Detection of circulating tumor cells using antibody-functionalized microchips to monitor tumorigenesis in a mouse model of metastatic breast cancer

Circulating tumor cell (CTC)-based liquid biopsy has been a promising and potentially informative diagnostic approach. However, its clinical application has remained limited until now, in part due to the lack of systematic research to validate the new technologies for CTC enrichment. In this work, we established a 4T1 mouse model of breast cancer recurrence after surgery to evaluate microfluidic-based CTC detection and monitor tumor recur-rence. The time point detected by CTC analysis using EpCAM antibody-functionalized chip was first compared with in vivo bioimaging and pathological examination for monitoring metastasis. The CTCs were monitored after tumor resection to evaluate CTC detection for postoperative monitoring of tumor recurrence. Using an antibody-functionalized chip, CTCs can be detected 10-days earlier than being detected with other imaging technologies. The CTC detection assay also showed that EpCAM+ CTC populations increased with tumor growth, whereas EpCAM+ CSV+ CTCs increased first and then decreased, possibly indicating multistep tumorigenesis in this model. Monitoring of CTCs after tumor resection indicated that CTCs were gradually cleared from the blood during mice recovery. These results provide a basis for CTC detection to monitor tumorigenesis and metastasis, as well as a model for validating other liquid biopsy methods.

Automated summary

Circulating tumor cell (CTC)-based liquid biopsy has great potential as a diagnostic approach, but its clinical application has been limited due to a lack of systematic research. In this study, a mouse model of breast cancer recurrence was used to evaluate a microfluidic-based CTC detection method. The results showed that CTCs could be detected earlier using an EpCAM antibody-functionalized chip compared to other imaging technologies. Monitoring of CTCs after tumor resection indicated their gradual clearance from the blood. These findings provide a basis for CTC detection in monitoring tumorigenesis and metastasis.