Characterization of isolated disseminated tumor cells from breast cancer patients

Background Disseminated tumor cells (DTCs) from the bone marrow (BM) are an independent predictor of breast cancer (BC) patients’ poor prognosis. However, few methods exist for DTC isolation. This study aimed to compare different DTC isolation approaches to select the best method for capturing and isolating single DTCs.

Materials and methods Three methods were first tested with spiking experiments: size-based isolation with the Parsortix system (ANGLE plc, UK) and anti-EpCAM based positive selection with nanomagnet beads/ferrofluid using a hand-held magnet or the automated CellSearch® system (Menarini, Italy). Used exact numbers of prelabeled MCF7 cell line cells spiking in BM, detected and calculated three methods´ enrichment rates. Second, the CellSearch system combined CellCelector (ALS GmbH, Germany) platform to detect and isolate putative DTCs from BC patients’ BM. To prove the tumor origin of isolated putative DTCs, genomic DNA was amplified by Ampli1 whole genome amplification (WGA), and low pass genome sequencing was performed.

Results The enrichment rates of the three methods achieved 56 %±0.063, 62 %±0.038, and 75 %±0.04, respectively. From 31 collected BM of BC patients 11 putative DTCs were found in 7 samples (22.5 %). WGA quality control confirmed good-quality DNA with the presence of 3 to 4 electrophoretic bands in all 7 randomly picked and isolated cells. Low pass genome sequencing showed genomic aberrations proving tumor origin of isolated and captured cells.

Conclusion We have established a workflow for DTCs enrichment, detection, and isolation from breast cancer patients´ bone marrow suspension by combined use of CellSearch and CellCelector systems.

Interessenkonflikt

Es bestehen keine Interessenkonflikte.

Publication History

Article published online:
01 June 2021