Targeting DNA-Dependent Protein Kinase for Cancer Therapy

The catalytic activity of DNA-dependent protein kinase (DNA-PK) is critical to its ability to repair lethal DNA double-strand breaks (DSBs). This includes repair of DSB lesions resulting from oxidative stress, oncogene-induced transcription, or following therapeutic treatment of cancer cells. Armed with this knowledge, many attempts have been made to identify small-molecule inhibitors of DNA-PK activity as an approach to induce tumour chemo- and radiosensitisation. This review examines the structures of known reversible and irreversible inhibitors, including those based on chromen-4-one, arylmorpholine, and benzaldehyde scaffolds. DNA-PK catalytic inhibitors, such as VX-984 (8-[(1S)-2-[[6-(4,6-dideuterio-2-methylpyrimidin-5-yl)pyrimidin-4-yl]amino]-1-methylethyl]quinoline-4-carboxamide) and M3814 ((S)-[2-chloro-4-fluoro-5-(7-morpholinoquinazolin-4-yl)phenyl]-(6-methoxypyridazin-3-yl)methanol), have now progressed into clinical development which should help to further advance our understanding of whether this approach is a promising therapeutic strategy for the treatment of cancer.