A Novel Platform for Detection of CK+ and CK− CTCs

Abstract

Metastasis is a complex, multistep process that begins with the epithelial-mesenchymal transition (EMT). Circulating tumor cells (CTCs) are believed to have undergone EMT and thus lack or express low levels of epithelial markers commonly used for enrichment and/or detection of such cells. However, most current CTC detection methods only target EpCAM and/or cytokeratin to enrich epithelial CTCs, resulting in failure to recognize other, perhaps more important, CTC phenotypes that lack expression of these markers. Here, we describe a population of complex aneuploid CTCs that do not express cytokeratin or CD45 antigen in patients with breast, ovarian, or colorectal cancers. These cells were not observed in healthy subjects. We show that the primary epithelial tumors were characterized by similar complex aneuploidy, indicating conversion to an EMT phenotype in the captured cells. Collectively, our study provides a new method for highly efficient capture of previously unrecognized populations of CTCs. Significance Current assays for CTC capture likely miss populations of cells that have undergone EMT. Capture and study of CTCs that have undergone EMT would allow a better understanding of the mechanisms driving metastasis.

Circulating Tumor Cells and Circulating Tumor DNA: Challenges and Opportunities on the Path to Clinical Utility

“…As such, because epithelial cells are rarely present in blood samples from healthy individuals and because circulating epithelial cells (CEC) in patients with cancer often carry the same genetic aberrations seen in the primary tumor (13), the common definition of CTCs has been equivalent to that of CECs: nucleated cells in the bloodstream that express epithelial cytokeratins and do not express the white blood cell surface antigen CD45. More recently, cytokeratin-negative CTCs have been identified, potentially representing tumor cells undergoing epithelial-mesenchymal transition (EMT), or alternatively, cancer stem cells that have not yet shown epithelial differentiation (14)(15)(16)(17).…”

Cytotoxicity of Human Endogenous Retrovirus K–Specific T Cells toward Autologous Ovarian Cancer Cells

“…S4 and S5). Considering the accumulating evidence for the importance of CSCs in therapy resistance and tumor relapse and of circulating tumor cells in dissemination and metastasis (31)(32)(33)(34)(35)(36)(37)(38)(39)(40), our characterizations provide potential clues to why ovarian cancer cells are generally very aggressive, invasive, drug-resistant, and metastatic.…”

Configurable 2D and 3D spheroid tissue cultures on bioengineered surfaces with acquisition of epithelial–mesenchymal transition characteristics

“…Moreover, the present approach does not require growth factors and possesses the potential to handle rare cells, which is especially important for clinical samples and circulating tumor cells. 31 For comparison with conventional cultures, microscale cultures in the chip generally use significantly less reagent, which results in a greater volume density (1605 cells ml À1 ), that is, more cells in a specific volume of reagent, than in macrocultures in cell culture dishes (500 cells ml À1 ). The surface density 4 of cells in the chip was 5.4 Â 10 À4 cells mm À2 , which is comparable to that in dishes (with a surface density of 5.2 Â 10 À4 cells mm À2 ).…”