# Quantitative oncogene-mapping within malignant tumors through Multi-parameter MRI based on RNA-triggered nanoprobes

## TL;DR

Researchers developed a new MRI method using nanoprobes to detect and quantify cancer-related miRNA in tumors, offering a potential tool for early and precise tumor diagnosis.

## Contribution

A novel RNA-triggered nanoprobe strategy using MRET for in vivo quantitative miRNA imaging in tumors.

## Key findings

- Nanoprobes enabled in vivo tumor detection using T1/T2 dual-modality MRI.
- Quantitative visualization of miR-21 was achieved in subcutaneous tumor models.
- A direct correlation between MRI signals and miR-21 concentration was established in vivo.

## Abstract

Genomic instability is the important foundation and feature of cancer; hence, the precise oncogene detection is crucial for early diagnosis and pathological analysis of tumors. However, the in vivo oncogene-imaging is confronted with great challenge, due to the extremely low copies of oncogene in cancer cells. Herein, we proposed a strategy of T1/T2 magnetic resonance imaging (MRI) based on magnetic resonance tuning (MRET) to analyze tumor-associated miRNA quantitatively. The superparamagnetic quencher Fe3O4 nanoparticles and the paramagnetic enhancer Gd-DTPA were integrated by the DNA linker. The AS1411 aptamer was embedded at the end of the DNA linker to effectively target nucleolins that are overexpressed in tumor cells. As hybridization with targeted miRNA, the Gd3+ labeled tumor-associated nucleotide sequence is released, enhancing T1 signals and enabling specific localization and quantification of the targeted miRNA. The MRET effect was verified in vitro through mixing with varying concentrations of miR-21. Enhanced T2 signals and activated T1 signals were visualized in 4T1 or CT26 subcutaneous tumor models in vivo. Ultimately, the quantitative relation between MRI signals and local miR-21 concentration was established in vivo. These results indicated the potential of nanoprobes for tumor-related genes diagnosis and quantification, further affirming the possibility of prompt and precise tumor diagnosis.

The T1 signals of magnetic resonance imaging (MRI) nanoprobes were activated via magnetic resonance tuning (MRET), enabling quantitative visualization the cancer-related miR-21 in vivo.Image 1

•RNA-triggered nanoprobes were developed via MRET strategy upon RNA hybridization.•The nanoprobes enabled in vivo tumor detection through T1/T2 dual-modality MRI.•The nanoprobes enabled in vivo quantitative visualization of miR-21.

RNA-triggered nanoprobes were developed via MRET strategy upon RNA hybridization.

The nanoprobes enabled in vivo tumor detection through T1/T2 dual-modality MRI.

The nanoprobes enabled in vivo quantitative visualization of miR-21.