Bone morphogenetic proteins and their receptor signaling in prostate cancer

Bone morphogenetic proteins (BMPs) belong to the TGF-Beta superfamily and are vital bone inductive factors. BMPs also play important roles during embryonic development and the postnatal homeostasis of various organs and tissues, by controlling cellular differentiation, proliferation and apoptosis. Prostate cancer is the most common cancer in men in Western countries, with a high incidence of bone metastasis. Once bony metastasis developed, the condition is incurable, and contributes significant disease specific morbidity and mortality. However, the mechanisms underlying the development of bone metastasis remain unclear. BMPs have been implicated in the development of both primary and secondary tumors, particularly skeletal metastasis. Aberrations in BMPs signaling have also been identified in various neoplasms. Recently studies have also suggested a pivotal role in bone metastasis for Noggin, which is a BMP antagonist. In this review, we discuss the current knowledge of BMPs signaling, abnormalities which have been identified and their involvement in tumour progression, and particularly in the development of bone metastasis in prostate cancer.