title: Photodynamic therapy targeting neuropilin-1: Interest of pseudopeptides with improved stability properties.
abstract: The general strategy developed aims to favor the vascular effect of photodynamic therapy by targeting tumor vasculature. Since angiogenic endothelial cells represent an interesting target to potentiate this vascular effect, we previously described the conjugation of a photosensitizer to a peptide targeting neuropilins (NRPs) over-expressed specially in tumor angiogenic vessels and we recently characterized the mechanism of photosensitization-induced thrombogenic events. Nevertheless, in glioma-bearing nude mice, we demonstrated that the peptide moiety was degraded to various rates according to time after intravenous administration. In this study, new peptidases-resistant pseudopeptides were tested, demonstrating a molecular affinity for NRP-1 and NRP-2 recombinant chimeric proteins and devoid of affinity for VEGF receptor type 1 (Flt-1). To argue the involvement of NRP-1, MDA-MB-231 breast cancer cells were used, strongly over-expressing NRP-1 receptor. We evidenced a statistically significant decrease of the different peptides-conjugated photosensitizers uptake after RNA interference-mediated silencing of NRP-1. Peptides-conjugated photosensitizers allowed a selective accumulation into cells. In mice, no degradation was observed in plasma in vivo 4h after intravenous injection by MALDI-TOF mass spectrometry. This study draws attention to this potential problem with peptides, especially in the case of targeting strategies, and provides useful information for the future design of more stable molecules.
authors.affiliation: Centre de Recherche en Automatique de Nancy, Nancy-University, CNRS, Vandoeuvre-lès-Nancy, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Thomas
authors.forename: Marlène
authors.initials: M
authors.lastname: Pernot
authors.forename: Régis
authors.initials: R
authors.lastname: Vanderesse
authors.forename: Philippe
authors.initials: P
authors.lastname: Becuwe
authors.forename: Ezatul
authors.initials: E
authors.lastname: Kamarulzaman
authors.forename: David
authors.initials: D
authors.lastname: Da Silva
authors.forename: Aurélie
authors.initials: A
authors.lastname: François
authors.forename: Céline
authors.initials: C
authors.lastname: Frochot
authors.forename: François
authors.initials: F
authors.lastname: Guillemin
authors.forename: Muriel
authors.initials: M
authors.lastname: Barberi-Heyob
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D045744:Cell Line, Tumor; D004355:Drug Stability; D005260:Female; D020868:Gene Silencing; D006801:Humans; D039942:Neuropilin-1 / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011166:Porphyrins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D011994:Recombinant Proteins; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D009842:Oligopeptides; D017319:Photosensitizing Agents; D011166:Porphyrins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D039942:Neuropilin-1; C006969:chlorin