It has been acknowledged that
circulating tumor cells (CTCs) are promising
biomarkers in liquid biopsy for
cancer diagnosis and prognosis. However, the relationship between the CTC number and
gastric cancer has scarcely been quantitatively investigated. Moreover, the single criterion of
epithelial cell adhesion molecule (
EpCAM) antibody/aptamer to specifically recognize epithelial CTCs cannot be universally applied for clinical applications, as it fails to recognize
EpCAM-negative CTCs. Herein, we propose simple, low-cost, dual-aptamer (
EpCAM and PTK7)-modified immunomagnetic Fe3O4 particles (IMNs) for efficient capture of heterogeneous CTCs and downstream analysis in
gastric cancer patients. High PTK7 expression and a significant negative correlation between PTK7 and
EpCAM expression were observed in primary
gastric cancer tissues. Taking MGC-803 and BGC-823 cells as CTC models, the obtained dual-targeting IMNs could distinguishably recognize these cells with both high or low
EpCAM and PTK7 expressions, which enhanced the accuracy of CTC recognition in
gastric cancer. More than 95% of these two kinds of cells could be captured within 20 min of incubation, which was significantly more efficient than that of single
EpCAM- or PTK7-modified IMNs. With this strategy, as low as five CTCs could be captured from
phosphate-buffered saline (PBS), a cell mixture containing THP-1 cells, and lysed blood mediums. Moreover, the obtained CTCs can be used for subsequent gene analysis. Finally, the fabricated IMNs were successfully applied for CTC capture in 1.0 mL of peripheral blood samples from patients with
gastric cancer. The detected CTC numbers in 72 participants were found to have close relationships with
chemotherapy sensitivity, diagnosis, stage, and distant
metastasis of patients. This work provides important references for further investigations on CTC-related diagnosis and individualized treatment.