Background and Objectives: Colorectal cancer (CRC) is one of the most common malignant cancers of the colon worldwide. Several novel approaches to cancer treatment have emerged, including gene therapy, targeted therapy, and adjuvant therapies. One of the most dangerous effects of chemotherapy is the induction of double-strand DNA breaks, which can lead to cell cycle arrest and cell death. Inhibition of DNA-PK can increase cellular sensitivity to radiotherapy and DNA-damaging agents. The present study aimed to evaluate the anti-cancer effect of the DNA-PK inhibitor (DNA-PKi) NU7441 on the HCT116 cell line.

Method: HCT116 colorectal cancer cells were cultured under standard conditions. The effects of NU7441, a DNA-PKi, on cell viability and cell cycle were evaluated. WST-1 and FACS cell cycle assays were used to assess cell proliferation and cell cycle. Data were analyzed using GraphPad Prism 8.4.

Results: DNA-PKi showed dose-dependent effects on cell death and proliferation inhibition in HCT116 cells in vitro. The groups treated with DNA-PKi at concentrations of 0.125, 0.250, and 0.500 μM all had significantly lower cell survival rates than the control group (p < 0.05). However, DNA-PKi did not affect cell cycle distribution in HCT116 colorectal cancer cells.

Conclusion: DNA-PKi NU7441 exerted a dose-dependent effect on cell death and proliferation inhibition in HCT116 cells in vitro.