EGFR Amplified and Overexpressing Glioblastomas and Association With Better Response to Adjuvant Metronomic Temozolomide

Abstract

EGFR-amplified/overexpressing glioblastomas strongly benefit from metronomic temozolomide-based therapies.

Epidermal Growth Factor Receptor Variant III (EGFRvIII) Positivity in EGFR-Amplified Glioblastomas: Prognostic Role and Comparison between Primary and Recurrent Tumors

“…In contrast, MGMT promoter methylation was not prognostic in the subgroup of patients with EGFRvIII-positive glioblastomas. However, we could not confirm the suggestion of a prognostic interaction between EGFRvIII expression and MGMT promoter methylation in a published data set of 13 patients with EGFRvIII-positive tumors and available MGMT promoter methylation status (16), and in the large ACT IV phase III data set (46).…”

“…Individual studies suggested that these alterations are associated with shorter overall survival (OS) among anaplastic astrocytoma patients (12) and glioblastoma patients (11), while other authors found a prognostically favorable role of EGFRvIII positivity in glioblastoma patients (16). Yet other studies, including previous publications of the German Glioma Network (13,17), as well as a recent meta-analysis of eight publications (18), did not confirm a distinct prognostic role of EGFR amplification and EGFRvIII positivity, although a trend toward decreased long-term survival with EGFRvIII-positive glioblastoma has been reported (13,19,20).…”

Precision knockdown of EGFR gene expression using radio frequency electromagnetic energy

“…To demonstrate the specificity and cellular effects in vitro and in vivo, we used the human derived glioblastoma (GBM) cell line U-87 MG. We recorded the magnetic field signals of siRNA oligonucleotide molecule for the epidermal growth factor receptor (EGFR) gene, which plays a key role in cancer biology [9][10][11][12][13]. Here we show that we can specifically knock down EGFR gene expression, with resulting biological effects, in human U-87 MG and primary (GBM) cells by exposing these cells to physical-EGFR siRNA and RFE-siEGFR signal.…”

Progress in the application of molecular biomarkers in gliomas

“…The constitutively active mutant EGFRvIII, which is also known as de2-7 EGFR or DEGFR, is present in 25%e30% of GBMs with concurrent EGFR amplification/overexpression [30,31]. EGFR amplification is observed in most (97%) Classical subtype gliomas but is infrequently observed in other subtypes.…”