Fig. 2.

HMGA1 regulates FoxO1 gene transcription. a FoxO1-Luc reporter vector was transfected into HepG2 cells, either in the absence or presence of siRNA against HMGA1, or a nontargeting control siRNA, and Luc activity was measured 72 to 96 h later. b FoxO1-Luc reporter vector was transfected into HEK-293 cells, with increasing amounts (0, 0.5, 1 µg) of pcDNA3-HMGA1 effector vector, in the absence or presence of 10 µM distamycin A, and Luc activity was measured as in a. In both experimental conditions, Luc activity from the reporter plasmid was normalized by the renilla Luc activity produced from a pRL Renilla-Luc control vector cotransfected as an internal control. White bar, mock (no DNA); black bar, (pGL3 basic vector, without the FoxO1 promoter). Results are means ± S.E.M. of three independent experiments, each in triplicate. *P < 0.05 compared with nontargeting (control) siRNA; **P < 0.05 vs. the FoxO1-Luc, in the absence of a HMGA1 effector vector, which is assigned an arbitrary value of 1. Representative WBs of HMGA1 out of three independent experiments for each condition are shown in the autoradiograms. Bar graphs above the gel panels are derived from densitometric scanning of WBs, using the ImageJ software program. *P < 0.05 vs. control (first column in each condition). Sp1, control of nuclear protein loading