D-loop Mitochondrial DNA Mutation In Gastric Cancer And Its Significance

Objective To analyze the relation between mutations in the D-Loop region of mitochondrial DNA (mtDNA) and the clincopathological characteristics of gastric cancers by detecting mutations in the D-loop region of the mtDNA, thereby providing theory evidence for the early diagnosis of gastric cancer.Methodsâ‘ Polymerase chain reaction (PCR) and sequencing were applied to the D-loop region of mitochondrial genome in 17 gastric cancers specimens and corresponding non-cancerous stomach tissues. The sequences were compared with the Revised Cambridge Reference Sequence in Mitomap.â‘¡PPMS 1.5 software and exact method were used in analyzing the relation between mutations in the D-Loop region of mitochondrial DNA (mtDNA) and the clincopathological characteristics of gastric cancers.Resultsâ‘ Onehundred and seventy-five polymorphisms, eight (4.6%) of which were novel, were found in the seventeen gastric cancers. Thirteen mutations were observed in eight (47.1%) of the seventeen cases. HV1 (23.1%) and HV 2(53.9%) were hot spots of mutation, with HV2 being more susceptible to mutation.â‘¡Mutation rate in the mtDNA D-Loop region was not correlated with patient's age, sex and differentiation,infiltration and lymph node metastasis profile (P>0.05)..Conclusions The D-loop region of mitochondrial DNA, especially HV 1 and HV 2, is highly polymorphic and mutable and the mutation rate is relatively high in patients with gastric cancer. Mutation in the mtDNA D-loop region may be an eraly event in the tumorigenesis of gastric cancer and it is go hand in hand with theprogression of gastric cancer. Detection of mtDNA D-loop region is expected to be used in the early diagnosis of tumor.