PTN activates stromal cells and alone is sufficient to stimulate signaling pathways.
Scientists discovered that pleiotrophin (PTN) accelerates the progression of breast cancer, remodels the tumor microenvironment, and increases the number of receptors for different markers of aggressive breast cancers.
“We’ve shown that PTN secreted from breast cancer cells is the key mechanism of stromal cell activation and that PTN alone is sufficient to stimulate many of the critical signaling pathways that aggressively promote breast cancer progression,” states Thomas Deuel, M.D., the Scripps Research scientist whose laboratory made the discovery. “Our findings demonstrate that PTN-activated stromal cells are responsible for the ultimate remodeling of extracellular matrix proteins as well as the release of factors that stimulate the growth of malignant cancer cells.”
Using genetically modified mouse models that inappropriately expressed PTN, highly malignant cells of scirrhous carcinoma were found to express high levels of the mouse mammary tumor virus PTN transgene along with increases in collagen, elastin, and tumor angiogenesis and the size of new blood vessels within the breast cancers, all of which are markers for the cancer.
The study was published in an advanced online edition of the Proceedings of the National Academy of Sciences.