Transcription Factor Stat5, A Novel Therapeutic Protein, Inhibits Metastatic Potential and Invasive Characteristics of Human Breast Cancer Cells
Abstract
Signal transducer and activator of transcription-5 (Stat5) mediates prolactin (PRL)-induced differentiation and growth of breast epithelial cells. We have recently identified active Stat5 as tumor marker of favorable prognosis in human breast cancer, and determined that Stat5 activation is lost during metastatic progression. Here we provide novel evidence for an invasion-suppressive role of Stat5 in human breast cancer. Activation of Stat5 by PRL in human breast cancer lines was associated with increased surface levels of the invasion- suppressive adhesion molecule, E-cadherin, in vitro and in xenotransplant tumors in vivo. Inducible E-cadherin was blocked by dominant-negative (Dn) Stat5 or Dn-Jak2, but not by Dn-Stat3. Further experimental data indicated a role of Stat5 as a coordinate regulator of additional invasion-related characteristics of human breast cancer cells, including cell surface-association of Q-catenin, homotypic cell clustering, invasion through Matrigel, cell migration, and matrix metalloproteinase activity. A role of Stat5 as a suppressor of breast cancer invasion and metastatic progression provides a biological mechanism to explain the favorable prognosis associated with active Stat5 in human breast cancer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2004
- Accession Number
- ADA433241
Entities
People
- Ahmad S. Sultan
Organizations
- Georgetown University