Establishment of a canine mammary gland tumor cell line and characterization of its miRNA expression

Canine mammary gland tumors (CMGTs), which are the most common neoplasms in sexually intact female dogs, have been suggested as a model for studying human breast cancer because of several similarities, including relative age of onset, risk factors, incidence, histological and molecular features, biological behavior, metastatic pattern, and responses to therapy. In the present study, we established a new cell line, the SNP cell line, from a CMGT. A tumor formed in each NOD.CB17-Prkdc(scid)/J mouse at the site of subcutaneous SNP cell injection. SNP cells are characterized by proliferation in a tubulopapillary pattern and are vimentin positive. Moreover, we examined miRNA expression in the cultured cells and found that the expression values of miRNA-143 and miRNA-138a showed the greatest increase and decrease, respectively, of all miRNAs observed, indicating that these miRNAs might play a significant role in the malignancy of SNP cells. Overall, the results of this study indicate that SNP cells might serve as a model for future genetic analysis and clinical treatments of human breast tumors.