APOBEC3A catalyzes mutation and drives carcinogenesis in vivo.

The APOBEC3 family of antiviral DNA cytosine deaminases is implicated as the second largest source of mutation in cancer. This mutational process may be a causal driver or inconsequential passenger to the overall tumor phenotype. We show that human APOBEC3A expression in murine colon and liver tissues increases tumorigenesis. All other APOBEC3 family members, including APOBEC3B, fail to promote liver tumor formation. Tumor DNA sequences from APOBEC3A-expressing animals display hallmark APOBEC signature mutations in TCA/T motifs. Bioinformatic comparisons of the observed APOBEC3A mutation signature in murine tumors, previously reported APOBEC3A and APOBEC3B mutation signatures in yeast, and reanalyzed APOBEC mutation signatures in human tumor datasets support cause-and-effect relationships for APOBEC3A-catalyzed deamination and mutagenesis in driving multiple human cancers.
Competing Interests: Disclosures: D.A. Largaespada reported other from NeoClone Biotechnology, Inc., personal fees from BmoGen Biotechnology, Inc., other from Luminary Therapeutics, Inc., other from Recombinetics, Inc., other from ImmuSoft, Inc., and grants from Genentech, Inc. outside the submitted work. R.S. Harris reported personal fees from ApoGen Biotechnologies outside the submitted work. No other disclosures were reported.
(© 2020 Law et al.)