Detection and Characterization of Circulating Tumour Cells from Frozen Peripheral Blood Mononuclear Cells

David Lu; Ryon P. Graf; Melissa Harvey; Ravi A. Madan; Christopher Heery; Jennifer Marte; Sharon Beasley; Kwong Y. Tsang; Rachel Krupa; Jessica Louw; Justin Wahl; Natalee Bales; Mark Landers; Dena Marrinucci; Jeffrey Schlom; James L. Gulley; Ryan Dittamore

doi:10.33393/jcb.2015.2054

Authors

David Lu Epic Sciences, Inc., San Diego, CA, USA
Ryon P. Graf Epic Sciences, Inc., San Diego, CA, USA
Melissa Harvey Epic Sciences, Inc., San Diego, CA, USA
Ravi A. Madan National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Christopher Heery National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Jennifer Marte National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Sharon Beasley Epic Sciences, Inc., San Diego, CA, USA
Kwong Y. Tsang National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Rachel Krupa National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Jessica Louw Epic Sciences, Inc., San Diego, CA, USA
Justin Wahl Epic Sciences, Inc., San Diego, CA, USA
Natalee Bales Epic Sciences, Inc., San Diego, CA, USA
Mark Landers Epic Sciences, Inc., San Diego, CA, USA
Dena Marrinucci Epic Sciences, Inc., San Diego, CA, USA
Jeffrey Schlom National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
James L. Gulley National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
Ryan Dittamore Epic Sciences, Inc., San Diego, CA, USA

DOI:

https://doi.org/10.33393/jcb.2015.2054

Keywords:

Circulating Tumour Cells, Peripheral Blood Mononuclear Cells, Metastatic Castrate Resistant Prostate Cancer, Androgen Receptor, Biorepository

Abstract

Retrospective analysis of patient tumour samples is a cornerstone of clinical research. CTC biomarker characterization offers a non-invasive method to analyse patient samples. However, current CTC technologies require prospective blood collection, thereby reducing the ability to utilize archived clinical cohorts with long-term outcome data. We sought to investigate CTC recovery from frozen, archived patient PBMC pellets. Matched samples from both mCRPC patients and mock samples, which were prepared by spiking healthy donor blood with cultured prostate cancer cell line cells, were processed “fresh” via Epic CTC Platform or from “frozen” PBMC pellets. Samples were analysed for CTC enumeration and biomarker characterization via immunofluorescent (IF) biomarkers, fluorescence in-situ hybridization (FISH) and CTC morphology. In the frozen patient PMBC samples, the median CTC recovery was 18%, compared to the freshly processed blood. However, abundance and localization of cytokeratin (CK) and androgen receptor (AR) protein, as measured by IF, were largely concordant between the fresh and frozen CTCs. Furthermore, a FISH analysis of PTEN loss showed high concordance in fresh vs. frozen. The observed data indicate that CTC biomarker characterization from frozen archival samples is feasible and representative of prospectively collected samples.