The relationship between HVRII mutation of mitochondrial DNA and squamous cell carcinoma of the lung

Abstract

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. 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. 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). 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.