BACKGROUNDSmoking plays an important role in the development of carcinoma of human lung,but the mechanism is unknown.The objective of this study is to investigate the mutation in the coding region of mitochondrial DNA(mtDNA) in patients with squamous cell carcinoma of the lung and to explore its significance in carcinogenesis.

METHODSWhite blood cells,pericarcinomatous tissues and cancer tissues were obtained from 15 cases of lung squamous cell carcinoma and mtDNA was extracted by one step method.The part of coding region fragments was amplified by PCR.Mutations were determined by DNA sequencing.

RESULTSFifteen pairs of matched pericarcinomatous tissues and cancer tissues were screened for mutation in coding regions,18 mutations were detected in the coding region of mtDNA in 11 patients,of which 10 cases were smokers.

CONCLUSIONSThe mutations of the coding region of mtDNA in squamous cell carcinoma of the lung may be correlative with smoking.