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dc.contributor.authorJones, Sarah
dc.contributor.authorHowl, John D.
dc.date.accessioned2008-06-20T17:27:21Z
dc.date.available2008-06-20T17:27:21Z
dc.date.issued2005
dc.identifier.citationNeuro-oncology, 7(3): 373
dc.identifier.issn1522-8517
dc.identifier.doi10.1215/ S1152851705200388
dc.identifier.urihttp://hdl.handle.net/2436/30277
dc.descriptionAbstracts from Neuro-Oncology are provided here courtesy of Society for Neuro-Oncology and Duke University Press.
dc.description.abstractThe cell-type-specific targeting of cytotoxic agents and other functional moieties can be achieved by using peptidyl address motifs that selectively bind protein targets expressed at high density at the cell membrane. Indeed, numerous studies have confirmed the utility of ligands for G protein–coupled receptors as components of heterofunctional peptide chimeras that are selective biological probes. Our current efforts are directed toward the further development of chimeric peptidyl constructs that employ sequences derived from GPCR ligands or cell penetrant motifs to affect the selective delivery of cytotoxins and signal transduction modulators to tumor cells. We have designed and synthesized a range of hybrid constructs consisting of cytotoxins (peptide and non-peptide) covalently linked to an address peptide derived from the C-terminal of gastrin (G7; H-AYGWMDF-NH2). The G7 homing motif targets a novel binding site expressed by U373MG astrocytic tumor cells that is distinct from classical CCK1/CCK2 receptors. Moreover, biological responses following activation of this novel membrane-bound protein may offer additional therapeutic advantages. For example, G7 receptor activation is reported to inhibit the motility of malignant astrocytoma in vivo while avoiding the growth-promoting effects of gastrin (Pannequin et al., J. Pharmacol. Exp. Ther. 302, 274, 2002). We evaluated the cytotoxicity of our chimeric peptides by comparing changes in cellular viability using MTT conversion assays. Our data indicate that chimeric peptides dose-dependently and rapidly (<8 h) reduced the viability of U373MG cells. Moreover, as a chimeric amino-terminal extension, the G7 address motif enhanced the cytotoxicity of both mastoparan (H-INLKALAALAKKIL-NH2) and D(KLAKLAK)2 peptides reported to stimulate necrosis and/or apoptosis of eukarytoic cells. In conclusion, hybrid G7 chimeras enhance the efficacy of cytotoxic agents and may be valuable probes to investigate and manipulate additional aspects of astrocytoma cell biology. This work was supported by The Wellcome Trust.
dc.language.isoen
dc.publisherSociety for Neuro-oncology and Duke University Press
dc.relation.urlhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1871910
dc.subjectCytotoxicity
dc.subjectChimerism
dc.subjectCell Penetrating Peptides (CPP)
dc.subjectCPP
dc.subjectSignal Transduction
dc.subjectMolecular Biology
dc.subjectOncology
dc.subjectAstrocytoma
dc.subjectBrain Tumours
dc.subjectLigands
dc.subjectPeptides
dc.titleChimeric peptides as tumour-selective delivery systems.
dc.title.alternativeIn: Abstracts from the World Federation of Neuro-Oncology 2nd Quadrennial Meeting and the 6th Meeting of the European Association for Neuro-Oncology, Edinburgh, UK, 5-8 May 2005, No.373.
dc.typeJournal article
dc.identifier.journalNeuro-oncology
html.description.abstractThe cell-type-specific targeting of cytotoxic agents and other functional moieties can be achieved by using peptidyl address motifs that selectively bind protein targets expressed at high density at the cell membrane. Indeed, numerous studies have confirmed the utility of ligands for G protein–coupled receptors as components of heterofunctional peptide chimeras that are selective biological probes. Our current efforts are directed toward the further development of chimeric peptidyl constructs that employ sequences derived from GPCR ligands or cell penetrant motifs to affect the selective delivery of cytotoxins and signal transduction modulators to tumor cells. We have designed and synthesized a range of hybrid constructs consisting of cytotoxins (peptide and non-peptide) covalently linked to an address peptide derived from the C-terminal of gastrin (G7; H-AYGWMDF-NH2). The G7 homing motif targets a novel binding site expressed by U373MG astrocytic tumor cells that is distinct from classical CCK1/CCK2 receptors. Moreover, biological responses following activation of this novel membrane-bound protein may offer additional therapeutic advantages. For example, G7 receptor activation is reported to inhibit the motility of malignant astrocytoma in vivo while avoiding the growth-promoting effects of gastrin (Pannequin et al., J. Pharmacol. Exp. Ther. 302, 274, 2002). We evaluated the cytotoxicity of our chimeric peptides by comparing changes in cellular viability using MTT conversion assays. Our data indicate that chimeric peptides dose-dependently and rapidly (<8 h) reduced the viability of U373MG cells. Moreover, as a chimeric amino-terminal extension, the G7 address motif enhanced the cytotoxicity of both mastoparan (H-INLKALAALAKKIL-NH2) and D(KLAKLAK)2 peptides reported to stimulate necrosis and/or apoptosis of eukarytoic cells. In conclusion, hybrid G7 chimeras enhance the efficacy of cytotoxic agents and may be valuable probes to investigate and manipulate additional aspects of astrocytoma cell biology. This work was supported by The Wellcome Trust.


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