Rengucci Claudia, De Maio Giulia, Menghi Maura, Benzi Francesca, Calistri Daniele
Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy
Diatech Pharmacogenetics srl.
J Vis Exp. 2020 Jun 8(160). doi: 10.3791/59426.
Nowadays, stool DNA can be isolated and analyzed by several methods. The long fragments of DNA in stool can be detected by a qPCR assay, which provides a reliable probability of the presence of pre-neoplastic or neoplastic colorectal lesions. This method, called fluorescence long DNA (FL-DNA), is a fast, non-invasive procedure that is an improvement upon the primary prevention system. This method is based on evaluation of fecal DNA integrity by quantitative amplification of specific targets of genomic DNA. In particular, the evaluation of DNA fragments longer than 200 bp allows for detection of patients with colorectal lesions with very high specificity. However, this system and all currently available stool DNA tests present some general issues that need to be addressed (e.g., the frequency at which tests should be carried out and optimal number of stool samples collected at each timepoint for each individual). However, the main advantage of FL-DNA is the possibility to use it in association with a test currently used in the CRC screening program, known as the immunochemical-based fecal occult blood test (iFOBT). Indeed, both tests can be performed on the same sample, reducing costs and achieving a better prediction of the eventual presence of colorectal lesions.
如今，粪便DNA可通过多种方法进行分离和分析。粪便中的长片段DNA可通过定量聚合酶链反应（qPCR）检测，该方法能可靠地检测出癌前或肿瘤性结直肠病变的存在可能性。这种方法称为荧光长链DNA（FL-DNA），是一种快速、非侵入性的检测方法，是对一级预防系统的改进。该方法基于通过对基因组DNA的特定靶点进行定量扩增来评估粪便DNA的完整性。特别是，对长度超过200bp的DNA片段进行评估，可以非常高的特异性检测出患有结直肠病变的患者。然而，该系统以及目前所有可用的粪便DNA检测都存在一些需要解决的普遍问题（例如，检测的频率以及每个个体在每个时间点采集的最佳粪便样本数量）。然而，FL-DNA的主要优点是可以将其与目前用于结直肠癌筛查项目的一种检测方法联合使用，即基于免疫化学的粪便潜血试验（iFOBT）。实际上，这两种检测都可以在同一样本上进行，从而降低成本并更好地预测结直肠病变的最终存在情况。
