Fig. 1.

Targeting TAMs blocks tumor growth in murine PDGFB-driven proneural-like gliomas. (A) Experimental design of PLX3397 treatment in PDGFB-driven glioma. Animals were treated every day post-tumor implant (dpi) and monitored by bioluminescent imaging. (B) Kaplan-Meier survival curve of mice treated with PLX3397 or vehicle. Log-rank test. (C) Representative bioluminescent images of mice treated with vehicle or PLX3397. Bar graph: average photon flux at each time point. (D) Representative H&E-stained sections of PDGFB-driven tumors treated with vehicle or PLX3397. Low power scale: 1 mm, High power scale: 300 µM. (E–G) Left: Representative immunostaining for p-H3 (E), CD31 (F), or IBA1 (G) in PDGFB-driven GBM treated with vehicle or PLX3397 for 3 days post-tumor implant. Right: Quantification of label-positive cells per unit area (n = 3 mice/group); **P < .01; ***P < .001, unpaired t test. Scale bars in E and F, 100 µM; G, 300 µM. (H) Experimental design of PLX3397 treatment of established PDGFB-driven tumors. Mice were treated daily with PLX3397 or vehicle beginning 14 days after tumor implantation. (I) Kaplan-Meier survival curve of mice. Log-rank test. (J) Representative bioluminescent images. Bar graph of average photon flux at 14, 21, and 26 days. (K) Western blot of phospho-CSF1R from mouse PDGFB tumors (n = 2 samples per group and repeated twice) treated with vehicle or 100 mg/kg PLX3397 for 2 days from day 14 to 16. Abbreviations: CSF1R, colony-stimulating factor 1 receptor; GBM, glioblastoma; PDGFB, platelet-derived growth factor subunit B; TAMs, tumor-associated macrophages/microglia.