title: Genetic polymorphism of cytochrome P4501A1 and susceptibility to oral squamous cell carcinoma and oral precancer lesions associated with smoking/betel use.
abstract: BACKGROUND
  The importance of the CYP1A1 polymorphisms at exon 7 (Ile/Val) and 3'-untranslated region (3'-UTR) has been controversial in oral squamous cell carcinoma (OSCC) or head and neck SCC (HNSCC) denoting the value of exploring the correlation between these polymorphisms and risk of betel/smoking associated OSCC. It is also important to evaluate the association between CYP1A1 polymorphisms and susceptibility of oral precancerous lesion (OPL) to confirm the findings in OSCC cases.
  
  
  METHODS
  We examined polymorphic prevalence of CYP1A1 at exon 7 (Ile/Val) and 3'-UTR in 106 cases with OSCC, 60 cases with OPL, and 146 controls. DNA isolated from surgical specimens and whole blood was used for PCR-based genotyping.
  
  
  RESULTS
  The prevalence of the CYP1A1 A/G genotype (Ile/Val) and G/G genotype (Val/Val) in exon 7 of cases with OSCC (79.2 and 7.6%) and OPL (68.3 and 10%) were significantly higher than in controls (53.4 and 1.4%) (P < 0.0001). The novelty of the present study is that we identified the onset age of OSCC in CYP1A1 A/G genotype to be significantly younger than that in A/A genotype (P < 0.01). No significant difference was seen between cases and controls regarding the polymorphisms at 3'-UTR.
  
  
  CONCLUSIONS
  The findings indicate that the individuals with the CYP1A1 exon 7 containing G allele were at increased risk for OSCC and OPL.
authors.affiliation: Department of Dentistry, Oral and Maxillofacial Surgery, Taipei Veterans General Hospital, Taiwan, ROC. sykao@vghtpe.gov.tw
authors.forename: Shou-Yen
authors.initials: SY
authors.lastname: Kao
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Wu
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Lin
authors.forename: Soon-Kiong
authors.initials: SK
authors.lastname: Yap
authors.forename: Che-Shoa
authors.initials: CS
authors.lastname: Chang
authors.forename: Yong-Kie
authors.initials: YK
authors.lastname: Wong
authors.forename: Lin-Yang
authors.initials: LY
authors.lastname: Chi
authors.forename: Tsung-Yun
authors.initials: TY
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D001114:Areca / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000209:etiology / Q000235:genetics*; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000201:enzymology / Q000209:etiology / Q000235:genetics*; D020125:Mutation, Missense; D012150:Polymorphism, Restriction Fragment Length; D011230:Precancerous Conditions / Q000201:enzymology / Q000209:etiology / Q000235:genetics*; D012907:Smoking / Q000009:adverse effects / Q000235:genetics; D020506:Untranslated Regions / Q000235:genetics; D014633:Valine / Q000235:genetics
chemical_list: D020506:Untranslated Regions; D019363:Cytochrome P-450 CYP1A1; D014633:Valine