(a) Breast cancer cells were treated with 10 μM nelfinavir at indicated times and SOD activity (relative to activity of untreated cells) was analyzed as indicated in Material and Methods. Values are representative of three independent biological experiments ± S.D., (*p< 0.05 vs ctrl). (b) Protein lysates derived from MDA-MB231, MCF-7, or breast epithelial cells, treated with 10 μM nelfinavir for the indicated time points, were immunoblotted with anti- SOD1, anti-SOD2 and anti-catalase. Beta-actin was used as loading control. (c) MCF-7 cells, treated with 10 μM nelfinavir ± 35 μM tocopherol for 30 minutes or 24 hours, were lysed and subjected to western blot analysis for SOD1. Beta-actin was used as loading control. Densitometric analysis of SOD1 signal relative to beta-actin signal was represented. The values represent the means ± S.D. of three independent biological experiments and are compared to control value (*p< 0.05 vs ctrl).