Abstract 1591: Comprehensive molecular profiling of circulating tumor cells from metastatic breast cancer patients

Background: Recent enumeration studies on CTCs have demonstrated the clinical value of these cells. The molecular biology of CTCs, however, remains poorly understood. Methods: We performed RNA and DNA profiling of CTCs from metastatic breast cancer (MBC) patients. 244 blood samples from 162 MBC patients were subjected to immunomagnetic enrichment and fluorescence activated cell sorting (IE/FACS) to isolate highly pure CTCs. Microfluidic-based multiplex QPCR analysis was utilized to determine the expression levels of 64 cancer-related genes. Parallel genome-wide copy number analysis by array comparative genomic hybridization was also performed on CTCs isolated from the same enriched blood samples. Results: Transcriptional analysis of CTCs was successfully performed in 151 samples from 105 patients. We observed the up-regulation of several genes including CCND1, EPCAM, KRT7 and MUC1 and the down-regulation of hematopoietic-related genes including PTPRC (CD45) and CD68 (adjusted p