Encoding DNA Frameworks for Amplified Multiplexed Imaging of Intracellular microRNAs

Area of Science:

• Biomedical Engineering
• Molecular Biology
• Nanotechnology

Background:

• Simultaneous imaging of low-abundance microRNAs (miRNAs) in living cells is crucial for cancer diagnosis and prognosis.
• Developing stable, signal-amplifying nanoprobes for in vivo imaging remains a challenge due to enzyme degradation.

Purpose of the Study:

• To develop a sensitive and selective method for real-time, multicolor imaging of multiple miRNAs in living cells.
• To create a stable nanoprobe with enhanced signal amplification for intracellular miRNA detection.
• To utilize the nanoprobe for discriminating cancer cells from normal cells.

Main Methods:

• One-pot assembly of multicolor tetrahedral DNA frameworks (TDFs) encoding multicomponent nucleic acid enzymes (MNAzymes).
• Encoding MNAzymes specific for miRNA-21 and miRNA-155 with fluorescein labeling within TDFs.
• Utilizing AS1411 aptamer for targeted binding to nucleolin on cancer cells.

Main Results:

• TDFs demonstrated self-delivery into cells with good biocompatibility and stability.
• The TDFs enabled specific binding to target miRNAs, triggering circular fluorescence signal amplification.
• High sensitivity and selectivity were achieved for miRNA identification in different cell lines.
• The TDFs effectively discriminated between cancer cells and normal cells based on nucleolin expression.

Conclusions:

• The developed TDFs provide a sensitive and stable platform for multiplexed miRNA imaging in living cells.
• This strategy offers an efficient tool for understanding miRNA roles in cancer pathogenesis.
• The TDFs hold potential for cancer diagnosis and therapeutic applications.