PML/RARα restores STAT3 activity inhibited by PML.

(A-B) 293T cells were transfected with pEF-BOS-G-CSF-R/gp130 and the indicated amounts of expression vectors, and cultured with or without 1 μM all-trans retinoic acid (ATRA). Total cell lysates prepared after G-CSF treatment were subjected to coimmunoprecipitation analyses. (C) NIH3T3 cells were transfected with 4 × APRE-Luc and the effector genes indicated. After IL-6 stimulation, relative luciferase activities were quantitated. (D) 293T cells were transfected with pEF-BOS-G-CSF-R/gp130, 4 × APRE-Luc, and the indicated amounts of effector genes. After G-CSF stimulation, relative luciferase activities were quantitated. The results are shown as the means ± SDs of triplicate cultures. Similar results were obtained from at least 4 independent experiments.