【摘要】 目的 血液中肿瘤细胞释放的DNA长链有望成为肿瘤检测的标志物，与正常组织细胞凋亡释放较短和均匀一致DNA片段相比，肿瘤坏死导致释放异常的DNA片断。方法 为了验证血液中长链DNA是肿瘤相关标志物，用实时PCR方法检测了45例肺癌患者和45例非肿瘤患者血液中长链DNA的浓度及其指数。结果 发现平均长链DNA指数在肺癌组明显高于对照组非肿瘤患者(P<0.01)，在ROC曲线上，假设长链DNA对肺癌特异性是100%，长链DNA指数的临界点是0.59，长链DNA诊断肺癌最高敏感性是 67%(95%可信区间=0.54～0.74)，55.6%Ⅰ期肺癌患者长链DNA指数在这个临界点以上，72.2%Ⅱ期以上肺癌患者长链DNA指数在这个临界点以上。结论 研究提示血浆长链DNA与癌症有一定关联，血浆长链DNA的检测可能提供了一个简单和不太昂贵的癌症检测方法。

    【关键词】 肺癌；标志物；长链DNA

    The study of the detection of plasma DNA integrity for lung comcer patient

    XIA Ming-cheng,MA Jia-yong,LI Hou-huai,et al.

    Department of Respiratory,Affiliated Jiangbei People’s Hospital,the Medical College of the Dongnan University Nanjing 210048,China

    【Abstract】 Objective Tumor-released DNA in blood represents a promising biomarker for cancer diagnosis. It has been supposed that tumor necrosis causes release of DNA of varying sizes, which contrasts apoptosis in normal tissue that releases smaller and more uniform DNA fragments.Methods To test the hypothesis that increased DNA integrity,ie,a longer DNA strand is a tumor-associated marker in plasma DNA.We determined the genomic DNA integrity index in plasma DNA, using real-time PCR assay. A DNA integrity index and DNA concentration in plasma were determined in 45 patients with lung cancer and 45 patients without neoplastic disease. Results We found the median DNA integrity index in the neoplastic group was significantly higher than that in the noneoplastic group(P<0.0001),under the receiver-operating characteristic curve ......