Fig. 7.

Disorazole C₁ retains activity against epothilone B-resistant cells. A549 lung cancer cells (closed inverted triangles) and their epothilone B-resistant counter parts (epob40) (open inverted triangles) were plated at 1000 cells/well in 384-well collagen-coated plates and allowed to adhere overnight. The cells were treated the next day and incubated for 72 h. The number of cells was determined by Hoechst 33342 stained nuclei using an ArrayScan reader as described under Materials and Methods. Data are the mean results of four determinations. A, epothilone B. B, paclitaxel. C, disorazole C₁.