Circulating microRNA expression in canine apocrine gland anal sac adenocarcinoma

Webster, Jade (2025) Circulating microRNA expression in canine apocrine gland anal sac adenocarcinoma. MVM(R) thesis, University of Glasgow.

Abstract

Aberrant blood or tissue miRNA profiles have been documented in multiple different diseases in both humans and animals. There is growing interest in positively exploiting the different miRNA expression profiles for research and medical purposes by identification of biomarkers that link to specific diseases and can be used for diagnostic, monitoring or prognostic purposes.

The aims of this study were to examine the plasma microRNA expression in dogs diagnosed with apocrine gland anal sac adenocarcinoma (AGASACA) and to identify potential miRNA biomarkers for diagnosis and disease staging. The second aim was to validate selected candidate miRNAs using RT-PCR.

Initial miRNA profiling was performed using single-end sequencing on an Illumina NovaSeq 6000 System at LC Sciences, comparing dogs with AGASACA to healthy controls, as well as across different clinical stages of disease (non-metastatic, lymph node metastasis and distant metastasis). Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed overexpression of genes involved in PI3K and Wnt signalling, cell cycle control and cell adhesion; concepts important in tumorigenesis and epithelial-mesenchymal transition (EMT).

Several differentially expressed miRNAs were identified and shortlisted for further analysis based on statistical significance and known oncological relevance. Validation using RT-qPCR focused on promising candidates. MiR-92b emerged as a reliable and reproducible diagnostic biomarker showing consistent upregulation in AGASACA cases across two independent cohorts. MiR-1246 demonstrated potential for detection of distant metastasis and also diagnosis of AGASACA. Interpretation of miR-1246 was limited by low case numbers and possible interference of different isoforms. Despite these challenges, the study provides compelling evidence for the use of circulating miRNAs as non-invasive biomarkers for the diagnosis (and possible staging) of AGASACA in dogs.

• Item Type: Thesis (MVM(R))
• Qualification Level: Masters
• Additional Information: Supported by funding from the University of Glasgow Veterinary Fund Small Grant Scheme (145973-18).
• Subjects: Q Science > QR Microbiology; S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine > Veterinary Biosciences
• Funder's Name: University of Glasgow Veterinary Fund Small Grant Scheme (145973-18)
• Supervisor's Name: Morris, Professor Joanna and Capewell, Dr. Paul
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-85504
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 27 Nov 2025 15:39
• Last Modified: 27 Nov 2025 15:42
• Thesis DOI: 10.5525/gla.thesis.85504
• URI: https://theses.gla.ac.uk/id/eprint/85504