An ‘activatable’ aptamer-based fluorescence probe for the detection of HepG2 cells

Abstract

It is significant to develop a probe with sensitivity and specificity for the detection of cancer cells. The present study aimed to develop an ‘activatable’ aptamer-based fluorescence probe (AAFP) to detect cancer cells and frozen cancer tissue. This AAFP consisted of two fragments: aptamer TLS11a that targets HepG2 cells, and two short extending complementary DNA sequences with a 5′- and 3′-terminus that make the aptamer in hairpin structure a capable quencher to fluorophore. The ability of the AAFP to bind specifically to cancer cells was assessed using flow cytometry, fluorescence spectroscopy and fluorescence microscopy. Its ability to bind to frozen cancer tissue was assessed using fluorescence microscopy. As a result, in the absence of cancer cells, AAFP showed minimal fluorescence, reflecting auto-quenching. In the presence of cancer cells, however, AAFP showed a strong fluorescent signal. Therefore, this AAFP may be a promising tool for sensitive and specific detection of cancer.

Aptamer: A potential oligonucleotide nanomedicine in the diagnosis and treatment of hepatocellular carcinoma

“…By using HCC cell lines and frozen HCC tissue section, the probe emitted a strong fluorescent signal only in the presence of the target cancer cells. This versatile technology can be adapted for other aptamer sequences targeting various cancers and diseases [ 71 ].…”

A Graphene Oxide-Based Fluorescent Aptasensor for the Turn-on Detection of CCRF-CEM

“…Based on the special tertiary structures, aptamers have robust binding affinity and high specificity with targets, including small organic molecules, proteins, and even cells [ 18 – 20 ]. Moreover, aptamers also have the characteristics of being easily synthesized and modified so that they are widely used as cancer detection probes [ 21 ]. Functionalized nanomaterials based on aptamers for detection of cancer are also hotspots in recent years [ 22 , 23 ], such as quantum dots and silica nanoparticles [ 24 ].…”

“…At present, a great deal of researches reported that the strategy of graphene oxide-based fluorescent aptasensor for detection target is feasible [ 21 , 32 ]. Nevertheless, few studies have been carried out using a GO-based aptasensor for leukemia cells, so far.…”

Current Advances in Aptamers for Cancer Diagnosis and Therapy

“…In their study, a short 5′ strand was added to the fluorescent tag FAM and a complimentary 3′ C-strand was conjugated to the fluorescent quencher Eclipse. The quencher prevented fluorophore expression unless the aptamer came into contact with its target, allowing a conformational change that separated the quencher from the fluorophore [ 93 ]. The activatable aptamer approach was taken further by Lei et al, who developed a theranostic method that not only activates a fluorescent signal upon interaction with its target, but induces the release of a drug.…”