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Ratajczyk T, Buntkowsky G, Gutmann T, Fedorczyk B, Mames A, Pietrzak M, Puzio Z, Szkudlarek PG. Magnetic Resonance Signal Amplification by Reversible Exchange of Selective PyFALGEA Oligopeptide Ligands Towards Epidermal Growth Factor Receptors. Chembiochem 2020; 22:855-860. [PMID: 33063920 DOI: 10.1002/cbic.202000711] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Indexed: 12/13/2022]
Abstract
The biorelevant PyFALGEA oligopeptide ligand, which is selective towards the epidermal growth factor receptor (EGFR), has been successfully employed as a substrate in magnetic resonance signal amplification by reversible exchange (SABRE) experiments. It is demonstrated that PyFALGEA and the iridium catalyst IMes form a PyFALGEA:IMes molecular complex. The interaction between PyFALGEA:IMes and H2 results in a ternary SABRE complex. Selective 1D EXSY experiments reveal that this complex is labile, which is an essential condition for successful hyperpolarization by SABRE. Polarization transfer from parahydrogen to PyFALGEA is observed leading to significant enhancement of the 1 H NMR signals of PyFALGEA. Different iridium catalysts and peptides are inspected to discuss the influence of their molecular structures on the efficiency of hyperpolarization. It is observed that PyFALGEA oligopeptide hyperpolarization is more efficient when an iridium catalyst with a sterically less demanding NHC ligand system such as IMesBn is employed. Experiments with shorter analogues of PyFALGEA, that is, PyLGEA and PyEA, show that the bulky phenylalanine from the PyFALGEA oligopeptide causes steric hindrance in the SABRE complex, which hampers hyperpolarization with IMes. Finally, a single-scan 1 H NMR SABRE experiment of PyFALGEA with IMesBn revealed a unique pattern of NMR lines in the hydride region, which can be treated as a fingerprint of this important oligopeptide.
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Affiliation(s)
- Tomasz Ratajczyk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Gerd Buntkowsky
- Institute of Physical Chemistry, Technical University Darmstadt, Alarich-Weiss-Straße 8, 64287, Darmstadt, Germany
| | - Torsten Gutmann
- Institute of Physical Chemistry, Technical University Darmstadt, Alarich-Weiss-Straße 8, 64287, Darmstadt, Germany
| | - Bartłomiej Fedorczyk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland.,Biological and Chemical Research Centre, University of Warsaw, Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Adam Mames
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Mariusz Pietrzak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Zuzanna Puzio
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland
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Mao J, Ran D, Xie C, Shen Q, Wang S, Lu W. EGFR/EGFRvIII Dual-Targeting Peptide-Mediated Drug Delivery for Enhanced Glioma Therapy. ACS APPLIED MATERIALS & INTERFACES 2017; 9:24462-24475. [PMID: 28685576 DOI: 10.1021/acsami.7b05617] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Tumor-homing peptides have been widely used to mediate active targeted drug delivery. l-AE is a reported targeting peptide demonstrating high binding affinity to epidermal growth factor receptor (EGFR) and mutation variant III (EGFRvIII) overexpressed on neovasculature, vasculogenic mimicry, tumor cells, and tumor stem cells. To improve its proteolytic stability, a d-peptide ligand (termed d-AE, the enantiomer of l-AE) was developed. d-AE was confirmed to bind receptors EGFR and EGFRvIII with targeting capability comparable to l-AE. In vivo biodistribution demonstrated the superiority of d-AE in prolonged circulation and enhanced intratumoral accumulation. Furthermore, stabilized peptide modification endowed micelles higher transcytosis efficiency and penetrating capability on blood-brain tumor barrier/U87 tumor spheroids coculture model. When paclitaxel (PTX) was loaded, d-AE-micelle/PTX demonstrated excellent antitumor effect in comparison to Taxol, micelle/PTX, and l-AE-micelle/PTX. These findings indicated that the multitargeted drug delivery system enabled by d-AE ligand provides a promising way for glioma therapy.
