Chen Hang, Zhang Shurui, Hsiao Yung-Chin, Wang Qun, Yu Jau-Song, Li Wanming
Experiment Teaching Center of Functional Subjects, College of Basic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, China.
Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, China.
Polymers (Basel). 2022 Jul 27;14(15):3040. doi: 10.3390/polym14153040.
Early diagnosis of metastatic colorectal cancer (mCRC) is extremely critical to improve treatment and extend survival. W3 is an aptamer that can specifically bind to mCRC cells with high affinity. Graphene oxide (GO) is a two-dimensional graphitic carbon nanomaterial, which has widely used in constructing biosensors. In this study, we have developed a no-wash fluorescent aptasensor for one-step and sensitive detection of mCRC LoVo cells. It is based on fluorescence resonance energy transfer (FRET) between GO and the W3 aptamer labeled with 5-carboxyfluorescein (FAM). GO can quench the green fluorescence of the FAM-labeled W3 (FAM-W3). In the presence of the target cells, FAM-W3 preferentially binds the target cells and detaches from the surface of GO, leading to the fluorescence of FAM recovery. It was demonstrated that the fluorescence recovery increases linearly in a wide range of 0~10 cells/mL (R = 0.99). The GO-based FAM-labeled W3 aptasensor (denoted as FAM-W3-GO) not only specifically recognizes mCRC cell lines (LoVo and HCT116), but also sensitively differentiates the target cells from mixed cells, even in the presence of only 5% of the target cells. Furthermore, FAM-W3-GO was applied to detect LoVo cells in human whole blood, which showed good reproducibility with an RSD range of 1.49% to 1.80%. Therefore, FAM-W3-GO may have great potential for early diagnosis of mCRC. This strategy of GO-based fluorescent aptasensor provides a simple, one-step, and highly sensitive approach for the detection of mCRC cells.
转移性结直肠癌（mCRC）的早期诊断对于改善治疗和延长生存期极为关键。W3是一种适体，能够以高亲和力特异性结合mCRC细胞。氧化石墨烯（GO）是一种二维石墨碳纳米材料，已广泛应用于构建生物传感器。在本研究中，我们开发了一种无需洗涤的荧光适体传感器，用于一步法灵敏检测mCRC LoVo细胞。它基于GO与标记有5-羧基荧光素（FAM）的W3适体之间的荧光共振能量转移（FRET）。GO可以淬灭FAM标记的W3（FAM-W3）的绿色荧光。在存在靶细胞的情况下，FAM-W3优先结合靶细胞并从GO表面脱离，导致FAM荧光恢复。结果表明，在0~10个细胞/mL的宽范围内，荧光恢复呈线性增加（R = 0.99）。基于GO的FAM标记的W3适体传感器（记为FAM-W3-GO）不仅能特异性识别mCRC细胞系（LoVo和HCT116），还能灵敏地将靶细胞与混合细胞区分开来，即使在仅存在5%靶细胞的情况下。此外，FAM-W3-GO被应用于检测人全血中的LoVo细胞，其相对标准偏差（RSD）范围为1.49%至1.80%，显示出良好的重现性。因此，FAM-W3-GO在mCRC的早期诊断中可能具有巨大潜力。这种基于GO的荧光适体传感器策略为mCRC细胞的检测提供了一种简单、一步法且高度灵敏的方法。
