Mapping of genomic EGFRvIII deletions in glioblastoma: insight into rearrangement mechanisms and biomarker development

Koga, Tomoyuki; Li, Bin; Figueroa, Javier; Ren, Bing; Chen, Clark C.; Carter, Bob S.; Furnari, Frank B.

doi:10.1093/neuonc/noy058

Cited by 29 publications

(27 citation statements)

References 46 publications

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“…Low-molecular hairpin-type ribozymes were able to specifically inhibit EGFR expression, as well as proliferation and clonogenicity of GB cells in vitro [60,239]. In terms of gene-editing approaches, it is worth to mention that CRISPR-based technologies have only little chance of being successfully applied in case of EGFR vIII , as deletions within EGFR leading to the formation of this oncogenic variant are quite extensive and tend to differ between patients [240]. It is worth to mention that RNA interference can be achieved by miRNA upregulation.…”

Section: Anti-egfr VIII Therapy Based On Rna Interferencementioning

confidence: 99%

EGFR^vIII: An Oncogene with Ambiguous Role

Rutkowska

Stoczyńska-Fidelus

Janik

et al. 2019

Journal of Oncology

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Epidermal growth factor receptor variant III (EGFRvIII) seems to constitute the perfect therapeutic target for glioblastoma (GB), as it is specifically present on up to 28–30% of GB cells. In case of other tumor types, expression and possible role of this oncogene still remain controversial. In spite of EGFRvIII mechanism of action being crucial for the design of small active anticancer molecules and immunotherapies, i.e., CAR-T technology, it is yet to be precisely defined. EGFRvIII is known to be resistant to degradation, but it is still unclear whether it heterodimerizes with EGF-activated wild-type EGFR (EGFRWT) or homodimerizes (including covalent homodimerization). Constitutive kinase activity of this mutated receptor is relatively low, and some researchers even claim that a nuclear, but not a membrane function, is crucial for its activity. Based on the analyses of recurrent tumors that are often lacking EGFRvIII expression despite its initial presence in corresponding primary foci, this oncogene is suggested to play a marginal role during later stages of carcinogenesis, while even in primary tumors EGFRvIII expression is detected only in a small percentage of tumor cells, undermining the rationality of EGFRvIII-targeting therapies. On the other hand, EGFRvIII-positive cells are resistant to apoptosis, more invasive, and characterized with enhanced proliferation rate. Moreover, expression of this oncogenic receptor was also postulated to be a marker of cancer stem cells. Opinions regarding the role that EGFRvIII plays in tumorigenesis and for tumor aggressiveness are clearly contradictory and, therefore, it is crucial not only to determine its mechanism of action, but also to unambiguously define its role at early and advanced cancer stages.

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Section: Anti-egfr VIII Therapy Based On Rna Interferencementioning

confidence: 99%

EGFR^vIII: An Oncogene with Ambiguous Role

Rutkowska

Stoczyńska-Fidelus

Janik

et al. 2019

Journal of Oncology

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“…The qualitative discrepancy between EGFR1 and EGFR2 amplicons for detecting the gene copy number from the same tumor is probably due to breakpoint variability of the EGFRvIII variant. The EGFR1 amplicon is located at the start of intron 1 in an area containing various breakpoints for the EGFRvIII splicing variant [27]. The EGFR1 amplicon may therefore match with tumor DNA if the breakpoint is closer to exon 2 but may mismatch with the tumor DNA if the breakpoint is closer to exon 1.…”

Section: Discussionmentioning

confidence: 99%

“…As shown in our results, the value of using EGFR2 resides in its location within the spliced area, regardless of the breakpoint. Therefore, the comparison of the copy number estimation using EGFR2 and EGFR3 assays should be a more sensitive method than dPCR using an amplicon located at the end of exon 1 [27,28].…”

Section: Discussionmentioning

confidence: 99%

Simultaneous detection of EGFR amplification and EGFRvIII variant using digital PCR-based method in glioblastoma

