First Author | Schaffner F | Year | 2013 |
Journal | PLoS One | Volume | 8 |
Issue | 4 | Pages | e61071 |
PubMed ID | 23593394 | Mgi Jnum | J:200026 |
Mgi Id | MGI:5506839 | Doi | 10.1371/journal.pone.0061071 |
Citation | Schaffner F, et al. (2013) Endothelial protein C receptor function in murine and human breast cancer development. PLoS One 8(4):e61071 |
abstractText | Several markers identify cancer stem cell-like populations, but little is known about the functional roles of stem cell surface receptors in tumor progression. Here, we show that the endothelial protein C receptor (EPCR), a stem cell marker in hematopoietic, neuronal and epithelial cells, is crucial for breast cancer growth in the orthotopic microenvironment of the mammary gland. Mice with a hypomorphic allele of EPCR show reduced tumor growth in the PyMT-model of spontaneous breast cancer development and deletion of EPCR in established PyMT tumor cells significantly attenuates transplanted tumor take and growth. We find expansion of EPCR(+) cancer stem cell-like populations in aggressive, mammary fat pad-enhanced human triple negative breast cancer cells. In this model, EPCR-expressing cells have markedly increased mammosphere- and tumor-cell initiating activity compared to another stable progenitor-like subpopulation present at comparable frequency. We show that receptor blocking antibodies to EPCR specifically attenuate in vivo tumor growth initiated by either EPCR(+) cells or the heterogenous mixture of EPCR(+) and EPCR(-) cells. Furthermore, we have identified tumor associated macrophages as a major source for recognized ligands of EPCR, suggesting a novel mechanism by which cancer stem cell-like populations are regulated by innate immune cells in the tumor microenvironment. |