Abstract

Integrated Microfluidic System for Single Cell Analysis of Circulating Tumor Cell Sub-populations with Divergent Phenotypes

Steve Soper, Foundation Distinguished Professor; Director, Center of BioModular Multi-scale System for Precision Medicine, Adjunct Professor, Ulsan National Institute of Science & Technology, The University of Kansas

Steven A. Soper,1,2,5 Jen Jen Yeh,3,4 George Martin,6 Makgorzata Witek,1 Joyce Kumande,1 Matthew Jackson2 and Mateusz Hupert1,5 University of North Carolina, Chapel Hill, 1Department of Biomedical Engineering 2Department of Chemistry, 3Department of Surgery, 4 Lineberger Comprehensive Cancer Center Chapel Hill, North Carolina, 5 BioFluidica Chapel Hill, NC,  6 Roche Molecular Systems, Pleasanton, CA
While metastatic disease causes ~90% of all cancer related deaths, determining the role of various cancer cells, either from the primary tumor or those in circulation (circulating tumor cells, CTCs), in the metastatic process has been difficult due to the continuum of phenotypes they possess and/or the rare nature of these cells, especially CTCs. To assist in studies based on the use of rare CTCs that may be involved in metastasis, an integrated microfluidic system was designed, fabricated and evaluated, which could select multiple types of cells, including cells that have an epithelial phenotype and those that possess the ability to  digest the extracellular matrix (ECM). The system consisted of two CTC selection units, an electrical impedance sensor for single cell characterization, an imaging unit for phenotyping single cells and a molecular analysis unit for detecting mutations or expression profiling certain genes. The integrated system could correlate a cell’s phenotype to its genotype. The CTC selection units contained a series of 190 nL fluidic channels the walls of which were decorated with antibodies used to recognize and select various sub-populations of CTCs from a single sample. The cell selection unit could process 7.5 mL of whole blood in ~20 min with a selection recovery of 97% and purity >80%. Individual CTCs could be released from the surface-immobilized antibodies and counted by measuring impedance signatures of single cells that traversed through a pair of electrodes. The CTCs were then stained and phenotyped with the appropriate cell