Effects of H19/SAHH/DNMT1 on the oxidative DNA damage related to Benzo[a]pyrene exposure

Abstract

Background: The mechanisms that long noncoding RNA (lncRNA) H19 binding to S-adenosylhomocysteine hydrolase (SAHH) interacted with DNA methyltransferase 1 (DNMT1) and then regulated DNA damage caused by PAHs remain unclear. Results: We documented that urinary 1-hydroxypyrene (1-OHP) levels were positively associated with blood H19 RNA expression (OR: 1.51, 95% CI: 1.03 - 2.19), but opposite to plasma SAHH activity (OR: 0.63, 95% CI: 0.41 - 0.98) in coke oven workers. Moreover, by constructing various BEAS-2B cell models exposed to Benzo[a]pyrene (BaP), we investigated that H19 binding to SAHH exaggerated DNMT1 expressions and activity. Suppression of H19 enhanced the interaction of SAHH and DNMT1 in BaP-treated cells, decreased OGG1 methylation, reduced oxidative DNA damage and lessened S phase arrest. However, SAHH or DNMT1 single knockdown and SAHH/DNMT1 double knockdown showed the opposite trend. Conclusions: A H19/SAHH/DNMT1 axis was involved in OGG1 methylation, oxidative DNA damage and cell cycle arrest by carcinogen BaP.