Accession Number:

ADA409627

Title:

Membrane Estrogen and HER-2 Receptors in Human Breast Cancer

Descriptive Note:

Annual rept. 1 Jul 2001-1 Jul 2002

Corporate Author:

CALIFORNIA UNIV LOS ANGELES

Personal Author(s):

Report Date:

2002-07-01

Pagination or Media Count:

103.0

Abstract:

Patients with breast cancers that express estrogen receptor ER commonly receive antiestrogen therapy. The efficacy of this therapy depends on close regulation of breast growth by estrogen. However, as breast cancers progress, they often become resistant to estrogens, and most patients no longer respond to antiestrogen therapy. New antiestrogen treatment options are needed, and alternative therapies may derive from findings showing that some ER molecules occur in plasma membranes of breast cancer cells and interact with transmembrane HER-2 growth factor receptors. Expression of HER-2 receptors occurs in many breast cancers, and the protein kinase activity of HER-2 may modulate ligand-independent activation of ER. If active cross-communication between ER and HER-2 receptor occurs and leads to the promotion of cancer growth, this axis may offer a new target for therapeutic intervention. We have detected a membrane-associated form of ER in breast cancer cells and have evidence that it promotes tumor growth. Using this novel signaling pathway as a target, we are now testing new treatment options to prevent cancer progression in models of human breast cancer. Since HER-2 overexpression in breast cancer is associated with failure of antiestrogen therapy, understanding the basis of associations between ER and HER-2 receptors may help to improve patient management and enhance survival.

Subject Categories:

  • Biochemistry
  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE