Validation of CTC-Race
assay using breast, lung, and prostate cancer
cell lines. ∼5000 cancer cells were loaded into the device
for each cell line experiment. Optimized conditions (0.1 μL/min
perfusion rate, 10% FBS concentration, and 24-h assay time) were used
for all experiments. After the assay, cells were fixed and stained
with four markers (EpCAM, vimentin, CD44, and DAPI). Migration distance,
migration speed, cellular aspect ratio, and marker expressions of
cells were analyzed from bright-field and fluorescent imaging. (a)
Plots of migration distances of 10 different cancer cell lines in
the CTC-Race assay (non-small-cell lung cancer, A549, H3122, H1299;
small-cell lung cancer, DMS79, H69; breast cancer, HCC70, HCC1806,
MCF7, and MDA-MB-231; prostate cancer, PC-3). Box plots include the
smallest, lower quartile, mean, upper quartile, and largest final
positions for cells. Mean final positions are 191.53 ± 33.03
μm (MCF7, n = 5293), 232.09 ± 77.47 μm
(HCC70, n = 5419), 190.57 ± 33.32 μm (H3122, n = 5528), 199.03 ± 30.05 μm (DMS79, n = 5176), 198.48 ± 24.43 μm (H69, n = 5331), 384.76 ± 195.81 μm (HCC1806, n = 5469), 318.25 ± 189.51 μm (H1299, n = 5173), 358.96 ± 143.91 μm (A549, n = 5575), 467.88 ± 317.74 μm (PC-3, n = 5411), and 556.89 ± 303.54 (MDA-MB-231, n = 5278). All values are mean ± sd. (b) Migration speed of cancer
cell lines. Mean speed for each cell line: 0.01 ± 0.02 μm
min–1 (MCF7, n = 5293), 0.03 ±
0.05 μm min–1 (HCC70, n =
5419), 0.01 ± 0.02 μm min–1 (H3122, n = 5528), 0.01 ± 0.02 μm min–1 (DMS79, n = 5176), 0.08 ± 0.02 μm min–1 (H69, n = 5331), 0.15 ± 0.11
μm min–1 (HCC1806, n = 5469),
0.12 ± 0.10 μm min–1 (H1299, n = 5173), 0.12 ± 0.09 μm min–1 (A549, n = 5575), 0.21 ± 0.20 μm min–1 (PC-3, n = 5411), and 0.27 ±
0.19 μm min–1 (MDA-MB-231, n = 5278). All values are mean ± sd. (c) Selected immunofluorescence
images of migratory cells from cell lines. Four channels are used
in the immunofluorescence staining, including an epithelial maker
EpCAM (green), a mesenchymal marker vimentin (magenta), a cell-migration
marker CD44 (yellow), and a nucleus marker DAPI (blue). (d–f)
Mean intensities (n = 2000) of EpCAM, vimentin, and
CD44 markers across cancer cell lines. The intensities are normalized
using maximal intensity (EpCAM, H3122; vimentin, MDA-MB-231; CD44,
H3122). (g) Mean cellular aspect ratio of cancer cell lines (n = 2000).