Multigated DNA Cascade Amplifier for Ultrasensitive Spatiotemporal Imaging of PLS3 mRNA at the Single-Cell Level for Early Detection of Breast Cancer Metastasis.

Early detection of small metastatic foci is crucial for improving breast cancer patient survival. Plastin-3 (PLS3) has emerged as a key biomarker in breast cancer metastasis due to its role in cytoskeletal remodeling and cell motility. Herein, we developed a multigated DNA cascade amplifier (MDCA) for the highly sensitive and specific detection of PLS3 mRNA. This system integrates a multigated activation strategy and dual signal amplification, ensuring both precise spatiotemporal control and high sensitivity in imaging of breast cancer metastasis. DNA hairpin probes were preadsorbed on MnO2 nanoflowers to facilitate intracellular delivery, while intracellular glutathione (GSH) and external UV light enabled programmed probe release. The combination of PLS3 mRNA-triggered hybridization chain reaction (HCR) and APE1-mediated enzyme catalytic amplification leads to a notable increase in detection sensitivity, achieving a detection limit of 5.8 aM. The MDCA was applied for in vitro sensing of PLS3 mRNA in breast cancer cell lines at the single-cell level. More importantly, with the aid of machine learning models, the MDCA facilitates the visualization of breast cancer metastasis in clinical tissue samples, with an excellent accuracy of more than 92%. This method holds great promise for early diagnosis, evaluating metastasis risk, and advancing precision oncology.