Journal: Journal of Experimental & Clinical Cancer Research : CR
Article Title: Targeting E2F8 sensitizes gemcitabine-resistant gallbladder cancer to PARP inhibitors by disrupting RRM2-driven DNA repair
doi: 10.1186/s13046-025-03586-2
Figure Lengend Snippet: E2F8 deficiency sensitizes gemcitabine-resistant gallbladder cancer cells to PARP inhibition. ( A ) Knockdown of E2F8 enhances sensitivity to Olaparib and gemcitabine in NOZ-R cells. Cells were transduced with control sgRNA (sgNC) or two independent sgRNAs targeting E2F8 (sgE2F8 #1 and sgE2F8 #2), followed by treatment with DMSO, Olaparib (1 µM), or gemcitabine (0.1 µM). Cell viability was measured at the indicated time points using the CellTiter-Glo assay. Data are shown as mean ± SD from three independent experiments (two-tailed t-test; * p < 0.05, ** p < 0.01, *** p < 0.001) ( B ) Apoptosis analysis of NOZ-R cells transduced with sgNC or sgE2F8 (#1 and #2) and treated with DMSO, Olaparib (1 µM), or gemcitabine (0.1 µM) for three days. Apoptotic cells were detected by Annexin V/PI staining followed by flow cytometry. Data are presented as mean ± SD from three independent experiments (t-test; *** p < 0.001) ( C ) Quantification of apoptotic cells in GBC-SD-R cells transduced with sgNC or sgE2F8 (#1 and #2) and treated with DMSO, Olaparib (1 µM), or gemcitabine (0.1 µM) for three days, as determined by Annexin V/PI staining and flow cytometry ( D - E ) Apoptosis assays in NOZ-R ( D ) and GBC-SD-R ( E ) cells stably expressing control (shNC) or E2F8-targeting shRNA (shE2F8), with or without E2F8 overexpression, followed by treatment with DMSO or Olaparib (1 µM). Apoptotic cells were quantified by flow cytometry after Annexin V/PI staining. E2F8 expression levels were confirmed by western blotting ( F ) Western blot analysis of γ-H2AX levels in NOZ, NOZ-R, GBC-SD, and GBC-SD-R cells pretreated with gemcitabine (0.5 µM) for 30 min and harvested 4 h later. Quantitative of γ-H2AX levels was performed using ImageJ software and normalized to total H2AX ( G ) Immunofluorescence detection and quantification of γ-H2AX foci per nucleus in the same panel of cell lines treated as in (F). Foci were quantified using Image-Pro Plus software. Scatter dot plots represent mean ± SD ( n = 3 independent experiments, unpaired t-test; *** p < 0.001)
Article Snippet: A genome-wide CRISPR-Cas9 loss-of-function screen was performed using the human GeCKO v2 pooled sgRNA library (Addgene, #52961), which encodes both sgRNAs and Cas9 in a single lentiviral construct.
Techniques: Inhibition, Knockdown, Transduction, Control, Glo Assay, Two Tailed Test, Staining, Flow Cytometry, Stable Transfection, Expressing, shRNA, Over Expression, Western Blot, Software, Immunofluorescence