Role of erbB-2 and erbB-3 in the Activation of Phosphatidylinositol 3 -Kinase.
Abstract
We sought to assess the importance of cooperative interactions between p185(erbB-2) and erbB-3 in growth factor-independent proliferation and the neoplastic transformation of breast carcinoma cells with c-erbB-2 gene amplification. To emulate the process in genetically engineered non-transformed mammary epithelial cells that co-express c-erbB-3, MCF-10A cell populations were derived that overexpress c-erbB-2 at very high levels comparable to that seen in breast carcinoma cells with c-erbB-2 gene amplification. While the previously engineered clones of MCF-10AerbB-2 cells overexpress c-erbB-2 at only moderate levels, the selection of cells using Flow Cytometry with anti-p185(erbB-2) antibody gave rise to very high-level p185(erbB-2)-overexpressing cell populations, and further passage in the complete absence of growth factors results in the selection of cells expressing the highest level of p185(erbB-2). These and the other cell lines presently under construction will allow us to study the constitutive activation of PI 3-kinase, growth factor independence in culture, and the in vivo transformation of human mammary epithelial cells that co-express c-erbB-3. The other major focus of this project involves the construction of cell lines expressing dominant negative forms of c-erbB-2 and c-erbB-3. The use of the expression vectors presently under construction will allow us to test the potential of this approach for blocking p185(erbB-2)/erbB-3 heterodimer function.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1997
- Accession Number
- ADA328987
Entities
People
- Stephen P. Ethier
Organizations
- University of Michigan