(A and B) Western blot analysis of Nrf2, INrf2 and Nrf2 downstream proteins in MCF-7Ca, LTLTCa and LTLTCaNrf2KD cells. (C) Comparative sensitivities of MCF-7Ca, LTLTCa and LTLTCa-Nrf2KD cells to exemestane. The cells were exposed to 10% ethanol in PBS (vehicle control represented by 0 exemestane) and varying concentrations of exemestane (1, 2.5, 5.0. 10, 20, 30 μM) for 72 h and analyzed for cell survival by MTT assay. Cell survival obtained at 1 and 2.5μM has been excluded from the graph as the results were similar to those obtained from 5μM. Each data point represents a mean±S.D. from three independent experiments.