Figure 6: Cancer cell–endothelial intercellular transfer alters the endogenous miRNA profile and phenotype of recipient endothelial cells.

(a) Schema shows the experimental design. CFSE(green)-loaded MDA-MB-231 cells were co-cultured with the Dil-Ac-LDL (red)-labelled HUVECs. A miRNA microarray was used to evaluate the transport of endogenous miRNAs. The intercellular CFSE-transfer−ve and -transfer+ve endothelial cells were sorted from the same pool. The heat map shows potential miRNA candidates that were significantly upregulated in the cells receiving transfer of intercellular contents from the cancer cells. HUVECs that were not exposed to cancer cells were used as a baseline control. (b) The volcano plot shows the statistically significant upregulated (red) and downregulated (green) miRNAs in the HUVEC cells that received intercellular transfer compared with those that did not receive transfer. (c,d) Sorting of the endothelial cells from the co-cultures with MDA-MB-231 cells reveal higher expression of tumour endothelial markers CD137 and CD276 in intercellular transfer +ve endothelial cell populations compared with intercellular transfer −ve cells. (e,f) Pharmacological inhibition of nanoscale tether formation reduced the expression of CD137 and CD276 in endothelial cells isolated from the co-cultures. Data shown are mean±s.e.m. (n=5 studies, with 3 replicates per study, ****P<0.0001, ***P<0.001, *P<0.05. Analysis of variance followed by Bonferroni’s post-hoc test).