Abstract

Molecular mechanism of bone metastasis development is extremely complex. It is determined by intrinsic properties of cancer cells or cancer stem cells (CSCs) and intricate bone microenvironment. Therefore, molecular treatment strategies have been suggested to directly induce cancer cells apoptosis and to target vascular and bone microenvironment as well, thus inhibiting vicious cycles established between osteoblasts/osteoclasts and metastatic cancer cells. Chemokine/chemokine receptor pathway, adhesion molecules, and proteinases are crucial for bone metastatic process, including migration, adhesion and invasion into bone, angiogenesis and cell proliferation, which could provide potential targets for prevention and treatment of bone metastasis. Restoration of metastasis suppressor genes and microRNAs inhibits bone metastasis. Furthermore, targeting the bone marrow endothelium around cancer cells by use of both antiangiogenic inhibitors and vascular disrupting agents is another promising and valid therapeutic approach. On the other hand, many antitumor drugs/small molecules are limited in reaching tumor site due to a very complex vasculature. Nanotechnology aids in the targeted delivery of antitumor drugs/small molecules. For severe bone lesion, multifunctional implants integrating with antitumor drugs/small molecules and bone forming factors could be effective to reconstruct bone defects and to improve the quality of life in patients with bone metastasis.