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Affiliation(s)
- Jiani Mao
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, (Fudan University), Ministry of Education, Shanghai 201203, China
| | - Danni Ran
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, (Fudan University), Ministry of Education, Shanghai 201203, China
| | - Cao Xie
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, (Fudan University), Ministry of Education, Shanghai 201203, China
| | - Qing Shen
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai 200030, China
| | - Songli Wang
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, (Fudan University), Ministry of Education, Shanghai 201203, China
| | - Weiyue Lu
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, (Fudan University), Ministry of Education, Shanghai 201203, China
- Minhang Hospital, Fudan University , Shanghai 201199, China
- State Key Laboratory of Medical Neurobiology, The Collaborative Innovation Center for Brain Science, Fudan University , Shanghai 200032, China
- Institute of Integrative Medicine of Fudan University , Shanghai 200040, China
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BH3 mimetic-elicited Ca 2+ signals in pancreatic acinar cells are dependent on Bax and can be reduced by Ca 2+-like peptides. Cell Death Dis 2017; 8:e2640. [PMID: 28252652 PMCID: PMC5386550 DOI: 10.1038/cddis.2017.41] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/20/2016] [Accepted: 01/11/2017] [Indexed: 02/07/2023]
Abstract
BH3 mimetics are small-molecule inhibitors of B-cell lymphoma-2 (Bcl-2) and Bcl-xL, which disrupt the heterodimerisation of anti- and pro-apoptotic Bcl-2 family members sensitising cells to apoptotic death. These compounds have been developed as anti-cancer agents to counteract increased levels of Bcl-2 proteins often present in cancer cells. Application of a chemotherapeutic drug supported with a BH3 mimetic has the potential to overcome drug resistance in cancers overexpressing anti-apoptotic Bcl-2 proteins and thus increase the success rate of the treatment. We have previously shown that the BH3 mimetics, BH3I-2' and HA14-1, induce Ca2+ release from intracellular stores followed by a sustained elevation of the cytosolic Ca2+ concentration. Here we demonstrate that loss of Bax, but not Bcl-2 or Bak, inhibits this sustained Ca2+ elevation. What is more, in the absence of Bax, thapsigargin-elicited responses were decreased; and in two-photon-permeabilised bax-/- cells, Ca2+ loss from the ER was reduced compared to WT cells. The Ca2+-like peptides, CALP-1 and CALP-3, which activate EF hand motifs of Ca2+-binding proteins, significantly reduced excessive Ca2+ signals and necrosis caused by two BH3 mimetics: BH3I-2' and gossypol. In the presence of CALP-1, cell death was shifted from necrotic towards apoptotic, whereas CALP-3 increased the proportion of live cells. Importantly, neither of the CALPs markedly affected physiological Ca2+ signals elicited by ACh, or cholecystokinin. In conclusion, the reduction in passive ER Ca2+ leak in bax-/- cells as well as the fact that BH3 mimetics trigger substantial Ca2+ signals by liberating Bax, indicate that Bax may regulate Ca2+ leak channels in the ER. This study also demonstrates proof-of-principle that pre-activation of EF hand Ca2+-binding sites by CALPs can be used to ameliorate excessive Ca2+ signals caused by BH3 mimetics and shift necrotic death towards apoptosis.
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Feiner RC, Müller KM. Recent progress in protein-protein interaction study for EGFR-targeted therapeutics. Expert Rev Proteomics 2016; 13:817-32. [PMID: 27424502 DOI: 10.1080/14789450.2016.1212665] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Epidermal growth factor receptor (EGFR) expression is upregulated in many tumors and its aberrant signaling drives progression of many cancer types. Consequently, EGFR has become a clinically validated target as extracellular tumor marker for antibodies as well as for tyrosine kinase inhibitors. Within the last years, new mechanistic insights were uncovered and, based on clinical experience as well as progress in protein engineering, novel bio-therapeutic approaches were developed and tested. AREAS COVERED The potential therapeutic targeting arsenal in the fight against cancer now encompasses bispecific or biparatopic antibodies, DARPins, Adnectins, Affibodies, peptides and combinations of these binding molecules with viral- and nano-particles. We review past and recent binding proteins from the literature and include a brief description of the various targeting approaches. Special attention is given to the binding modes with the EGFR. Expert commentary: Clinical data from the three approved anti EGFR antibodies indicate that there is room for improved therapeutic efficacy. Having choices in size, affinity, avidity and the mode of EGFR binding as well as the possibility to combine various effector functions opens the possibility to rationally design more effective therapeutics.
