TCM-induced tumor angiogenesis and recruitment/attachment of Q-dot-labeled newly formed pericytes on blood vessels formed on gel-foam inserted into mice. A. Representative images show the effect of MCF-7-CM on in vivo angiogenesis. Gelfoams, soaked with water (NC), regular media (RM) or tumor cell-derived media (TCM), were transplanted into the subcutis of mice and angiogenesis was viewed under the microscope. B. The photograph showing the recruitments of q-dot labeled pericytes on in vivo angiogenesis in three different conditions [Gelfoam soaked with water (NC), regular media (RM) and tumor-cell-derived condition media (TCM)]. The bar graph represents the number of Q-dot-labeled blood vessels per field in different treatment conditions. The data represent mean ± SME of three different experiments. *p of <0.0012 vs negative controls (NC); **p <0.0001 vs RM. C. Diagrammatic illustrations of signaling pathways involved in tumor cells-generated PDGF-B-induced differentiation of pericytes from mesenchymal stem cells. The studies demonstrate that PDGF-B is responsible for the differentiation of pericytes from mesenchymal stem cells through PDGF-B-NRP-1 signaling pathway.