NU7441 (KU-57788)

2 years -80 in solvent

Intraperitoneally administrated

SW620, LoVo, V3-YAC and V3 cells

10 mg/kg

14 nM [1], 14 nM [1], 14 nM [1], 14 nM [1], 14 nM [1], 14 nM [1]

NU7441 intraperitoneally administrated at dose of 10 mg/kg maintains for at least 4 hours shows nontoxic and increases etoposide-induced tumor growth delay 2-fold in mice bearing SW620 xenografts. [2]

The effect of NU7441 on cellular survival following exposure to etoposide, doxorubicin, and ionizing radiation is measured in SW620, LoVo, V3, and V3-YAC cells by clonogenic assays. Briefly, growing cells in six-well plates or 6-cm dishes are exposed to etoposide or doxorubicin with or without NU7441 (0.5 or 1.0 uM) for 16 hours. For radiosensitization studies, NU7441 is added to the cells 1 hour before irradiation. V3 and V3-YAC cells are exposed to gamma-irradiation (3.1 Gy/min 137Cesium). SW620 and LoVo are exposed to X-irradiation (2.9 Gy/min at 230 kV, 10 mA) due to the equipment available. After irradiation, the cells are incubated with or without NU7441 for a further 16 hours. Cells are then harvested by trypsinization, counted, and seeded into 10-cm diameter Petri dishes at densities varying from 100 to 105 per dish in drug-free medium for colony formation. Colonies are stained with crystal violet after 10 to 14 days and counted with an automated colony counter. The survival reduction factor (SRF) is calculated as the surviving fraction of cells in the absence of NU7441 divided by the surviving fraction of cells in the presence of NU7441 for any given dose or concentration of cytotoxic agent. The dose modification ratio (DMR90) is calculated as the concentration/dose of cytotoxic agent required to kill 90% of the cells in the absence of NU7441 divided by the concentration/dose of cytotoxic agent required to kill 90% of the cells in the presence of NU7441.

NU7441 (KU-57788) is a highly potent and selective DNA-PK inhibitor with IC50 of 14 nM and also inhibits mTOR and PI3K with IC50 of 1.7 μM and 5 μM in cell-free assays, respectively. It reduces the frequency of NHEJ while increasing the rate of HDR following Cas9-mediated DNA cleavage.