An APOBEC3A hypermutation signature is distinguishable from the signature of background mutagenesis by APOBEC3B in human cancers.
Nat Genet
; 47(9): 1067-72, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26258849
ABSTRACT
Elucidation of mutagenic processes shaping cancer genomes is a fundamental problem whose solution promises insights into new treatment, diagnostic and prevention strategies. Single-strand DNA-specific APOBEC cytidine deaminase(s) are major source(s) of mutation in several cancer types. Previous indirect evidence implicated APOBEC3B as the more likely major mutator deaminase, whereas the role of APOBEC3A is not established. Using yeast models enabling the controlled generation of long single-strand genomic DNA substrates, we show that the mutation signatures of APOBEC3A and APOBEC3B are statistically distinguishable. We then apply three complementary approaches to identify cancer samples with mutation signatures resembling either APOBEC. Strikingly, APOBEC3A-like samples have over tenfold more APOBEC-signature mutations than APOBEC3B-like samples. We propose that APOBEC3A-mediated mutagenesis is much more frequent because APOBEC3A itself is highly proficient at generating DNA breaks, whose repair can trigger the formation of single-strand hypermutation substrates.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article