Evaluation of circulating miRNAs as prognostic and early metastasis biomarkers in dogs with breast cancer

Abstract

Breast neoplasms in dogs represent the most common class of tumors in veterinary medicine. Its a potentially malignant neoplasms with a variable biological behavior, with metastasis occurring in 25 to 50% of cases. Due to its aggressive behavior, there is currently a search for early diagnostic biomarkers of metastasis and prognostic markers that assist in clinical practice in order to corroborate for increased survival of patients diagnosed with the disease. Among the desired characteristics of a biomarker, it is sought for molecules with high specificity that can be measured by techniques that have reproducibility and low cost, so as to be used on a large scale. In this context, microRNAs (miRNAs) are promising molecules. The miRNAs are post-transcriptional non-coding molecules responsible for regulating gene expression and maintaining cellular homeostasis, and their over-expression in tissue is associated with the development of neoplastic diseases, tumor progression, and metastasis. Their presence in various body fluids such as blood, saliva, and urine ensures their minimally invasive measurement, and their different serum levels may indicate responses to treatment, clinical stages, and tumor grading. Therefore, circulating miRNAs represent promising biomarkers for neoplasms. However, although the different levels of miRNAs in mammary carcinomas have been reported at tissue level, few studies have measured the presence of this biomarker systemically in the bloodstream of bitches. In this context, this study aims to evaluate the different levels of serum miRNA expression in female dogs diagnosed with mammary neoplasms and associate them with several clinicopathological factors, including the presence of metastasis and the prognosis of patients. The expression profile of miRNAs miR-195, miR-127-3p, miR-148b, miR-409-3p, miR-652, miR-4270, miR-133a and miR-801 will be evaluated using the RT -qPCR technique. (AU)