Fig. 7: Type A pericyte-derived cells contribute to the tumor stroma.

a Glioblastoma model and experimental timeline. Red represents the tumor. b Tumor cell mass is confined to the striatum (hematoxylin and eosin stain). c Area occupied by the tumor cell mass. Distribution of EYFP⁺ cells in the contralateral (d) and ipsilateral (e) side to the tumor. Type A pericytes and progeny (EYFP⁺GFAP⁻) are found within the tumor core, whereas partially recombined GFAP⁺ reactive astrocytes border the tumor. Dashed line separates the cortex (Ctx) and striatum (St) in (d) and outlines the tumor core in (e). f, g EYFP⁺ cells intermingle with GL261 tumor cells (labeled with an antibody against NG2⁵⁸). h A fraction of EYFP⁺PDGFRβ⁺ cells locates outside the vascular wall (arrowheads; endothelial cells marked by CD31), i, j EYFP⁺ cells proliferate in contact (arrowhead) and away (arrow) from the vascular wall. Insets in (j) show a EYFP⁺ cell associated with the vascular wall (CD31⁺) expressing the mitotic marker Ki67. EYFP⁺ cells express αSMA (k; arrowhead) and vimentin (l), and are surrounded by fibronectin (m) and collagen I (n) ECM. Number (o) and density (p) of EYFP⁺PDGFRβ⁺ cells in the tumor core and contralateral side. q Percentage of EYFP⁺PDGFRβ⁺ cells associated with (ON vessel) or located outside (OFF vessel) the vascular wall. r Distance of EYFP⁺PDGFRβ⁺ cells ON vessel (contralateral side to the tumor) or OFF vessel (tumor) from the nearest vessel surface. Each dot represents one cell. s Percentage of PDGFRβ⁺ cells that express EYFP out of total PDGFRβ⁺ cells. TAM tamoxifen; Scale bars: 1.5 mm (b), 200 μm (d, e), 100 μm (f, g), 50 μm (i, k) and 20 μm (h, l, m, n, j and insets in j). Data shown as mean ± s.e.m. n = 3 (Contralateral) and n = 4 (3w) animals in (c, o, p, s); n = 3 (Contralateral) and n = 5 (3w) animals in (q); n = 36 (Contralateral) and n = 189 (3w) cells examined over 3 animals in (r). ns non-significant; **p < 0.01, ****p < 0.0001 by two-sided, unpaired Student’s t test in (o, p, s) and two-sided Mann–Whitney test in (r). f, g denote paired images. All images show coronal sections. Images are representative of two independent experiments. Source data and statistical test results are provided as a Source Data file.