Abstract 675: Effects of PBN and OKN007 in rodent glioma models assessed by 1H MR spectroscopy

Gliomas are the most common and lethal primary brain tumors in the adult, with a median survival time of 12 to 15 months for grade IV gliomas, glioblastoma multiforme. PBN and OKN007 are nitrones which have demonstrated beneficial effects in many aging diseases. In this study, we evaluated the anti-tumor effects of PBN or OKN007 in several rodent glioma models (C6, RG2, and GL261) by assessing metabolite alterations with magnetic resonance spectroscopy (MRS). PBN or OKN007 was administered in drinking water prior to or post tumor formation. MRI and short echo time, single-voxel point-resolved spectroscopy (PRESS) were obtained to assess tumor morphology and metabolites, respectively, following therapy. Major metabolite ratios (Choline, N-acetyl aspartate (NAA), Lipid (methylene), and Lipid (methyl), all compared to Creatine) were assessed. Nitrones induced tumor metabolism changes that resulted in restoring major metabolite ratios close to their normal levels, in the glioma regression phase. Nitrones treatment decreased the Lipid (methylene) to Creatine ratio significantly, which can be a useful marker for evaluation of the efficacy of the treatments, and was found to be related with the reduction of necrosis. OKN007 was more effective than PBN when administered post-tumor formation in the C6 glioma model. OKN007 was able to inhibit angiogenic factors (VEGF, bFGF and HGF) and induce apoptosis (indicated by an increase of the apoptotic marker m30) in C6 gliomas, which might be potential mechanisms that are involved in the anti-glioma effects. In conclusion, OKN007 and PBN are effective in inhibiting the growth of several experimental gliomas and may be considered as potential therapeutics for a clinical trial in human gliomas. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 675. doi:10.1158/1538-7445.AM2011-675