Figure 3: CHK1 inhibition does not induce replication stress or synergize with TAZ:

(A) DESeq2-normalized read counts of cells treated with 10 μM TAZ versus equivalent volume of DMSO for 11 days. n=3 biological replicates per condition. (B) Dose-response curves of G401 cells treated with the CHK1 inhibitor SRA737 for 9 days. (C) Western blot assaying replication stress as measured by RPA phosphorylation at S4/8 and T21. Camptothecin treatment (1.5 μM) for 2 h was used as a positive control for replication stress. Autophosphorylation of CHK1 at S296 was used to confirm CHK1 inhibition. Cells were pre-treated with 10 μM TAZ or DMSO for 9 days. Cells were then split and additionally treated with SRA737 (3 μM) or equivalent volume of DMSO for 2 days. (D) Cells treated with 10 μM TAZ or DMSO for 11 days do not express MYCN protein. MYCN-amplified neuroblastoma cell line IMR5 was used as a positive control for MYCN expression.