The reduction was enhanced with incubation time and concentration improvement. Hundred to 500 M Pivanex improved the caspase activity in K562 cells somewhat after only 4 h of incubation with 500 M. The experience increased with incubation time and at higher concentrations but there was a reduced influence when exposed for longer periods, probably as a result of necrosis. Combination of 100 M Pivanex and 0. 2-5 M STI571 increased Docetaxel ic50 the caspase exercise greater than additively. Fig. 5 shows the result of Pivanex o-n cell cycle parameters. Pivanex induced enhancement in the G2 M phase, a moderate enhancement in the S phase and a small decrease in G0 G1 of the cell cycle at 200 M after 48 h of exposure. The advancement in the S phase on the consideration of the G0 G1 could reflect cells entering the G2 M arrest. Comparable results were obtained after 72 h of exposure but because many of the cell population was killed and eliminated from the data, the results reflect only a small percentage of the cells. When 100 Michael Pivanex and 0. 25 Michael STI571 were combined an additive effect was confirmed on S phase reduction. In the other cell cycle parameters, the drugs acted differently: STI571 did not alter the G2 M phase while 100 MPivanex increased it slightly. The mixture of the two had the exact same effect as Pivanex alone. Pivanex had no effect Mitochondrion on G0 G1 while STI571 at 0. 25 M improved the G0 G1 slightly but somewhat and the effect of the two had the same effect of STI571 alone. Fig. 6A demonstrates Pivanex caused a dose dependent decrease in the levels of BCR ABL protein at 150 500 M after 24 72 h of incubation. Actinwas employed as a housekeeping gene for quantitative standardization of the BCR ABL protein. Fig. 6B suggests that mix of Pivanex and STI571 at low levels had a synergistic effect on the reduction of the BCR ABL protein. Fifty to 200 M Pivanex induced a substantial and dosedependent erythroid differentiation. The proportion of tetrabenzidine positive cells is found in cells treated with low concentrations of STI571 and Pivanex alone and in combination. The figure demonstrates STI571 natural product library also caused significant erythroid differentiation in K562 cells. Combining STI571 and Pivanex had an additive effect. Difference for the myeloid linage was also determined using NBT test and threat of CD11b positive cells evaluated by flow cytometer. The information showed the granulocyte lineage differentiation wasn’t affected by these agents or by their combination. Histone deacetylase inhibitors have demonstrated an ability to induce maturation in several human leukemia cell lines but under some circumstances induce apoptosis in the place of maturation. This method is shown with sodium butyrate in leukemic cells such as the CML derived cell line K562.