FIGURE 7: Silencing COX4-1 reduces SC assembly in in GBM cells with acquired radioresistance. (A) Representative Western blot showing COX4-1 expression in U251-RR and D456-RR cells transfected with shRNA targeting COX4-1 or scramble shRNA. Citrate synthase (CS) served as the loading control. (B) Quantification of CcO activity in in U251-RR and D456-RR cells transfected with shRNA targeting COX4-1 or scramble shRNA. Data are presented as the mean ± SEM (n=3) (C) Digitonin-solubilized mitochondria from the indicated cell lines were subjected to BN-PAGE followed by complex I and IV IGA assays and complex III Western blot analysis. Representative images from 4 independent preparations. p < 0.0001 (****), calculated by Student t-test.