Pressure Sensitivity of HSP70 Promoter in Transformed 3T3-L1 Cells

Mouse 3T3-L1 cells were stably transfected with a plasmid encoding heat shock protein 70 (HSP70) promoter and luciferase gene to probe pressure sensitivity by measuring luminescence. When the cells are exposed in extremely high hydrostatic pressure, the HSP70 promoter can activate expression of luciferase, which induces luminescence. HSP70 promoter activity enhanced by exposure to 40MPa or greater hydrostatic pressure for 30min, although significant morphological changes occurred. In the pressure ranges between 40 to 60 MPa (0.1MPa≒1atm), more than 95% of the cells kept alive according to the cytotoxicity assay and respreaded on pressure release and proliferated normally through the cell cycle. At 70MPa-pressure application, HSP70 promoter activity became at maximum and majority of the cells (>76%) damaged or died.