Abrogation of mouse tumor growth by MSCs. Data are for tumors grown for 18 days after subcutaneous injections of B16F10 melanoma cells. The tumors were untreated (CT) or inoculated with 10⁶ MSCs or mouse lung fibroblasts (FB) on day 7 of tumor growth. (A) Photographs show tumors in situ (top) and the excised tumor masses (bottom). Replicated 4 times. (B,C) Time-dependent changes in tumors. Mean plus or minus SD; n = 4 for each group. *P < .05 relative to CT. (D) Histologic sections show blood vessels in an untreated (left image, ) and MSC-inoculated (right image) tumors. Bar = 300 μm. Bar graphs show vessel density quantified in histologic sections. Mean plus or minus SD; n = 4 each group. *P < .05 relative to CT. (E) Expression of indicated EC markers in tumor tissue. Lysates were subjected to immunoprecipitation (IP) and immunoblot (IB) analyses as indicated. Replicated 3 times. (F) Group data show hemoglobin content of tumor tissue. Mean plus or minus SD; n = 4 each group. *P < .05 relative to CT. (G) Immunoblots for indicated proteins in tumor lysates. Replicated 3 times.