Nanobiosensors and Bioanalytical Applications Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain; CIBER-BBN Networking Center on Bioengineering, Biomaterials and Nanomedicine, Spain.
CIBER-BBN Networking Center on Bioengineering, Biomaterials and Nanomedicine, Spain; Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC), CSIC, c/Jordi Girona 18-26, 08034 Barcelona, Spain.
Biosens Bioelectron. 2018 Nov 30;120:47-54. doi: 10.1016/j.bios.2018.08.027. Epub 2018 Aug 15.
Cancer diagnosis continuously evolves due to the better understanding of tumorigenic processes. DNA-methylation is consolidated as an effective biomarker for cancer prognosis and diagnostic even in tumors of unknown origin. The reversibility of this epigenetic mechanism also places it as a high-profile tool for the development of more sophisticated and personalized therapies. Current methodologies, such as bisulfite conversion or PCR amplification, rely on complex procedures that make difficult the standardization of epigenetics analyses. Here we present an optical biosensor methodology based on Surface Plasmon Resonance that employs poly-purine reverse-Hoogsten hairpin probes capable of interacting directly with ds-DNA fragments by triple helix formation. The direct interaction with the material of interest can greatly enhance the reliability of the analysis providing a more accurate and precise diagnosis. We have demonstrated the capabilities of our methodology for the direct capture of ds-DNA fragments and specific methyl-cytosine quantification. Our poly-purine hairpin probe demonstrated the specific capture of ds-DNA fragments while the standard duplex-forming probes failed to do so. In addition, the biosensor methodology showed a strong correlation with the different DNA methylation status between the sequences with a low signal variation (≤ 8%CV) along 35 hybridization/regeneration cycles. Through its straightforward procedure and versatility of detecting different DNA modifications related to the DNA methylation process, we anticipate that our strategy will enable a greater level of accuracy and precision in cancer diagnostics making a strong impact on the development of personalized therapies.
由于对肿瘤发生过程的更好理解，癌症诊断不断发展。DNA 甲基化已被确立为癌症预后和诊断的有效生物标志物，即使在来源不明的肿瘤中也是如此。这种表观遗传机制的可逆性也使其成为开发更复杂和个性化治疗方法的重要工具。目前的方法，如亚硫酸氢盐转化或 PCR 扩增，依赖于复杂的程序，使得表观遗传学分析的标准化变得困难。在这里，我们提出了一种基于表面等离子体共振的光学生物传感器方法，该方法采用多嘌呤反向 Hoogsten 发夹探针，能够通过三螺旋形成直接与 ds-DNA 片段相互作用。与感兴趣的材料直接相互作用可以极大地提高分析的可靠性，提供更准确和精确的诊断。我们已经证明了我们的方法用于直接捕获 ds-DNA 片段和特定甲基胞嘧啶定量的能力。我们的多嘌呤发夹探针能够特异性捕获 ds-DNA 片段，而标准的双链形成探针则不能。此外，生物传感器方法显示出与序列之间不同的 DNA 甲基化状态之间的强相关性，在 35 个杂交/再生循环中信号变化很小（≤8%CV）。通过其简单的程序和检测与 DNA 甲基化过程相关的不同 DNA 修饰的多功能性，我们预计我们的策略将在癌症诊断中实现更高的准确性和精度，并对个性化治疗的发展产生重大影响。
