Gene expression profile of the mammary stroma in Rarb -/- mice compared to their wild type littermates

Inactivation of RAR-b, which has been reported as a tumor suppressing gene by numerous studies, results in protective effect against the tumorigenesis induced by activated ErbB2. Moreover, tissue recombination indicates that the RAR-b deficient-microenvironment, rather than the RAR-b status of mammary epithelial cells, plays a key-determining role in the initiation and progression of the mammary carcinoma. Ablation of RAR-b extensively modulates the remodeling of stroma during tumor progression through suppressing the activation and transdifferetiation of myofibroblasts. RNA microarray has been employed to identify the gene expression signature in the mammary stroma of our RAR-b null animals. We want to find out the underlining mechanism of the protective effects resulted from Rarb abliton. A global gene expression profile of mouse mammary stroma was obtained on total RNA from the cleared mammary fat pads (stroma) of both RAR-b KO (n=3) and their wild type (n=3) littermates at the age of four weeks.