The Significance of Erythropoietin Receptor (EpoR) Acquisition by Breast Cancer Cells

Data from our lab and others indicate that normal breast cells do not express the erythropoietin receptor EpoR conversely, breast cancer cells express functional EpoR. Expression of EpoR appears greatest in poorly oxygenated tumor regions and in patients with negative estrogen receptor status, a sign of more aggressive disease. In addition one study demonstrated that the EpoR gene is overexpressed in patients with micrometastatic disease. The differential expression of EpoR between normal and cancerous breast cells has led us to hypothesize that acquisition of EpoR expression by mammary epithelial cells may be part of malignant transformation and may impact disease progression and metastasis. Our proposal investigates changes in mammary epithelial cell biology associated with acquisition of EpoR expression. Our results will lead to a better understanding of the appropriate use of Epo in breast cancer patients and may lead to development of the EpoR as a novel therapeutic target in the treatment of breast cancer.