mRNA and functional analyses of PML-RARα targets. (A) Changes in mRNA expression of selected genes between zinc-induced U937-PML-RARα and U937–empty vector cells were confirmed by real-time RT-PCR. The bars indicate the fold mRNA repression upon PML-RARα expression for the microarray data and the real-time RT-PCR data (mean plus standard deviation). (B) Protein expression of ANKRD2 and RGS2 was decreased in U937-PML-RARα cells compared with U937–empty vector cells 12 hours after zinc induction as analyzed by Western blotting. (C) S100P expression can overcome the PML-RARα–induced differentiation block. U937-PML-RARα and U937–empty vector cells were transfected with GFP or GFP-S100P, subsequently zinc induced, and exposed to vitamin D₃ 24 hours after transfection. After 48 hours, cells were analyzed for CD11b and CD14 expression in GFP⁺ cells (mean plus standard deviation of 2 independent experiments).