Fig. 6. Treatment with ATI alleviates splenomegaly and hepatomegaly, revealed by evaluation of the weight of spleens (A) and livers (B).

Fig. 7. ATI induces terminal differentiation of leukemic cells expressing PML-RARa in vivo, as revealed by morphological examination.

Fig. 8. ATI treatment alleviates infiltration and dissemination of leukemic cells in bone marrow (Top), spleen (Middle), and liver (Bottom) and prevents destruction of tissue architectures.

Fig. 9. Immunofluorescence analysis of the subcellular localization of PML-RARa/PML in NB4 and NB4-R2 cells treated with protocols indicated, and leukemic cells from APL mice treated with regimens indicated.

As₄S₄ was dissolved in 0.1 N sodium hydroxide to make a stock solution of 0.5 mM. T and I were dissolved in DMSO. Nitroblue tetrazolium (NBT), propidium iodide (PI), and dithiothreitol (DTT) were purchased from Sigma. Anti-RARa, PML, C/EBPa, C/EBPb, C/EBPe, PU.1,_{C-Myc, CDK2, Rb, P27, P21, Cyclin D1, horseradish peroxidase-conjugated goat anti-mouse IgG, and goat anti-rabbit IgG were obtained from Santa Cruz Biotechnology. Underphosphorylated Rb monoclonal antibody was from BD Biosciences, anti-AQP9 antibody from Chemicon, anti-b-actin antibody from Abcam, while Alexa Fluor 488 donkey anti-rabbit IgG antibody was obtained from Molecular Probes. The chemiluminescence phototope-horseradish peroxidase kit was from Cell Signaling.}

Four RNAi candidate target sequences to human AQP9 (SI Table 2) were designed following the procedure of Dharmacon siDESIGN center, and were cloned into pFIV-H1/U6-copGFP vector. AQP9-Si1 (SI Table 2) had the best interference efficiency in 293T cells cotransfected with AQP9 and siRNA expression constructs revealed by Western blot and immunofluorescence assays and was selected to knockdown the endogenous AQP9 in NB4 cells. Nonsilencing (NS)-siRNA was used as a control. The oligonucleotides encoding the AQP9-Si1 or NS-siRNA sequence and a loop sequence separating the complementary domains, were synthesized and inserted into the pGCL-GFP (Shanghai GeneChem). The recombinant virus was packaged using Lentivector Expression Systems (Shanghai GeneChem). NB4 cells were infected by Enhanced infection solution and cultured in RPMI-1640 medium containing 10% FBS. After 1 week, GFP-positive cells were sorted by Moflow (DakoCytomation). Experiments were performed with sorted GFP⁺ cells (purity, >97%).

Variance between the treatment groups was measured by two-tailed t test. Survival functions were estimated by using the Kaplan--Meier method and compared by the log-rank test. P<0.05 was considered statistically significant. All statistical analyses were performed on SAS 8.2 software (SAS Institute).