From chromosomal abnormalities to the identification of target genes in mouse models of breast cancer.

Cytogenetic studies of breast cancer cells have identified numerous chromosomal imbalances, including gains in human chromosome regions 1q, 4p, 8q, and 20q and losses in regions 1p, 3p, 6q, 11q, 16q, 17p, and 22q. Mouse models have been developed to study the mechanisms of mammary carcinogenesis, and in most cases, the corresponding karyotypes have been reported. Here, I summarize the cytogenetic findings and the candidate genes that are involved in mammary tumorigenesis. The most commonly altered chromosomes in mouse breast cancer models are chromosomes 4 and 11, which are orthologous to human chromosomes that are also affected by chromosomal abnormalities in human breast cancer. The genes that are affected by chromosomal imbalances in mouse models have also been found to participate in human breast cancer. In addition, the amplification and overexpression of several new genes in mouse models have subsequently been confirmed in human breast cancer. In this review, I compile information on the available karyotypes for mouse breast cancer models.