Extended Data Figure 2: 4175-LuT cell-derived exosomes localize to lung and dictate future metastatic sites.
From: Tumour exosome integrins determine organotropic metastasis
a, Electron microscopy imaging of FM1-43-labelled 4175-LuT exosomes. Red arrows, FM1-43-positive exogenous exosomes; black arrows, endogenous exosomes. Two mice were tested, images were taken for several sections from each organ (n = 30 images in total). b, Representative NIR imaging of lung whole mount after daily exosome injections. Exosomes (10 μg) derived from 4175-LuT cells were injected daily for three consecutive days via the retro-orbital sinus and the whole lung was imaged by Odyssey imaging (n = 4). c, Representative haematoxylin/eosin staining of the lung from Fig. 1f at 20× magnification; n = 5 for all, except for LuT exo/LuT cells, in which n = 4; data representative of two independent experiments. Arrows indicate lung metastasis. d, Analysis of 1833-BoT cell metastasis to the lung, after 3 weeks of continuous treatment with PBS or 4175-LuT exosomes, followed by intracardiac injection of 1 × 105 tumour cells. Mice were injected retro-orbitally with exosomes every other day for 3 weeks, before tumour cell injection. Quantitative bioluminescence imaging of luciferase activity by IVIS imaging. Metastasis was quantified 3 weeks after tumour cell injection (n = 4). Scale bars, 100 nm (a), 5 mm (b, d) and 500 μm (c). Data are mean ± s.e.m. ***P < 0.001 by two-tailed Student’s t-test.
