title: Promoter polymorphisms of DNMT3B and the risk of colorectal cancer in Chinese: a case-control study.
abstract: BACKGROUND
  DNA-methyltransferase-3B (DNMT3B), which plays a role in DNA methylation, is usually aberrant expression involved in carcinogenesis. Polymorphisms of the DNMT3B gene may influence DNMT3B activity on DNA methylation in several cancers, thereby modulating the susceptibility to cancer.
  
  
  METHODS
  DNMT3B -579G>T genotypes and -149C>T were determined by PCR-RFLP and sequencing in 137 colorectal cancer patients and 308 controls matched for age and sex, who did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed colorectal cancer. The association between two SNPs of the DNMT3B promoter and the risk of the development of colorectal cancer was analyzed in a population of Chinese.
  
  
  RESULTS
  The allele frequency of -149C >T among patients and controls was 0.73% versus 0.65%, respectively. The allele frequency of -597G>T for patients and controls was 6.57% versus 11.53%, respectively. Individuals with at least one -149C>T allele were no at a significantly increase risk of colorectal cancer compared with those having a -149TT genotype. However, Individuals with at least one 579G>T allele were decreased risk of colorectal cancer compared with those having a -579TT genotype.
  
  
  CONCLUSIONS
  The relative distribution of -149C>T DNMT3B SNPs among a Chinese population can not be used as a stratification marker to predict an individual's susceptibility to colorectal cancer. However, the DNMT3B -579G>T polymorphism may contribute to the genetic susceptibility to colorectal cancer.
authors.affiliation: Key Laboratory of Developmental genes and Human diseases, Ministry of Education, Southeast University, 210009, Nanjing, PR China. fanh@seu.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Fan
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Jiabo
authors.initials: J
authors.lastname: Hu
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Liu
authors.forename: Zhujiang
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D000368:Aged; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012307:Risk Factors; D000097584:DNA Methyltransferase 3B
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases; D000097584:DNA Methyltransferase 3B