Biosynthesis and glycosylation of the epidermal growth factor receptor in human tumor-derived cell lines A431 and Hep 3B

1986 ◽  
Vol 6 (1) ◽  
pp. 257-264
Author(s):  
C R Carlin ◽  
B B Knowles
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Lines ◽  
Related Species ◽  
Growth Factor Receptor ◽  
Human Tumor ◽  
Early Time ◽  
Charge Heterogeneity ◽  
Epidermal Growth ◽  
Related Proteins

Biosynthesis of the receptor for epidermal growth factor was investigated in two human tumor-derived cell lines, Hep 3B and A431. When grown in the presence of tunicamycin, both cells expressed a receptor-related species p135, the presumptive aglycosylated form of the biosynthetic precursor, gp145, of the mature form of the receptor, gp165, expressed at the cell surface. Two additional receptor-related species, p115 and p70, were detected when A431, but not Hep 3B, cells were treated with tunicamycin. Furthermore, digestion of the A431 receptor-related proteins with endoglycosidase F resulted in the detection of these three aglycosylated species. P70 appears to be the aglycosylated form of gp95, the presumptive intracellular precursor of the receptor-related species gp120 that is secreted by A431 but not Hep 3B cells; gp120 has a complex pattern of N-linked glycosylation, with consequent molecular weight and charge heterogeneity. P115 may be the aglycosylated form of a third biosynthetic intermediate, possibly a gp135 species detected in the early time points of pulse-chase labeling. Alternatively, p115 and gp135 may be derived co- or post-translationally by Ca2+-mediated proteolysis from p135 and gp145, respectively. The implications of the complexity of the biosynthesis of this molecule with regard to the multiple opportunities it affords the cell to modulate cell proliferation are discussed.

scholarly journals Biosynthesis and glycosylation of the epidermal growth factor receptor in human tumor-derived cell lines A431 and Hep 3B.

1986 ◽  
Vol 6 (1) ◽  
pp. 257-264 ◽  
Author(s):  
C R Carlin ◽  
B B Knowles
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Lines ◽  
Related Species ◽  
Growth Factor Receptor ◽  
Human Tumor ◽  
Early Time ◽  
Charge Heterogeneity ◽  
Epidermal Growth ◽  
Related Proteins

Biosynthesis of the receptor for epidermal growth factor was investigated in two human tumor-derived cell lines, Hep 3B and A431. When grown in the presence of tunicamycin, both cells expressed a receptor-related species p135, the presumptive aglycosylated form of the biosynthetic precursor, gp145, of the mature form of the receptor, gp165, expressed at the cell surface. Two additional receptor-related species, p115 and p70, were detected when A431, but not Hep 3B, cells were treated with tunicamycin. Furthermore, digestion of the A431 receptor-related proteins with endoglycosidase F resulted in the detection of these three aglycosylated species. P70 appears to be the aglycosylated form of gp95, the presumptive intracellular precursor of the receptor-related species gp120 that is secreted by A431 but not Hep 3B cells; gp120 has a complex pattern of N-linked glycosylation, with consequent molecular weight and charge heterogeneity. P115 may be the aglycosylated form of a third biosynthetic intermediate, possibly a gp135 species detected in the early time points of pulse-chase labeling. Alternatively, p115 and gp135 may be derived co- or post-translationally by Ca2+-mediated proteolysis from p135 and gp145, respectively. The implications of the complexity of the biosynthesis of this molecule with regard to the multiple opportunities it affords the cell to modulate cell proliferation are discussed.

Computational Evaluation and In Vitro Validation of New Epidermal Growth Factor Receptor Inhibitors

2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Affinity ◽  
Cell Lines ◽  
Growth Factor Receptor ◽  
Significant Activity ◽  
Epidermal Growth

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.

scholarly journals Characteristics of specific binding of epidermal growth factor (EGF) on human tumor cell lines.

1983 ◽  
Vol 30 (5) ◽  
pp. 601-607 ◽  
Author(s):  
YUKIO HIRATA ◽  
MASAHITO UCHIHASHI ◽  
TAKUO FUJITA ◽  
SHIGERU MATSUKURA ◽  
TEIICHI MOTOYAMA ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tumor Cell ◽  
Cell Lines ◽  
Specific Binding ◽  
Human Tumor ◽  
Tumor Cell Lines ◽  
Human Tumor Cell ◽  
Human Tumor Cell Lines ◽  
Epidermal Growth

scholarly journals Receptor dimerization is not a factor in the signalling activity of a transforming variant epidermal growth factor receptor (EGFRvIII)

1997 ◽  
Vol 324 (3) ◽  
pp. 855-861 ◽  
Author(s):  
Charleen T. CHU ◽  
Keith D. EVERISS ◽  
Carol J. WIKSTRAND ◽  
Surinder K. BATRA ◽  
Hsing-Jien KUNG ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Lines ◽  
Cellular Proliferation ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Receptor Activation ◽  
Receptor Dimerization ◽  
Epidermal Growth

The type-III deletion variant of the epidermal growth factor receptor (EGFRvIII) is frequently found in glioblastomas and other malignant human tumours. Although EGFRvIII confers ligand-independent oncogenic transformation of cell lines, the mechanism by which it promotes aberrant cellular proliferation is unknown. Using cell lines expressing comparable numbers of either wild-type receptor (EGFRwt) or EGFRvIII, we compared several parameters of receptor activation: dimerization, tyrosine phosphorylation and activation of intracellular signalling proteins. Like activated EGFRwt, EGFRvIII was phosphorylated and bound constitutively to the Shc adapter protein. Indeed, EGFRvIII-associated Shc had a higher phosphotyrosine content than Shc associated with stimulated EGFRwt. EGFRwt dimerized in response to either EGF or transforming growth factor α. Higher cross-linker concentrations and incubation at higher temperatures (37 °C) allowed detection of EGFRwt dimers even in the absence of exogenous ligand. In contrast, EGFRvIII failed to dimerize under any conditions studied. Moreover, neither mitogen-activated protein kinase nor phospholipase Cγ were phosphorylated in EGFRvIII-expressing cells. We conclude that the deletion of 267 amino acids from the 621-amino-acid N-terminal domain of EGFR does not result simply in a constitutively activated receptor, but alters the spectrum of signalling cascades utilized. Furthermore the ligand-independent transforming activity of EGFRvIII is independent of receptor dimerization.

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