DNA Damages by Catechol Estrogens Using Click-Seq

Genotoxic estrogen metabolites generate various endogenous DNA lesions but their carcinogenesis mechanisms have been overlooked by well-known cell proliferation pathways through estrogen receptor (ER). Genome-wide sequencing using click probe enrichment coupled with liquid chromatography-mass spectrometry (click probe-Seq/LCMS2) was developed to identify damaged genes and characterize global generation profiles of depurinating and stable adducts induced by 4-hydrolyxyl estradiol (4OHE2) in MCF-7 chromatin. Both data were combined to show guanine nucleobase in GC-rich transcription-relevant domain are main target sites. The damage abundance exhibited positive correlation with DNase hypersensitive sites, indicating 4OHE2 attacks chromatin exposure region beyond ER binding. Cell-based comparability studies indicated accumulated 4OHE2 caused suppressed transcription of target genes, in-effective damage repair, and decreased cell viability, differing from uncontrolled cell growth by extensive ER-signaling. Click probe-Seq/LCMS2 approach revealed the first chromatin damage map by endogenous metabolites, exposing a previously unexplored landscape in cancer research and being applicable to other genotoxic species.