Bone morphogenetic proteins in development and progression of breast cancer and therapeutic potential (review)

Bone morphogenetic proteins (BMPs) belong to the TGF-beta superfamily, which plays important roles in foetal and postnatal development and also maintains the homeostasis of various tissues and organs. Due to the critical role played by BMPs in bone formation and bone turnover, the implication of these molecules in bone metastasis has been intensively studied over the past decade. BMPs have been implicated in the development and progression of solid tumours, particularly the disease-specific bone metastasis. In breast cancer, a tumour type which most commonly metastasizes to bones, aberrations of both BMP expression and their signalling have been recently demonstrated. These aberrations have certain correlations with the development and progression of the disease. Recent in vitro studies have also demonstrated that BMPs can regulate a range of biological functions of breast cancer cells. Targeting BMPs or BMP signalling may provide novel therapeutic approaches for breast cancer. In the current review, we discuss the present knowledge on BMP abnormalities and their implication in the development and progression of breast cancer, particularly in the disease-specific bone metastasis