Fig. 7
Antagonists against the endothelin receptor induce fusion of MVEs with lysosomes in MDA-MB231 cells. a TEM analysis of ETA-antagonist-treated MDA-MB231 cells. Scale bar, 5 μm. b Measurement of lysotracker (red) intensity in rapamycin-treated or antagonist (Zibotentan and PD156707)-treated MDA-MB231. Lysotracker intensity measurement >100 cells per group. c Top, Immunoblot of LAMP-1 protein in antagonist (Zibo, BQ-123, and PD156707)-treated MDA-MB231. Bottom, Immunoblot of LAMP-1 protein in ETA-siRNA-transfected MDA-MB231 and in ETA-K/D MDA-MB231. n = 3. d Left, Image of MDA-MB231 treated by SFX. Green, CellLight-Lysosome-GFP (GFP-LAMP1). Red, CellLight-late endosome/MVE-RFP (RFP-RAB7). Scale bar, 2 μm. Right, Quantitative colocalization rates of lysosomes and MVE in MDA-MB231 treated with Zibotentan, PD156707, or BQ123. Colocalization puncta count >65 cells per group. e Images of ETA K/D MDA-MB231 or WT MDA-MB231 cells. Different colors represent the same markers as described in d. Scale bar, 2 μm. Experiments were performed with 95% confluent cells. Significance was determined using an unpaired two-tailed Student’s t-test. ***p < 0.001, **p < 0.005 and *p < 0.05. Error bar, SD. Source data (b, d) are provided as a Source Data file
