FIG. 8.

siRNA-mediated CLOCK knockdown in HC11-3×ERE luciferase cells influences ERE-dependent transcriptional activity. After CLOCK siRNA transfection, HC11-3×ERE cells were incubated for 24 h and treated with 10 nM PPT (A), 10 nM E2 (B), or 100 nM DPN (C) for another 24 h before luciferase measurement. E2- and DPN (ERβ selective ligand)-induced transcriptional activity but not PPT (ERα selective ligand)-induced transcriptional activity was upregulated upon cotransfection of siRNA toward CLOCK. Activity of scrambled siRNA-transfected groups was arbitrarily set to be 1; data are expressed as means standard deviations of three independent experiments performed in triplicate (*, P < 0.05; Student's t test).