Figure 4. HDACIs That Simultaneously Inhibit HDACs 1 and 6 Showed Greater Antileukemic Activities than HDACIs that Don't at Cmax Concentrations.

THP-1 cells were treated with LBH-589, PXD101, SAHA, VPA, MS-275 and MGCD0103 at C_max concentrations for 3 h and 24 h, respectively. The cells post 3 h treatments were washed three times with complete medium and divided into two halves. One half of the cells was resuspended in complete media and cultured for up to 24 h to determine the effects of the 3 h treatments on cell proliferation and apoptosis. The other half of the cells was used to prepare whole cell lysates. Whole cell lysates from the 3 h and 24 h treatments were extracted and subjected to Western blots probed by anti-ac-tubulin or –β-actin antibody (panels A&B), or subjected to HDAC1 enzymatic assays post IP as described in the Materials and Methods (Panels C&D). The effects of the 3 h and 24 h HDACI treatments on cell proliferation, as reflected by percent decrease of live cells relative to untreated cells (panel E), and apoptosis (panel F) were determined by flow cytometry analysis as described in the Materials and Methods.