Fig. 4.

Assessment of HR deficiency and rucaparib sensitivity in BRCA1-methylated cell lines. a RAD51 foci formation assessed 6 h post exposure to 10 Gy irradiation in HR-competent OC cell line (OV90), immortalized fallopian tube cell line (FT282), OC cell line with heterozygous BRCA1 methylation (OVCAR8), OVCAR8 derivative with RAD51C KO, and HGSOC cell line with homozygous BRCA1 methylation (WEHICS62). b Quantification of RAD51 foci formation in EdU-positive cells for OV90, FT282, OVCAR8, OVCAR8 derivative with RAD51C KO, and WEHICS62. RAD51 foci formation ability was compared to the untreated controls. At least 170 EdU-positive cells were counted for each cell type and treatment (multiple fields of view from three independent experiments). Mean ± SEM. c Colony formation assay assessing rucaparib response at 14 days in HR-competent OC cell line (PEO4), at 10 days in OC cell line with heterozygous BRCA1 methylation (OVCAR8) and HR-deficient OC cell line (PEO1), and at 21 days in HGSOC cell line with homozygous BRCA1 methylation (WEHICS62); n = 3 independent experiments. Mean ± SEM. d In vitro rucaparib response assessed by cell count proliferation time course assay using IncuCyte ZOOM of OC cell lines OVCAR8, OVCAR8 derivative with RAD51C KO and WEHICS62. One of three similar independent experiments shown. Mean ± SEM; * denotes p < 0.05 for post-IR WEHICS62 % comparison with irradiated OVCAR8 and OV90 counterparts. IR irradiated, Cntrl untreated control, ND not detected