Luciferase reporter assay
BLIMP-1 promoter regions were assessed in 3 kb upstream from the transcription start site of the mouse Blimp-1 sequences. To construct the Blimp-1 Luc luciferase reporter plasmid, approximately 0.9-1 kb of each sequence of the Blimp-1 promoter region were amplified by PCR using specific primers and subsequently cloned into the pGL4.10 vector (Promega). HEK293T cells were cotransfected with 500 ng of luciferase reporter, and 100 nM of Brd4-siRNA or control-siRNA. After 72 hours of transfection, luciferase activities were measured by the Dual-Luciferase Reporter Assay System (Promega) according to the manufacturer’s instructions. The sequences of primer used were listed in supplemental Table S3.