Ghrelin and growth hormone secretagogue receptor expression at mRNA level in canine mammary carcinoma cell lines. The relative gene expression level (ratio) of (A) ghrelin and (B) growth hormone secretagogue receptor in canine mammary carcinoma cell lines (CMT-W1, CMT-W2) and their lung metastases (CMT-W1M and CMT-W2M) determined using Real-time qPCR. The result are presented as a mean (±SEM). The statistical analysis was performed using Prism version 5.00 software (GraphPad Software, USA). The one-way ANOVA and Tukey HSD post-hoc were applied to analyze the results. p < 0.05 was regarded as significant and marked as *.