Su Ying-Hsiu, Wang Mengjun, Aiamkitsumrit Benjamas, Brenner Dean E, Block Timothy M
Department of Microbiology and Immunology, College of Medicine, Drexel University, 700 E. Butler Ave., Doylestown, PA 18901, USA.
Cancer Biomark. 2005;1(2-3):177-82. doi: 10.3233/cbm-2005-12-305.
We previously demonstrated that human urine contains small, 150 to 250 nucleotide-sized, soluble DNA derived from the circulation, which may be useful in the detection of colorectal cancer. In this report we have determined the stability of DNA in urine and have found that the half-life time interval of this small, fragmented DNA is at least 4 hours post collection. We further compared, in a blinded study, the frequency of detecting mutated K-ras sequence in DNA isolated from plasma and urine derived from individuals who have either a colorectal carcinoma (CRC), or adenomatous polyps that contain a mutation in codon 12 of the K-ras proto-oncogene. There was an 83% concurrence of mutated DNA detected in urine and its corresponding disease tissue from the same individuals, when paired urine and tissue sections from 20 patients with either CRC or adenomatous polyps were analyzed for K-ras mutation. However, only a 56% concurrence was observed when the matched plasma specimens were tested from these 20 patients. These results suggest that urine might be a better resource for detecting K-ras mutation in circulating DNA.
我们之前证明，人类尿液中含有源自循环系统的、大小为150至250个核苷酸的可溶性小DNA，其可能有助于检测结直肠癌。在本报告中，我们测定了尿液中DNA的稳定性，发现这种小片段DNA在收集后的半衰期时间间隔至少为4小时。我们在一项盲法研究中进一步比较了从患有结直肠癌（CRC）或K-ras原癌基因第12密码子发生突变的腺瘤性息肉患者的血浆和尿液中分离出的DNA中检测突变K-ras序列的频率。当对20例CRC或腺瘤性息肉患者的配对尿液和组织切片进行K-ras突变分析时，在尿液及其来自同一患者的相应疾病组织中检测到的突变DNA的一致性为83%。然而，当对这20例患者的匹配血浆标本进行检测时，仅观察到56%的一致性。这些结果表明，尿液可能是检测循环DNA中K-ras突变的更好来源。
