title: [The relationship between HVRII mutation of mitochondrial DNA and squamous cell carcinoma of the lung].
abstract: BACKGROUND
  Mitochondrial DNA (mtDNA) is the only hereditary substance besides nucleus, which is composed of a code region and a non-code D-loop region. The aim of this study is to investigate the hypervariable region II (HVRII) mutation of mtDNA in peripheral blood leucocyte, pericancerous tissues and cancer tissues of lung squamous cell carcinoma patients, and to explore its significance.
  
  
  METHODS
  White blood cells, pericancerous tissues and cancer tissues were obtained from 15 cases of lung squamous cell carcinoma patients and mtDNA were extracted by one step method. HVRII fragments were amplified by PCR. Mutations were determined by DNA sequencing and the mutations of HVRII were analysed.
  
  
  RESULTS
  In 15 lung squamous cell carcinoma patients, 14 patients showed mutation in HVRII(93.33%), 88 mutations were found totally. Eighty-seven mutations located in H-strand origin region, especially in the conserved sequence blocks and the mtTF1, 2 binding site (TFX and TFY).
  
  
  CONCLUSIONS
  The results suggest that the mutation frequency of HVRII in cancer tissues of lung squamous cell carcinoma patients is very high and it might play an important role in carcinogenesis of the lung.
authors.affiliation: PLA Cancer Center of Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R.China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Liu
authors.forename: Yide
authors.initials: Y
authors.lastname: Hu
authors.forename: Junze
authors.initials: J
authors.lastname: Liu
authors.forename: Haihong
authors.initials: H
authors.lastname: Qian
authors.forename: Pin
authors.initials: P
authors.lastname: Qian
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhang