Breast Cancer Prevention by a Fatty Acid Binding Protein MRG-Induced Pregnancy Like Mammary Gland Differentiation
Annual summary rept. 1 Aug 2001-31 Jul 2002
LONG ISLAND JEWISH MEDICAL CENTER LAKE SUCCESS NY
Pagination or Media Count:
A mammary derived growth inhibitor related gene MRG was previously identified and characterized. MRG induces differentiation of mammary epithelial cells in vitro and its expression is associated with mammary differentiation. Overexpression of MRG in human breast cancer cells induced differentiation with changes in cellular morphology and a significant increase in the production of lipid droplets. Treatment of mouse mammary gland in organ culture with MRG protein resulted in a differentiated morphology and stimulation of beta-casein expression. To further define the role of MRG on mammary differentiation, a MRG transgenic mice model under the control of MMTV promoter was established and investigated. While there was no lobulo-alveolar structure in control virgin mice, expression of MRG transgene in the mammary gland resulted in the formation of alveolar-like structure. Consistent with the morphological change, expression of MRG also increased milk protein beta-casein expression in the gland. Our results suggest that MRG is a candidate mediator of the differentiating effect of pregnancy on breast epithelial cells.
- Anatomy and Physiology
- Medicine and Medical Research