Gilat Noa, Tabachnik Tzlil, Shwartz Amit, Shahal Tamar, Torchinsky Dmitry, Michaeli Yael, Nifker Gil, Zirkin Shahar, Ebenstein Yuval
School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel.
Clin Epigenetics. 2017 Jul 14;9:70. doi: 10.1186/s13148-017-0368-9. eCollection 2017.
The DNA modification 5-hydroxymethylcytosine (5hmC) is now referred to as the sixth base of DNA with evidence of tissue-specific patterns and correlation with gene regulation and expression. This epigenetic mark was recently reported as a potential biomarker for multiple types of cancer, but its application in the clinic is limited by the utility of recent 5hmC quantification assays. We use a recently developed, ultra-sensitive, fluorescence-based single-molecule method for global quantification of 5hmC in genomic DNA. The high sensitivity of the method gives access to precise quantification of extremely low 5hmC levels common in many cancers.
We assessed 5hmC levels in DNA extracted from a set of colon and blood cancer samples and compared 5hmC levels with healthy controls, in a single-molecule approach.
Using our method, we observed a significantly reduced level of 5hmC in blood and colon cancers and could distinguish between colon tumor and colon tissue adjacent to the tumor based on the global levels of this molecular biomarker.
Single-molecule detection of 5hmC allows distinguishing between malignant and healthy tissue in clinically relevant and accessible tissue such as blood and colon. The presented method outperforms current commercially available quantification kits and may potentially be developed into a widely used, 5hmC quantification assay for research and clinical diagnostics. Furthermore, using this method, we confirm that 5hmC is a good molecular biomarker for diagnosing colon and various types of blood cancer.
DNA修饰5-羟甲基胞嘧啶（5hmC）现在被称为DNA的第六碱基，有证据表明其具有组织特异性模式，并与基因调控和表达相关。这种表观遗传标记最近被报道为多种癌症的潜在生物标志物，但其在临床上的应用受到近期5hmC定量检测方法实用性的限制。我们使用一种最近开发的基于荧光的超灵敏单分子方法对基因组DNA中的5hmC进行全局定量。该方法的高灵敏度能够精确量化许多癌症中常见的极低5hmC水平。
我们采用单分子方法评估了从一组结肠癌和血癌样本中提取的DNA中的5hmC水平，并将5hmC水平与健康对照进行比较。
使用我们的方法，我们观察到血癌和结肠癌中5hmC水平显著降低，并且能够根据这种分子生物标志物的全局水平区分结肠肿瘤和肿瘤旁的结肠组织。
5hmC的单分子检测能够在血液和结肠等临床相关且可获取的组织中区分恶性组织和健康组织。所提出方法优于目前市售的定量试剂盒，并且有可能开发成为一种广泛用于研究和临床诊断的5hmC定量检测方法。此外，使用该方法，我们证实5hmC是诊断结肠癌和各种血癌的良好分子生物标志物。
