Concordance of hydrogen peroxide–induced 8-oxo-guanine patterns with two cancer mutation signatures of upper GI tract tumors
Menée in vitro, cette étude cartographie deux types de dommage par oxydation de l'ADN (guanines oxydées par le peroxyde d'hydrogène et thymines oxydées par le permanganate de potassium) et met en évidence une concordance entre les séquences trinucléotidiques issues de l'oxydation de la guanine et les profils de substitution SBS18 et SBS36 retrouvés respectivement dans les tumeurs du tractus gastro-intestinal supérieur liées à l'inflammation et les tumeurs colorectales avec mutation du gène MUTYH
Oxidative DNA damage has been linked to inflammation, cancer, and aging. Here, we have mapped two types of oxidative DNA damage, oxidized guanines produced by hydrogen peroxide and oxidized thymines created by potassium permanganate, at a single-base resolution. 8-Oxo-guanine occurs strictly dependent on the G/C sequence context and shows a pronounced peak at transcription start sites (TSSs). We determined the trinucleotide sequence pattern of guanine oxidation. This pattern shows high similarity to the cancer-associated single-base substitution signatures SBS18 and SBS36. SBS36 is found in colorectal cancers that carry mutations in MUTYH, encoding a repair enzyme that operates on 8-oxo-guanine mispairs. SBS18 is common in inflammation-associated upper gastrointestinal tract tumors including esophageal and gastric adenocarcinomas. Oxidized thymines induced by permanganate occur with a distinct dinucleotide specificity, 5′T-A/C, and are depleted at the TSS. Our data suggest that two cancer mutational signatures, SBS18 and SBS36, are caused by reactive oxygen species.
Science Advances 2022