Ligand-Induced Transformation by a Noninternalizing Epidermal Growth Factor Receptor

Wells, Alan; Welsh, J B; Lazar, Cheri S.; Wiley, H. Steven; Gill, G N; Rosenfeld, M G

doi:10.1126/science.2305263

Cited by 393 publications

(281 citation statements)

References 26 publications

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“…Such relatively higher or prolonged phosphorylation of the IR R252C or both and the two substrates could be related to the prolonged exposure of IR R252C to insulin on the cell surface (particularly on microvilli), as well as to a reduced rate of dephosphorylation which might be relat-ed to their cycling inside the cell. Thus, defective endocytic trafficking could lead to an enhancement of some biological responses which suggests that receptormediated endocytosis could be critical for attenuating receptor signalling as proposed many years ago [39] and supported by more recent observations regarding the epidermal growth factor receptor [43,44,45].…”

Section: Discussionmentioning

confidence: 87%

“…Position of Arg 252 and Cys 3 in the three dimensional structure of the insulin molecule. A model of the three N-terminal modules of the IR (L1-Cys-rich-L2) was generated by threading the IR amino acid sequence onto the 3-D structure of the equivalent modules of the IGF-I receptor determined by X-ray crystallography [43], using the Automated Protein Modelling Server Swiss-Model [44] running at the Glaxo-Wellcome Experimental Research in Geneva, Switzerland. The resulting structure is displayed using the program RasMol version 2.6 [45].…”

Section: Discussionmentioning

confidence: 99%

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An arginine to cysteine252 mutation in insulin receptors from a patient with severe insulin resistance inhibits receptor internalisation but preserves signalling events

et al. 2002

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Aims/hypothesis. We examined the properties of a mutant insulin receptor (IR) with an Arg 252 to Cys (IR R252C ) substitution in the α-subunit originally identified in a patient with extreme insulin resistance and acanthosis nigricans. Methods. We studied IR cell biology and signalling pathways in Chinese Hamster Ovary cells overexpressing this IR R252C . Results. Our investigation showed an impairment in insulin binding to IR R252C related mostly to a reduced affinity of the receptor for insulin and to a reduced rate of IR R252C maturation; an inhibition of IR R252C -mediated endocytosis resulting in a decreased insulin degradation and insulin-induced receptor down-regulation; a maintenance of IR R252C on microvilli even in the presence of insulin; a similar autophosphorylation of mutant IR R252C followed by IRS 1/IRS 2 phosphorylation, p85 association with IRS 1 and IRS 2 and Akt phosphorylation similar to those observed in cells expressing wild type IR (IRwt); and finally, a reduced insulin-induced Shc phosphorylation accompanied by decreased ERK1/2 phosphorylation and activity and of thymidine incorporation into DNA in cells expressing IR R252C as compared to cells expressing IRwt. Conclusion/interpretation. These observations suggest that: parameters other than tyrosine kinase activation participate in or control the first steps of IR internalisation or both; IR-mediated IRS 1/2 phosphorylation can be achieved from the cell surface and microvilli in particular; Shc phosphorylation and its subsequent signalling pathway might require IR internalisation; defective IR endocytosis correlates with an enhancement of some biological responses to insulin and attenuation of others. [Diabetologia (2002) 45:657-667]

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Section: Discussionmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

An arginine to cysteine252 mutation in insulin receptors from a patient with severe insulin resistance inhibits receptor internalisation but preserves signalling events

et al. 2002

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“…We have expressed exogenously encoded EGFR in DU-145 cells (Xie et al, 1995). Utilising established protocols, DU-145 cells were transfected by retroviral-containing EGFR constructs (Wells et al, 1990). The wild-type (WT) EGFR construct is a full-length cDNA derived from a placental cDNA library.…”

Section: Du-145 Cell Linesmentioning

confidence: 99%

Luteinising hormone-releasing hormone analogue reverses the cell adhesion profile of EGFR overexpressing DU-145 human prostate carcinoma subline

