Novel Peptide-Based Magnetic Nanoparticle for Mesenchymal Circulating Tumor Cells Detection.

The monitoring of circulating tumor cells (CTCs) has recently served as a promising approach for assessing prognosis and evaluating cancer treatment. We have already developed a CTCs enrichment platform by EpCAM recognition peptide-functionalized magnetic nanoparticles (EP@MNPs). However, considering heterogeneous CTCs generated through epithelial-mesenchymal transition (EMT), mesenchymal CTCs would be missed with this method. Notably, N-cadherin, overexpressed on mesenchymal CTCs, can facilitate the migration of cancer cells. Hence, we screened a novel peptide targeting N-cadherin, NP, and developed a new CTCs isolation approach via NP@MNPs to complement EpCAM methods' deficiencies. NP@MNPs had a high capture efficiency (about 85%) of mesenchymal CTCs from spiked human blood. Subsequently, CTCs were captured and sequenced at the single-cell level via NP@MNPs and EP@MNPs, RNA profiles of which showed that epithelial and mesenchymal subgroups could be distinguished. Here, a novel CTCs isolation platform laid the foundation for mesenchymal CTCs isolation and subsequent molecular analysis.