Effects of doxorubicin, of PIKK/PI3K inhibitors and of combination treatment with doxorubicin and PIKK/PI3K inhibitors on [18F]-FDG uptake and expression of glycolytic enzymes and apoptotic marker proteins in OPM-2 cells. OPM-2 cells were left untreated (Co), treated for 24 h with doxorubicin (0.4 µM) (Doxo, A-D), with (A) BEZ235 (200 nM), (B) KU55933 (10 µM), (C) MK-2206 (1 µM) and (D) NU7026 (10 µM) as a single treatment, respectively, or subjected to a combination treatment with doxorubicin and the different PIKK/PI3K inhibitors (A-D). Subsequently, [18F]-FDG uptake of the cells was quantified (means ± SEM; n ≥ 3; fold of control, f.c.) and expression of GLUT-1, HKII, cleaved caspase-3 and cleaved PARP was monitored in corresponding cell lysates by Western blot analysis. Significances of differences in [18F]-FDG uptake were calculated using the students t-test. n.s. not significant; *significant.