The aim of this study was the investigation of the circulating concentration of IGF-1 in female dogs with spontaneous mammary tumours. The study was performed on 34 female dogs undergoing surgery due to spontaneously occurring mammary gland tumours (24 malignant and 10 benign) and 10 clinically healthy fe-male dogs. The serum concentrations of IGF-1 were determined by specific ELISA Kit assay. The mean con-centrations of IGF-1 were significantly higher (P < 0.05) both in dogs with malignant (173.35 ± 120.45 ng/ml) and benign (130.58 ± 59.0 ng/ml) mammary tumours than in healthy controls (117.45±71.0 ng/ml). In the group of female dogs with mammary carcinomas, the mean concentration of IGF-1 gradually increased from 132.85 ± 65.64 ng/ml in dogs with grade 1 tumours to 317.74 ± 119.25 ng/ml in those with grade 3 tumours, and significant differences (P < 0.05) were found among dogs with various grade tumours. These findings suggest that circulating IGF-1 may play an important role in the pathogenesis of canine mammary tumour. Moreover, high IGF-1 levels may reflect tumour cell differentiation into a more aggressive phenotype. .
Key roles for MED1 LxxLL motifs in pubertal mammary gland development and luminal-cell differentiation