Thrombospondins (TSPs) are a family of five multimeric matricellular proteins. Through a wide range of interactions, TSPs play pleiotropic roles in embryogenesis and in tissue remodeling in adult physiology as well as in pathological conditions, including cancer development and metastasis. TSPs are active in bone remodeling, the process of bone resorption (osteolysis) and deposition (osteogenesis) that maintains bone homeostasis. TSPs are particularly involved in aberrant bone remodeling, including osteolytic and osteoblastic skeletal cancer metastasis, frequent in advanced cancers such as breast and prostate carcinoma. TSPs are major players in the bone metastasis microenvironment, where they finely tune the cross-talk between tumor cells and bone resident cells in the metastatic niche. Each TSP family member has different effects on the differentiation and activity of bone cells - including the bone-degrading osteoclasts and the bone-deposing osteoblasts - with different outcomes on the development and growth of osteolytic and osteoblastic metastases. Here we overview the involvement of TSP family members in the bone tissue microenvironment, focusing on their activity on osteoclasts and osteoblasts in bone remodeling, and present the evidence to date of their roles in bone metastasis establishment and growth.

中文翻译：

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血小板反应蛋白与骨重塑和转移性骨病有关。

血小板反应蛋白（TSP）是五个多聚体基质细胞蛋白家族。通过广泛的相互作用，TSP在成人生理以及包括癌症发展和转移在内的病理状况中，在胚胎发生和组织重塑中发挥多效性作用。TSPs在维持骨骼动态平衡的骨骼重塑，骨骼吸收（溶骨）和沉积（成骨）过程中很活跃。TSP特别参与异常的骨骼重塑，包括溶骨和成骨的骨骼癌转移，在乳腺癌和前列腺癌等晚期癌症中经常发生。TSP是骨转移微环境的主要参与者，它们在转移微环境中微调肿瘤细胞与骨驻留细胞之间的串扰。每个TSP家族成员对骨细胞的分化和活性（包括降解骨的破骨细胞和沉积骨的成骨细胞）具有不同的影响，对溶骨和成骨转移的发展和生长具有不同的结果。在这里，我们概述了TSP家族成员在骨组织微环境中的参与，着重介绍了它们对破骨细胞和成骨细胞在骨重塑中的活性，并提供了迄今为止它们在骨转移建立和生长中作用的证据。