Accession Number:

ADA361890

Title:

Pgp Concentration of Carcinogens in Breast Epithelia

Descriptive Note:

Final rept. 1 Sep 96-31 Aug 98

Corporate Author:

MEDICAL UNIV OF SOUTH CAROLINA CHARLESTON

Personal Author(s):

• Karnaky, Karl J.

Report Date:

1998-09-01

Pagination or Media Count:

33.0

Abstract:

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.

Descriptors:

• *EPITHELIUM
• *CARCINOGENS
• *BREAST CANCER
• HORMONES
• SUBSTRATES
• DEOXYRIBONUCLEIC ACIDS
• TRANSPORT
• CELLS(BIOLOGY)
• MAMMARY GLANDS
• CYTOCHEMISTRY
• IMMUNOCHEMISTRY
• ESTROGENS

Subject Categories:

• Biochemistry
• Anatomy and Physiology
• Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE