Pgp Concentration of Carcinogens in Breast Epithelia
Final rept. 1 Sep 96-31 Aug 98
MEDICAL UNIV OF SOUTH CAROLINA CHARLESTON
Pagination or Media Count:
Our central hypothesis is that breast ductule epithelial cells possess excretory transporters which could transport hydrophobic carcinogenic molecules to the lumen of the ductules. These deposited carcinogens could diffuse back through the apical membrane and attack DNA of the lining cells. So far, all of our data support the conclusion that human breast ductules possess one of these excretory transporters, Mrp2, which transports anionic, hydrophobic, xenobiotic molecules. First, immunocytochemical studies show that the apical membrane of ductules epithelial cells possesses Mrp2. Second, our transport studies show that freshly isolated ductules transport sulforhodamine 101, a substrate for the Mrp2 transporter, into their lumens and that this transport is stimulated by estrogen This transport process is tremendously enhanced by exposure of ductules to estrogen. Since lifetime exposure to estrogen is considered the major risk factor in breast cancer, this estrogen regulation of the transport phenomenon may be especially significant.
- Anatomy and Physiology
- Medicine and Medical Research