Mel, but not CPT, blocks HSF-1-mediated transcription. A, B: A549 cells were treated with Mel, 100 nM GA+Mel, CPT, or 100 nM GA+CPT in doses indicated. Cells were treated for 24 h, then washed and incubated for 3 days in drug-free medium. Cell survival was estimated using MTS assay and measuring absorbance. C: A549 cells were treated with vehicle (DMSO, lane 1) or drugs as indicated for 24 h. Western blotting was performed using 50 μg of cell lysates harvested after treatment and separated by SDS-PAGE.