PTC299 and decitabine exert synergistic effects in the xenograft MDS model. (A) Schematic representation of the xenograft MDS model using NOG mice. Bioluminescence signals in NOG mice infused with 2 × 10⁶ SKM-1/Akaluc cells via the tail vein. NOG mice were irradiated at a dose of 0.5 Gy just before transplantation. Starting on day 12 posttransplantation, recipient mice received vehicle once a day (QD) orally every day (n = 5), 10 mg/kg of PTC299 QD orally every day (n = 5), 0.3 mg/kg of DAC intraperitoneally 3 times per week (n = 5), and PTC299 and DAC (n = 5) for 3 weeks. (B) Quantification of photon counts from SKM-1/Akaluc cells in xenograft MDS mice. Bioluminescence signals taken by a photon-counting analyzer, are shown in the left panel. Akaluc activity in treated mice was detected weekly. A Kaplan-Meier survival curve is depicted in the right panel. The data shown were obtained from 2 independent experiments. **P < .01 by the log-rank test. (C) Schematic representation of the xenograft MDS model using NOG IL-3/GM-TG mice. Bioluminescence signals in NOG IL-3/GM-TG mice infused with 7.5 × 10⁶ MDS-L/Akaluc cells via the tail vein. NOG IL-3/GM-TG mice were received transplantation without any preconditioning. Starting on day 8 posttransplantation, recipient mice received vehicle QD or 10 mg/kg of PTC299 QD orally for 5 consecutive days for the first week and followed by 3 days per week for 2 weeks (n = 7), and PTC299 and DAC (n = 7) for 3 weeks. DAC was administered in a dose of 0.3 mg/kg intraperitoneally 3 times per week. (D-E) Quantification of photon counts from MDS-L/Akaluc cells in xenograft MDS mice. Bioluminescence activity in treated mice was detected. (D) Images of bioluminescence signals in representative mice (2 mice each) at different time points during the treatment. € The quantitative photon count in each group. (F) Body weight (BW) and hemoglobin (Hb) levels of mice. Data are shown as the mean ± standard error of the mean. *P < .05; ns, not significant by 1-way ANOVA.