Asymmetric Hairpins DNA Encapsulated Silver Nanoclusters for In Situ Fluorescence Imaging of Fusion Gene Isoforms in Bone Marrow

Abstract

Rapid and accurate imaging of the BCR/ABL fusion gene isoforms (e.g., e13a2, e14a2 and co‐expression type) of chronic myeloid leukemia (CML) is of vital importance to first‐line drug selection, but there is no assay that meets clinical needs (e.g., clinical kits > 18 h without isoforms information). Herein, an in situ imaging platform is developed for the rapid and accurate detection of CML fusion gene isoforms using asymmetric sequence‐enhanced hairpins DNA encapsulated silver nanoclusters (ADHA) and catalyzed hairpin assembly (CHA). The specific detection of e13a2 and e14a2 fusion gene isoforms with detection limits of 19.2 am (11.558 copies µL−1) and 32.56 am (19.601 copies µL−1) in one‐pot is achieved. The feasibility of the developed assay for real‐world applications are demonstrated by one‐step fluorescence imaging (40 min) of e13a2, e14a2 and co‐expression type in bone marrow quantitatively (International Standard: 15.66%–168.878%) and further validated by cDNA‐sequencing. This work suggests that the developed imaging platform holds great potential for rapid identification of the fusion gene isoforms and isoform related treatment monitoring.

Recent Advances in the Preparation and Application of DNA-Encoded Metal Nanoclusters

“…This strategy exhibited good applicability in detecting actual samples containing complex components and holds potential for rapid quantitative detection of ARGs in various environmental media. Moreover, varieties of bioanalytical platforms have been constructed [2,64,78] on the basis of direct fluorescence regulation of DNA-MNCs. For example, our group adopted strand exchange reaction to reversibly regulate fluorescence of dsDNA-Ag NCs [79] and developed a DNA-Ag NC-based molecular beacon for detection of virus genes [80].…”

“…In recent years, various amplification strategies, such as polymerase chain reaction (PCR) [82], loop-mediated isothermal amplification (LAMP) [83], and nuclease-assisted signal amplification (DSNSA) [63], have been successfully integrated into DNA-Ag NCbased analytical systems to achieve a limit of detection (LOD) as low as fM or aM. For Moreover, varieties of bioanalytical platforms have been constructed [2,64,78] on the basis of direct fluorescence regulation of DNA-MNCs. For example, our group adopted strand exchange reaction to reversibly regulate fluorescence of dsDNA-Ag NCs [79] and developed a DNA-Ag NC-based molecular beacon for detection of virus genes [80].…”

“…This work provided one new approach to fabricating cost-effective logic systems. On the basis of head-to-head dimerization of DNA-Ag NCs and concomitant fluorescence change, an in situ imaging platform was developed for rapid identification of fusion gene subtypes and subtype (e13a2 and e14a2) [2]. As shown in Figure 5B, four DNA-Ag NC-loaded hairpin DNA fuels (ADHA1, ADHA2, ADHA3, and ADHA4) were prepared for recognizing e13a2 and e14a2 with CHA1 and CHA2, respectively.…”

“…Metal (Ag, Au, Cu, etc.) nanoclusters (MNCs) with sub-nanometer sizes have been prepared with DNA strands as templates and widely studied in the past decade due to prominent optical, catalytic, or antibacterial features [2][3][4][5]. The physicochemical characteristics of MNCs are closely related to DNA templates and can be adjusted with dictated DNA strands, and thus so-called DNA-encoded MNCs (DNA-MNCs) can be defined and have been developed.…”