title: [Promoter hypermethylation and loss of heterozygosity of the APC gene in patients with familial adenomatous polyposis].
abstract: OBJECTIVE
  To investigate the status of hypermethylation in the promoter 1A region of the adenomatus polyposis coli (APC) gene in 3 familial adenomatous polyposis (FAP) pedigrees and to screen large fragment deletions in the APC gene.
  
  
  METHODS
  DNA from tumor tissues and corresponding normal tissues of 5 FAP patients was modified by sodium bisulfite. Then the methylation status of the APC gene was analyzed by methylation specific-PCR (MSP) and DNA sequencing. Multiplex ligation-dependent probe amplification (MLPA) was used to screen aberrations involving large fragments from all the 15 exons and promoter region of APC gene.
  
  
  RESULTS
  No methylation was present in normal tissues. Hypermethylation was found in tumor tissues of one proband and her son. Loss of heterozygosity was observed in another patient from the same FAP family.
  
  
  CONCLUSIONS
  Aberrant methylation of the APC promoter region provides an important mechanism for impairing APC function and may occur early during colon neoplasia progression. Loss of heterozygosity may play a role in patients with classical polyposis.
authors.affiliation: Department of Genetics and Molecular Biology, Jiangsu Institute of Cancer Research, Nanjing, Jiangsu, 210009 People's Republic of China. Yuanying_z@163.com
authors.forename: Yuan-ying
authors.initials: YY
authors.lastname: Zhang
authors.forename: Sen-qing
authors.initials: SQ
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.forename: Jin-tian
authors.initials: JT
authors.lastname: Li
authors.forename: Guo-jian
authors.initials: GJ
authors.lastname: Ma
authors.forename: Xiao-mei
authors.initials: XM
authors.lastname: Zhang
authors.forename: Jian-nong
authors.initials: JN
authors.lastname: Zhou
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000235:genetics*; D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics; D000328:Adult; D001483:Base Sequence; D015179:Colorectal Neoplasms / Q000235:genetics; D018899:CpG Islands; D019175:DNA Methylation; D004273:DNA, Neoplasm; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D017491:Genes, APC / Q000502:physiology*; D006579:Heterozygote; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000502:physiology*
chemical_list: D025601:Adenomatous Polyposis Coli Protein; D004273:DNA, Neoplasm