Fig. 7.

PKCε controls etoposide-mediated cell survival and proliferation in cancer cells by degradation of Nrf2 and downregulation of Nrf2 signaling. (A) Etoposide-mediated histone-associated DNA fragmentation from PKCε^+/+, PKCε^−/− and FLAG-PKCε overexpressed in PKCε^−/− MEFs were measured and plotted. The data shown are means ± s.d. of three independent experiments. (B) MTT assay. PKCε^−/−, PKCε^+/+ MEFs and PKCε^−/− MEFs transfected with FLAG PKCε cells were treated with DMSO or etoposide in eight replicate wells, incubated with MTT solution and absorbance at 570 nm was measured. Data represent means ± s.d. and are normalized to the value of the corresponding control cells. (C) Analysis for apoptotic cells by Flow-cytometry. PKC^−/− and PKC^+/+ MEFs were treated with DMSO or 20 µM etoposide for 30 hours. Cells were harvested for analysis of apoptosis. (D) For the cell proliferation assay, PKCε^−/− and PKCε^+/+ MEFs, and PKCε^−/− MEFs transfected with FLAG-PKCε were subjected to the Xcelligence cell proliferation system. Cell proliferation was also monitored from PKCε^−/−, PKCε^+/+ MEFs after pre-treating the cells with DMSO or etoposide (5 µM) for 30 hours. (E) Protein microarray analysis of Nrf2 and PKCε levels in human lung cancer tissue (left) and human liver cancer tissue (right), along with adjacent normal tissue were measured and plotted.