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Free keywords:
Animals
Cell Line, Tumor
Colonic Neoplasms/*drug therapy/pathology
DNA-Activated Protein Kinase/*antagonists & inhibitors/*genetics
DNA-Binding Proteins/*genetics
Genome, Human
Humans
Male
Mice
MutS Homolog 3 Protein
Mutation
Neoplasms, Experimental
Nuclear Proteins/*antagonists & inhibitors/*genetics
Xenograft Model Antitumor Assays
Abstract:
Here, we use a large-scale cell line-based approach to identify cancer cell-specific mutations that are associated with DNA-dependent protein kinase catalytic subunit (DNA-PKcs) dependence. For this purpose, we profiled the mutational landscape across 1,319 cancer-associated genes of 67 distinct cell lines and identified numerous genes involved in homologous recombination-mediated DNA repair, including BRCA1, BRCA2, ATM, PAXIP, and RAD50, as being associated with non-oncogene addiction to DNA-PKcs. Mutations in the mismatch repair gene MSH3, which have been reported to occur recurrently in numerous human cancer entities, emerged as the most significant predictors of DNA-PKcs addiction. Concordantly, DNA-PKcs inhibition robustly induced apoptosis in MSH3-mutant cell lines in vitro and displayed remarkable single-agent efficacy against MSH3-mutant tumors in vivo. Thus, we here identify a therapeutically actionable synthetic lethal interaction between MSH3 and the non-homologous end joining kinase DNA-PKcs. Our observations recommend DNA-PKcs inhibition as a therapeutic concept for the treatment of human cancers displaying homologous recombination defects.
