title: High rate of mutation in mitochondrial DNA displacement loop region in human colorectal cancer.
abstract: OBJECTIVE
  Mitochondrial DNA mutations are found in many kinds of human cancer and the 1.1 kb displacement loop region has been identified as a "hot spot" for mutation in mitochondrial DNA of tumors. This study evaluated the mutation frequencies in hypervariable regions of mitochondrial displacement loop in patients with colorectal cancer.
  
  
  METHODS
  We examined the frequency of mutations in the mitochondrial DNA displacement loop region of 40 colorectal cancer samples in comparison to 150 samples from people without any type of familial cancer history, by automated DNA sequencing. Alignment was made with the revised Cambridge Reference Sequence and any differences recorded as single base substitution, insertions, and deletions.
  
  
  RESULTS
  Our results showed that the rate of displacement loop variations was higher in colorectal cancer patients than controls. Nineteen single nucleotide polymorphisms were found; among them eighteen occurred in the displacement loop region.
  
  
  CONCLUSIONS
  Mutations in mtDNA D-loop region probably do not cause colorectal cancer but are more likely to be epiphenomena; patients with the high mtDNA variants are at a higher risk of colorectal cancer.
authors.affiliation: Department of Biology, Leibniz University Hanover, Hanover, Germany.
authors.forename: Mansoureh
authors.initials: M
authors.lastname: Akouchekian
authors.forename: Massoud
authors.initials: M
authors.lastname: Houshmand
authors.forename: Simin
authors.initials: S
authors.lastname: Hemati
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ansaripour
authors.forename: Mehdi
authors.initials: M
authors.lastname: Shafa