Fig. 4.

ZBTB20-mediated transcriptional repression of AFP activity. (A) 293T cells were cotransfected with different amounts of Gal4-ZBTB20 fusion expression vector, (GAL)₅-sv40-Luc reporter, and pCMV-β-Gal. Results are expressed as fold repression of luciferase normalized to the internal control. (B–E) HepG2 cells were cotransfected with ZBTB20 expression plasmids, different luciferase reporters, and the internal control pCMV-β-Gal. Results are expressed as fold repression or relative luciferase activity normalized to the internal control. n = 3 experiments. (B) ZBTB20 overexpression repressed AFP-2309Luc reporter (−2309 to +27) activity in HepG2 cells in a dose-dependent manner. n = 4 experiments. (C) ZBTB20 overexpression repressed AFP-2309Luc reporter activity in HepG2 cells but showed no effects on Gck or Alb reporter activity. Gray bar = mock control of empty vector; black bar = ZBTB20 expression vector. n = 3 experiments. (D) ZBTB20 overexpression repressed the activity of the AFP reporter driven by the AFP promoter −2309/+27 or 5′ truncations at −1103, −837, −200, −178, −162, or −151. n = 5 experiments. ∗, P < 0.01; Error bar represents SD.