Fig. 4

Tumor cell lipid loading promotes paracrine activation of vascular cells and macrophages. a, Schematic overview of functional assays with conditioned medium (CM) isolated from GBM cells (U-87 MG) grown in serum-free (SF) medium without and with extracellular lipid (+LDL) in normoxia or hypoxia. b and c, HBMECs were assessed for transwell migration over a period of 6 h towards SF medium (CTRL) and the various GBM CM variants described in (a). LDL = SF medium supplemented with LDL. Shown are representative images of migrated ECs (b) and quantification (c). d, HBMECs were cultured for 72 h at the same conditions as described in (b) and assessed for cell proliferation. e and f, HBMECs were cultured for 24 h at the same conditions as in (b) and then allowed to form tube structures on Matrigel for 20 h. Shown are representative images of EC tubes from the indicated treatments (e) and quantification of number of tubes (f). g and h, Human-derived monocytes differentiated into macrophages (THP-1) were assessed for transwell migration over a period of 6 h towards the same media conditions as described in (b). Shown are representative images of migrated THP-1 cells (g) and quantification (h). b-h Data are presented as the mean fold of untreated (CTRL) ± SD from at least three independent experiments