Circulating Tumor Cell Enumeration with a Combination of Epithelial Cell Adhesion Molecule– and Cell-Surface Vimentin–Based Methods for Monitoring Breast Cancer Therapeutic Response

Abstract

Background Detection, isolation and enumeration of circulating tumor cells (CTCs) from cancer patients has become an important modality in clinical management of patients with breast cancer. Although CellSearch, an EpCAM based method that is used to isolate epithelial CTCs has gained immense importance, its inability to detect mesenchymal CTCs from breast cancer patients raises concerns for its utility as a clinical management tool. Methods To address this gap in technology, we recently discovered the utility of cell-surface vimentin (CSV) as a marker for detecting mesenchymal CTC from sarcoma tumors. Here in this study, we tested the sensitivity and specificity of detecting CTC from blood collected at a random time during therapy from each of the 58 patients with metastatic breast cancer utilizing 84-1 (mAb against CSV to detect epithelial mesenchymal transitioned CTC) and CellSearch methods. Also we tested the possibility of improving the sensitivity and specificity of detection using additional parameters including nuclear EpCAM localization and epithelial mesenchymal ratios. Results CTC counts using CSV were significant in differentiating treatment responding (stable) and treatment non-responding (progression) populations in comparison to the CellSearch method. The results also indicated that a summation of CTCs detected from both methods with a threshold of 8 CTCs/7.5mL increased the specificity of CTC detection substantially in comparison with other tested combinations as determined by ROC curves. Conclusions Collectively, utilizing a summation of CellSearch and CSV methods provide new insights into using CTC enumeration to assess therapeutic response and thus provides a new approach to personalized medicine in breast cancer patients.

Senescent cells expose and secrete an oxidized form of membrane-bound vimentin as revealed by a natural polyreactive antibody

“…Detection of vimentin is currently being explored as a biomarker in cancer (41,(83)(84)(85), and ongoing studies are currently being conducted to correlate the presence of oxidized proteins, like oxidized LDL to aging and organismal frailty (86,87). Here, we have developed a sandwich ELISA to detect secreted MDAmodified vimentin using our 9H4 antibody in the context of profiling cellular senescence in vitro and in vivo.…”

Clinical Applications of Circulating Tumor Cells and Circulating Tumor DNA as Liquid Biopsy

“…In this context, it should be emphasized that mesenchymal markers such as vimentin are expressed on blood cells in various degrees and are therefore not suitable for CTC detection unless combined with other markers, excluding blood cell origin. Interestingly, tumor cells can show a cell-surface expression of vimentin, which might also be used as a CTC marker ( 108 ).…”

Circulating tumor cell technologies

“…Many affinity-based enrichment technologies use epithelial markers, which are down-regulated during EMT, to capture CTCs. In response, researchers have expanded the antigen repertoire used in affinity-based capture to include stem cell markers (e.g., CD133), mesenchymal markers (e.g., cellsurface vimentin, CSV) (Satelli et al, 2014), and cancerspecific antigens (e.g., HER2, PSMA) (Galletti et al, 2014;Kirby et al, 2012;Winer-Jones et al, 2014 Another commercially available platform for CTC detection is AdnaTest (Adnagen AG). AdnaTest enriches CTCs through the use of magnetic, antibody-coated beads.…”