Establishment of a pair of novel cloned tumour cell lines with or without metastatic potential from canine mammary adenocarcinoma.

We produced 23 cloned cell lines from parental CHMp, which was previously established from a canine mammary adenocarcinoma patient in our laboratory. Two representative cloned cell lines, namely, CHMp-5b and -13a, were selected and characterized for cellular morphology, growth potential and expression of some tumour-related proteins. Subsequently, we transplanted the 2 tumour cell lines orthotopically into female nude mice to examine their tumorigenicity and metastatic potential. Interestingly, despite sharing the same origin, only CHMp-5b cells metastasized to the lung. Our results indicate that a comparison between these 2 cell lines at the molecular level will help us understand mechanisms of tumour progression, especially in the context of distant metastases originating from canine mammary gland tumours.