Potential Role of the Tumor Suppressor ADENOMATOUS POLYPOSIS COLI in Polarization of Breast Epithelial Cells.
Abstract
Recent evidence suggests that the adenomatous polyposis coli (APC) gene participates in breast tumorigenesis. Although a precise biological function for APC protein has not yet been determined, it has been shown that the APC protein interacts with beta-catenin and plakoglobin in vivo. Beta-catenin and plakoglobin are components of two specialized anchoring junctions, the adherens junction, a site of attachment for bundles of actin filaments, and the desmosome, a site of attachment for intermediate filaments (e.g. keratin). A direct correlation has been shown between loss of adherens junction components and the metastatic potential of breast cancer. I have used a combination of immunofluorescence microscopy and biochemical fractionation to determine the location of APC protein in epithelial cells from both normal and breast cancer tissue. APC protein was located in the nucleus and the cytoplasm of all breast epithelial cells tested. APC protein concentrated at the edge of breast epithelial cells was eliminated by disruption of keratin filaments and microtubules, but not by actin disruption. APC protein appeared tightly associated with intermediate filaments of the normal breast epithelial cell following sequential extraction. These findings are consistent with APC protein interacting with intermediate filaments, but not with actin filaments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1997
- Accession Number
- ADA332878
Entities
People
- Kristi Neufeld
Organizations
- University of Utah