BCOR-RARA inhibits RARA transcriptional activation by ATRA in a dominant-negative manner. (A) Input proteins in HepG2 cells. An asterisk indicates a protein included in the lower lane. (B) BCOR-RARA itself induced weak transcriptional activation by ATRA. Luciferase assays were performed on cell extracts from HepG2 transiently transfected with the 4× RAREs containing a luciferase reporter, RXRA and 1μM of ATRA or vehicle control. (C) Dominant-negative effects of BCOR-RARA on RARA transcriptional activation by ATRA. Plasmids of 4× RAREs containing luciferase reporter, RARA, RXRA, and the fusion proteins were cotransfected into HepG2 cells with various concentrations of ATRA.