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Affiliation(s)
- Rebecca Christine Feiner
- a Cellular and Molecular Biotechnology group, Faculty of Technology , Bielefeld University , Bielefeld , Germany
| | - Kristian Mark Müller
- a Cellular and Molecular Biotechnology group, Faculty of Technology , Bielefeld University , Bielefeld , Germany
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Han CY, Yue LL, Tai LY, Zhou L, Li XY, Xing GH, Yang XG, Sun MS, Pan WS. A novel small peptide as an epidermal growth factor receptor targeting ligand for nanodelivery in vitro. Int J Nanomedicine 2013; 8:1541-9. [PMID: 23626467 PMCID: PMC3632632 DOI: 10.2147/ijn.s43627] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) serves an important function in the proliferation of tumors in humans and is an effective target for the treatment of cancer. In this paper, we studied the targeting characteristics of small peptides (AEYLR, EYINQ, and PDYQQD) that were derived from three major autophosphorylation sites of the EGFR C-terminus domain in vitro. These small peptides were labeled with fluorescein isothiocyanate (FITC) and used the peptide LARLLT as a positive control, which bound to putative EGFR selected from a virtual peptide library by computer-aided design, and the independent peptide RALEL as a negative control. Analyses with flow cytometry and an internalization assay using NCI-H1299 and K562 with high EGFR and no EGFR expression, respectively, indicated that FITC-AEYLR had high EGFR targeting activity. Biotin-AEYLR that was specifically bound to human EGFR proteins demonstrated a high affinity for human non-small-cell lung tumors. We found that AEYLR peptide-conjugated, nanostructured lipid carriers enhanced specific cellular uptake in vitro during a process that was apparently mediated by tumor cells with high-expression EGFR. Analysis of the MTT assay indicated that the AEYLR peptide did not significantly stimulate or inhibit the growth activity of the cells. These findings suggest that, when mediated by EGFR, AEYLR may be a potentially safe and efficient delivery ligand for targeted chemotherapy, radiotherapy, and gene therapy.
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Affiliation(s)
- Cui-yan Han
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, People's Republic of China
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Denholt CL, Kuhnast B, Dollé F, Hinnen F, Hansen PR, Gillings N, Kjaer A. Fluorine-18 labelling of a series of potential EGFRvIII targeting peptides with a parallel labelling approach using [18F]FPyME. J Labelled Comp Radiopharm 2010. [DOI: 10.1002/jlcr.1795] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Iqbal U, Trojahn U, Albaghdadi H, Zhang J, O'Connor-McCourt M, Stanimirovic D, Tomanek B, Sutherland G, Abulrob A. Kinetic analysis of novel mono- and multivalent VHH-fragments and their application for molecular imaging of brain tumours. Br J Pharmacol 2010; 160:1016-28. [PMID: 20590596 DOI: 10.1111/j.1476-5381.2010.00742.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The overexpression of epidermal growth factor receptor (EGFR) and its mutated variant EGFRvIII occurs in 50% of glioblastoma multiforme. We developed antibody fragments against EGFR/EGFRvIII for molecular imaging and/or therapeutic targeting applications. EXPERIMENTAL APPROACH An anti-EGFR/EGFRvIII llama single-domain antibody (EG(2)) and two higher valency format constructs, bivalent EG(2)-hFc and pentavalent V2C-EG(2) sdAbs, were analysed in vitro for their binding affinities using surface plasmon resonance and cell binding studies, and in vivo using pharmacokinetic, biodistribution, optical imaging and fluorescent microscopy studies. KEY RESULTS Kinetic binding analyses by surface plasmon resonance revealed intrinsic affinities of 55 nM and 97 nM for the monovalent EG(2) to immobilized extracellular domains of EGFR and EGFRvIII, respectively, and a 10- to 600-fold increases in apparent affinities for the multivalent binders, V2C-EG(2) and EG(2)-hFc, respectively. In vivo pharmacokinetic and biodistribution studies in mice revealed plasma half-lives for EG(2), V2C-EG(2) and EG(2)-hFc of 41 min, 80 min and 12.5 h, respectively, as well as a significantly higher retention of EG(2)-hFc compared to the other two constructs in EGFR/EGFRvIII-expressing orthotopic brain tumours, resulting in the highest signal in the tumour region in optical imaging studies. Time domain volumetric optical imaging fusion with high-resolution micro-computed tomography of microvascular brain network confirmed EG(2)-hFc selective accumulation/retention in anatomically defined tumour regions. CONCLUSIONS Single domain antibodies can be optimized for molecular imaging applications by methods that improve their apparent affinity and prolong plasma half-life and, at the same time, preserve their ability to penetrate tumour parenchyma.
