Tumor Cell Heterogeneity and Dormancy in Single Disseminated Prostate Cancer Cells

Prostate cancer (PCa) disseminated tumor cells (DTC) in the bone marrow (BM) can remain dormant for prolonged periods before recurrence. Our aim was to characterize individual prostate DTC, analyze tumor cell heterogeneity, and identify markers of tumor dormancy. Custom Agilent 44K whole human genome expression oligonucleotide microarrays were used to profile single disseminated tumor cells isolated from bone marrow (BM) samples of four patients with no evidence of disease (NED) upon follow-up and six advanced disease (ADV) prostate cancer patients. Essentially, a two-step selection process was employed, in which anti-CD45 and anti-CD61 conjugated to immunomagnetic beads were used for negative selection, and anti-HEA was used for positive selection. Cells were then fluorescently stained for BerEP4, counter stained with RPE anti-CD45, and individually selected (10 single cells each per patient) under fluorescent light using a micropipette system for further analysis. RNA was amplified using the WT-Oviation one-direct system and hybridized against a common reference pool of prostate tumor cell lines.