Bone morphogenetic protein-6: potential mediator of osteoblastic metastases in prostate cancer

The mechanisms by which prostate cancer metastasizes to bone with a strong osteoblastic reaction remain poorly understood. Several factors have been previously implicated, including transforming growth factor-beta, fibroblast growth factors, endothelin-1 and bone morphogenetic proteins (BMPs). BMP-6 expression has been shown exclusively in the malignant epithelial cells of prostate cancers that have metastasized, but not in organ confined disease. Expression of BMP-6 in radical prostatectomy specimens has been shown to correlate with increased recurrence rates and decreased survival. This article presents the results of work by the authors' group in this field and a current literature review.