Abstract 1688: Mutation and gene expression analysis of circulating tumor cells (CTCs) enriched and retrieved by a sensitive microfluidic device

Abstract

Abstract Molecular characterization of CTCs is hindered by low sensitivity and high level of background leukocytes of currently available CTC enrichment devices and assays. We have developed a novel technology to enrich and retrieve CTCs from blood samples using a microfluidic chip. The Celsee PREP100 device captures CTCs with high sensitivity and then allows the captured CTCs to be retrieved for subsequent molecular analysis. The Celsee PREP100 system uses the microfluidic chip which has approximately 56,320 capture chambers. Based on differences in cell size and deformability, each chamber ensures that small blood cells such as red blood cells and most leukocytes escape while larger CTCs are trapped and isolated in the chambers. In the work we used the Celsee PREP100 to capture breast and lung cancer cells spiked into normal donor blood samples, including SKBR3 and NCI-H1975. We were able to show that the device can capture 20 cells with high reproducibility. The captured CTCs were retrieved from the microfluidic chip and further purified with anti-CD45 magnetic beads. Our results suggest that the cell recovery rate of this back-flow procedure is greater than 80% and the level of remaining background leukocytes is very low (about 100 cells). Work in progress to extract DNA and RNA. The resulting DNA samples are subjected to mutation analysis of a panel of cancer markers by using PCR and sequencing. The resulting RNA samples are converted to cDNAs, and gene expression analysis of selected cancer markers are carried out by using RT-QPCR. Specific DNA mutations such as EGFR exon 21 (L585R) in NCI-H1975 and mRNA expression markers including CK-19, TTF1 are tested in the retrieved cells. The sensitive and easy-to-use Celsee PREP100 system represents a promising technology for CTC capturing and molecular characterization. Clinical blood samples from patients with metastatic cancer are being tested on the Celsee PREP100 device and the results will be discussed. Citation Format: Yixin Wang. Mutation and gene expression analysis of circulating tumor cells (CTCs) enriched and retrieved by a sensitive microfluidic device. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1688.