Universität zu Köln

Richter, Susan, Bouvet, Vincent, Wuest, Melinda, Bergmann, Ralf, Steinbach, Joerg ORCID: 0000-0002-1708-6440, Pietzsch, Jens ORCID: 0000-0002-1610-1493, Neundorf, Ines ORCID: 0000-0001-6450-3991 and Wuest, Frank (2012). F-18-Labeled phosphopeptide-cell-penetrating peptide dimers with enhanced cell uptake properties in human cancer cells. Nucl. Med. Biol., 39 (8). S. 1202 - 1213. NEW YORK: ELSEVIER SCIENCE INC. ISSN 1872-9614

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Abstract

Introduction: Phosphopeptides represent interesting compounds to study and elucidate cellular protein phosphorylation/dephosphorylation processes underlying various signal transduction pathways. However, studies of phosphopeptide action in cells are severely constrained by the negatively charged phosphate moiety of the phosphopeptide resulting in poor transport through the cell membrane. The following study describes the synthesis and radiopharmacological evaluation of two F-18-labeled phosphopeptide-cell-penetrating peptide dimers. The polo-like kinase-1-binding hexaphosphopeptide H-Met-Gln-Ser-pThr-ProLeu-OH was coupled to cell-penetrating peptides (CPPs), either sC18, a cathelicidin-derived peptide, or the human calcitonin derivative hCT(18-32)-k7. Methods: Radiolabeling was accomplished with the prosthetic group N-succinimidyl 4-[F-18]fluorobenzoate ([F-18]SFB) using both, conventional and microfluidic-based bioconjugation of [F-18]SEB to N-terminal end of phosphopeptide part of the peptide dimers. Cellular uptake studies in human cancer cell lines HT-29 and FaDu cells at 4 T and 37 T and small animal PET in BALB/c mice were utilized for radiopharmacological characterization. Results: Isolated radiochemical yields ranged from 2% to 4% for conventional bioconjugation with [F-18]SFB. Significantly improved isolated radiochemical yields of up to 26% were achieved using microfluidic technology. Cellular uptake studies of radiolabeled phosphopeptide and phosphopeptide-CPP dimers indicate enhanced internalization of 50% ID/mg protein after 2 h for both phosphopeptide dimers compared to the phosphopeptide alone (<1% ID/mg protein). In vivo biodistribution of F-18-labeled peptide dimers was determined with small animal PET revealing a superior biodistribution pattern of sC18-containing peptide dimer MQSpTPL-sC18 [F-18]4. Conclusion: [F-18]SFB labeling of the phosphopeptide-CPP dimers using a microfluidic system leads to an improved chemoselectivity towards the N-terminal NH2 group compared to the conventional labeling approach. Cell-penetrating peptide sC18 can be considered as an ideal molecular shuttle for intracellular delivery of the Plk1-PBD-binding hexaphosphopeptide as demonstrated by its favourable radiopharmacological profile. (C) 2012 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Richter, Susan UNSPECIFIED UNSPECIFIED UNSPECIFIED Bouvet, Vincent UNSPECIFIED UNSPECIFIED UNSPECIFIED Wuest, Melinda UNSPECIFIED UNSPECIFIED UNSPECIFIED Bergmann, Ralf UNSPECIFIED UNSPECIFIED UNSPECIFIED Steinbach, Joerg UNSPECIFIED orcid.org/0000-0002-1708-6440 UNSPECIFIED Pietzsch, Jens UNSPECIFIED orcid.org/0000-0002-1610-1493 UNSPECIFIED Neundorf, Ines UNSPECIFIED orcid.org/0000-0001-6450-3991 UNSPECIFIED Wuest, Frank UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-479953
DOI:	10.1016/j.nucmedbio.2012.06.003
Journal or Publication Title:	Nucl. Med. Biol.
Volume:	39
Number:	8
Page Range:	S. 1202 - 1213
Date:	2012
Publisher:	ELSEVIER SCIENCE INC
Place of Publication:	NEW YORK
ISSN:	1872-9614
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language POLO-LIKE KINASES; MICROFLUIDIC TECHNOLOGY; DELIVERY; PET; BIODISTRIBUTION; INHIBITION; METABOLISM; MECHANISMS; PRINCIPLES; CHEMISTRY Multiple languages Radiology, Nuclear Medicine & Medical Imaging Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/47995