title: Somatic mutations of mitochondrial DNA in digestive tract cancers.
abstract: BACKGROUND
  Somatic mutations of mitochondrial DNA (mtDNA) have been reported to play an important role in the carcinogenesis of several human cancers. However, there are few reports on mtDNA mutations in digestive tract cancers, including esophageal, gastric and colorectal cancers. The present study examined somatic mtDNA mutations in these cancers.
  
  
  METHODS
  Samples of 82 esophageal cancers, 96 gastric cancers and 138 colorectal cancers were collected. Mutations in the D310 mononucleotide repeat of mtDNA were examined by microsatellite assay.
  
  
  RESULTS
  Frequencies of mtDNA mutations were similar in each digestive tract cancer: 14% (7/51) in esophageal cancers, 15% (14/94) in gastric cancers and 8% (11/133) in colorectal cancers. There were no significant relationships between mtDNA mutations and clinicopathological features, such as patient age or sex, tumor location, depth of tumor invasion and lymph node metastasis in each digestive tract cancer.
  
  
  CONCLUSIONS
  The results suggest that mtDNA mutations play a role in the development but not progression in each digestive tract cancer, and that the role of mtDNA mutations might be similar among the digestive tract cancers.
authors.affiliation: Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kose
authors.forename: Toru
authors.initials: T
authors.lastname: Hiyama
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshihara
authors.forename: Wataru
authors.initials: W
authors.lastname: Yasui
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D004272:DNA, Mitochondrial / Q000235:genetics*; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009361:Neoplasm Invasiveness; D017678:Sex Distribution; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology
chemical_list: D004272:DNA, Mitochondrial