%0 Generic %A Webster, Peter John %A Littlejohns, Anna Tiffany %A Gaunt, Hannah Jane %A Prasad, K. Raj %A Beech, David John %A Burke, Dermot Anthony %D 2017 %T AZD1775 induces toxicity through double-stranded DNA breaks independently of chemotherapeutic agents in p53-mutated colorectal cancer cells %U https://tandf.figshare.com/articles/dataset/AZD1775_Induces_Toxicity_Through_Double-Stranded_DNA_Breaks_Independently_of_Chemotherapeutic_Agents_in_p53-Mutated_Colorectal_Cancer_Cells/4754500 %R 10.6084/m9.figshare.4754500 %2 https://ndownloader.figshare.com/files/7797607 %2 https://ndownloader.figshare.com/files/7797610 %K colorectal cancer %K checkpoint kinase %K cell cycle %K DNA damage %K mitosis %X

AZD1775 is a small molecule WEE1 inhibitor used in combination with DNA-damaging agents to cause premature mitosis and cell death in p53-mutated cancer cells. Here we sought to determine the mechanism of action of AZD1775 in combination with chemotherapeutic agents in light of recent findings that AZD1775 can cause double-stranded DNA (DS-DNA) breaks. AZD1775 significantly improved the cytotoxicity of 5-FU in a p53-mutated colorectal cancer cell line (HT29 cells), decreasing the IC50 from 9.3 μM to 3.5 μM. Flow cytometry showed a significant increase in the mitotic marker pHH3 (3.4% vs. 56.2%) and DS-DNA break marker γH2AX (5.1% vs. 50.7%) for combination therapy compared with 5-FU alone. Combination therapy also increased the amount of caspase-3 dependent apoptosis compared with 5-FU alone (4% vs. 13%). The addition of exogenous nucleosides to combination therapy significantly rescued the increased DS-DNA breaks and caspase-3 dependent apoptosis almost to the levels of 5-FU monotherapy. In conclusion, AZD1775 enhances 5-FU cytotoxicity through increased DS-DNA breaks, not premature mitosis, in p53-mutated colorectal cancer cells. This finding is important for designers of future clinical trials when considering the optimal timing and duration of AZD1775 treatment.

%I Taylor & Francis