Comparative proteogenomic characterization of glioblastoma.

Aim: Glioblastoma multiforme (GBM) carries a dismal prognosis. Integrated proteogenomic analysis was performed to understand GBM pathophysiology. Patients & methods: 17 patient samples were analyzed for driver mutations, oncogenes, major pathway alterations and molecular changes at gene and protein level. Clinical, treatment and survival data were collected. Results: Significantly mutated genes included TP53, EGFR, PIK3R1, PTEN, NF1, RET and STAG2. EGFR mutations noted included EGFRvIII-expression, EGFR-L816Q missense mutation-exon 21 and EGFR fusion (FGFR3-TACC3). TP53 mutations were noticed in COSMIC hot-spot driver gene and accompany IDH1 and ATRX mutations suggesting low- to high-grade glioma transformation. Proteomics showed higher (53%) EGFR expression than genomic expression (23%). MGMT methylation was present in two-thirds of cases. Conclusion: This study identifies a distinct biological process that may characterize each GBM differently. Proteogenomic data identify potential therapeutic targets of GBM.