Oncogene activation and oncogene cooperation in MMTV-induced mouse mammary cancer.

In this short review, we will give an overview of the various genes that can be activated by insertion of proviral DNA of the mouse mammary tumor virus during the formation of mammary cancer. These genes fall within three families: Wnt genes, FGF genes and Notch-related genes. We will summarize our current understanding of the roles of these genes in tumorigenesis and in normal development, and the mechanisms of action of their gene products. Finally, we will give some examples of cooperation between these genes in various biological settings.