title: [Analysis of the relationship between polymorphism of angiotensin-converting enzyme gene and lung cancer].
abstract: BACKGROUND
  Angiotensin-converting enzyme (ACE), the key enzyme of RAS, is expressed in abundance in lung. Recent studies show that it plays various biological roles and even contributes importantly to the carcinogenesis of malignant tumors. The aim of this study is to investigate whether the insertion (I)/deletion (D) polymorphism of ACE is related to the susceptibility, pathological type or staging of lung cancer.
  
  
  METHODS
  DNA was extracted from the peripheral veinous blood derived from 47 lung cancer patients and 54 normal persons. The ACE genotype of each sample was amplified with PCR.
  
  
  RESULTS
  The frequencies of II, ID and DD genotype of ACE in lung cancer group were 0.447, 0.447 and 0.106 respectively, and the frequencies of I and D allele were 0.670 and 0.330 respectively. The frequencies of II, ID and DD geno-(type) of ACE in control group were 0.370, 0.556 and 0.074 respectively, and the frequencies of I and D allele were 0.648 and 0.352 respectively. There was no significant difference of ACE genotypes or alleles frequencies between the lung cancer and control groups. No significant difference of ACE genotypes or alleles frequencies was found between small cell lung cancer and non-small cell lung cancer groups or between the different staging groups of lung cancer patients.
  
  
  CONCLUSIONS
  No association is found between the polymorphism of ACE gene and the susceptibility, pathological type or clinical staging of lung cancer.
authors.affiliation: Department of Gerontology, Peking University First Hospital, Beijing 100034, P.R.China.
authors.forename: Qingzhao
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xinmin
authors.initials: X
authors.lastname: Liu
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lvhua
authors.initials: L
authors.lastname: Wang