Irvine, Calif. -- The chemical compound for the abortion pill has been found to prevent the growth of mammary tumors caused by the mutant gene responsible for a majority of breast and ovarian cancers, according to UC Irvine scientists.
This compound, called mifepristone, prevented breast tumors by inhibiting progesterone, a hormone involved with the female reproductive cycle, in breast tissue cells. The discovery points to new prevention methods for women who have a genetic predisposition to breast and ovarian cancers. Currently, these women often have their breasts or ovaries surgically removed to reduce the risk of developing cancer.
The study appears in the Dec. 1 issue of Science.
We found that progesterone plays a role in the development of breast cancer by encouraging the proliferation of mammary cells that carry a breast cancer gene, said Eva Lee, lead author of the study and professor of developmental and cell biology and biological chemistry at UCI. Mifepristone can block that response. Were excited about this discovery and hope it leads to new options for women with a high risk for developing breast cancer.
In the study, Lee and her colleagues addressed how mifepristone affects the function of mutated BRCA-1 genes in tissue. BRCA-1 is widely studied by cancer geneticists because a mutated version of this gene significantly raises the possibility of breast and ovarian cancers. By age 70, more than 50 percent of women with the mutated BRCA-1 gene develop breast or ovarian cancer.
The researchers studied mice that carried the mutated BRCA-1 gene. Mice treated with mifepristone, an anti-progesterone compound, did not develop mammary tumors by the time they reached one year of age. All of the untreated mice, however, developed tumors by eight months of age.
Progesterone, secreted by the ovaries, is essential to the maintenance of a pregnancy. Mifepristone, also called RU486, is designed to abort pr
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Contact: Jennifer Fitzenberger
jfitzen@uci.edu
949-824-3969
University of California - Irvine
30-Nov-2006