title: Novel and differential accumulation of mitochondrial DNA deletions in Swedish and vietnamese patients with colorectal cancer.
abstract: BACKGROUND
  Mitochondrial DNA (mtDNA) has been proposed to be involved in carcinogenesis and aging. The mtDNA 4977 bp deletion is one of the most frequently observed mtDNA mutations in human tissues and may play a role in colorectal cancer (CRC). In the present study, we aimed to evaluate the frequency of mtDNA 4977 bp deletion in CRC tissues and its association with clinical factors.
  
  
  METHODS
  We determined the presence of the 4977 bp common deletion in cancer and normal paired tissue samples from 105 Swedish and 88 Vietnamese patients with CRC using polymerase chain reaction (PCR) assays.
  
  
  RESULTS
  The mtDNA 4977 bp deletion was shown to be significantly more frequent in normal tissues in comparison with paired cancer tissues in both Swedish and Vietnamese patients. The 4977 bp common deletion was significantly more frequent in cancer tissues of the Vietnamese patients compared to the Swedish patients, and in Vietnamese cancer tissues, the 4977 bp deletion was significantly over represented in those with localized disease compared to those with disseminated disease. Moreover, we detected nine novel mtDNA deletions and found a significantly higher rate of these in CRC tissues in Swedish in comparison to Vietnamese patients.
  
  
  CONCLUSIONS
  The mtDNA 4977 bp deletion seems to have an impact on the clinical outcome of CRC in Vietnamese patients, that the Swedish patients accumulate more of the detected novel deletions in CRC tissue compared to Vietnamese patients probably indicates divergent mechanisms in colorectal carcinogenesis.
authors.affiliation: Department of Laboratory Services, Ryhov County Hospital, SE-551 85, Jönköping, Sweden. Andreas.Matussek@lj.se.
authors.forename: Jan
authors.initials: J
authors.lastname: Dimberg
authors.forename: Thai Trinh
authors.initials: TT
authors.lastname: Hong
authors.forename: Marita
authors.initials: M
authors.lastname: Skarstedt
authors.forename: Sture
authors.initials: S
authors.lastname: Löfgren
authors.forename: Niklas
authors.initials: N
authors.lastname: Zar
authors.forename: Andreas
authors.initials: A
authors.lastname: Matussek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D017384:Sequence Deletion; D013548:Sweden
chemical_list: D004272:DNA, Mitochondrial
keywords: Colorectal cancer; mitochondrial DNA; mtDNA deletion