The bone microenvironmental effect in the dormancy of Cancer

Tumors have already threatened human life and health for centuries, especially the recurrent of bone metastases is difficult to cure. Relapse can occur years to decades after resection of primary tumor. This phenomenon is common in many clinical cases and animal experimental studies. The effect of traditional radiotherapy and chemotherapy on relapse is very limited, and the patients’ prognosis is poor. Because the delayed occurrence of metastases, researchers put forward a new concept “dormancy”, including a single dormant tumor cell (growth-arrest) and tumor mass dor-mancy (equivalence of the proliferation rate and apoptosis rate). It is probable that dormant tu-mor cells are the resource of relapse and the main reason of chemotherapy resistance. The me-chanisms mediated tumor cell dormancy are complex and poorly understood, and bone marrow microenvironment plays an important role in this process. This review focuses on the bone mar-row microenvironmental effect in inducing cancer cells to dormancy uncovered by the latest re-searches