Isolation and molecular analysis of circulating tumor cells from lung cancer patients using a microfluidic chip type cell sorter

Abstract

Circulating tumor cells (CTCs) are a tumor‐derived material utilized for liquid‐based biopsy; however, capturing rare CTCs for further molecular analysis remains technically challenging, especially in non‐small‐cell lung cancer. Here, we report the results of a clinical evaluation of On‐chip Sort, a disposable microfluidic chip‐based cell sorter, for capture and molecular analysis of CTCs from patients with lung adenocarcinoma. Peripheral blood was collected from 30 metastatic lung adenocarcinoma patients to enumerate CTCs using both On‐chip Sort and CellSearch in a blind manner. Captured cells by On‐chip Sort were subjected to further molecular analysis. Peripheral blood samples were also used for detection of EGFR mutations in plasma using droplet digital PCR. Significantly more CTCs were detected by On‐chip Sort (22/30; median 5; range, 0–18 cells/5 mL blood) than by CellSearch (9/30; median, 0; range, 0–12 cells/7.5 mL) (P < 0.01). Thirteen of 30 patients who had a negative CTC count by CellSearch had a positive CTC count by On‐chip Sort. EGFR mutations in CTCs captured by On‐chip Sort were observed in 40.0% (8/20) of patients with EGFR‐mutated primary tumor. EGFR mutations were often observed in 53.3% (8/15) of patients detected in plasma DNA. Expressions of EGFR and vimentin protein on CTCs were also successfully assessed using On‐chip Sort. These results suggest that On‐chip Sort is an efficient method to detect and capture rare CTCs from patients with lung adenocarcinoma that are undetectable with CellSearch. Mutation detection using isolated CTCs remains to be further tackled (UMIN000012488).

A Novel Model of Cancer Drug Resistance: Oncosomal Release of Cytotoxic and Antibody-Based Drugs

“…The Sca-1+ metastatic phenotype was inhibited by both COX2 inhibitors and PGE2 receptor antagonists [95]. In addition to the COX2/prostaglandins cascade, other eicosanoids such as LTs and EETs, FAs, fatty acid-binding proteins (FABPs), and sphingolipids, are signaling lipids that induce malignant phenotypes, including EMT, CSC/CIC pool, circulating tumor cells (CTCs), and metastatic dissemination of exosome/ oncosome [157][158][159]. Moreover, the transfer of acid sphingomyelinase (ASM) contributes to drug resistance in multiple myeloma (MM) [160].…”

Detection of AXL expression in circulating tumor cells of lung cancer patients using an automated microcavity array system

“…CTCs are thought to be metastatic cells from the solid tumor site and are one of the avenues for metastasis from the primary tumor site to distant tissues, thus CTCs are associated with tumor progression and patient prognosis . Moreover, because it is thought that CTCs reflect characteristics of the primary solid tumor such as genetic alterations and expression of therapeutic targets, CTCs may be useful for estimating established biomarkers that can monitor response to treatment and the presence or lack of tumor‐specific therapeutic targets . Therefore, the detection and analysis of CTCs could be a minimally invasive diagnostic procedure for repetitive monitoring and deciding on therapeutic strategy.…”

“…6,7 Moreover, because it is thought that CTCs reflect characteristics of the primary solid tumor such as genetic alterations and expression of therapeutic targets, 8,9 CTCs may be useful for estimating established biomarkers that can monitor response to treatment and the presence or lack of tumor-specific therapeutic targets. [10][11][12] Therefore, the detection and analysis of CTCs could be a minimally invasive diagnostic procedure for repetitive monitoring and deciding on therapeutic strategy. CellSearch is the only FDA-approved CTC enumeration platform and has demonstrated the clinical utility of CTCs in a several cancers, 7,13,14 however, their utility in non-small cell lung cancer (NSCLC) has been limited by the low expression of EpCAM in CTCs derived from NSCLC patients.…”

Heterogeneous Expression of Programmed Death Receptor-ligand 1 on Circulating Tumor Cells in Patients With Lung Cancer

“…[6][7][8] Moreover, it has been reported that CTCs could potentially serve as an alternative to tumor tissue as a source of material for the detection of genetic alterations and the expression of therapeutic targets. 9 This approach of analyzing CTCs for diagnostic or prognostic purposes is termed a "liquid biopsy," owing to its minimal invasiveness. We previously reported that more CTCs were detectable with a high specificity using a novel sensitive microcavity array (MCA) system in patients with lung cancer among whom it is difficult to detect CTCs using the United States Food and Drug Administration-approved CELLSEARCH system.…”