Fig. 3

proNGF enhances trans-BBB migration through Src activation independently of TrkA phosphorylation in TNBC. A Schematic representation of human BBB in vitro model, this one is characterized by a luminal compartment that allow culture of human BLEC on insert filtered (3 µm) and an abluminal compartment with plated human brain pericyte. Cancer cells are load with CellTracker™ before being incubated in the upper side. B-E Representative overlay (B & D) and associated quantification (C & E) of CellTracker™ stained MDA-MB-231-TrkA or CellTracker™ stained MDA-MB-231-TrkA-KD (green) on the lower compartment after a 16 h trans-BBB migration. (F) Emission ratio images of the ECFP/YPet-based Src biosensor during MDA-MB-231-TrkA-KD trans-BBB migration under abluminal proNGF stimulation. Data inB-E are representative of 3 independents experiments with all condition realized in duplicate. Data in C and E are represented by min to max interleaved box graph with median (black line). Two-way ANOVA followed by Tukey’s test for D and F. ***P ≤ 0.001, ****P ≤ 0.0001, ns (non-significant). For B and D scale bar = 100 µm, for D and F scale bare = 15 µm