Significance of caveolin-1 and matrix metalloproteinase 14 gene expression in canine mammary tumours

•Molecular biomarkers were investigated in an endeavour to improve the accuracy of diagnosis of canine mammary tumours (CMTs).•We examined whether caveolin 1 (Cav-1) and matrix metalloproteinase 14 (MMP14) genes were associated with CMT malignancy.•The expression of Cav-1 and MMP14 correlated with invadopodia activity and invasion in CMTs.

Canine mammary tumours (CMTs) are the most common neoplasms affecting female dogs. There is an urgent need for molecular biomarkers that can detect early stages of the disease in order to improve accuracy of CMT diagnosis. The aim of this study was to examine whether caveolin-1 (Cav-1) and matrix metalloproteinase 14 (MMP14) are associated with CMT histological malignancy and invasion. Sixty-five benign and malignant CMT samples and six normal canine mammary glands were analysed using quantitative reverse transcription-polymerase chain reaction.Cav-1 and MMP14 genes were highly expressed in CMT tissues compared to normal tissues. Cav-1 especially was overexpressed in malignant and invasive CMT tissues. When a CMT cell line was cultured on fluorescent gelatin-coated coverslips, localisation of Cav-1 was observed at invadopodia-mediated degradation sites of the gelatin matrix. These findings suggest that Cav-1 may be involved in CMT invasion and that the markers may be useful for estimating CMT malignancy.