Cytochrome P450 1A1 genetic polymorphisms and risk of hepatocellular carcinoma among chronic hepatitis B carriers.
Cigarette smoking has been associated with increased risk of hepatocellular carcinoma (HCC) in some epidemiological studies. Cytochrome P450 1A1 (CYP1A1) is involved in the biotransformation of tobacco-derived polycyclic aromatic hydrocarbons (PAHs) into carcinogenic metabolites. The aim of this study was to determine whether CYP1A1 polymorphisms were related to HCC risk among chronic hepatitis B virus (HBV) carriers. Genotypic variants of CYP1A1 were determined using polymerase chain reaction in 81 incident cases of HCC and 409 controls nested in a cohort study of 4841 male chronic HBV carriers. No overall association between CYP1A1 genotypes and HCC was observed. The presence of the Mspl (odds ratio (OR) 3.15, P = 0.0196) or Ile-Val (OR 1.99, P = 0.0855) variant allele of CYP1A1 increased HCC risk among smokers, but posed no increased risk among non-smokers. The smoking-related HCC risk was most pronounced among those who had a susceptible allele of the CYP1A1 and a deficient genotype of glutathione S-transferase M1, which detoxifies PAH electrophilic metabolites produced by CYP1A1. In the absence of the Ile-Val variant allele, the Mspl polymorphism was still associated with smoking-related HCC. This study suggests that tobacco-derived PAHs play a role in HCC risk among chronic HBV carriers, and CYP1A1 polymorphism is an important modulator of the hepatocarcinogenic effect of PAHs. The Mspl and Ile-Val polymorphisms of CYP1A1 may have different mechanisms for increasing susceptibility to smoking-related HCC.
Yu
M W
MW
School of Public Health and Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei.
Chiu
Y H
YH
Yang
S Y
SY
Santella
R M
RM
Chern
H D
HD
Liaw
Y F
YF
Chen
C J
CJ
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics* / Q000821:virology; D002353:Carrier State / Q000201:enzymology* / Q000453:epidemiology / Q000821:virology; D016022:Case-Control Studies; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics* / Q000378:metabolism; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus; D019694:Hepatitis B, Chronic / Q000097:blood / Q000150:complications* / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics* / Q000821:virology; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
D006514:Hepatitis B Surface Antigens; D019363:Cytochrome P-450 CYP1A1