Figure 7. Experimental Model: Disseminated tumor cells (DTC) alter hematopoietic stem cell function to regulate bone phenotype.

At early stage of dissemination process, osteoblastic PCa activate BMP production by HPCs that induce osteoblastic differentiation from mixed bone marrow stromal cells. At the same time, osteolytic PCa activate HSCs to direct the differentiation of osteoclasts through IL-6 pathway. Although further study to exclude the paracrine effects or the effects from DTCs will be needed, the activation of HSCs/HPCs by PCa may be a molecular mechanism for the PCa bone phenotype.