Search results for "bombesin"
showing 10 items of 11 documents
Analysis of the gastrin-releasing peptide receptor gene in Italian patients with autism spectrum disorders
2008
The gastrin-releasing peptide receptor (GRPR) was implicated for the first time in the pathogenesis of Autism spectrum disorders (ASD) by Ishikawa-Brush et al. [Ishikawa-Brush et al. (1997): Hum Mol Genet 6: 1241-1250]. Since this original observation, only one association study [Marui et al. (2004): Brain Dev 26: 5-7] has further investigated, though unsuccessfully, the involvement of the GRPR gene in ASD. With the aim of contributing further information to this topic we have sequenced the entire coding region and the intron/exon junctions of the GRPR gene in 149 Italian autistic patients. The results of this study led to the identification of four novel point mutations, two of which, that…
Multiple Peptide Hormone Producing Adenocarcinoma of Lung with Neurotensin and CRF-like Immunoreactivity
1988
Summary A pulmonary cancer of a 43 year-old-man was classified according to WHO-criteria as a poorly differentiated adenocarcinoma because of demonstration of mucinous substances in tumor cells and in rarely occurring acinar lumina. Immunohistochemical reactivity for several peptide hormones was detected in the predominant solid parts of the carcinoma. In many tumor cells an immunoreactivity to neurotensin, bombesin and — according to the elevated serum levels — to ACTH, CRF and calcitonin was found. Therefore the present lung cancer must be defined as a combined carcinoma composed of mucous producing and endocrine cell types. Because peptide hormone production is not restricted to the clas…
Direct subphthalocyanine conjugation to bombesin vs. indirect conjugation to its lipidic nanocarrier
2016
International audience; Bombesin (BBN) was covalently bound to graftable subphthalocyanine (SubPc) or to a cholesterol derivative, a component of a liposome that encapsulates non-graftable SubPc. The latter bioconjugation approach was suitable to address the stability of SubPc and was achieved by copper-free click-chemistry on the outer-face of the liposome. Liposomes were purified (FPLC) and then analyzed in size (outer diameter about 60 nm measured by DLS). In vitro binding studies allowed to determine the IC50 13.9 nM for one component of the liposome, cholesterol, conjugated to BBN. Hence, azido- (or alkynyl-) liposomes give fluorophores with no reactive functional group available on th…
Continuously manufactured magnetic polymersomes--a versatile tool (not only) for targeted cancer therapy.
2013
Micromixer technology was used to prepare polymeric vesicles (Pluronic® L-121) dual loaded with the anti-cancer drug camptothecin and magnetic nanoparticles. Successful incorporation of the magnetic nanoparticles was confirmed by transmission electron microscopy. Dynamic light scattering measurements showed a relatively narrow size distribution of the hybrid polymersomes. Camptothecin polymersomes reduced the cell viability of prostate cancer cells (PC-3) measured after 72 h significantly, while drug-free polymersomes showed no cytotoxic effects. Covalent attachment of a cancer targeting peptide (bombesin) as well as a fluorescent label (Alexa Fluor® 647) to the hybrid polymersomes was perf…
Towards the elaboration of new gold-based optical theranostics.
2014
Four new red BODIPY–gold(I) theranostic compounds were synthesized. Some of them were vectorized by tethering a biovector (glucose or bombesin derivatives) to the metallic center. Their photophysical properties were studied. Additionally, their cytotoxicity was examined on different cancer cell lines and on a normal cell line, they were tracked in vitro by fluorescence detection, and their uptake was evaluated by ICP-MS measurements.
DMAP-BODIPY Alkynes: A Convenient Tool for Labeling Biomolecules for Bimodal PET-Optical Imaging
2014
Several new boron dipyrromethene/N,N-dimethylaminopyridine (BODIPY-DMAP) assemblies were synthesized as precursors for bimodal imaging probes (optical imaging, OI/positron emission tomography, PET). The photophysical properties of the new compounds were also studied. The first proof-of-concept was obtained with the preparation of several new BODIPY-labeled bombesins and evaluation of the affinity for bombesin receptors by using a competition binding assay. Fluorination reactions were investigated on DMAP-BODIPY precursors as well as on DMAP-BODIPY-labeled bombesins. Chemical modifications on the BODIPY core were also performed to obtain luminescent dyes emitting in the therapeutic window (6…
44Sc-DOTA-BN[2-14]NH2 in comparison to 68Ga-DOTA-BN[2-14]NH2 in pre-clinical investigation. Is 44Sc a potential radionuclide for PET?
2011
In the present study we demonstrate the in vitro and in vivo comparison of the (44)Sc and (68)Ga labeled DOTA-BN[2-14]NH(2). (44)Sc is a positron emitter with a half life of 3.92 h. Hence it could be used for PET imaging with ligands requiring longer observation time than in the case of (68)Ga.The binding affinity of (nat)Sc-DOTA-BN[2-14]NH(2) and (nat)Ga-DOTA-BN[2-14]NH(2) to GRP receptors was studied in competition to [(125)I-Tyr(4)]-Bombesin in the human prostate cancer cell line PC-3. A preliminary biodistribution in normal rats was performed, while first microPET images were assessed in male Copenhagen rats bearing the androgen-independent Dunning R-3327-AT-1 prostate cancer tumor.The …
Amide-to-triazole switch vs. in vivo NEP-inhibition approaches to promote radiopeptide targeting of GRPR-positive tumors
2017
Abstract Introduction Radiolabeled bombesin (BBN)-analogs have been proposed for diagnosis and therapy of gastrin-releasing peptide receptor (GRPR)-expressing tumors, such as prostate, breast and lung cancer. Metabolic stability represents a crucial factor for the success of this approach by ensuring sufficient delivery of circulating radioligand to tumor sites. The amide-to-triazole switch on the backbone of DOTA-PEG 4 -[Nle 14 ]BBN(7–14) ( 1 ) was reported to improve the in vitro stability of resulting 177 Lu-radioligands. On the other hand, in-situ inhibition of neutral endopeptidase (NEP) by coinjection of phosphoramidon (PA) was shown to significantly improve the in vivo stability and …
Photoperiod effects on bombesin- and cholecystokinin-like immunoreactivity in the suprachiasmatic nuclei of the Djungarian hamster (Phodopus sungorus)
1991
The immunocytochemical distribution of the putative satiety peptides bombesin (BBS) and cholecystokinin (CCK) were studied in the hypothalamic suprachiasmatic nuclei (SCN) of male and female Djungarian hamsters (Phodopus sungorus) held under either long (light/dark, LD 16:8 h) or short (LD 8:16) photoperiod. The animals were killed by perfusion with a fixative at the middle of the light period and the tissue was processed by routine immunohistochemical methods. Perikarya exhibiting BBS- or CCK-like immunoreactivity (LI) were found in the SCN of animals of all groups. Sex-related differences were not observed. In contrast, long-term exposure to short days decreased the number of neurons exhi…
Role of central oxytocin in the inhibition by endotoxin of distension-stimulated gastric acid secretion
2000
The gastric acid hyposecretory state associated with endotoxemia is mediated by a nervous reflex involving the central nervous system. The aim of the present study was to analyse the central effects of different peptides on distension-stimulated gastric acid secretion and the endogenous role of such peptides on the hyposecretory effects of endotoxin. The effect of an intracisternal (i.c.) administration of oxytocin, vasopressin, corticotropin releasing factor (CRF), bombesin, somatostatin and the opioid receptor agonist BW443C or an intravenous (i.v.) injection of a small dose of endotoxin on distension-stimulated gastric acid secretion was studied in the continuously perfused stomach of an…