FIG. 2.

Brd4 knockdown by siRNAs leads to chromosome missegregation. (A) C33A cells were transfected with either one of the four Brd4 siRNAs (Si1 to -4) or a control siRNA (CO) or were mock transfected. At 72 h posttransfection, protein lysates were harvested. Western blotting was performed using Brd4 and actin antibodies. (B) C33A cells were transfected with either Brd4 Si1 or a control siRNA. Cells were fixed and subjected to anti-Brd4 immunofluorescent staining. Cells were counterstained with DAPI to identify nuclei and mitotic chromosomes. Cells were examined under a Zeiss LSM 510 UV upright confocal microscope. Arrows indicate the Brd4 knockdown cells with abnormal chromatin structure. The experiment shown is representative of over 10 experiments. (C) C33A cells were transfected with either a control siRNA or a Brd4 siRNA as indicated. Cells were stained as for panel B and examined under a Leica DMLB epifluorescence microscope equipped with a Leica DC 500 digital camera.