宫颈癌细胞中线粒体DNA D-环区突变及其对细胞内活性氧、细胞周期的影响

Mutations in D-loop region of mitochondrial DNA in cervical cancer and its influence on reactive oxygen species and cell cycle

背景与目的:线粒体DNA突变可能与肿瘤的发生、发展有关。DNA D-环区作为线粒体DNA中突变发生的热点,受到广泛的关注。因此本研究旨在研究线粒体DNA D-环区在宫颈癌细胞中的突变情况,以及突变对细胞内活性氧(reactive oxygen species,ROS)水平及细胞周期的影响。方法:选择60例人宫颈癌组织及其邻近的正常组织,采用PCR方法将线粒体DNA D-环区扩增测序,用流式细胞仪测定ROS及细胞周期,根据测序结果分为突变组和无突变组,比较突变对细胞中的ROS含量及细胞周期的影响。结果:在60例癌组织中有18例存在线粒体DNA D-环区突变,突变率为30%,突变位点21个,其中4个属微卫星不稳定。突变组中ROS水平、细胞增殖及凋亡与无突变组相比,差异有统计学意义(P<0.05)。结论:宫颈癌细胞线粒体DNA D-环区是一个具有高度突变性的区域,这种突变可能通过影响细胞内ROS水平和细胞周期从而在宫颈癌的发生、发展过程中起着重要的作用。

Background and purpose： In recent years, mutation of mitochondrial DNA （mtDNA） has been associated with the occurrence and progression of tumor. The mitochondrial D-loop is a hotspot for gene mutation research. In this study, we aimed to investigate the mutation in D-loop region of mitochondrial DNA in cervical cancer and its influence on the changes of reactive oxygen species（ROS） and cell cycle. Methods： The D-loop region was amplified by PCR and sequenced. Reactive oxygen species and cell cycle were detected by flow cytometry in 60 specimens from cervical cancer and adjacent normal tissues. According to the sequence results, cancer tissues were divided into mutation group and control group. Reactive oxygen species, apoptosis and proliferation in the 2 groups were compared. Results： Among the 60 cervical cancer specimens, 21 mutations were identified in 18 patients, the mutation rate being 30%. There were 4 microsatellite instabilities in the mutations. No mutation was found in the adjacent tissues. Reactive oxygen species, apoptosis and proliferation in mutation group were all significantly higher than those in control group. Conclusion： The mutation rate of the D-loop region is relatively high in patients with cervical cancer and the mutation in D-loop region plays a role in the genesis and development of cervical cancer through its influence on intracellular reactive oxygen species and cell cycle.