Inactivation of neuregulin-1 by nitration

2007 ◽  
Vol 292 (1) ◽  
pp. L287-L293 ◽  
Author(s):  
David E. Nethery ◽  
Sudakshina Ghosh ◽  
Serpil C. Erzurum ◽  
Jeffrey A. Kern
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Protein Function ◽  
Growth Factor Receptor ◽  
Normal Growth ◽  
Receptor Activation ◽  
Receptor Interaction ◽  
Neuregulin 1 ◽  
Mcf 7

Nitration is a posttranslational modification that can compromise protein function. We hypothesized that nitration of growth factors secreted in the lung may alter their interaction with their respective receptors and modulate the normal growth and differentiation program induced by ligand-receptor interaction. We tested this hypothesis in vitro by nitration of neuregulin-1's (NRG-1) EGF-like domain and studying the effect on NRG-1's activity. Nitration of NRG-1's (nNRG-1) EGF-like domain resulted in an inability to activate its receptor, the human epidermal growth factor receptors 2 and 3 (HER2/HER3) heterodimer, as defined by loss of HER2 tyrosine phosphorylation induced by nNRG-1 in MCF-7 cells. Receptor activation was not restored with increasing nNRG-1 concentration or exposure times. nNRG-1 did not compete with NRG-1 for HER2/HER3 binding in competition assays. In addition, nNRG-1 no longer induced proliferation of the MCF-7 cell line, as MCF-7 cells exposed to nNRG-1 and NRG-1 concurrently had the same proliferation rate as that induced by NRG-1 alone. Thus nitration of NRG-1's EGF-like domain caused it to lose its ability to bind and activate its receptor with loss of ligand-induced proliferation. Posttranslational nitration of growth factors in states where reactive nitrogen species are increased may be an important means of regulating growth factor receptor effects in the lung.

scholarly journals Development and preclinical evaluation of cixutumumab drug conjugates in a model of insulin growth factor receptor I (IGF-1R) positive cancer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Viswas Raja Solomon ◽  
Elahe Alizadeh ◽  
Wendy Bernhard ◽  
Amal Makhlouf ◽  
Siddesh V. Hartimath ◽  
...  
Keyword(s):  
Growth Factor ◽  
Ex Vivo ◽  
Growth Factor Receptor ◽  
Ct Imaging ◽  
Insulin Growth Factor ◽  
Drug Conjugates ◽  
Insulin Growth Factor Receptor ◽  
Ex Vivo Biodistribution ◽  
Mcf 7

Abstract Overexpression of insulin growth factor receptor type 1 (IGF-1R) is observed in many cancers. Antibody drug conjugates (ADCs) with PEGylated maytansine (PEG6-DM1) show promise in vitro. We developed PEG6-DM1 ADCs with low and high drug to antibody ratios (DAR) using an anti-IGF-1R antibody cixutumumab (IMC-A12). Conjugates with low (cixutumumab-PEG6-DM1-Low) and high (cixutumumab-PEG6-DM1-High) DAR as 3.4 and 7.2, respectively, were generated. QC was performed by UV spectrophotometry, HPLC, bioanalyzer, and biolayer-interferometry. We compared the in vitro binding and internalization rates of the ADCs in IGF-1R-positive MCF-7/Her18 cells. We radiolabeled the ADCs with 111In and used microSPECT/CT imaging and ex vivo biodistribution to understand their in vivo behavior in MCF-7/Her18 xenograft mice. The therapeutic potential of the ADC was studied in vitro and in mouse xenograft. Internalization rates of all ADCs was high and increased over 48 h and EC50 was in the low nanomolar range. MicroSPECT/CT imaging and ex vivo biodistribution showed significantly lower tumor uptake of 111In-cixutumumab-PEG6-DM1-High compared to 111In-cixutumumab-PEG6-DM1-Low and 111In-cixutumumab. Cixutumumab-PEG6-DM1-Low significantly prolonged the survival of mice bearing MCF-7/Her18 xenograft compared with cixutumumab, cixutumumab-PEG6-DM1-High, or the PBS control group. Cixutumumab-PEG6-DM1-Low ADC was more effective. The study highlights the potential utility of cixutumumab-ADCs as theranostics against IGF-1R positive cancers.

