Role of Stat-3 in ER - Breast Tumors
Abstract
The hypothesis to be tested in this application is whether STAT family of transcription factors play a role in the development of ER- negative breast carcinomas. During the past year, we have examined the activation status of two STATs, STAT-3 and STAT-5, known to be associated with the proliferation of normal and cancerous breast cell lines. Our results indicate that in a vast majority of theER- negative breast tumor cell lines, STAT-3 exists in a constitutively activated state and is localized in the nucleus. Normal human cell ines do not exii%bit such aii activat%d stat% ur r'ucl%ar localization of STAT-3. Co-immunoprecipitation studies show that Src kinases immnunoprecipitate along with STAT-3 suggesting a physical association between these two proteins. These results suggest that several of the ER-negative breast carcinomas express constitutively activated Src kinases, which mediate the phosphorylation of STAT-3, which in turn could mediate their proliferative function and oncogenicity. The constitutively activated status of STAT-3, therefore serves as a good diagnostic marker for the detection of ER-negative breast carcinoma development. Since STAT-3 activation appears to play a critical role in the proliferative flinction of ER-negative breast carcinomas, Src-STAT-3 pathway offers an excellent target for the development of cancer therapeutic agents.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2000
- Accession Number
- ADA392389
Entities
People
- Premkumer Reddy
Organizations
- Temple University