Aptamer-Based Detection of Epithelial Tumor Marker Mucin 1 with Quantum Dot-Based Fluorescence Readout

Abstract

Mucin 1 (MUC1) is a glycoprotein expressed on most epithelial cell surfaces, which has been confirmed as a useful biomarker for the diagnosis of early cancers. In this paper, we report an aptamer-based, quantitative detection protocol for MUC1 using a 3-component DNA hybridization system with quantum dot (QD)-labeling: in the absence of MUC1 peptides, strong fluorescence is observed upon mixing the three specially designed DNA strands (quencher, QD-labeled reporter, and the MUC1 aptamer stem); in the presence of MUC1 peptides, a successive decrease in fluorescence intensity is detected since the MUC1 peptide binds to the aptamer strand in such a way to allow the quencher and fluorescence reporter to be brought into close proximity (which leads to the occurrence of fluorescence resonance energy transfer, FRET, between the quencher and QD). The detection limit for MUC1 with this novel approach is in the nanomolar (nM) level, and a linear response can be established for the approximate range found in blood serum. This study also provided further insight into the aptamer/analyte binding site/mode for MUC1, which augments the possibility of improving this detection methodology for the early diagnosis of different types of epithelial cancers of large populations.

Self-assembled polymeric nanoparticles as new, smart contrast agents for cancer early detection using magnetic resonance imaging

“…27 In addition MUC1 has been tested as target for quantum dot and gold nanoparticle-mediated cancer diagnosis or therapy. [31][32][33] Confirming previously published data, 34 we verified that the MDA-MB-468 and MCF-7 human breast adenocarcinoma cell lines, but not the unrelated HEK293T cell line, expressed high levels of MUC1 mRNA ( Figure 7A) …”

Applications of Aptamers in Drug Delivery System

“…After the final round, the PCR products are cloned into a vector and sequenced to allow for identification of the best binding sequences. [14] reported a MUC1 aptamer-based, quantitative detection protocol for MUC1 using a three-component DNA hybridization system labeled with quantum dot (QD). In the absence of MUC1 peptides, strong fluorescence is observed after mixing the designed DNA strands (quencher, QD-labeled reporter, and the MUC1aptamer stem) while in the presence of MUC1 peptides, a decrease in fluorescence intensity is detected.…”

“…MUC1 aptamers (Fig.4) can recognize MUC1 which was overexpressed in all human epithelial cell adenocarcinomas [14,[32][33][34][35] They connected MUC1 aptamer with Qdots. Dox was attached to Qdots via a pH-sensitive hydrazone bond.…”

Quantum Dots in Cell Biology

“…Single-bead FRET-based immunoassays have been developed to detect anti-topoisomerase I antibodies, a marker of systemic sclerosis autoimmune disease (Sukhanova and Nabiev 2008;Sukhanova et al 2007). Recently, aptamers have been used in the detection of epithelial tumor marker mucin 1 using a FRET-based assay (Cheng AK et al 2009). FRET is an adequate strategy for the development of assays for disease biomarkers because it can be performed in the presence of unbound as well as bound QD probes, avoiding time-consuming wash steps (Wagner et al 2010).…”