关键词: 线粒体DNA, D-Loop, 原发性肝癌, 突变, 活性氧类物质

Abstract: Abstract: To explore the relationship between ROS level and mutations in D?Loop region of mtDNA, mutations in the D?Loop region of mt DNA and the ROS level in primary hepatocarcinoma tissues were studied. We amplified the D?Loop region of mtDNA of 20 hepatocarcinomas and their adjacent tissue by PCR and then sequencing. ROS in tissue was measured by flow cytometry. mtDNA mutations were detected in 40%(8 of 20)tumor samples. 53 point mutations were detected in 8 tumour samples,including 2 insertions,11 deletions and 40 point mutations.75% point mutations were T-C and C-T transition.There were 4 microsatellites among the mutations. Mutations in the adjacent tissues were always companied with Mutations in tumor tissues.The mutation frequency in tumor tissues was higher than that in adjacent tissue .There was a larger unidentified deletion. The ROS level in hepatocarcinoma tissue was much higher than control (P<0.01).Meanwhile,we found the ROS level in hepatocarcinoma tissues with mutated mtDNA D?Loop was higher than that in hepatocarcinoma tissue with normal mtDNA D?Loop ,and the ROS level in hepatocarcinoma adjacent tissue with mutated mtDNA D?Loop was higher than that in hepatocarcinoma adjacent tissue with normal mtDNA D?Loop . It was concluded that the D?Loop region of mitochondrial DNA was a highly polymorphoric and mutable region and the mutation rate was relatively high in patients with hepaticellular carcinoma,and the abnormal ROS level might be the point mutation in the mitochondrial DNA and hepatocarcinogenesis related to ROS.

Key words: mitochondrial DNA； D-Loop, region； primary hepatocellular carcinoma； mutation；reactive oxygen species(ROS)