FIG 2.

Treatment with conditioned medium of MSCs decreases cancer stem cell frequency. The side population (SP) fraction was isolated from H1299 lung cancer cells that had been treated with conditioned medium of MSCs (MSC CM) or mock-conditioned medium (control CM). For limiting dilution analyses, the indicated numbers of side population cells were subcutaneously injected into female BALB/c nu/nu mice (n = 4 per group). (A) Representative macroscopic images of resulting tumors (indicated by arrows) 50 days after the injection. Scale bar, 5 mm. ND, not detected. (B) Tumor development from side population cells 50 days after the injection. The tumor volume is reported as the mean ± standard error number of detected tumors.