Effects of FOS, JUN, TGF-B, and Glucorticoids on Polarized Membrane Traffic.
Abstract
Mammary cells undergo a physiological cycle of growth, differentiation, lactation, and involution. During transformation mammary cells lose polarity, and the extent of loss of polarity correlates with the degree of malignancy. The physiological and oncogenic changes in mammary cell polarity can be studied using highly differentiated cultured mammary epithelial cell lines, such as the 3 lEG4 cell clone. Glucocorticoids cause an increase in polarity. In contrast, exposure to TGF beta or over-expression of oncogenes (c-Fos or c-Jun) cause a spectrum of loss of polarity. For instance, c- Jun over-expression causes a reversible, partial loss of polarity, whereas over-expression of c-Fos causes a severe and irreversible loss of polarity. In contrast, exposure to TGF beta acts primarily to antagonize glucocorticoids, and physiologically is probably involved in involution of the mammary gland. In this grant proposal we have been studying the normal pathways used for polarized membrane traffic in well-differentiated cultured mammary epithelial cells. We have begun to study the effects of glucocorticoids, addition of TGF BETA, or overexpression of c-Jun or c-Fos on these pathways.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1998
- Accession Number
- ADA360926
Entities
People
- Keith E. Mostov
Organizations
- University of California, San Francisco