Original Contribution Phenyl-tert-butylnitrone induces tumor regression and decreases angiogenesis in a C6 rat glioma model Sabrina Doblas a,b,c , Debbie Saunders b,c , Preeti Kshirsagar d , Quentin Pye c , Jenny Oblander e , Brian Gordon e , Stanley Kosanke f , Robert A. Floyd c,g,h , Rheal A. Towner b,c,f, ⁎ a Oklahoma University Bioengineering Center, Norman, OK, USA b Small Animal MRI Facility, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA c Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA d Advanced Imaging Research Center, University of Texas Southwestern, Dallas, TX, USA e Comparative Medicine, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA f Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA g Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA h Merrick Foundation Chair of Aging Research, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA Received 13 April 2007; revised 7 September 2007; accepted 10 September 2007 Available online 20 September 2007 Abstract The prognosis of patients who are diagnosed with glioblastoma multiforme is very poor, due to the difficulty of an early and accurate diagnosis and the lack of currently efficient therapeutic compounds. The efficacy of phenyl-tert-butylnitrone (PBN) as a potential anti-glioma therapeutic drug was assessed by magnetic resonance (MR) imaging (T 1 /T 2 -weighted imaging) and MR angiography (time-of-flight imaging, in conjunction with a Mathematica-based program) methods by monitoring morphologic properties, growth patterns, and angiogenic behaviors of a moderately aggressive rat C6 glioma model. MR results from untreated rats showed the diffusive invasiveness of C6 gliomas, with some associated angiogenesis. PBN administration as a pretreatment was found to clearly induce a decrease in growth rate and tumor regression as well as preventing angiogenesis. This compound even had a 40% efficiency in reducing well-established tumors. MR findings rivaled those from histology and angiogenesis marker immunostaining evaluations. In this study we demonstrated the efficiency of PBN as a potential anti-glioma drug and found it to inhibit tumor cell proliferation and prevent vascular alterations in early stages of glioma progression. The MR methods that we used also proved to be particularly suitable in following the angiogenic behavior and treatment response of a potential anti-glioma agent in a rat C6 glioma model. © 2007 Elsevier Inc. All rights reserved. Keywords: Phenyl-tert-butyl-nitrone; Angiogenesis; Rat glioma; C6 cells; Magnetic resonance angiography; Magnetic resonance imaging; Free radicals Glioblastoma multiforme, the most common and malignant type of gliomas in humans, represents 20% of all primary brain tumors. In the best current treatment situation (surgical removal of the tumor followed by radiation and/or chemo- therapy sessions), patients diagnosed with a grade IV glioma have an average survival time of 15 months, and only 3% of them will survive after 5 years [1]. This poor prognosis is largely due to the difficulty of obtaining early and accurate diagnoses and also due to the lack of efficient therapeutic drugs. In order for clinicians to decide on an adequate therapeutic drug for treatment, the growth pattern, morpho- logy, and vascular properties of the glioma must be accurately and quickly characterized. Also, new therapeutic drugs with the ability to inhibit tumor growth or to suppress the Available online at www.sciencedirect.com Free Radical Biology & Medicine 44 (2008) 63 – 72 www.elsevier.com/locate/freeradbiomed Abbreviations: MR, magnetic resonance; MRI, magnetic resonance imaging; MRA, magnetic resonance angiography; PBN, phenyl-tert-butylni- trone; LPS, lipopolysaccharide; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; TR, repetition time; TE, echo time; FLASH, fast low angle shot; ROI, region of interest; vWF, von Willebrand factor; VEGF, vascular endothelial growth factor; CT, computed tomography; COX2, cyclooxygenase 2; NF-κB, nuclear factor κB; iNOS, inducible nitric oxide synthase. ⁎ Corresponding author. Fax: +1 405 271 7254. E-mail address: Rheal-Towner@omrf.ouhsc.edu (R.A. Towner). 0891-5849/$ - see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.freeradbiomed.2007.09.006