title: In vitro benzo[a]pyrene diol epoxide-induced DNA damage and chromosomal aberrations in primary lymphocytes, smoking, and risk of squamous cell carcinoma of the head and neck.
abstract: Cigarette smoking is a major risk factor for squamous cell carcinoma of the head and neck (SCCHN), but only a fraction of those exposed to cigarette smoke develops SCCHN, suggesting variation in individual susceptibility. Tobacco smoke contains a number of carcinogens that cause various kinds of damage to DNA. In this study, we simultaneously measured benzo[a]pyrene diol epoxide-induced DNA damage and chromosomal aberrations by the comet assay and the mutagen sensitivity assay, respectively, in cultured primary lymphocytes from newly recruited 123 patients with SCCHN and 136 age- and sex-matched controls. Using the control median as the cut-off, the elevated risk of SCCHN was 2.35 (95% CI, 1.37-4.03), 2.28 (95% CI, 1.34-3.98) and 3.25 (95% CI, 1.85-5.07) for high levels of tail extension, tail length and oliver tail moment of the comet assay, respectively, and 1.75 (95% CI, 1.04-2.94) for high levels of chromosomal aberrations of the mutagen sensitivity assay. The effects of these 2 types of measurements were additive; subjects with high levels of both DNA damage and chromosomal aberrations had a 4.77-fold increased risk (95% CI, 2.73-8.36) of SCCHN. Cigarette smoking further elevated this risk to more than 20-fold (OR 23.6; 95% CI, 8.92-62.3). These data support our previous finding that suboptimal repair contributed to susceptibility to SCCHN and the new data further suggests a possible gene-environment interaction that may play an important role in the etiology of SCCHN. Further validation studies are warranted.
authors.affiliation: Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Xiong
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Hu
authors.forename: Chunying
authors.initials: C
authors.lastname: Li
authors.forename: Li-E
authors.initials: LE
authors.lastname: Wang
authors.forename: Adel K
authors.initials: AK
authors.lastname: El-Naggar
authors.forename: Erich M
authors.initials: EM
authors.lastname: Sturgis
authors.forename: Qingyi
authors.initials: Q
authors.lastname: Wei
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000633:toxicity*; D000328:Adult; D000368:Aged; D002273:Carcinogens / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D016022:Case-Control Studies; D002869:Chromosome Aberrations / Q000139:chemically induced*; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair; D005260:Female; D020022:Genetic Predisposition to Disease; D006258:Head and Neck Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D006801:Humans; D008214:Lymphocytes; D008297:Male; D008875:Middle Aged; D009153:Mutagens / Q000633:toxicity*; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013781:Texas / Q000453:epidemiology
chemical_list: D002273:Carcinogens; D009153:Mutagens; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide