Extended Data Fig. 8: ecDNA containing tumour cells are sensitive to targeted CHK1 inhibition.

(a-e) Cell viability curve of COLO320DM, COLO320HSR, GBM39ec, GBM39HSR and SNU16 in response to different chemicals targeting CHK1 or CHK2. a. CHK2i, CCT241533; b. CHK1i, GDC0575; c. CHK1i, SRA737; d, CHK1i, CHIR-124; e, CHK1i, Ly2606368. Half maximal inhibitory concentrations (IC50) for each inhibitor in individual cell lines were listed on the bottom. (sample size in a-c, n = 2; d-e, n = 4, mean ± SD) (f) FACS analysis of Annexin V staining in COLO320DM and COLO320HSR cells subjected to 1 µM CHIR-124 for indicated time. Left, gating setting and representative plots, Early apoptotic cells: Annexin V + and PI-; late apoptotic cells: Annexin V + and PI +. Right, % of apoptotic cells (mean± SEM, P values quantified by two-tailed students’ t test, n = 2.) (g) Quantification of mean EdU intensity (arbitrary units) in dataset shown in Fig. 3f. (mean± SD, P values quantified by two-tailed students’ t test. Sample size from left to right: n = 419, 284, 1085, 596, 209, 242). (h) pRPA2-S33 IF combined with MYC FISH staining in COLO320DM and COLO320HSR cells treated with 100 nM CHIR-124 for 2 h, EdU was added 30 min before fixing. Accumulation of further RS upon CHK1i was quantified by total pRPA2-S33 fluorescence intensity in EdU+ cells. COLO320DM and COLO320HSR cells were grouped into 3 subgroups with different amplicon content based on MYC DNA FISH staining. (Box plot parameters were same as in Fig. 2b, two-tailed Wilcoxon test, Two-tailed Wilcoxon test, sample number from left to right: 355, 337, 466, 315; 472, 448, 622, 420; 354, 337, 466, 315).