Figure 3.

GSC EVs Support Subpopulation-Specific Invasive Phenotype

(A) Heterogeneity of GSC spheroids promotes migration of invasive GSCs. Representative micrographs of GSC spheroids in monoculture (n = 3 independent experiments per three independent GSCs) (left) and heterogeneous co-culture (n = 3 independent experiments per three independent GSCs) (middle) in 3D time-lapse frames are shown. GFP-labeled invasive GSCs and PALM-Tomato-labeled nodular GSCs. Scale bar, 100 μm. Relative quantification of migratory zone volume (top right) and number of cells migrated out of spheroid core (bottom right) in mono- versus co-culture. ^∗∗p < 0.01.

(B) Nodular and invasive phenotype of GSCs is recapitulated in vivo. Representative micrographs of co-implanted heterogeneous tumors (n = 6 independent experiments) are shown. GFP-labeled invasive GSCs and PALM-Tomato-labeled nodular GSCs. Nodular tumor burden and infiltrating tumor cells are indicated by dashed line and arrows, respectively. Intratumoral EV transfer between cells is shown on high-power magnification inset. Scale bars, 150 μm and 10 μm.

(C) GSC EV is transferred intratumorally. Representative micrographs of co-implanted heterogeneous tumors (n = 3 independent experiments) are shown. Scrambled or microRNA ISH (nodular specific miR-31) (top) and GFP-labeled invasive GSCs and PALM-Tomato-labeled nodular GSCs (bottom) from consecutive sections. Positive and negative microRNA detection is indicated by arrows. Scale bars, 100 μm.

See also Figure S3.