Fig 3.

HSP70 functions in combination with HSF1 in the repression of the c-fos promoter. (A) HSP70 repression of c-fos promoter activity was abolished in cells transfected with HSF1-dominant negative construct cotransfection. Varying amounts of dominant negative HSF1 (HSF1-(1-229)) were cotransfected with constant dosages of Ras (100 ng/well) and HSP70 (50 ng/well) plasmids in CHO-K1. Cells then were subjected to luciferase assay 20 hours later. HSF1-M: HSF1 (1-229). Bars represent mean relative luciferase activity ± standard deviation and show results from 3 independently performed experiments. (B) HSP70 antisense oligonucleotides (μM) were partially effective in reversing HSF1 repression of c-fos. Different dosages of HSP70 antisense oligos were cotransfected with a constant amount of HSF1 (25 ng/well) as well as Ras (100 ng/well) expression plasmids in CHO-K1. Cells were collected 20 hours later and subjected to luciferase assay. Anti: HSP70 antisense oligos; Sense: HSP70 sense oligos. Bars represent mean relative luciferase activity ± standard deviation and show results from 3 independently performed experiments