Fig. 1.

Chaetocin inhibits the activities of cancer cells and displays potent Hsp90 inhibition effects. (A, B) Chaetocin inhibits activities of K562 and HL-60 cells. Cells were treated with Chaetocin at the indicated concentrations for 24 h, 48 h, and 72 h. Cell vitality was determined by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Data are presented as the mean ± SD from three independent experiments. (C, D) Chaetocin inhibits the expression and activation of some client proteins in K562 and HL-60 cells. Cells were treated with Chaetocin at the indicated concentration for 24 h. Protein levels were analyzed by WB. (E, F) Chaetocin at different concentrations was incubated with K562 and HL-60 cells for 24 h, following which the interaction of Hsp90 with its co-chaperones and client proteins were tested with IP by Hsp90 antibody. Results are representative of at least three independent experiments.