Endosteal Niche

The endosteal niche is the interface between the bone marrow and the mineralized bone surface, lined by osteolineage cells such as osteoblasts and osteoclasts along the trabeculae and cortical bone. Bone metastasis is thought to proceed through colonization of this niche, where cancer cells exploit osteoblast-derived signals and matrix components to anchor and proliferate.

Bone is a highly nonuniform mechanical environment, with rigid trabeculae immediately adjacent to soft marrow, so cells colonizing the endosteal niche and cells expanding into the marrow space are subject to very different mechanical surroundings.