T-cell leukemia 1A knockdown and NF-κB transcriptional activity. (A) T-cell leukemia 1A (TCL1A) expression in U2OS-estrogen receptor alpha (ERα) cells before and after siRNA knockdown (KD), with or without the addition of 0.1 nM estradiol (E2) for an additional 24 hours. (B) NF-κB transcriptional activity after co-transfection with an NF-κB reporter construct together with TCL1A-negative siRNA or TCL1A-specific siRNA. Forty-eight hours after transfection, the cells were exposed to 0.1 nM E2 for an additional 24 hours. All values are the mean ± standard error of the mean of triplicate determinations. (C) Western blots for TCL1A, phosphorylated IκB, IκB and actin after TCL1A knockdown in U2OS-ERα cells, with or without the addition of 0.1 nM E2 for an additional 24 hours.