GM-CSF+4-IPP therapeutic effect in immunodeficient mice MM xenograft models. (A) NCI-H929 cells were inoculated subcutaneously into the flank of NSG (left graph) or SCID mice (right graph). When tumors reached volumes of 100 mm³, mice were treated every 2 days until sacrifice (day 18) with the indicated treatments (left, n = 6-10 per group; right, n = 8). (B) NSG mice displaying 100-mm³ subcutaneous NCI-H929 tumors were injected IV with clodronate, and 2 days later, mice were treated with GM-CSF+4-IPP every 2 days. Tumor growth was measured daily. Data show tumor-volume average of 5 mice per group ± SEM. (C) M1 and M2 polarization murine marker expression in CD11b⁺ cells isolated from tumors grown in SCID mice, as determined by qRT-PCR (n = 10). Relative expression (log scale) indicates the expression of each marker after GM-CSF+4-IPP treatment relative to its expression in the absence of treatment. (D-E) MM.1S-GFP cells were IV injected into NSG mice, and 10 days later, mice were treated with GM-CSF/4-IPP or with vehicle. Mice were sacrificed after 2 weeks of treatment, and BM cells were analyzed by flow cytometry for human HLA-1 and green fluorescent protein (GFP) expression. Representative dot-plots panels showing HLA-1⁺/GFP⁺ percentages (left) and quantification of BM infiltration (right) are displayed. (B) qRT-PCR analyses of human GAPDH expression of BM samples from vehicle- or GM-CSF/4-IPP-treated mice. Data show the mean ± SEM of 14 mice. (F) M1 and M2 polarization murine marker expression in the BM from NSG mice infiltrated with MM.1S-GFP cells, shown as in (C). mRNA, messenger RNA. *P < .05; **P < .01; ***P < .001.