Figure 5.

Effect of obtusaquinone (OBT) on intracranial glioblastoma (GBM) tumors in vivo. U87 cells expressing Fluc were implanted intracranially in nude mice. One week later, mice were intraperitoneally injected once a day over 14 days with dimethyl sulfoxide (DMSO) (control [Ctrl]) or OBT (7.5mg/kg body weight) (n = 8 per group). A) Mice were imaged weekly, and the Fluc signal was quantified over 5 weeks after implantation. *P < .05, two-sided Student t test. B) At day 21 after implantation, two mice from each group were killed; brains were isolated, sectioned, and analyzed by hematoxylin and eosin staining. Micrographs from one representative mouse per group are shown. Scale bar = 500 µm. C) Kaplan–Meier survival curve for intracranial U87 xenografted mice (n = 6 for control and n = 7 for OBT) with P = .04 (two-sided log-rank test). D) Kaplan–Meier survival curve for intracranial U251 xenografted mice treated with OBT for 21 days (n = 6 for control and n = 8 for OBT) with P = .008 (two-sided log-rank test). The number of mice at risk at any given time point are indicated below the Kaplan–Meir curves in (C and D).