mRNA-Seq of single prostate cancer circulating tumor cells reveals recapitulation of gene expression and pathways found in prostate cancer

PLoS One. 2012;7(11):e49144. doi: 10.1371/journal.pone.0049144. Epub 2012 Nov 7.

Abstract

Circulating tumor cells (CTC) mediate metastatic spread of many solid tumors and enumeration of CTCs is currently used as a prognostic indicator of survival in metastatic prostate cancer patients. Some evidence suggests that it is possible to derive additional information about tumors from expression analysis of CTCs, but the technical difficulty of isolating and analyzing individual CTCs has limited progress in this area. To assess the ability of a new generation of MagSweeper to isolate intact CTCs for downstream analysis, we performed mRNA-Seq on single CTCs isolated from the blood of patients with metastatic prostate cancer and on single prostate cancer cell line LNCaP cells spiked into the blood of healthy donors. We found that the MagSweeper effectively isolated CTCs with a capture efficiency that matched the CellSearch platform. However, unlike CellSearch, the MagSweeper facilitates isolation of individual live CTCs without contaminating leukocytes. Importantly, mRNA-Seq analysis showed that the MagSweeper isolation process did not have a discernible impact on the transcriptional profile of single LNCaPs isolated from spiked human blood, suggesting that any perturbations caused by the MagSweeper process on the transcriptional signature of isolated cells are modest. Although the RNA from patient CTCs showed signs of significant degradation, consistent with reports of short half-lives and apoptosis amongst CTCs, transcriptional signatures of prostate tissue and of cancer were readily detectable with single CTC mRNA-Seq. These results demonstrate that the MagSweeper provides access to intact CTCs and that these CTCs can potentially supply clinically relevant information.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biomarkers, Tumor / blood
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • Metabolic Networks and Pathways
  • Neoplasm Metastasis / genetics
  • Neoplasm Metastasis / pathology
  • Neoplastic Cells, Circulating* / metabolism
  • Neoplastic Cells, Circulating* / pathology
  • Prognosis
  • Prostatic Neoplasms* / blood
  • Prostatic Neoplasms* / genetics
  • Prostatic Neoplasms* / pathology
  • RNA, Messenger* / blood
  • RNA, Messenger* / genetics
  • Sequence Alignment
  • Sequence Analysis, RNA

Substances

  • Biomarkers, Tumor
  • RNA, Messenger

Grant support

This study was supported in part by Department of Defense grant W81XWH-10-1-0510 (to JDB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.