Fig. 6: Microconstrictions facilitate increased engagement of melanoma stem cell-like cells with endothelial cells.

A Representative image showing Crystal Violet dye signal from WT and KO melanoma cells migrating through the transwell membrane before and after been squeezed into the microfluidic chip. The image highlights the cells that have successfully migrated through the membrane pores and adhered to the bottom surface of the transwell insert. B Bar graph showing the fold change of WT and KO cell coverage area, compared to their relative controls. Results represent the mean ± SEM from 3 independent experiments. Statistical significance was assessed using two-sided unpaired t-tests. Asterisks indicate p-values, p = 0.0142 (*) 95% CI: [−1.682, −0.3339]. C A simplified schematic illustrating the co-culture of melanoma cancer cells with a functional monolayer of endothelial cells. D Bar graph displaying the fluorescence expression of VCAM protein from endothelial cells cultured under CTRL condition and with the presence of WT and KO cells, before or after being squeezed into the microfluidic device. The results are expressed as the mean ± SEM from 3 (Endothelium, WT_CTRL, WT_SQZD) and n = 2 (KO_CTRL and KO_SQZD) independent experiments. Statistical significance was assessed using one-way ANOVA (two-sided). Asterisks indicate p-values, as follow, Endothelium vs. WT (SQZD) p = 0.0019 (**) 95% CI: [−7.288, −2.037]; WT (CTRL) vs. WT(SQZD) p = 0.0006 (***) 95% CI: [−8.149, −2.898]; WT (SQZD) vs. KO (CTRL) p = 0.036 (*) 95% CI: [0.2070, 6.077]; WT (SQZD) vs. KO (SQZD) p = 0.0012 (**) 95% CI: [−2.628, 8.499]. Source data are provided as a Source Data file. E Representative fluorescence images of vascular endothelial proteins, e.g., Vascular endothelial cadherin junction (VE-Cadherin) and Vascular Cell Adhesion Protein (VCAM), when the endothelial monolayer is co-cultured with melanoma cells. Experimental numbers and associated statistical analysis for the full data set are shown in panel D. Asterisks are reported in monolayer’s area, where VE-Cadherin remodel and leave gap in between cells.