Spatially Selective MicroRNA Imaging in Human Colorectal Cancer Tissues Using a Multivariate-Gated Signal...

Area of Science:

• Biomedical Engineering
• Molecular Oncology
• Diagnostic Imaging

Background:

• MicroRNA (miRNA) dysregulation is crucial in colorectal cancer (CRC) development and progression.
• Accurate in vivo imaging of miRNAs in tumors is vital for understanding CRC pathology and identifying therapeutic targets.
• Challenges include low miRNA abundance and background signal in normal tissues, hindering precise imaging.

Purpose of the Study:

• To develop a specific, amplified imaging nanosensor for microRNA-21 (miR-21) in human colorectal cancer tissues.
• To elucidate the molecular mechanism underlying miR-21's role in CRC.
• To improve the accuracy of in vivo miRNA detection for clinical applications.

Main Methods:

• A multivariate-gated catalytic hairpin assembly (CHA) nanosensor was designed, incorporating endogenous glutathione and exogenous near-infrared triggers.
• The nanosensor utilizes CHA probes for signal amplification and background noise reduction.
• In vivo imaging and analysis of miR-21 expression in human colorectal cancer and normal tissues were performed.

Main Results:

• The nanosensor achieved specific amplified imaging of miR-21 in vivo with a 1.6-fold improvement in signal-to-background ratio compared to traditional CHA methods.
• Preliminary identification of tumor and normal tissues from clinical samples was achieved.
• Overexpressed miR-21 was found to suppress human mutS homologue 2, a DNA repair protein, thereby inhibiting CRC therapeutic efficacy.

Conclusions:

• The developed multivariate-gated CHA nanosensor enables accurate and amplified in vivo imaging of miR-21 in colorectal cancer.
• This approach facilitates the investigation of miRNA-associated molecular mechanisms, such as miR-21's suppression of DNA repair pathways.
• The strategy holds promise for advancing miRNA imaging and molecular mechanism research in cancer.