Detection Of Mitochondrial Dna Mutations In Ascites

The mechanism of tumorigenesis remains unclear. Mitochondrion is the most capital organelle, and its dysfunction is one of the most profound features of cancer cells. Mitochondria are dynamic organelles that play a central role in cellular metabolism, and mitochondria are also sites for several additional key cellular processes such as the oxidative decarboxylation of pyruvate, the tricarboxylic acid cycle, fatty acid oxidation, cellular movement, cellular proliferation and apoptosis. Mitochondria are involved either directly or indirectly in many aspects of altered metabolism in cancer cells, and several notable differences have been discovered between the mitochondria of normal cells and that of transformed cells. For example, various tumor cells exhibit differences in the number, size and shape of their mitochondria relative to normal controls.MtDNA (mitochondrial DNA) is the extra-nuclear gene. Studies have shown that mitochondrial genome has relation with cancer genesis and development , which has been brought into the limelight for a broader audience. mtDNA encodes the polypeptides required for oxidative phosphorylation and synthesis of ATP. Because of its special biological and structural characters , mtDNA is more vulnerable to oxidative damage and undergoes a higher rate of mutation than nDNA. Various tumors contained mtDNA mutations that were not present in healthy tissues from the same individuals. The mechanism of nDNA mutagenesis involving the integration of mtDNA fragments may play an important role in carcinogenesis. Furthermore , mtDNA mutations may become a potential effective molecular marker in view of the role on noninvasive detection of carcinoma.Objective:To investigate the mitochondrial DNA(ND3,16s rRNA,D-loop) mutations in benign and malignant ascites and analyze differences among them.Methods:The sample of 21 benign and 9 malignant ascites were obtained from 30 patients and total DNA were extracted.ND3,16s rRNA and D-loop fragments were amplified by PCR and PCR products were sequenced.The variants of the mtDNA were analyzed using bioinformatic methods.Results:The mutation rates and sites are similar in 16s rRNA between benign and malignant ascites. The mutation rates of ND3 10401 C T and D-loop in malignant ascites were much more frequent than that in benign ascites. HVⅠand HVⅡare recognized as mutational hotspots in the D-loop region.Conclusions:MtDNA of ascite cells has high mutation rates, and detection of mutations in ND3 10401 C T and D-loop might be a useful molecular marker in differentiation of benign and malignant ascites.