多肽-核酸偶联物在肿瘤细胞检测中的研究

The development of the early diagnosis methods for cancer is one of the effective means to improve the cure rate of cancer. Therefore, this project uses peptide-oligonucleotide conjugates (POCs) acting as sensing element to develop the novel and sensitive methods for the early diagnosis of cancer. Due to the small molecular weight and simpleness in synthesis and preservation of the peptide which can recognize the tumor, and its both existing in organism and getting though artificial screening, it can overcome the shortcomings of antibody and aptamer. Therefore, this project employs peptides as target recognition molecules, combing with the existing mature nucleic acid signal amplification method (including nucleic acid in vitro amplification and DNAzyme technology), designs and synthetizes the POCs to develop the detection method for the tumor cells. The POCs molecular probe used in this project is capable to recognize the target with high affinity and amplification of the signal meanwhile, can introduce the nucleic acid signal amplification mechanism by nucleic acid region after the peptide region identified the tumor cells. This behavior can greatly improve the sensitivity of the method, thus to realize the sensitive detection of tumor cells. Two kinds of method will be developed according to different sensing mechanism: the interface of electrochemical sensing method and the homogeneous phase of the photochemical sensing method. This project is to provide new methods of cancer early diagnosis.

寻找癌症早期诊断方法是提高癌症治愈率的有效手段之一，本项目拟利用多肽-核酸偶联物（POCs）为传感元件来发展新型的灵敏的癌症诊断方法。由于能识别肿瘤的多肽分子量小、合成与保存简单，且既在生物体内存在，又能通过筛选得到，可克服抗体与核酸适体的不足，因此本项目采用多肽为识别元件，并结合现有成熟的核酸信号放大方法（包括核酸体外扩增技术与DNAzyme技术），设计并合成POCs，用于肿瘤细胞检测方法的开发。本项目中使用的POCs分子探针同时具有目标识别与信号放大的功能，能在多肽部位特异性识别肿瘤细胞后，通过核酸部位引入核酸信号放大机制，大大提高方法的灵敏度，实现对癌症细胞的灵敏检测。利用不同的传感机理，拟开发两种类型的方法用于肿瘤细胞检测：界面上的电化学传感方法以及均相中的光化学传感方法。本项目以期为癌症早期诊断提供适用灵敏的新方法。

癌症早期诊断是提高癌症治愈率的有效手段之一，因此，检测手段需要高灵敏度及低检测限。针对这一需求，本项目利用多肽核酸为传感元件来发展新型的具有高灵敏及低检测限的癌症相关目标物检测方法。主要取得以下成果：（1）设计并合成了具有多种功能的多肽核酸复合物，并详细研究其制备条件对合成产率的影响，及不同的分离条件对回收产率的影响；（2）基于核酸多肽与其目标分子不同的识别方式，建立了多种灵敏的适合癌症相关目标物检测的界面电化学方法及均相中的荧光或化学发光方法；（3）研究发现掺氮氧化石墨烯量子点的多种新性能，详细考察了各种性能的影响因素及适用范围，并开发了多种高灵敏检测小分子及金属离子的新方法。以上工作具有高特异性及灵敏度，步骤简单快速、免分离等特点，将为建立具有快速检测特点的超敏生物分析新方法提供坚实基础。通过该项目，发表SCI学术论文10篇，培养毕业4名研究生。