HSP70 ligands regulate HEXIM1 expression in LNCaP prostate cancer cells. (A) A HSP70 inhibitor and activator show opposing effects to HEXIM1 expression; (B) A HSP70 inhibitor and an activator were antagonistic to each other to stimulate HEXIM1expression. Cells were treated with DMSO, 5 mM HMBA, 200 μM 4a1, 250 μM SW02, 25 μM PIF or their combinations with the indicated concentrations for 24 h. The results are representative of three independent experiments and the representative one or the mean are presented (±SD). The densitometry measurement of the band intensities of three western blots were listed on the right. *P <0.01 vs. DMSO by unpaired t test, #p <0.05 vs DMSO by unpaired t test.