Fig. 2

Arrest of CTCs Depends on Early Cellular Adhesion Forces

(A) Quantification of the diameters of human CTCs (green, five breast cancer patients and one lung cancer patient) and 1675, D2A1, JIMT-1, A431, 4T1, and ZMEL1 cells (red) in suspension. Representative images of human CTCs and D2A1 are also provided. Human CTCs are labeled with pan-keratin (CTC marker), CD45, and DAPI (nucleus).

(B) Representative confocal z projection image of the CP. Red shows highly perfused vessels with diameters over 10 μm.

(C) Quantification of the number of arrested cells per ISV in the yellow dashed region depicted in (B).

(D) Quantification of the repartition of arrested cells in the plexus of 59 embryos, between the regions of bigger (red) and smaller (white) than 10 μm vessels in diameter.

(E) Experimental workflow and depletion of ITGB1 via small interfering RNA (siRNA) in D2A1 cells: control siRNA (siCTL) and two distinct sequences of the siRNA targeting ITGB1 (siITGB1 no. 1 and siITGB1 no. 2). Representative western blot images are shown. Heatmaps of arrested CTCs after 3 hpi are shown for CTCs transfected with siRNAs (n = 77, 63, and 55, respectively). Quantification of the ratio of arrested CTCs in the indicated region is provided. Norm., normalized to siCTL AVJ.

(F) Graph depicts the number of adhesion events (CTCs to HUVECs) quantified in our microfluidic approach (see also Videos S6 and S7). Norm., normalized to siCTL.

(G) Experimental setup of intravital CLEM performed on arrested CTCs only 15 mpi. Representative EM images of arrested CTCs (red) in vascular lumen (green) are provided from two different sections (top and bottom). A reconstruction of an electron tomogram is provided. The yellow outline highights the area quantified in (C).

(H) Experimental setup, representative image, and quantification of optical tweezing experiments of arrested CTCs in the AVJ (n = 37 arrested cells, n > 10 embryos) (see also Video S7).

Values are mean ± SD. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001.