Poly-adenine-mediated spherical nucleic acid probes for live cell fluorescence imaging of tumor-related microRNAs.

Abstract

BACKGROUND:

Accurately detecting and quantifying tumor-related microRNAs (miRNAs) in living cells is of great value for early cancer diagnosis. Herein, we present poly-adenine (polyA)-mediated spherical nucleic acid (SNA) nanoprobes for intracellular miRNA imaging in living cells.

METHODS AND RESULTS:

polyA-mediated spherical nucleic acid (pASNA) nanoprobes consist of gold nanoparticles (AuNPs) anchored with fluorophore-labeled DNA molecules pre-hybridized with recognition sequences and polyA tails. The detection performance for miRNAs in vitro was studied to confirm the feasibility of pASNA nanoprobes for imaging live cell miRNAs. Before the pASNA nanoprobes were used for imaging intracellular miRNAs in MCF-7, HeLa, and LO2 cells, the stability and non-cytotoxicity were investigated using Dnase I and a standard colorimetric CCK8 assay. Flow cytometry, qRT-PCR analyses were conducted to confirm the different expression levels of miR-155 in live cells. Results showed that the pASNA nanoprobes had good detection sensitivity and specificity, excellent stability, and low toxicity. After incubating with pASNA nanoprobes, noticeable fluorescence signal enhancement could be clearly observed in MCF-7 and HeLa cells but not LO2 cells by confocal microscopy. Flow cytometry analysis and qRT-PCR indicated that MCF-7 and HeLa cells had higher miR-155 expression levels compared to LO2 cells.

CONCLUSIONS:

The pASNA nanoprobes we developed had good sensitivity and specificity, excellent nuclease stability and low toxicity, thus representing a new approach to exquisitely reveal the distribution of endogenous miRNAs in live cells.

• Authors: Qiuling Qian, Guifang He, Chenguang Wang, Shuainan Li, Xiaoshuang Zhao, Yi Xu, Xianqiang Mi
• Journal: Molecular biology reports (Mol Biol Rep) Vol. 49 Issue 5 Pg. 3705-3712 (May 2022) ISSN: 1573-4978 [Electronic] Netherlands
• PMID: 35122597 (Publication Type: Journal Article)
• Copyright: © 2022. The Author(s), under exclusive licence to Springer Nature B.V.

Chemical References

• MicroRNAs
• Nucleic Acid Probes
• Nucleic Acids
• polyadenine
• Poly A
• Gold

Topics

• Gold
• HeLa Cells
• Humans
• Metal Nanoparticles
• MicroRNAs (analysis, genetics)
• Nucleic Acid Probes
• Nucleic Acids
• Optical Imaging
• Poly A