The Role of Id Proteins in Breast Cancer
Abstract
E2A gene products (E47 and E12) are potent transcription factors containing the basic helix-loop-helix (bHLH) domain for DNA binding and dimerization. E2A proteins are thought to control cell growth and differentiation. E2A is also implicated to have a role as a tumor suppressor. E2A function can be inhibited by a group of inhibitors called Id. Thus, overexpression of Id proteins could diminish the function of E2A as a tumor suppressor, and potentially cause breast cancer. To test this hypothesis, we have generated transgenic mice expressing Id-i in mammary epithelial cells, but have not detected any tumor formation. On the other hand, we have found Id-i overexpression in a large fraction of archived human breast cancer samples. The significance of Id-i overexpression in human breast cancer remains to be understood. Furthermore, we have shown that E2A proteins in primary mammary epithelial cells and in the MDA-MB-23 1 breast cancer cell line are degraded through a proteasome mediated pathway. This provides an additional mode of regulation for E2A function in mammary epithelial cells.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2000
- Accession Number
- ADA389454
Entities
People
- Xiao H. Sun
Organizations
- New York Medical College