Substantially reduced risk of cancer of the aerodigestive tract in subjects with variant--463A of the myeloperoxidase gene.
Myeloperoxidase (MPO), an enzyme that is highly expressed in neutrophil leukocytes, transforms precarcinogens such as benzo(a)pyrene and aromatic amines to highly reactive intermediates. A G/A polymorphism located 463 bp upstream of exon 1 in the promoter region strongly reduces MPO mRNA expression. In a matched case-control study, 196 lung cancer, 245 laryngeal cancer, and 255 pharyngeal cancer patients from the Berlin area were investigated for frequency of the G-463A polymorphism by PCR/RFLP, using AciI. They were matched by age and gender to hospital patients without known malignancies. Moreover, 270 healthy volunteers were genotyped, obtaining 61.1% of individuals with MPO genotype -463G/G, 34.8% of individuals with genotype G/A, and 4.1% of individuals with genotype A/A. In lung and laryngeal cancer patients, but not in pharyngeal cancer patients, mutant genotypes were significantly less frequent. Crude odds ratios for carriers of one or two A alleles, compared to wild-type G/G, were 0.58 [95% confidence interval (CI), 0.38-0.88; P = 0.011] for lung cancer patients, 0.63 (95% CI, 0.43-0.92; P = 0.017) for laryngeal cancer patients, and 0.82 (95% CI, 0.57-1.17; P = 0.27) for pharyngeal cancer patients. The relative risks, adjusted for age, gender, and extent of cigarette smoking were 0.47 (95% CI, 0.28-0.79; P = 0.004), 0.66 (95% CI, 0.44-1.01; P = 0.054), and 0.75 (95% CI, 0.51-1.12; P = 0.16) for lung, larynx, and pharyngeal cancer, respectively. Strikingly, relative risk for carriers of -463A among adenocarcinoma of the lung was 0.24 (95% CI, 0.10-0.58; P = 0.002). Two cases with larynx cancer, one case with lung cancer, and one reference subject displayed novel G/A mutations at -297 nucleotide and -296 nucleotide, destroying a constitutive AciI cleavage site. Our data finally suggest that the MPO -463A variant is a protective factor in the etiology of lung and larynx cancer, but possibly not of pharyngeal cancer.
Cascorbi
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Institute of Clinical Pharmacology, University Medical Center Charité, Humboldt University of Berlin, Germany. ingolf.cascorbi@charite.de
Henning
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S
Brockmöller
J
J
Gephart
J
J
Meisel
C
C
Müller
J M
JM
Loddenkemper
R
R
Roots
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I
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000201:enzymology / Q000209:etiology*; D008175:Lung Neoplasms / Q000201:enzymology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009195:Peroxidase / Q000235:genetics*; D010610:Pharyngeal Neoplasms / Q000201:enzymology / Q000209:etiology*; D011110:Polymorphism, Genetic; D012306:Risk
D009195:Peroxidase; D019363:Cytochrome P-450 CYP1A1