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Affiliation(s)
- U Iqbal
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada
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Differential tumor-targeting abilities of three single-domain antibody formats. Cancer Lett 2010; 289:81-90. [DOI: 10.1016/j.canlet.2009.08.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/22/2009] [Accepted: 08/02/2009] [Indexed: 11/21/2022]
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Identification of novel peptide ligands for the cancer-specific receptor mutation EFGRvIII using a mixture-based synthetic combinatorial library. Biopolymers 2009; 91:201-6. [DOI: 10.1002/bip.21117] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Piao Y, Jiang H, Alemany R, Krasnykh V, Marini FC, Xu J, Alonso MM, Conrad CA, Aldape KD, Gomez-Manzano C, Fueyo J. Oncolytic adenovirus retargeted to Delta-EGFR induces selective antiglioma activity. Cancer Gene Ther 2008; 16:256-65. [PMID: 18927600 DOI: 10.1038/cgt.2008.75] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The fact that glioblastomas, which are one of the most devastating cancers, frequently express the Delta-EGFR (epithelial growth factor receptor) also called mutant variant III of EGFR (EGFRvIII) suggests that this cancer cell-specific receptor might serve as an ideal target for cancer therapy. To assess its potential as such a target, we constructed an oncolytic adenovirus with Retargeted Infectivity Via EGFR (Delta-24-RIVER) on the backbone of Delta-24. This new oncolytic adenovirus targets, as Delta-24 does, the disrupted Rb pathway in cancer cells; in addition, this adenovirus has also been retargeted through the abrogation of CAR binding (Y477A mutation in adenoviral fiber protein) and insertion of an EGFRvIII-specific binding peptide in the HI loop of the fiber protein. As compared with Delta-24, Delta-24-RIVER induced EGFRvIII-selective cytotoxicity in U-87 MG isogenic cell lines and in tetracycline-inducible EGFRVIII expressing U-251 MG cells. Accordingly, by tittering the viral progeny and examining fiber protein expression in the above cells, we showed that the replication of this new construct also correlated with EGFRvIII expression. Consistently, immunohistochemistry staining of the adenoviral capsid protein hexon in the virus-treated tumors revealed that the virus replicated more efficiently in EGFRvIII-expressing U-87 MG.DeltaEGFR xenografts than in the tumors grown from U-87 MG cells. Importantly, treatment with Delta-24-RIVER prolonged the survival of animals with intracranial xenografts derived from U-87 MG.DeltaEGFR cells. Therefore, our results constitute the first proof of the direct targeting of a cancer-specific receptor using an oncolytic adenovirus.
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Affiliation(s)
- Y Piao
- Department of Neuro-Oncology, Brain Tumor Center, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Hansen CL, Hansen PR, Pedersen N, Poulsen HS, Gillings N, Kjaer A. Identification of Amino Acid Residues in PEPHC1 Important for Binding to the Tumor-Specific Receptor EGFRvIII. Chem Biol Drug Des 2008; 72:273-8. [DOI: 10.1111/j.1747-0285.2008.00706.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wu C, Lo SL, Boulaire J, Hong MLW, Beh HM, Leung DSY, Wang S. A peptide-based carrier for intracellular delivery of proteins into malignant glial cells in vitro. J Control Release 2008; 130:140-5. [PMID: 18632177 DOI: 10.1016/j.jconrel.2008.05.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 05/09/2008] [Accepted: 05/11/2008] [Indexed: 11/18/2022]
Abstract
Aiming at identification of novel peptides that can be employed for effective targeting of malignant gliomas, we used a 12-mer peptide phage display library and cultured human malignant glioma cells for phage selection. Several common phage clones emerged after 4 rounds of biopanning against the U87MG glioblastoma cell line. The most abundant phage clone VTW, expressing a sequence of VTWTPQAWFQWV, bound to U87MG cells 700-fold more efficiently than the original unselected library. The VTW phage also bound strongly to other human glioma cell lines, including H4, SW1088 and SW1783, but very weakly to normal human astrocytes and SV40-immortalized human astroglial cells. When compared to other non-glial tumor cells, the phage showed 400- to 1400-fold higher binding efficiency for U87MG cells. After linked to positively charged lysine peptides, the VTW peptide became water soluble and was able to deliver biologically active, hydrophilic beta-galactosidase into U87MG cells, with up to 90% of the cells being stained intensively blue. This peptide carrier did not show obvious protein delivery activities in the human astrocytes. Our results provide a proof of principle to the concept that peptides identified through phage display technology can be used to develop protein carriers that are capable of mediating intracellular delivery of hydrophilic macromolecules in a tumor cell-specific manner.
