A. DNA binding of HSF-1 after heat shock in naïve, non target siRNA and PARP-1 siRNA transfected cells. Cells were subjected to heat shock at 43°C for 30 min followed by recovery at 37°C for 45 min. Autoradiograph of EMSA for HSF-1 is representative of 3 similar separate experiments. B. Mean ± SEM of scanned densitometry data demonstrating the effect of PARP-1 silencing on DNA binding of HSF-1 obtained from three independent experiments.