A two-layer circuit cascade-based DNA machine for highly sensitive miRNA imaging in living cells

Lin Yang ¹, Yan Zang ¹, Peng Liu ¹

⁰School of Chemical Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying 257061, P. R. China. 2021020@sdipct.edu.cn.

The Analyst +

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April 8, 2024

View abstract on PubMed

Summary

This study introduces a novel DNA machine for ultrasensitive detection of microRNA (miRNA) in living cells. The system achieves highly sensitive quantification and imaging of low-abundance miRNA, crucial for early cancer diagnosis.

Area Of Science

Biotechnology
Molecular Biology
Nanotechnology

Background

MicroRNAs (miRNAs) are vital biomarkers for cancer diagnosis.
Low miRNA expression levels necessitate ultrasensitive detection methods.
Existing methods often lack the sensitivity and selectivity required for clinical applications.

Purpose Of The Study

To develop an ultrasensitive and highly selective DNA machine for detecting and imaging low-abundance miRNA in living cells.
To create a cascade system for amplified miRNA detection based on toehold-mediated strand displacement reactions (TMSDR).
To establish a sensitive platform for quantifying specific miRNA biomarkers like miR-203.

Main Methods

Construction of a two-layer, enzyme-free DNA machine utilizing TMSDR.
Integration of two DNA circuits in a cascade system for signal amplification.
Transfection of the DNA machine into breast cancer cells for in situ miRNA detection and fluorescence imaging via FRET.

Main Results

Achieved a detection limit as low as 4 fM for miR-203 quantification.
Demonstrated a 10,000-fold improvement in amplification efficiency compared to single circuits.
Successfully performed amplified analysis and imaging of low-abundance miRNA in living cells.

Conclusions

The developed two-layer cascade DNA machine offers a highly sensitive platform for analyzing low-abundance miRNAs.
This technology holds significant promise for advancing biomedical and clinical research, particularly in cancer diagnostics.
The enzyme-free, isothermal nature of the DNA machine enhances its applicability in various settings.