iTRAQ-based quantitative proteomic analysis of membrane and nuclear fractions of glioma (WHO grade II, III and IV) tissues to map on Chromosome 12 and identification of mass spectrometry evidence for 'missing proteins'

Glioma tumors arise from normal glial cells (astrocytes). Gliomas are morphologically and clinically classified into four malignancy grades as Grade I, II, III and IV. Grade I and II comprise low grade gliomas that grow slowly, are well differentiated and have a better prognosis and survival compared to grades III and IV. In contrast, grade III-IV lack endothelial proliferation and are highly vascular with a tendency to infiltrate and have areas of extensive necrosis and hypoxia. In the present study, we used iTRAQ (isobaric tags for relative and absolute quantitation) - based quantitative proteomic approach followed by liquid chromatography and high resolution tandem mass spectrometry (LC-MS/MS) to identify differential membrane and nuclear proteins mapping to Chromosome 12 from three different grades of astrocytoma tumors (WHO Grade II, III and IV) compared to control.