Fig. 1

The cytoprotective effect of 10 nM E2 on cisplatin cytoxicity in D283 Med cells. a Concentration response analysis of D283 Med viability following exposure to increasing concentrations of cisplatin with and without 10 nM E2 using the MTS-reduction assay. All data is expressed as a percentage (± SEM; n = 4 per dose group) relative to vehicle treated control cultures. Concentration response curves and indicated IC₅₀ values for cisplatin inhibition of viability were calculated using a normalized variable slope Hill model. b Concentration response analysis of the cytotoxic effects of cisplatin on D283 Med cells in the presence of 10 nM E2 plus or minus 10 nM fulvestrant (ICI 182,780) using the resazurine fluorescent dye assay (for vehicle and E2 groups n = 28 replicates; E2/ICI n = 20 replicates from 3 separate experiments). c Initial range finding concentration response analysis of the cytotoxic effects of cisplatin in D283 Med using a colony forming (clonogenic) assay of cell survival defined an IC₅₀ of 1.6 μM. d Representative images of plates stained with 0.1% coomassie brilliant blue in methanol to visualize colonies formed from cultures of 1000 D283 Med cells in the presence of 10 nM E2 or vehicle control that were treated with 2, 4 or 9 μM cisplatin. e Quantification of surviving colony numbers from clonogenic assays of D283 Med cells exposed to 2, 4, or 9 μM cisplatin with or without 10 nM E2 (n = 4 for each group). All results are expressed as mean ± SEM. Significant differences from the control group were determined by two-way ANOVA followed by post-test analysis; * p ≤ .05