Capture of esophageal and breast cancer cells with polymeric microfluidic devices for CTC isolation

The present study evaluated the capture efficiency of esophageal and breast cancer cells with a modified 'polymeric circulating tumor cells (CTC)-chip' microfluidic device, which was developed for the isolation of circulating tumor cells. Esophageal cancer cell lines KYSE150, KYSE220 and KYSE510, and breast cancer cell lines MCF7, SKBR3 and MDA-MB-231 were used for evaluation. The capture efficiencies of the esophageal cancer cell lines in phosphate-buffered saline (PBS) were ~0.9, irrespective of epithelial cell adhesion molecule (EpCAM) expression, which was represented as the mean fluorescent intensity from 528 to 76. In the breast cancer cell lines, efficient capture was observed for MCF7 and SKBR3 in PBS; however, a low value of ~0.1 was obtained for MDA-MB-231. Fluorescent imaging of immunolabeled cells revealed marginal EpCAM expression in MDA-MB-231. Using whole blood, no clogging occurred in the microstructure-modified CTC-chip and efficiency of capture was successfully evaluated. Capture efficiencies for KYSE220 and MCF7 in whole blood were >0.7, but were of either equal or lesser efficiency in comparison to PBS. Therefore, the modified CTC-chip appears useful for clinical application due to its cost, practicality of use, and efficient cancer cell capture.