TABLE 1.
Maximal activation of the IGFBP-1 promoter in nonhepatic cells after HNF-1 and IL-6/STAT3/AP-1 cotransfectiona
| Cotransfection
|
Luciferase activity
|
||||
|---|---|---|---|---|---|
| IL-6/STAT3 | c-Fos/c-Jun | HNF-1α | HNF-1β | Fold (avg) | SD |
| − | − | − | − | 1.0 | 0.16 |
| + | − | − | − | 1.1 | 0.08 |
| − | + | − | − | 2.5 | 0.03 |
| + | + | − | − | 3.3 | 0.41 |
| − | − | + | + | 4.1 | 0.56 |
| + | − | + | + | 6.5 | 0.57 |
| − | + | + | + | 8.2 | 0.69 |
| + | + | + | + | 23.5 | 2.35 |
| + | + | + | − | 26.0 | 1.86 |
a
HeLa cells were transfected with the pIBP-0.07 construct (29 ng) in 24-well plates. For cotransfection experiments, 29 ng of pCMV-STAT3, 29 ng of pCMV-c-jun, 29 ng of pCMV-c-fos, 29 ng of pBJ5-HNF-1α, or 29 ng of pBJ5-HNF-1β was (+) or was not (−) used. The transfected cells were treated with rhIL-6 (100 ng/ml) for 4 h. Luciferase activity was expressed as fold induction relative to the basal activity of the reporter construct in the absence of IL-6 treatment and in the absence of any indicated expression plasmids. Nine independent determinants were made for each construct by performing triplicates in three separate experiments.