Abstract 4901: Preliminary investigation of circulating NSCLC cells using dielectrophoresis-based instrumentation
Authors: Francesco Fabbri, Silvia Carloni, Paola Ulivi, Laura Mercatali, Carlo Milandri, Marianna Ricci, Dino Amadori, Wainer Zoli
Journal: Cancer Research (2011)

Abstract Aims: The study of rare cell populations is an extremely important field in cancer research. Our main aim was to carry out a preliminary investigation into a new technological platform capable of identifying and studying rare tumor cells in whole blood samples from patients with advanced cancer. Methods: The study was performed using DEPArray™, a new dielectrophoresis-based instrumentation capable of detecting, examining and sorting circulating tumor cells (CTCs) in a very small quantity (microliters) of enriched whole blood. Analyses were conducted on 3 blood samples from patients with EGFR-mutated metastatic NSCLC and on 15 samples composed of A549 cells spiked into the whole blood of healthy donors. Whole blood starting volume was 7.5 ml. After Ficoll-Paque centrifugation, tumor cells were immunomagnetically enriched via EpCam positive selection or CD45 negative depletion and then fixed and stained with Hoechst and fluorescent conjugated antibodies against CD45 and pan-cytokeratin. Cell recovery was followed by EGFR gene mutation evaluation through sequence analysis. Results: Preliminary data showed that DEPArray™ detected, isolated and sorted enriched CTCs with 100% purity, with no lymphocyte contamination in subsequent analyses. Single or multiple cell sorting was possible, making it simple to perform different downstream molecular assays. In particular, the EGFR gene mutation status of NSCLC was studied to find out whether mutations were present or whether gene status remained that observed in the primary tumor tissue. Although it was decided to work on fixed cells during the investigation of this first set of samples, DEPArray™ is also capable of sorting live cells with high specificity. Conclusions: The study of infrequent tumor or tumor-related cells such as circulating tumor cells, cancer stem cells and/or circulating endothelial cells is an increasingly important area of research from both a preclinical and clinical point of view. A growing number of studies have evaluated different methods and variables involved in the detection of rare cells, in particular CTCs, but there is still no general consensus on the most accurate method to use. DEPArray™ is an innovative dielectrophoresis-based instrument capable of identifying, manipulating and sorting rare live and fixed cells with extremely high purity. Although the most accurate markers to discriminate between normal epithelial cells and tumor cells have yet to be defined, DEPArray™ has already proven to be extremely versatile in the field of rare cell studies, introducing new possibilities such as 100%-pure retrieval of live cells and furthering its potential as a promising new strategy for cancer cell detection and characterization. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4901. doi:10.1158/1538-7445.AM2011-4901