Korean J Intern Med.
1997 Jun;12(2):128-136.
Association between genetic polymorphisms of the cytochromes P-450 (1A1, 2D6,
and 2E1) and the susceptibility to pancreatic cancer
- Affiliations
-
- 1Department of Internal Medicine, Seoul National University College of Medicine,
Korea.
Abstract
OBJECTIVES
Metabolic activation is a prerequisite for the carcinogenic effect
of many carcinogens, and considerable interindividual variation exists in the
metabolic capacity to activate the carcinogens. The cytochromes P-450 (CYPs) are
responsible for the activation mechanism, and polymorphisms of the CYPs (CYP1A1,
CYP2D6, and possibly CYP2E1) are known to be related to increased susceptibility
to smoking related Kreyberg type I lung cancer. The aim of this study is to
clarify the relationship of genetic polymorphisms of the CYPs to susceptibility
to pancreatic cancer, another smoking-related cancer. METHODS: We analyzed 45
samples from patients with pancreatic cancer and 53 samples from controls. DNA
was isolated from blood samples and the CYP1A1, 2D6 and 2E1 genes were amplified
by PCR. Analyzing the genotypes of the CYPs by allele-specific PCR or RFLP
analysis, we assessed the allele frequencies for each mutation of the CYPs among
the patients with pancreatic cancer and the controls. RESULTS: The allele
frequencies for the mutation in the 3'-flanking region of the CYP1A1 among the
cases and the controls were 0.31 and 0.36, respectively. The allele frequencies
for the exon 7 mutation of the CYP1A1 were 0.16 and 0.23, respectively, but with
no statistical significance. The frequencies for the mutant c2 allele of the
CYP2E1 were 0.19 and 0.30, respectively, but with no statistical significance.
Two persons homozygous for a gene deletion of the CYP2D6 were observed among
control subjects; other mutations were not observed among either the patients or
controls. CONCLUSION: We could not find any evidence that polymorphisms of the
CYPs are associated with increased susceptibility to pancreatic cancer.