Gene expression profiling of human and dog breast cancers

Spontaneous tumors in dog have been demonstrated to share many features with their human counterparts, including relevant molecular targets, histological appearance, genetics, biological behavior and response to conventional treatments. Mammary tumors in dog therefore provide an attractive alternative to more classical mouse models, such as transgenics or xenografts, where the tumour is artificially induced. To assess the extent to which dog tumors represent clinically significant human phenotypes, we performed the first genome-wide comparative analysis of transcriptional changes occurring in mammary tumors of the two species, with particular focus on the molecular pathways involved. Keywords: Expression profiling by array 26 breast tumors and 7 normal mammary glands from dogs. Each sample was hybridized in duplicate with fluor reversal to systematically correct for dye bias. 68 infiltrating ductal mammary carcinoma and 61 adjacent non-involved tissues from humans. Each sample was hybridized in duplicate with fluor reversal to systematically correct for dye bias.