Fig. 1

Olaparib-resistant HGSOC cells have increased H3K9me2. a PEO1 (TP53 and BRCA2-mutated) were treated in a step-wise fashion with increasing doses of olaparib. PEO1 sensitive and resistant (PEO1-OR) cells were plated in a 24-well plate and treated with increasing doses of olaparib for 12 days. Cells were stained with crystal violet. b Olaparib resistance was confirmed with a dose response colony formation assay. Dose response curves of PEO1 and PEO1-OR are graphed with IC50 indicated. c Histone modifications of PEO1 and PEO1-OR cells were analyzed by mass spectrometry. Heat map shows percent change of each modification in PEO1-OR relative to PEO1. Arrows indicate he most downregulated (unmodified H3K9, H3K9me1) and upregulated (H3K9me2) modifications. d Profile of H3K9 methylation in PEO1 and PEO1-OR cells (mean percent of total H3K9 ± SD, n = 3, unpaired t test). e Kaplan-Meier analysis of H3K9me2 staining in a TMA versus overall patient survival. f Representative images of Low and High H3K9me2 staining in the TMA