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Affiliation(s)
- Chunxiao Wu
- Institute of Bioengineering and Nanotechnology, Singapore 138669, Singapore
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Gandara DR, Aberle D, Lau D, Jett J, Akhurst T, Mulshine J, Berg C, Patz EF. Radiographic Imaging of Bronchioloalveolar Carcinoma: Screening, Patterns of Presentation and Response Assessment. J Thorac Oncol 2006. [DOI: 10.1016/s1556-0864(15)30005-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Abstract
New therapies aimed at molecular abnormalities are often more efficacious and less toxic than nontargeted therapies; however, with current technology, major treatment decisions are being made with inadequate data. This problem needs to be fixed by molecular imaging technology, enabling he noninvasive establishment of the presence of a molecular target, its spatial distribution and heterogeneity, and how this changes over time. This article discusses the status of molecular imaging in clinical trails today, and looks forward to what physicians would like it to become.
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Radiographic Imaging of Bronchioloalveolar Carcinoma: Screening, Patterns of Presentation and Response Assessment. J Thorac Oncol 2006. [DOI: 10.1097/01243894-200611001-00005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Modjtahedi H, Moscatello DK, Box G, Green M, Shotton C, Lamb DJ, Reynolds LJ, Wong AJ, Dean C, Thomas H, Eccles S. Targeting of cells expressing wild-type EGFR and type-III mutant EGFR (EGFRvIII) by anti-EGFR MAb ICR62: a two-pronged attack for tumour therapy. Int J Cancer 2003; 105:273-80. [PMID: 12673691 DOI: 10.1002/ijc.11055] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
With a view to their use in cancer therapy, we have produced rat monoclonal antibodies (MAbs) directed against 5 distinct epitopes (A-E) on the external domain of the wild-type human EGF receptor (EGFR). Here, we have investigated the relative binding and anti-tumour activity of our anti-EGFR MAbs against HC2 20d2/c cells, which have been engineered to overexpress the type-III mutated form of the human EGFR (EGFRvIII). We found that anti-EGFR MAbs that are the most effective antagonists of EGFR ligands (e.g., ICR16, ICR62 and ICR80) also bind to cells that overexpress the EGFRvIII. Although these antibodies are potent inhibitors of the growth of cells which express wild-type EGFR, they did not directly inhibit the growth in vitro of EGFRvIII expressing HC2 20d2/c cells, or the constitutive tyrosine kinase activity of this receptor. However, in the presence of human peripheral blood mononuclear cells (PBMC), the rat IgG2b MAb ICR62 induced strong antibody-dependent cell-mediated cytotoxicity (ADCC) against HC2 20d2/c cells in culture. Interestingly, MAb ICR62 also inhibited very effectively experimental lung metastases of HC2 20d2/c cells in athymic nude mice. Our results suggest that anti-EGFR MAb ICR62, which binds to the EGFRvIII, may have potential in the treatment of tumors which overexpress the EGFRvIII via immunological mechanisms such as ADCC. Since tumours that are EGFRvIII positive may also overexpress the wild-type EGFR, the use of anti-EGFR MAbs that target both wild-type and mutant receptors may have advantages over those that target only1form.
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Affiliation(s)
- Helmout Modjtahedi
- Division of Oncology, Postgraduate Medical School, Guildford, United Kingdom.
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Campa MJ, Serlin SB, Patz EF. Development of novel tumor imaging agents with phage-display combinatorial peptide libraries. Acad Radiol 2002; 9:927-32. [PMID: 12186442 DOI: 10.1016/s1076-6332(03)80463-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
RATIONALE AND OBJECTIVES Current radiologic methods do not provide sufficient information for unambiguous diagnosis and prognosis of cancer. The present investigation sought to address this deficiency by developing a system for designing novel small molecules targeted against tumor-specific molecules for use as radionuclide imaging agents. MATERIALS AND METHODS Part of a tumor-specific receptor, purified recombinant epidermal growth factor receptor (EGFR), variant III, extracellular domain (rEGFRvIII-ecd), was used as the target in the selection of EGFRvIII-specific peptide ligands from random peptide bacteriophage (phage) display libraries. After three rounds of screening, phage isolates were tested for binding affinity with an enzyme-linked immunosorbent assay. Positive phage were sequenced, and the peptides were synthesized and tested for binding affinity with a surface plasmon resonance assay. RESULTS Affinity screening identified 49 peptide-expressing phage that showed enhanced binding to the variant receptor compared with wild-type EGFR. Free peptides from the two phage isolates exhibiting the most favorable binding were tested for target binding. One of these demonstrated a binding affinity for rEGFRvIII-ecd in the 30-nmol/L range. CONCLUSION These data suggest that phage display libraries may be very useful in the design of novel, high-affinity tumor imaging agents.
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Affiliation(s)
- Michael J Campa
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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