2005

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Cetrorelix, a luteinising hormone-releasing hormone (LHRH) analogue, has been shown to limit growth of the human androgenindependent prostate cell line DU-145, although other inhibitory actions may also be affected. Both growth and invasion of DU-145 cells are linked to autocrine epidermal growth factor receptor (EGFR) signalling. Invasiveness requires not only cells to migrate to conduits, but also reduced adhesiveness between tumour cells to enable separation from the tumour mass. Thus, we investigated whether Cetrorelix alters the DU-145 cell -cell adhesion and if this occurs via altered EGFR signalling. Pharmacologic levels of Cetrorelix limited the invasiveness of a highly invasive DU-145 subline overexpressing full-length EGFR (DU-145 WT). Extended exposure of the cells to Cetrorelix resulted in increased levels of the cell -cell adhesion complex molecules E-cadherin, a-and bcatenin, and p120. Puromycin blocked the increases in E-cadherin and b-catenin levels, suggesting that de novo protein synthesis is required. The Cetrorelix effect appears to occur via transmodulation of EGFR by a protein kinase C (PKC)-dependent mechanism, as there were no changes in DU-145 cells expressing EGFR engineered to negate the PKC transattenuation site (DU-145 A654); downregulation of EGFR signalling produced a similar upregulation in adhesion complex proteins, further suggesting a role for autocrine signalling. Cetrorelix increased the cell -cell adhesiveness of DU-145 WT cells to an extent similar to that seen when autocrine EGFR signalling is blocked; as expected, DU-145 A654 cell -cell adhesion also was unaffected by Cetrorelix. The increased adhesiveness is expected as the adhesion complex molecules moved to the cells' periphery. These data offer direct insight into the possible crosstalk pathways between the LHRH and EGFR receptor signalling. The ability of Cetrorelix to downregulate EGFR signalling and subsequently reverse the antiadhesiveness found in metastatic prostate cancer highlights a novel potential target for therapeutic strategies.

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“…The cell lines NR6, NR6M and NR6W have been described previously and were kindly provided by Dr Darell Bigner, Duke University, NC, USA (Batra et al, 1995). The NR6wtEGFR cell line, which expresses a lower number of receptors as compared to NR6W, has also been described previously and is a generous gift from Dr Allan Wells, Department of Pathology, University of Pittsburgh (Wells et al, 1990).…”

Section: Cell Linesmentioning

confidence: 99%

Differential response to gefitinib of cells expressing normal EGFR and the mutant EGFRvIII

Pedersen

Ottesen³

et al. 2005

Br J Cancer

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Epidermal growth factor receptor (EGFR) is frequently amplified and/or mutated in a number of human tumours and abnormal signalling from this receptor is believed to contribute to the malignant phenotype seen in these tumours. Gefitinib is a small molecule inhibitor that specifically binds and inhibits the EGFR tyrosine kinase and has been shown to inhibit the growth, proliferation, survival and invasion of a range of tumour cells overexpressing EGFR. However, clinical response to gefitinib has failed to correlate with EGFR levels and activity, indicating that other molecular mechanisms such as downstream signalling and mutations could be of importance in predicting clinical response. We therefore investigated the effect of the specific EGFR inhibitor gefitinib on the phosphorylation level, signalling and growth of cells expressing the naturally occurring constitutively active EGFR variant EGFRvIII, a low nontransforming level of EGFR and a high transforming level of EGFR. Results show that levels of gefitinib sufficient to suppress EGFR phosphorylations, EGFR-mediated proliferation and EGFR-mediated anchorage-independent growth are not sufficient to inhibit these features in cells expressing EGFRvIII. Furthermore, the data indicate that long-term exposure of EGFRvIII-expressing cells to low concentrations of gefitinib (0.01 -0.1 mM) result in increased phosphotyrosine load of the receptor, increased signalling to ERK and stimulation of proliferation and anchorage-independent growth, presumably by inducing EGFRvIII dimerisation. Higher concentrations of gefitinib (1 -2 mM), on the other hand, significantly decreased EGFRvIII phosphotyrosine load, EGFRvIII-mediated proliferation and anchorageindependent growth. Further studies are needed to investigate the implications of these important findings in the clinical setting.

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Ligand-Induced Transformation by a Noninternalizing Epidermal Growth Factor Receptor

Cited by 393 publications

References 26 publications

An arginine to cysteine252 mutation in insulin receptors from a patient with severe insulin resistance inhibits receptor internalisation but preserves signalling events

An arginine to cysteine252 mutation in insulin receptors from a patient with severe insulin resistance inhibits receptor internalisation but preserves signalling events

Luteinising hormone-releasing hormone analogue reverses the cell adhesion profile of EGFR overexpressing DU-145 human prostate carcinoma subline

Differential response to gefitinib of cells expressing normal EGFR and the mutant EGFRvIII

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