title: Mitochondrial DNA mutations in exhaled breath condensate of patients with lung cancer.
abstract: BACKGROUND
  Lung cancer is a leading cause of cancer mortality worldwide. Non-invasively collected biofluids such as exhaled breath condensate (EBC) present a potential sampling medium to detect and study pathological changes implicated in tumourigenesis. Mitochondrial DNA changes have been implicated in the carcinogenesis process. Consequently, the detection of mitochondrial changes in EBC could expand our understanding of lung carcinogenesis as well as identifying specific markers for future studies.
  
  
  METHODS
  EBC and saliva was collected from newly diagnosed subjects with lung cancer and control subjects in a cross-sectional study. The EBC and saliva was analysed for mitochondrial DNA D-loop changes using a PCR sequencing approach. The sequences obtained were compared to paired salivary DNA and the revised Cambridge Reference Sequence (rCRS) to identify somatic mutations, and quantitative and qualitative differences in mutations were analysed between groups.
  
  
  RESULTS
  A total of 25 subjects (9 NSCLC patients, 10 smokers/ex-smokers and 6 non-smokers) were recruited. A significantly elevated D-loop mutation rate in the lung cancer group compared to the control groups was present (7 vs 3.5 for smokers/ex-smokers, and 7 vs. 4 for non-smokers, p = 0.034). The recognised mutation T16217C showed specificity for lung cancer.
  
  
  CONCLUSIONS
  Mitochondrial DNA mutations are more common in the EBC of patients with lung cancer. This suggests that these processes are associated with the carcinogenesis of lung cancer and may be a marker of the disease.
authors.affiliation: Inflammation and Infection Research Centre, Faculty of Medicine, University of New South Wales, Australia.
authors.forename: Sylvia Si
authors.initials: SS
authors.lastname: Yang Ai
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hsu
authors.forename: Cristan
authors.initials: C
authors.lastname: Herbert
authors.forename: Zujian
authors.initials: Z
authors.lastname: Cheng
authors.forename: John
authors.initials: J
authors.lastname: Hunt
authors.forename: Craig R
authors.initials: CR
authors.lastname: Lewis
authors.forename: Paul S
authors.initials: PS
authors.lastname: Thomas
mesh_terms: D000368:Aged; D001944:Breath Tests; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D003430:Cross-Sectional Studies; D004252:DNA Mutational Analysis / Q000379:methods; D004272:DNA, Mitochondrial / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging; D012463:Saliva / Q000378:metabolism; D012907:Smoking / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D004273:DNA, Neoplasm