The development of drugs to inhibit
glioblastoma (GBM) growth requires reliable pre-clinical models. To date, proteomic level validation of widely used patient-derived
glioblastoma xenografts (PDGX) has not been performed. In the present study, we characterized 20 PDGX models according to subtype classification based on The
Cancer Genome Atlas criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent
tumors. The 20 PDGXs belonged to three of four The
Cancer Genome Atlas subtypes: eight classical, eight mesenchymal, and four proneural; none neural. Amplification of EGFR gene was observed in 9 of 20 xenografts, and of these, 3 harbored the
EGFRvIII mutation. We then performed proteomic profiling of PDGX, analyzing expression/activity of several
proteins including EGFR. Levels of EGFR phosphorylated at Y1068 vary considerably between PDGX samples, and this pattern was also seen in primary GBM. Partitioning of 20 PDGX into high (n = 5) and low (n = 15) groups identified a panel of
proteins associated with high EGFR activity. Thus, PDGX with high EGFR activity represent an excellent pre-clinical model to develop
therapies for a subset of GBM patients whose
tumors are characterized by high EGFR activity. Further, the
proteins found to be associated with high EGFR activity can be monitored to assess the effectiveness of targeting EGFR. The development of drugs to inhibit
glioblastoma (GBM) growth requires reliable pre-clinical models. We validated proteomic profiles using patient-derived
glioblastoma xenografts (PDGX), characterizing 20 PDGX models according to subtype classification based on The
Cancer Genome Atlas (TCGA) criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent
tumors.
Proteins found to be associated with high EGFR activity represent potential
biomarkers for GBM monitoring.