Determination of EGFR Status in Gliomas

Guillaudeau, Angélique; Durand, Karine; Pommepuy, Isabelle; Robert, Sandrine; Chaunavel, Alain; Lacorre, Sylvain; DeArmas, Rafaël; Bourtoumieux, Sylvie; Demery, Mounira El; Moreau, Jean-Jacques; Labrousse, François

doi:10.1097/pai.0b013e31818db320

Cited by 20 publications

(11 citation statements)

References 32 publications

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“…EGFR gene amplification, associated or not to EGFRvIII mutant expression, is frequently observed in other tumors like gliomas [5], [52], [63], [64], [65], [66], lung cancers [67], [68], breast [69], and prostate adenocarcinomas [70]. EGFR gene amplification and EGFRvIII transcripts were not detected in our series, indicating that they are not involved in meningiomas oncogenesis.…”

Section: Discussioncontrasting

confidence: 49%

“…Sample slides were processed automatically (BenchMark XT ICH/ISH, Ventana Medical Systems, USA) according to protocols supplied by the antibody manufacturers. For each section, we recorded the type of cell expressing EGFR protein, the percentage of labeled cells, the labeling intensity and the resulting Hirsch score as previously described [52], [53], [54], [55], [56], [57]. For Ki67 labeling index, 10% of labeled cells was taken as a cut-off value for analyses.…”

Section: Methodsmentioning

confidence: 99%

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EGFR Soluble Isoforms and Their Transcripts Are Expressed in Meningiomas

et al. 2012

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The EGFR (epidermal growth factor receptor) is involved in the oncogenesis of many tumors. In addition to the full-length EGFR (isoform a), normal and tumor cells produce soluble EGFR isoforms (sEGFR) that lack the intracellular domain. sEGFR isoforms b, c and d are encoded by EGFR variants 2 (v2), 3 (v3) and 4 (v4) mRNA resulting from gene alternative splicing. Accordingly, the results of EGFR protein expression analysis depend on the domain targeted by the antibodies. In meningiomas, EGFR expression investigations mainly focused on EGFR isoform a. sEGFR and EGFRvIII mutant, that encodes a constitutively active truncated receptor, have not been studied. In a 69 meningiomas series, protein expression was analyzed by immunohistochemistry using extracellular domain targeted antibody (ECD-Ab) and intracellular domain targeted antibody (ICD-Ab). EGFRv1 to v4 and EGFRvIII mRNAs were quantified by RT-PCR and EGFR amplification revealed by MLPA. Results were analyzed with respect to clinical data, tumor resection (Simpson grade), histological type, tumor grade, and patient outcome.Immunochemical staining was stronger with ECD-Ab than with ICD-Ab. Meningiomas expressed EGFRv1 to -v4 mRNAs but not EGFRvIII mutant. Intermediate or high ECD-Ab staining and high EGFRv1 to v4 mRNA levels were associated to a better progression free survival (PFS). PFS was also improved in women, when tumor resection was evaluated as Simpson 1 or 2, in grade I vs. grade II and III meningiomas and when Ki67 labeling index was lower than 10%.Our results suggest that, EGFR protein isoforms without ICD and their corresponding mRNA variants are expressed in meningiomas in addition to the whole isoform a. EGFRvIII was not expressed. High expression levels seem to be related to a better prognosis. These results indicate that the oncogenetic mechanisms involving the EGFR pathway in meningiomas could be different from other tumor types.

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Section: Discussioncontrasting

confidence: 49%

Section: Methodsmentioning

confidence: 99%

EGFR Soluble Isoforms and Their Transcripts Are Expressed in Meningiomas

et al. 2012

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“…Sample slides were processed automatically (BenchMark XT ICH/ISH, Ventana Medical Systems, Tucson, AZ, USA) according to protocols supplied by the manufacturers. EGFR staining was quantified according to a semiquantitative method proposed by Hirsch et al (27), as previously described (28). Staining was scored for labeling intensity (1, negative or trace; 2, weak; 3, moderate; 4, intense), percentage of positive cells per slide (0%–100%) and for the Hirsch score resulting from multiplication of these two parameters (absolute values ranging from 0 to 400).…”

