Homotypic and heterotypic adhesion of cancer cells revealed by force-induced remnant magnetization spectroscopy.

Intercellular interaction has tremendous impacts on physiological processes, while unsuccessful cell-cell interaction causes diseases, such as tumorigenesis and metastasis. In-depth investigation of cell-cell adhesions is of great significance to understand the pathological state of cells, and for the rational design of drugs and therapies. Herein, we developed a force-induced remnant magnetization spectroscopy (FIRMS) method to measure cell-cell adhesion in a high throughput way. Our results showed that FIRMS is capable of quantifying and identifying cell-cell adhesion with high detection efficiency. Specifically, we quantified homotypic and heterotypic adhesion forces during tumor metastasis using breast cancer cell lines. We observed that homotypic and heterotypic adhesion forces of cancer cells were associated with degrees of malignancy. In addition, we revealed that CD43-ICAM-1 was a ligand-receptor pair mediating heterotypic adhesion of breast cancer cells to endothelial cells. These findings contribute to advance in-depth understanding of the process of cancer metastasis and provide insight into targeting intercellular adhesion molecules as a potential strategy to inhibit cancer metastasis.

Force-Coded Strategy for the Simultaneous Detection of Multiple Tumor-Related Proteins.

Multiplexed simultaneous detection of various cancer markers is required for accurate diagnosis and treatment of early cancer. In this work, we present a force-coded strategy for the simultaneous detection of tumor-related proteins with tunable dynamic range via magnetic sensing. The multiplexing capability of this method is achieved by designing DNA devices that can recognize different biomarkers and code them with different binding forces measured by the force-induced remnant magnetization spectroscopy, which is not influenced by the color of the light and the solution. Moreover, the force-coded assay with high sensitivity and adjustable detection range is robust, which could be used for practical biological applications such as magnetic sensing, handheld miniaturized systems, and potential in vivo diagnosis.

Advances in the Biological Application of Force-Induced Remnant Magnetization Spectroscopy.

Biomolecules participate in various physiological and pathological processes through intermolecular interactions generally driven by non-covalent forces. In the present review, the force-induced remnant magnetization spectroscopy (FIRMS) is described and illustrated as a novel method to measure non-covalent forces. During the FIRMS measurement, the molecular magnetic probes are magnetized to produce an overall magnetization signal. The dissociation under the interference of external force yields a decrease in the magnetic signal, which is recorded and collected by atomic magnetometer in a spectrum to study the biological interactions. Furthermore, the recent FIRMS development with various external mechanical forces and magnetic probes is summarized.