Figure S4 from CRISPR Screens Identify POLB as a Synthetic Lethal Enhancer of PARP Inhibition Exclusively in BRCA-Mutated Tumors

Supplementary Figure S4. Impact on DNA replication, cell cycle, and apoptosis with PARP inhibitor treatment in BRCA2 wildtype and mutant cells – related to Figure 5. A) Graph showing quantification of % EdU-positive ‘S’ phase cells. DLD-1 BRCA2 mutant control or POLB knockout cells treated with 500 nM niraparib for 5 days followed by staining with Click-iT EdU flow cytometric assay. FACS data was analyzed by FloJo software. B) Histogram plots of cell cycle analysis using a propidium iodide assay in DLD-1 BRCA2 WT control or POLB knockout cells treated with 500 nM niraparib for 5 days (left). Quantification of each cell cycle phase (% cells) across all treatment conditions is shown in the graph (right). C) FACS plots showing apoptosis analysis with Annexin-V/PI staining in DLD-1 BRCA2 WT control or POLB knockout cells treated with 500 nM niraparib for 7 days (left). Quantification of % apoptotic cells (annexin V positive + annexin-V/PI positive) is shown for all the conditions tested (right).