Fig. 2. TGF-β inhibits transcription from the cbfa1 promoter. ROS 17/2.8 (A) or 10T1/2 (B) cells were transfected with the pCbfa1-Luc or pCbfa1m-Luc reporter plasmids and expression plasmids, as indicated. 10T1/2 cells (B) were cotransfected with the CBFA1 expression plasmid (pRK5-CBFA1) or the control empty plasmid (pRK5). Cells were cultured in the presence or absence of TGF-β (1 ng/ml) 16 h after transfection. Forty-eight hours after transfection, cells were harvested and reporter activities measured. Values normalized for transfection efficiency are shown as fold induction relative to basal promoter activity as described in Materials and methods. (C) Whole 10T1/2 cell lysates were prepared from a parallel transfection experiment for visualization of CBFA1 protein levels by western analysis using Flag antibody.