Journal: International Journal of Molecular Sciences
Article Title: Olaparib Is a Mitochondrial Complex I Inhibitor That Kills Temozolomide-Resistant Human Glioblastoma Cells
doi: 10.3390/ijms222111938
Figure Lengend Snippet: High MGMT protein expression does not account for TMZ resistance in the U373/U373-R isogenic human glioblastoma model. ( a ) O6-methylguanine DNA methyltransferase (MGMT) and β-actin (loading control) protein expression as determined by Western blotting in U373 and U373-R glioblastoma cells in the absence of TMZ, with pictures on the left and quantification on the right ( n = 4). ( b ) Clonogenic assays of the cells that were pretreated for 72 h with increasing concentrations of MGMT inhibitor O6-benzylguanine (O6BG). Displayed are the plating efficiency of the vehicle-treated cells at 72 h (left; n = 6); and the surviving fraction (right; n = 6–12), where the data are normalized to the number of corresponding vehicle-treated cells. ( c ) Number of cells 72 h after treatment with the indicated concentrations of TMZ in combination with 50 µM O6BG (O6BG50; left; n = 4) or 100 µM O6BG (O6BG100; right; n = 4). ( d ) Clonogenic assays of the cells that were pretreated for 72 h with increasing concentrations of TMZ and O6BG. Displayed are the plating efficiency of the cells that were treated ± O6BG (left; n = 6); and the surviving fractions of the cells that received O6BG50 (middle; n = 6) or O6BG100 (right; n = 5–6), where the data are normalized to the number of corresponding vehicle-treated cells. All data are shown as means ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.005, ns: p > 0.05 versus the corresponding control; ### p < 0.005 for whole curve comparison; by Student’s t -test ( a , b left), two-way ANOVA with Sidak’s post hoc test ( b right, c , d middle, d right), or one-way ANOVA with Dunnett’s post hoc test ( d left).
Article Snippet: The primary antibodies were mouse monoclonals against human MGMT (Santa Cruz Biotechnology, Heidelberg, Germany; catalogue #sc-56157) and against β-actin (Sigma-Aldrich; catalogue #A5441).
Techniques: Expressing, Western Blot