Figure 2.

Cell viability of (A) MCF-7 and (C) MDA-MB-231 cells treated with tamoxifen at indicated doses, (B) MCF-7 and (D) MDA-MB-231 cells and their resistant clones against 5 μM and 10 μM tamoxifen treated with OP at indicated doses using the WST-1 assay.

Notes: Cells were incubated in 96-well plates (5,000 cells/well) and allowed to adhere for 24 hours in 1× DMEM media containing 10% FCS. The media were replaced with fresh DMEM media containing 5% FCS with or without various concentrations of tamoxifen or OP for indicated time periods. Cell viability was expressed as a percent of control ± SEM of triplicate values. The data are a representation of one out of three independent experiments showing similar results. LD₅₀ value is given as μM of drug concentration as determined by WST-1 assay after 72 hours for the indicated cell lines.

Abbreviations: DMEM, Dulbecco’s Modified Eagle’s Medium; FCS, fetal calf serum; IC₅₀, half maximal inhibitory concentration; LD₅₀, lethal dose to kill 50% of viable cells; OP, oseltamivir phosphate; SEM, standard error of the mean.