential of miRNA-based biomarkers for the diagnosis and treatment of CMTs.