biostudies-literatureUnknown13(6)Abbate JMThe expression of miRNAs is one of the main epigenetic mechanisms responsible for the regulation of gene expression in mammals, and in cancer, miRNAs participate by regulating the expression of protein-coding cancer-associated genes. In canine mammary tumors (CMTs), the <i>ESR1</i> gene encodes for ERα, and represents a major target gene for miR-18a and miR-18b, previously found to be overexpressed in mammary carcinomas. A loss in ERα expression in CMTs is commonly associated with poor prognosis, and it is noteworthy that the downregulation of the <i>ESR1</i> would appear to be more epigenetic than genetic in nature. In this study, the expression of <i>ESR1</i> mRNA in formalin-fixed, paraffin-embedded (FFPE) canine mammary tumors (CMTs) was evaluated and compared with the expression levelAnimals : an open access journal from MDPI1086https://www.ebi.ac.uk/biostudies/studies/S-EPMC10044548biostudies-literatureEpigenetics in Canine Mammary Tumors: Upregulation of miR-18a and miR-18b Oncogenes Is Associated with Decreased <i>ERS1</i> Target mRNA Expression and ERα Immunoexpression in Highly Proliferating Carcinomas.PMC10044548Capparucci FArfuso FRiolo KBrunetti BAbbate JMLanteri GfalseEpigenetics in Canine Mammary Tumors: Upregulation of miR-18a and miR-18b Oncogenes Is Associated with Decreased <i>ERS1</i> Target mRNA Expression and ERα Immunoexpression in Highly Proliferating Carcinomas.The expression of miRNAs is one of the main epigenetic mechanisms responsible for the regulation of gene expression in mammals, and in cancer, miRNAs participate by regulating the expression of protein-coding cancer-associated genes. In canine mammary tumors (CMTs), the <i>ESR1</i> gene encodes for ERα, and represents a major target gene for miR-18a and miR-18b, previously found to be overexpressed in mammary carcinomas. A loss in ERα expression in CMTs is commonly associated with poor prognosis, and it is noteworthy that the downregulation of the <i>ESR1</i> would appear to be more epigenetic than genetic in nature. In this study, the expression of <i>ESR1</i> mRNA in formalin-fixed, paraffin-embedded (FFPE) canine mammary tumors (CMTs) was evaluated and compared with the expression level2023-01-01T00:00:00Z2023 Mar2025-05-29T19:16:44.091Z2024-11-05T18:17:51.021ZS-EPMC100445483697862710.3390/ani13061086