Pang Jilei, Li Pengfei, He Hui, Xu Shuxin, Liu Zhen
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University 163 Xianlin Avenue Nanjing 210023 China
Chem Sci. 2022 Mar 17;13(16):4589-4597. doi: 10.1039/d2sc01093c. eCollection 2022 Apr 20.
Accurately analysing the particular glycosylation status of protein biomarkers is of significant importance in the precise, early diagnosis of cancer. Existing methods mainly rely on the use of antibodies and lectins. However, due to the macroscopic and microscopic heterogeneity of glycans, precise analysis of glycosylation status still remains a challenge. Molecularly imprinted polymers (MIPs), as a synthetic alternative to antibodies or lectins, may provide new solutions but have not yet been explored. Herein, we report an appealing strategy called triple MIP-based plasmonic immunosandwich assay (triMIP-PISA) for precise cancer diagnosis in terms of the relative glycosylation expression of glycoprotein biomarkers. As proof of the principle, alpha fetoprotein (AFP), which has been used as a clinical biomarker for early detection of hepatocellular carcinoma (HCC), as well as its agglutinin (LCA)-reactive fraction (AFP-L3), which is mainly composed of core-fucosylated glycans, were used as two target proteoforms to test in this study. Using two MIPs that can specifically recognize the peptide sequence of AFP as well as a fucose-imprinted MIP that can specifically recognize the AFP-L3 fraction, facile simultaneous plasmon-enhanced Raman detection of AFP and AFP-L3 in serum was achieved, which allowed HCC patients to be distinguished from healthy individuals. Due to the excellent recognition properties of the MIPs that are comparable to those of antibodies and superior to those of lectins, our triMIP-PISA method exhibited improved precision as compared with an antibody plus lectin-based immunofluorescence assay. Thus, this strategy opened a new avenue towards the precise diagnosis of cancer.
准确分析蛋白质生物标志物的特定糖基化状态对于癌症的精确早期诊断具有重要意义。现有方法主要依赖于抗体和凝集素的使用。然而，由于聚糖在宏观和微观上的异质性，糖基化状态的精确分析仍然是一个挑战。分子印迹聚合物（MIPs）作为抗体或凝集素的合成替代品，可能提供新的解决方案，但尚未得到探索。在此，我们报告了一种名为基于三重MIP的表面等离子体免疫夹心测定法（triMIP-PISA）的有吸引力的策略，用于根据糖蛋白生物标志物的相对糖基化表达进行精确的癌症诊断。作为原理验证，甲胎蛋白（AFP）已被用作早期检测肝细胞癌（HCC）的临床生物标志物，以及其凝集素（LCA）反应性部分（AFP-L3），其主要由核心岩藻糖基化聚糖组成，在本研究中用作两种目标蛋白变体进行测试。使用两种能够特异性识别AFP肽序列的MIP以及一种能够特异性识别AFP-L3部分的岩藻糖印迹MIP，实现了血清中AFP和AFP-L3的便捷同时表面等离子体增强拉曼检测，从而能够区分HCC患者和健康个体。由于MIPs具有与抗体相当且优于凝集素的优异识别特性，我们的triMIP-PISA方法与基于抗体加凝集素的免疫荧光测定法相比，精度有所提高。因此，该策略为癌症的精确诊断开辟了一条新途径。
