FIG. 8.

The ets/AP-1 enhancer is necessary for CSF-1 induction of uPA reporter gene activity in RAW264 cells. (A) RAW264 cells were transiently transfected with pGL2-uPA-6.6 with either the c-fms expression plasmid or the empty parent plasmid, pECE. Where indicated, 10⁴ U of CSF-1 per ml was added immediately after electroporation, while 10⁻⁷ M phorbol myristate acetate (PMA) was added after 6 h, and cells were harvested after 24 h. (B) RAW264 cells were transiently transfected with a series of uPA promoter and enhancer mutations as represented in the first column. The Δ indicates the deletion of the ets/AP-1 element from the −6.6-kb promoter. A c-fms expression plasmid was included with the various uPA reporters in the transient transfection, cells were treated with or without 10⁴ U of CSF-1 per ml for 24 h, and the cell lysates were assayed for luciferase activity. Luciferase activity is presented as relative light units per microgram of protein. The results of four experiments (A) or three experiments (B), each performed in duplicate, are presented with bars representing the standard error.