Novel Method For Rapid Enrichment Of High Purity Circulating Tumor Cells (Ctcs) For Prostate Cancer (Pca) Gene Expression Profiling.

271Background: CTC RNA analysis currently involves single cell recovery that is laborious and expensive, or alternatively lysis of preserved whole blood which yields RNA predominantly from leukocytes which vastly outnumber CTCs. To effectively characterize gene expression in large patient cohorts, new enrichment methodologies are needed that yield high purity CTC populations while preserving RNA integrity. Here we describe a simple yet robust method for enrichment of prostate CTCs for gene expression analysis. Methods: Blood was drawn with informed consent under an IRB-approved protocol. For initial optimization, CFSE-stained PCa cells were spiked into healthy blood and recovered using various combinations of 2 methods: microfluidic enrichment (Parsortix™ system) and CD45 depletion. For assay qualification, a prostate-specific multiplexed qRT-PCR gene expression panel was developed. Enrichment and gene expression were tested initially using PCa cell lines spiked into healthy blood, then metastatic castrat...