Improved antitumor therapy by dual targeting of estrogen and growth factor receptor signaling in human breast cancer cells

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 637-637 ◽  
Author(s):  
R. J. Pietras ◽  
D. C. Marquez ◽  
H. Chen ◽  
M. X. Sliwkowski ◽  
D. J. Slamon
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Growth Factor Receptor ◽  
Tamoxifen Resistance ◽  
Antitumor Efficacy ◽  
Her2 Overexpression ◽  
Antitumor Effects ◽  
Er Positive ◽  
Mcf 7

637 Background: Breast cancer growth is tightly regulated by interactions between growth factor and estrogen receptors. Dimerization is crucial for activation of HER receptors (EGFR, HER2, HER3, HER4) that contribute to modulation of tumor progression and the failure of antiestrogen therapy. HER2 is the preferred dimerization partner in a process stimulated by the several HER receptor ligands. HER2 antibody (trastuzumab) shows antitumor efficacy in HER2-overexpressing cancers. New antibodies that disrupt HER2 dimerization (pertuzumab) may be useful in treating cancers with normal HER2 levels. Methods: Estrogen receptor (ER)-positive tumor cells with normal HER levels (MCF-7, ZR75), as well as cells engineered for HER2-overexpression (MCF-7/HER2, ZR75/HER2) or tamoxifen resistance (MCF-7/TAM), were grown in vitro and as xenografts in nude mice and treated with tamoxifen, fulvestrant (Faslodex), trastuzumab or pertuzumab, alone or combined. Effects of agents on phosphorylation of ER and coactivator AIB1, ER-dependent transcripts, p27 and VEGF secretion were assessed. Results: Growth of ER-positive tumors with low HER is reduced by tamoxifen and fulvestrant. In contrast, HER2-overexpressing tumors are tamoxifen-resistant but retain sensitivity to fulvestrant and show greater, synergistic antitumor effects with trastuzumab-fulvestrant combined. Similarly, non-HER2-overexpressing tumors with or without tamoxifen resistance are sensitive to fulvestrant, but fulvestrant-pertuzumab elicits more profound antitumor effects (P<0.001). Enhanced inhibitory action of fulvestrant-pertuzumab is related, in part, to changes in phosphorylation of ER and AIB1, leading to blockade of ER-induced transcripts, as well as nuclear localization of p27, a CDK-inhibitor that downregulates cell proliferation. Further, enhanced tumor secretion of VEGF after estrogen and HER signaling is markedly reduced by fulvestrant-pertuzumab as compared with either agent alone (P<0.001). Conclusions: Pertuzumab promotes antitumor efficacy of the pure antiestrogen, fulvestrant, and dual disruption of ER and HER signaling may be a new way to optimize hormonal therapy and overcome antiestrogen resistance. Supported by US Army BCRP and Stiles Program. [Table: see text]

scholarly journals Grape Seed Procyanidins Inhibit the Growth of Breast Cancer MCF-7 Cells by Down-Regulating the EGFR/VEGF/MMP9 Pathway

2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199169
Author(s):  
Fan-ting Kong ◽  
Chen-xi He ◽  
Fan-lei Kong ◽  
Su-fen Han ◽  
Xiang-shun Kong ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Cell Apoptosis ◽  
Growth Factor Receptor ◽  
Grape Seed ◽  
Dependent Manner ◽  
Flow Cytometric Data ◽  
Mcf 7

Breast cancer is the most common invasive cancer in women and the second leading cause of cancer death in women. However, it is not clear about its effective treatments. As a potential anticancer agent, grape seed procyanidins (GSPs) have been shown to inhibit the proliferation of various cancer cells in vitro and in vivo. In this study, it was shown that GSPs significantly inhibit MCF-7 cell proliferation in a concentration/time-dependent manner. The flow cytometric data clearly demonstrated that GSPs cause cell cycle arrest in the G2/M phase, followed by cell apoptosis. Moreover, it also confirmed that growth inhibition mediated by treatment with GSPs is related to the induction of apoptosis due to p53 elevation, purportedly by inhibition of the epidermal growth factor receptor (EGFR)/vascular endothelial growth factor (VEGF)/matrix metalloproteinase 9 (MMP9) pathway. Taken together, these findings suggest that GSPs inhibit MCF-7 cells proliferation and induce cell apoptosis by suppressing EGFR/VEGF/MMP9 pathway.

