Circulating tumor cells exhibit a biologically aggressive cancer phenotype accompanied by selective resistance to chemotherapy

Cancer Lett. 2014 Oct 1;352(2):179-86. doi: 10.1016/j.canlet.2014.06.012. Epub 2014 Jul 10.


With prostate cancer (PCa), circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) portend a poor clinical prognosis. Their unknown biology precludes rational therapeutic design. We demonstrate that CTC and DTC cell lines, established from mice bearing human PCa orthotopic implants, exhibit increased cellular invasion in vitro, increased metastasis in mice, and express increased epithelial to mesenchymal transition biomarkers. Further, they are selectively resistant to growth inhibition by mitoxantrone-like agents. These findings demonstrate that CTC formation is accompanied by phenotypic progression without obligate reversion. Their increased metastatic potential, selective therapeutic resistance, and differential expression of potential therapeutic targets provide a rational basis to test further interventions.

Keywords: Circulating tumor cells; Drug resistance; EMT; MMP-2; Metastasis; Prostate cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Biomarkers, Tumor / metabolism
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm*
  • Epithelial-Mesenchymal Transition / drug effects
  • Humans
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Mitoxantrone / pharmacology*
  • Neoplasm Invasiveness
  • Neoplastic Cells, Circulating / drug effects*
  • Neoplastic Cells, Circulating / metabolism
  • Neoplastic Cells, Circulating / pathology
  • Phenotype
  • Prostatic Neoplasms / drug therapy*
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • Tumor Burden / drug effects
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Biomarkers, Tumor
  • Mitoxantrone