Drug screening in myeloma cell lines. (A) The overall screening results are displayed and expressed as survival index with results for 8226/Dox40 displayed on the Y axis and the parental RPMI 8226 cells on the X-axis. (B) Molecular structure and chemical properties of VLX40 (C) Activity of VLX40 against a cell line panel representing different forms of drug resistance. Cell survival was determined over 72 h using the FMCA assay in duplicate experiments. (D) Validation of VLX40 activity on 8226/Dox40 cells. Concentration-dependent effects of VLX40 on cell survival in RPMI 8226 (red line) and 8226/Dox40 (blue line) cell lines (triplicate samples). (E) Concentration-dependent effects of vincristine on cell survival in RPMI 8226 (red line) and 8226/Dox40 (blue line) cell lines. Survival in (D, E) was determined over 72 h using the FMCA assay. The results are expressed as percentage of the untreated control and presented as mean values +/- standard error of the mean (SEM) from three independent experiments.