Change and Signif icance of Mitochondrial DNA Copy Number in Esophageal Squamous Cell Carcinoma

OBJECTIVE To compare the differences of mitochondrial DNA (mtDNA) copies among the tissues of esophageal squamous cell carcinoma (ESCC), para-neoplastic tissue and normal mucous membrane of the esophagus, and to study the relationship between the mtDNA and the occurrence and devel- opment of esophageal squamous cell carcinoma. METHODS The mtDNA copies of 42 specimens with the ESCC, paraneoplastic mucous tissue and normal mucous membrane of the esophagus were determined using real-time fluorescence quantitative PCR. The mtDNA was analyzed using agarose gel electrophoresis. RESULTS The mtDNA from all of the tissues (42/42) from the ESCC, para-neoplastic tissue and normal esophageal mucous membranes was analyzed, showing that there were an average mtDNA copy number of 27.1894×106 μg DNA, 9.4102×106 μg DNA and 5.9347×106 μg DNA, from the respective tissues. There were signifi cant differences (F=27.83, P<0.05) in mtDNA copy number among the three. A positive band was shown at 403 bp after gel electrophoresis of the PCR products, and the lane where the ESCC mtDNA located was rather bright, which was in accordance with the result of the real-time PCR determination. CONCLUSION An increase in the mtDNA copy number is related to the occurrence and development of ESCC.