Detecting the transition from normal to malignant phenotype in the brain of rats bearing implanted C6 gliomas by multinuclear HR MAS and genomic analysis

We report a 1H and 13C HR-MAS NMR study of normal and diseased brain regions of rats bearing C6 gliomas implanted. The detection of selectively enriched metabolites through ex vivo HR-MAS spectroscopy and the correlations with the expression of the genes involved in the glycolytic metabolism are the aims of this work. C6 gliomas wereinduced in rats and tumour growth was evaluated in vivo using T1 andT2 weighted MRI. Three weeks after C6 implantation, rats wereinfused with [1-13C] glucose and then cerebral metabolism wasarrested. The fixed brain was removed from the skull and five biopsieswere taken from different brain regions. The 1H spectra show theincrease in Lac and mobile lipids in the tumour biopsies and the 13C spectra present a significant increase of (3-13C) Lac and decrease of (4-13C) Glu and (4-13C) Gln, revealing a marked increase in glycolytic metabolism in the tumour. Then, we investigated the individual expression of specific genes coding for enzymes involved in the glycolytic pathway, to improve our understanding of the genetic basis of the metabolic profile observed by 13C HR-MAS.