An Immune–Magnetophoretic Device for the Selective and Precise Enrichment of Circulating Tumor Cells from Whole Blood

Abstract

Here, we validated the clinical utility of our previously developed microfluidic device, GenoCTC, which is based on bottom magnetophoresis, for the isolation of circulating tumor cells (CTCs) from patient whole blood. GenoCTC allowed 90% purity, 77% separation rate, and 80% recovery of circulating tumor cells at a 90 μL/min flow rate when tested on blood spiked with epithelial cell adhesion molecule (EpCAM)-positive Michigan Cancer Foundation-7 (MCF7) cells. Clinical studies were performed using blood samples from non-small cell lung cancer (NSCLC) patients. Varying numbers (2 to 114) of CTCs were found in each NSCLC patient, and serial assessment of CTCs showed that the CTC count correlated with the clinical progression of the disease. The applicability of GenoCTC to different cell surface biomarkers was also validated in a cholangiocarcinoma patient using anti-EPCAM, anti-vimentin, or anti-tyrosine protein kinase MET (c-MET) antibodies. After EPCAM-, vimentin-, or c-MET-positive cells were isolated, CTCs were identified and enumerated by immunocytochemistry using anti-cytokeratin 18 (CK18) and anti-CD45 antibodies. Furthermore, we checked the protein expression of PDL1 and c-MET in CTCs. A study in a cholangiocarcinoma patient showed that the number of CTCs varied depending on the biomarker used, indicating the importance of using multiple biomarkers for CTC isolation and enumeration.

Relevance of Circulating Tumor Cells as Predictive Markers for Cancer Incidence and Relapse

“…CTCs are a noninvasive, surrogate sample accessible to longitudinal sampling and could provide a snapshot of PD-L1 status in patients. Detection of PD-L1 positive (PD-L1 + ) CTCs and their prognostic potential have been demonstrated in NSCLC [186][187][188][189][190][191][192][193], BC [194], urothelial carcinoma [195], gastric cancer [196], cholangiocarcinoma [17], and melanoma [197]. Dynamic changes in the expression of PD-L1 in response to radiotherapy have also been reported in a study in NSCLC [191].…”

“…In recent years, numerous systems that rely on the AB-based method for CTC isolation using these biomarkers for a multivalent capture of CTCs have been developed [22,54,55]. A more recent strategy for CTC isolation combines the immune-magnetophoretic approach with a microfluidic approach for more efficient CTC capture [17,[56][57][58].…”

“…Agents targeting MET proved to be effective in patients with MET exon14 deletion and are expected to be effective in MET amplification or MET overexpression; however, there is no consensus on the methods to determine MET amplification in the clinical setting. MET expression and alterations have been detected in CTCs and ctDNA from cancer patients by immunostaining, RT-PCR, dd-PCR or sequencing technologies [17,181,182], and might prove to be a promising strategy in identifying a biomarker to select a MET-addicted tumor that would benefit significantly from anti-MET targeted therapy.…”

Recent advances in targeted drug delivery systems for resistant colorectal cancer

“…a Antigen-dependent (immunoaffinity-based). From [ 46 ] under Creative Common Attribution License.3.0. Copyright (2020) MDPI, b Antigen-independent methods (e.g.…”

Progress and application of circulating tumor cells in non-small cell lung cancer

“…In addition to these, there are many other microdevices and microfluidic platforms to enrich and detect CTCs, such as herringbone chips and, more recently, the CTC-iChip, poly lactic-co-glycolic acid (PLGA)nanofiber (PN)-NanoVelcro chip, 31 a parallel flow micro-aperture chip system, 32 thermoresponsive NanoVelcro CTC purification system, 33 antigen-specific lysis (ASL), 34 and GenoCTC. 35…”