In Vitro Ubiquitination Platform Identifies Methyl Ellipticiniums as Ubiquitin Ligase Inhibitors

2021 ◽  
pp. 247255522110006
Author(s):  
Brice A. P. Wilson ◽  
Donna Voeller ◽  
Emily A. Smith ◽  
Antony Wamiru ◽  
Ekaterina I. Goncharova ◽  
...  
Keyword(s):  
Growth Factor ◽  
Ubiquitin Ligase ◽  
Protein Function ◽  
Antitumor Immunity ◽  
Ring Finger ◽  
Growth Factor Receptor ◽  
Ubiquitin Ligases ◽  
Cell Receptor ◽  
Ubiquitin Ligase E3

The transfer of the small protein ubiquitin to a target protein is an intricately orchestrated process called ubiquitination that results in modulation of protein function or stability. Proper regulation of ubiquitination is essential, and dysregulation of this process is implicated in several human diseases. An example of a ubiquitination cascade that is a central signaling node in important disease-associated pathways is that of CBLB [a human homolog of a viral oncogene Casitas B-lineage lymphoma (CBL) from the Cas NS-1 murine retrovirus], a RING finger ubiquitin ligase (E3) whose substrates include a number of important cell-signaling kinases. These include kinases important in immune function that act in the T cell receptor and costimulatory pathways, the Tyro/Axl/MerTK (TAM) receptor family in natural killer (NK) cells, as well as growth factor receptor kinases like epidermal growth factor receptor (EGFR). Loss of CBLB has been shown to increase innate and adaptive antitumor immunity. This suggests that small-molecule modulation of CBLB E3 activity could enhance antitumor immunity in patients. To explore the hypothesis that enzymatic inhibition of E3s may result in modulation of disease-related signaling pathways, we established a high-throughput screen of >70,000 chemical entities for inhibition of CBLB activity. Although CBLB was chosen as a proof-of-principle target for inhibitor discovery, we demonstrate that our assay is generalizable to monitoring the activity of other ubiquitin ligases. We further extended our observed in vitro inhibition with additional cell-based models of CBLB activity. From these studies, we demonstrate that a class of natural product–based alkaloids, known as methyl ellipticiniums (MEs), is capable of inhibiting ubiquitin ligases intracellularly.

scholarly journals Therapy that Targets Growth Factor Receptors: Novel Approach for Liver Cirrhosis Treatment

2021 ◽  
Author(s):  
Halyna Kuznietsova ◽  
Olexandr Ogloblya
Keyword(s):  
Cell Proliferation ◽  
Growth Factors ◽  
Growth Factor ◽  
Liver Fibrosis ◽  
Growth Factor Receptor ◽  
Growth Factor Receptors ◽  
In Vivo Models ◽  
Novel Approach

The background of liver fibrous degeneration is excessive cell proliferation including hepatic stellate cells, inflammatory cells, fibroblasts and myofibroblasts. Often it is the consequence of increased growth factors and/or their receptors expression. Key contributors to the liver cell proliferation are EGFR, FGFR, PDGFR, VEGFR, TGFβR, the increased expression of which is indicated on in vitro and in vivo models of liver fibrosis and in patients who experienced fibrosis-accompanied liver diseases. Elimination of growth factors/suppression of their receptors is associated with the weakening/elimination of certain processes responsible for fibrogenesis. This chapter represents the evidences of the efficacy of growth factor receptors signaling downregulation for the suppression of liver fibrosis and cirrhosis and their individual manifestations. The data on established and experimental therapeutics – specific and multikinase growth factor receptor inhibitors which demonstrated antifibrotic and anticirrhotic activity under in vitro and in vivo models, are also presented.

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.

Met -/- kidneys express epithelial cells that chemotax and form tubules in response to EGF receptor ligands

1997 ◽  
Vol 272 (2) ◽  
pp. F222-F228
Author(s):  
C. Kjelsberg ◽  
H. Sakurai ◽  
K. Spokes ◽  
C. Birchmeier ◽  
I. Drummond ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cell ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Receptor Ligands ◽  
Tubule Formation ◽  
Human Papillomavirus 16 ◽  
Immortalized Cells

The growth factor/receptor combination of hepatocyte growth factor (HGF)/c-met has been postulated to be critical for mesenchymal-to-epithelial conversion and tubule formation in the developing kidney. We therefore isolated and immortalized cells from embryonic kidneys of met -/- transgenic mice to determine whether these cells were epithelial and able to chemotax and form tubules in vitro. The cells were immortalized with retrovirus expressing human papillomavirus 16 (HPV 16) E6/E7 genes. Two rapidly dividing clones were isolated and found to express the epithelial cell markers cytokeratin, zonula occludens-1, and E-cadherin but not to express the fibroblast marker vimentin. The met -/- cells were able to chemotax in response to epidermal growth factor and transforming growth factor-alpha (TGF-alpha) and form tubules in vitro in response to TGF-alpha but not HGF. These experiments suggest that the HGF/c-met axis is not essential for epithelial cell development in the embryonic kidney and demonstrate that other growth factors are capable of supporting early tubulogenesis.

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