Fontanilles

Marguet

Ruminy

et al. 2020

acta neuropathol commun

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Epidermal growth factor receptor (EGFR) amplification and EGFR variant III (EGFRvIII, deletion of exons 2-7) are of clinical interest for glioblastoma. The aim was to develop a digital PCR (dPCR)-based method using locked nucleic acid (LNA)-based hydrolysis probes, allowing the simultaneous detection of the EGFR amplification and EGFRvIII variant. Sixty-two patients were included. An exploratory cohort (n = 19) was used to develop the dPCR assay using three selected amplicons within the EGFR gene, targeting intron 1 (EGFR1), junction of exon 3 and intron 3 (EGFR2) and intron 22 (EGFR3). The copy number of EGFR was estimated by the relative quantification of EGFR1, EGFR2 and EGFR3 amplicon droplets compared to the droplets of a reference gene. EGFRvIII was identified by comparing the copy number of the EGFR2 amplicon to either the EGFR1 or EGFR3 amplicon. dPCR results were compared to fluorescence in situ hybridization (FISH) and next-generation sequencing for amplification; and to RT-PCR-based method for EGFRvIII. The dPCR assay was then tested in a validation cohort (n = 43). A total of 8/19 EGFR-amplified and 5/19 EGFRvIII-positive tumors were identified in the exploratory cohort. Compared to FISH, the EGFR3 dPCR assay detected all EGFR-amplified tumors (8/8, 100%) and had the highest concordance with the copy number estimation by NGS. The concordance between RT-PCR and dPCR was also 100% for detecting EGFRvIII using an absolute difference of 10.8 for the copy number between EGFR2 and EGFR3 probes. In the validation cohort, the sensitivity and specificity of dPCR using EGFR3 probes were 100% for the EGFR amplification detection compared to FISH (19/19). EGFRvIII was detected by dPCR in 8 EGFR-amplified patients and confirmed by RT-PCR. Compared to FISH, the EGFR2/EGFR3 dPCR assay was estimated with a one-half cost value. These results highlight that dPCR allowed the simultaneous detection of EGFR amplification and EGFRvIII for glioblastoma.

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“…It results from the in-frame deletion of exons 2 to 7 and the generation of a novel glycine residue at the junction of exons 1 and 8. This novel juxtaposition of amino acids within the extracellular domain of the EGFR creates a tumor-specific, oncogenic, and immunogenic epitope [6]. This variant receptor expressed in numerous types of human tumors such as glioblastoma, breast, non-small-cell lung, liver and ovarian cancers [7].…”

Section: Ivyspring International Publishermentioning

confidence: 99%

EGFRvIII-specific CAR-T cells produced by piggyBac transposon exhibit efficient growth suppression against hepatocellular carcinoma

Ma¹,

Chang²,

Yan³

et al. 2020

Int. J. Med. Sci.

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Adoptive cellular immunotherapy employing chimeric antigen receptors-modified T (CAR-T) cells has demonstrated promising antitumor effects in hematologic cancers. However, CART therapy confront many challenges in solid tumors like immunosuppressive microenvironment, molecular heterogeneity, etc. The cancer genome atlas (TCGA) of hepatocellular carcinoma (HCC) revealed many genetic characteristic and molecular tumorigenesis. EGFRvIII is a tumor specific antigen widely expressed in a variety of cancers including HCC and an ideal therapeutic target for cancer therapy. The liver cancer cell line SMMC7721 express high level EGFRvIII and widely applied in HCC investigations. Herein, we developed EGFRvIII CART cells by piggyBac transposon system, and detected its specific killing effect against SMMC7721 cells in vitro and in vivo. Results indicated that transduction efficiency of CAR reached 53.1%. Expression of CAR protein was verified by immunoblotting as a band of approximate 57KD.

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Mapping of genomic EGFRvIII deletions in glioblastoma: insight into rearrangement mechanisms and biomarker development

Abstract: Our approach efficiently "fingerprints" each sample's EGFRvIII breakpoints. Breakpoint sequence analyses suggest that independent breakpoints arose from precursor amplified non-vIII EGFR through different DNA repair mechanisms.

Cited by 29 publications

References 46 publications

EGFR^vIII: An Oncogene with Ambiguous Role

EGFR^vIII: An Oncogene with Ambiguous Role

Simultaneous detection of EGFR amplification and EGFRvIII variant using digital PCR-based method in glioblastoma

EGFRvIII-specific CAR-T cells produced by piggyBac transposon exhibit efficient growth suppression against hepatocellular carcinoma

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Mapping of genomic EGFRvIII deletions in glioblastoma: insight into rearrangement mechanisms and biomarker development

Abstract: Our approach efficiently "fingerprints" each sample's EGFRvIII breakpoints. Breakpoint sequence analyses suggest that independent breakpoints arose from precursor amplified non-vIII EGFR through different DNA repair mechanisms.

Cited by 29 publications

References 46 publications

EGFRvIII: An Oncogene with Ambiguous Role

EGFRvIII: An Oncogene with Ambiguous Role

Simultaneous detection of EGFR amplification and EGFRvIII variant using digital PCR-based method in glioblastoma

EGFRvIII-specific CAR-T cells produced by piggyBac transposon exhibit efficient growth suppression against hepatocellular carcinoma

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EGFR^vIII: An Oncogene with Ambiguous Role

EGFR^vIII: An Oncogene with Ambiguous Role