Section: Methodsmentioning

confidence: 99%

“…They were investigated on consecutive paraffin sections from the same blocks used in immunohistochemical analyses. This technique was a modification of the method previously described (28): briefly, 4 μm paraffin sections were incubated 16 h at 56°C, submitted to deparaffinising, digested with pepsin (Abbott Molecular Inc.) at 37°C during 45 min and dehydrated in successive ethanol baths. Slides were incubated with 10 μl of each probe for 5 min at 73°C to denature DNA and 16 h at 37°C to ensure hybridization.…”

Section: Methodsmentioning

confidence: 99%

Adult diffuse gliomas produce mRNA transcripts encoding EGFR isoforms lacking a tyrosine kinase domain

Guillaudeau

Durand²,

Rabinovitch-Chable³

et al. 2011

International Journal of Oncology

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The epidermal growth factor receptor (EGFR) gene encodes four alternatively spliced mRNA, variants 1, 2, 3 and 4, respectively, encoding the whole isoform a (EGFR) and truncated isoforms b, c and d, all of which lack the receptor’s intracellular domain. In addition, a mutant EGFRvIII differs from isoform a in a truncated extracellular domain. The expression pattern of these isoforms is unknown in adult diffuse gliomas. Thus, we investigated in 47 cases: i) EGFR protein expression by immunohistochemistry using an extracellular domain-recognizing antibody (Ext-Ab) and an intracellular domain specific one (Int-Ab), ii) mRNA expression of EGFRv1, -v2, -v3, -v4 and -vIII by RT-PCR and iii) EGFR amplification by fluorescent in situ hybridization. The relation of these data with histological criteria and patient outcome was studied. The immunostaining was stronger with the Ext-Ab than with the Int-Ab. EGFRv1, -v2, -v3 and -v4 mRNA expression were highly correlated. They were expressed in all tumors, with highest levels in glioblastomas. EGFRv1 strong levels and the presence of vIII mRNAs were more closely associated with Int-Ab staining. EGFR gene amplification concerned only glioblastomas and was associated with the presence of EGFRvIII and high levels of EGFRv2, -v3 and -v4 transcripts. A pejorative outcome was associated with: histology (glioblastomas), EGFR amplification, strong Int-Ab labeling and high levels of variant mRNAs. Our results indicated that the full-length EGFR and mutant EGFRvIII are not the sole EGFR isoform expressed in diffuse gliomas. This could explain discordant immunohistochemical results reported in the literature and may have therapeutic implications.

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“…Although amplification of the gene encoding the EGFR can account for the aberrant EGFR expression detected in 30-40% of primary brain tumors or brain tumor-derived cell lines (Guillaudeau et al, 2009; Libermann et al, 1985), additional mechanisms must be involved to account for the increased EGFR protein levels observed in those glioblastoma cases where gene amplification does not occur, as well as for the excessive and sustained EGFR-signaling that is characteristic of these brain cancers. Thus, it seemed likely that the disruption of the normal (negative) regulation of EGFRs contributes to the aberrant EGFR-signaling capabilities exhibited in at least some glioblastomas.…”

Section: Introductionmentioning

confidence: 99%

A Mechanism for the Upregulation of EGF Receptor Levels in Glioblastomas

et al. 2013

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SUMMARY Tissue transglutaminase (tTG) is a GTP-binding protein/acyl transferase whose expression is up-regulated in glioblastoma and associated with decreased patient survival. Here we delineate a unique mechanism by which tTG contributes to the development of gliomas, by using two glioblastoma cell lines, U87 and LN229, whose growth and survival are dependent on tTG. We show that tTG significantly enhances the signaling activity and lifetimes of EGF-receptors (EGFRs) in these brain cancer cells. Moreover, over-expressing tTG in T98G glioblastoma cells that normally express low levels of tTG, caused a marked up-regulation of EGFR expression and transforming activity. We further show that tTG accentuates EGFR-signaling by blocking c-Cbl-catalyzed EGFR ubiquitylation, through the ability of tTG to bind GTP and adopt a specific conformation that enables it to interact with c-Cbl. These findings demonstrate that tTG contributes to gliomagenesis by interfering with EGFR down-regulation and thereby promoting transformation.

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Determination of EGFR Status in Gliomas

Cited by 20 publications

References 32 publications

EGFR Soluble Isoforms and Their Transcripts Are Expressed in Meningiomas

EGFR Soluble Isoforms and Their Transcripts Are Expressed in Meningiomas

Adult diffuse gliomas produce mRNA transcripts encoding EGFR isoforms lacking a tyrosine kinase domain

A Mechanism for the Upregulation of EGF Receptor Levels in Glioblastomas

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