The anti-hypertensive drug Prazosin inhibits glioblastoma growth via the PKCδ- dependent inhibition of the AKT pathway (2016)
Figure 2

Figure 2 - Prazosin inhibits glioblastoma growth in vivo.

A. Schematic representation of prazosin treatment in vivo. EGFR+/CD133+ GICs directly isolated from primary human glioblastoma samples (GBM44 and GBM5) were transduced with a GFP-luciferase construct and orthotopically implanted into the striatum of NSG mice. Treatment was initiated once the tumors were detected and bioluminescent analyses of tumor growth were performed after 45 days of treatment.

B, C. In vivo effect of prazosin treatment (1.5mg/Kg) on glioblastoma growth. Tumors were initiated with GBM44 GICs (B) or GMB5 GICs (C). Left panels: Bioluminescent in vivo images of tumors in mice treated with prazosin (PRZ) or vehicle for 45 days. Middle panels: Quantification of the bioluminescent signals. Fold change in total flux represents the ratio: total flux after treatment/total flux before treatment. *P=0.0002 and *P=0.003 for GBM44 and GBM5 respectively, n=8, two-sided Mann–Whitney U-test. Right panels: Kaplan-Meyer survival curves of mice treated with prazosin (PRZ) or vehicle demonstrating a significant survival benefit of prazosin as compared to vehicle, log-rank Mantel-Cox test. The treatment period is shaded in gray.

D. Example of hematoxilin/eosin staining of brain coronal sections from mice sacrificed after 45 days of treatment with prazosin (PRZ) or vehicle. i: tumor infiltration. n: tumor necrosis. Scale bar = 2 mm. GBM44 GICs.

E. Left panel: Representative flow cytometry plots depicting the percentage of CD133+ glioblastoma cells (GFP+) isolated from mice treated with prazosin (PRZ) or vehicle. Tumors were initiated with GBM44 GICs. Right panel: Quantification of flow cytometry analyses of CD133 expression by GFP+-tumor cells isolated from xenografts of three prazosin-treated (PRZ) mice and three vehicle-treated mice. *P=0.0003, n=6, two-sided Mann–Whitney U-test.

F. Secondary grafting of tumor cells (GBM44-GFP+) isolated from vehicle or prazosin-treated mice bearing primary tumors. Mice injected with glioblastoma cells isolated from prazosin-treated mice developed tumors at a lower frequency (50% versus 100%). Moreover, mice injected with glioblastoma cells isolated from prazosin-treated mice presented a statistically significant survival benefit. Left Panel: Bioluminescent in vivo images of secondary grafts. Middle panel: Quantification of the bioluminescent signals. *P=0.0004, n=8, two-sided Mann–Whitney U-test. Right panel: Kaplan-Meyer survival curves of mice bearing secondary graft from glioblastoma cells isolated from vehicle- and prazosin-treated mice.

G. Inhibitory effect of low doses of prazosin (0.15 mg/Kg) on glioblastoma growth in vivo. Left panel: Bioluminescent in vivo images of tumors in mice treated with vehicle or prazosin (PRZ) for 45 days. Tumors were initiated with GBM44 GICs (compare with panel B). Middle panel: Quantification of the bioluminescent signals. *P=0.0007, n=8, two-sided Mann–Whitney U-test. Right panel: Kaplan-Meyer survival curves of mice demonstrating a significant survival benefit of a treatment with low doses of prazosin, log-rank Mantel-Cox test. The treatment period is shaded in gray.