(A) Western blot of HDR factors after siRNA-mediated knockdown of VEGFR2 in SKOV3 cells (two-way ANOVA, effect of siRNA, P < 0.05; n = 3 independent experiments). (B) Relative HDR capacity in U2OS EJ-DR cells treated with a library of small-molecule kinase inhibitors. (C) List of top hits from small-molecule inhibitor screen, with relative HDR capacity and cell viability as compared with vehicle control–treated cells. (D) Western blot of HDR factors in SKOV3 cells treated with increasing doses of the PDGFR inhibitor crenolanib (two-way ANOVA, effect of crenolanib, P < 0.0001; n = 3 independent experiments). (E) Western blot of HDR factors in IGROV1 cells after siRNA-mediated knockdown of PDGFRα and PDGFRβ (two-way ANOVA, effect of siRNA, P < 0.0001; siSCR versus siPDGFRβ, P < 0.001; n = 3 technical replicates). (F) HDR activity in U2OS EJ-DR cells after siRNA-mediated knockdown of PDGFRβ and VEGFR2 (one-way ANOVA, P < 0.001; siSCR versus siPDGFRβ, P < 0.001; siSCR versus siVEGFR2, P = 0.25; n = 3 to 5 technical replicates). (G) Western blot of HDR factors in control (mock) and PDGFRβ- and VEGFR2-overexpressing SKOV3 cells treated with cediranib or not (two-way ANOVA, effect of overexpression, P < 0.01; mock versus PDGFRβ, P < 0.05; mock versus VEGFR2, P = 0.99; mock, n = 14; PDGFRβ, n = 7; VEGFR2, n = 5 biological replicates). (H) Cell viability (as measured by ATP-based CellTiter-Glo assay) of control and PDGFRβ-overexpressing SKOV3 cells treated with 5 μM cediranib and with or without 32 μM olaparib, as indicated (t test mock versus PDGFRβ: cediranib, P = 0.99; cediranib + olaparib, P < 0.05; n = 9 technical replicates). Data are represented as means ± SEM. Numbers below Western blot panels represent relative quantification of the respective bands normalized to loading control by densitometry.