Preparation and evaluation of tumor-targeting peptide - Oligonucleotide conjugates

Enormous progress has been made in the development of antisense oligodeoxynucleotides (ODNs) as therapeutic agents inhibiting gene expression. Unfortunately, the therapeutical application of ODNs is still held back because of the low cellular uptake and the lack of specific transport into particular...

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Detalles Bibliográficos
Autores: Mier, Walter, Eritja Casadellà, Ramón, Mohammed, Ashour, Haberkorn, Uwe, Eisenhut, Michael
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2000
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/141179
Acceso en línea:http://hdl.handle.net/10261/141179
Access Level:acceso abierto
Palabra clave:Antisense oligonucleotides
Drug targeting
Covalent bonds
Proto oncogene
Oligonucleotides
Neoplasms
Organophosphorus Compounds
Somatostatin
Descripción
Sumario:Enormous progress has been made in the development of antisense oligodeoxynucleotides (ODNs) as therapeutic agents inhibiting gene expression. Unfortunately, the therapeutical application of ODNs is still held back because of the low cellular uptake and the lack of specific transport into particular cells. In this paper, we report a drug-targeting system using somatostatin receptors (SSTRs) which are overexpressed in various tumors. Phosphorothioate ODNs were covalently linked to Tyr3-octreotate, an analogue of somatostatin. The peptide was assembled by solid-phase synthesis, oxidized to form the cyclic disulfide, and subsequently derivatized with a N-terminal maleimido functionality. 5'-Thiol derivatized phosphorothioate-ODNs directed against the protooncogene bcl-2 were conjugated to this maleimido-modified peptide. Binding studies revealed that the conjugates retain specific binding with nanomolar affinities to SSTRs (IC50-values between 1.83 and 2.52 nM). Furthermore, melting studies with complementary DNA revealed that the terminal conjugation of the ODNs did not significantly affect their hybridization affinity.