Human genome-wide repair map of DNA damage caused by the cigarette smoke carcinogen benzo[a]pyrene.
Level 5 - mechanism / opinion, no new human data
Bench research / in vitro methodological sequencing study without clinical subjects (Level 5 by design analogy)
PubMed 28607059 · doi:10.1073/pnas.1706021114
What was done
The authors developed translesion excision repair-sequencing (tXR-seq) to map nucleotide excision repair of bulky base adducts across the human genome. The method isolates excised oligonucleotides carrying UV-induced cyclobutane pyrimidine dimers (CPDs) or benzo[a]pyrene diol epoxide-deoxyguanosine (BPDE-dG), ligates adaptors, performs damage-specific immunoprecipitation, converts fragments to double-stranded DNA using translesion DNA synthesis polymerases, and performs PCR amplification and next-generation sequencing.
What was found
The abstract reports the successful generation of human genome-wide excision repair maps for both CPDs and BPDE-dG adducts and the identification of sequence specificity for BPDE-dG excision repair. No quantitative values, repair rates, or statistical metrics are reported in the abstract.
Why it matters
tXR-seq bypasses the requirement for enzymatic reversal or removal of damage in excised fragments before sequencing, enabling high-resolution genome-wide mapping for virtually any bulky lesion processed by nucleotide excision repair, including major tobacco-related carcinogens.
Limits
The abstract describes an in vitro/bench sequencing methodology without reporting the specific human cell line or tissue source used, sample size/replicates, quantitative repair efficiencies, or functional validation against in vivo mutation landscapes.
Cited by
- supports Cigarette smoke contains chemical carcinogens that directly damage the genome and cause genetic mutations.