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Sample records for bombesin

  1. Bombesin in short bowel syndrome.

    Science.gov (United States)

    Uluutku, Ahmet Haldun; Akin, Mehmet Levhi; Kurt, Yavuz; Yucel, Ergun; Cermik, Hakan; Avsar, Kadir; Celenk, Tuncay

    2004-01-01

    Short bowel syndrome comprises the sequel of nutrient, fluid, and weight loss that occurs subsequent to greatly reduced functional surface area of the small intestine. The aim of this study is to investigate the trophic and functional effects of bombesin on remaining gut in rats with experimentally induced short bowel syndrome. Thirty-two rats were allocated randomly and experimental short bowel syndrome was induced by 80% bowel resection in all rats. A regular enteral diet and isocaloric elemental enteral nutrition for 12 days were given in the control group and the elemental nutrition group, respectively. In the bombesin group 10 microg/kg subcutaneous bombesin (t.i.d.) for 10 days with regular enteral diet for 12 days was given. In the elemental nutrition and bombesin group the diet consisted of 10 microg/kg subcutaneous bombesin (t.i.d.) for 10 days with isocaloric elemental enteral nutrition for 12 days was given. All rats underwent physical, histological, and biochemical evaluation. Reduction in weight loss, bowel diameter, fecal fat content, and glycemia, increase in cellularity, and d-xylose absorption were observed in all treatment groups. These changes were more evident in the bombesin treatment groups. Increases in serum protein and albumin levels were seen with bombesin treatment with or without elemental diet, whereas reductions in villous height and crypt depth were observed only with bombesin treatment without elemental diet. Serum calcium, iron, and vitamin B(12) levels were not affected with any treatment. It is concluded that bombesin may be a useful trophic agent contributing to increased absorptive capacity and improved biochemical values even in the absence of elemental nutrition.

  2. Bombesin-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Yanaihara, N

    1981-01-01

    With immunocytochemical methods, nerve cells have been detected in Hydra attenuata containing bombesin-like immunoreactivity. These nerve cells are located in ectoderm of all body regions of the animal and are especially abundant in basal disk and tentacles. Radioimmunoassay of extracts of hydra ...

  3. A Stress-Related Peptide Bombesin Centrally Induces Frequent Urination through Brain Bombesin Receptor Types 1 and 2 in the Rat.

    Science.gov (United States)

    Shimizu, Takahiro; Shimizu, Shogo; Higashi, Youichirou; Nakamura, Kumiko; Yoshimura, Naoki; Saito, Motoaki

    2016-03-01

    Stress exacerbates symptoms of bladder dysfunction including overactive bladder and bladder pain syndrome, but the underlying mechanisms are unknown. Bombesin-like peptides and bombesin receptor types 1 and 2 (BB1 and BB2, respectively) in the brain have been implicated in the mediation/integration of stress responses. In this study, we examined effects of centrally administered bombesin on micturition, focusing on their dependence on 1) the sympathoadrenomedullary system (a representative mechanism activated by stress exposure) and 2) brain BB receptors in urethane-anesthetized (1.0-1.2 g/kg, i.p.) male rats. Intracerebroventricularly administered bombesin significantly shortened intercontraction intervals (ICI) at both doses (0.1 and 1 nmol/animal) without affecting maximal voiding pressure. Bombesin at 1 nmol induced significant increments of plasma noradrenaline and adrenaline levels, which were both abolished by acute bilateral adrenalectomy. On the other hand, adrenalectomy showed no effects on the bombesin-induced shortening of ICI. Much lower doses of bombesin (0.01 and 0.03 nmol/animal, i.c.v.) dose-dependently shortened ICI. Pretreatment with either a BB1 receptor antagonist (BIM-23127; d-Nal-cyclo[Cys-Tyr-d-Trp-Orn-Val-Cys]-Nal-NH2; 3 nmol/animal, i.c.v.) or a BB2 receptor antagonist (BEA; H-d-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHEt; 3 nmol/animal, i.c.v.), respectively, suppressed the BB (0.03 nmol/animal, i.c.v.)-induced shortening of ICI, whereas each antagonist by itself (1 and 3 nmol/animal, i.c.v.) had no significant effects on ICI. Bombesin (0.03 nmol/animal, i.c.v.) significantly reduced voided volume per micturition and bladder capacity without affecting postvoid residual volume or voiding efficiency. These results suggest that brain bombesin and BB receptors are involved in facilitation of the rat micturition reflex to induce bladder overactivity, which is independent of the sympathoadrenomedullary outflow modulation. Copyright © 2016 by The

  4. Receptors for GRP/bombesin-like peptides in the rat forebrain

    International Nuclear Information System (INIS)

    Wolf, S.S.; Moody, T.W.

    1985-01-01

    Binding sites in the rat forebrain were characterized using ( 125 I-Tyr4)bombesin as a receptor probe. Pharmacology experiments indicate that gastrin releasing peptide (GRP) and the GRP fragments GRP as well as Ac-GRP inhibited radiolabeled (Tyr4)bombesin binding with high affinity. Biochemistry experiments indicated that heat, N-ethyl maleimide or trypsin greatly reduced radiolabeled (Tyr4)bombesin binding. Also, autoradiographic studies indicated that highest grain densities were present in the stria terminalis, periventricular and suprachiasmatic nucleus of the hypothalamus, dorsomedial and rhomboid thalamus, dentate gyrus, hippocampus and medial amygdaloid nucleus. The data suggest that CNS protein receptors, which are discretely distributed in the rat forebrain, may mediate the action of endogenous GRP/bombesin-like peptides

  5. Autoradiographic localization of (125I-Tyr4)bombesin-binding sites in rat brain

    International Nuclear Information System (INIS)

    Zarbin, M.A.; Kuhar, M.J.; O'Donohue, T.L.; Wolf, S.S.; Moody, T.W.

    1985-01-01

    The binding of ( 125 I-Tyr 4 )bombesin to rat brain slices was investigated. Radiolabeled (Tyr 4 )bombesin bound with high affinity (K/sub d/ . 4 nM) to a single class of sites (B/sub max/ . 130 fmol/mg of protein); the ratio of specific to nonspecific binding was 6/1. Also, pharmacology studies indicated that the C-terminal of bombesin was important for the high affinity binding activity. Autoradiographic studies indicated that the ( 125 I-Tyr4)bombesin-binding sites were discretely distributed in certain gray but not white matter regions of rat brain. Highest grain densities were present in the olfactory bulb and tubercle, nucleus accumbens, suprachiasmatic and periventricular nuclei of the hypothalamus, central medial thalamic nucleus, medial amygdaloid nucleus, hippocampus, dentate gyrus, subiculum, nucleus of the solitary tract, and substantia gelatinosa. Moderate grain densities were present in the parietal cortex, deep layers of the neocortex, rhinal cortex, caudate putamen, stria terminalis, locus ceruleus, parabrachial nucleus, and facial nucleus. Low grain densities were present in the globus pallidus, lateral thalamus, and midbrain. Negligible grain densities were present in the cerebellum, corpus callosum, and all regions treated with 1 microM unlabeled bombesin. The discrete regional distribution of binding suggests that endogenous bombesin-like peptides may function as important regulatory agents in certain brain loci

  6. Click chemistry for [{sup 99m}Tc(CO){sub 3}] labeling of Lys{sup 3}-bombesin

    Energy Technology Data Exchange (ETDEWEB)

    Ferro-Flores, G., E-mail: ferro_flores@yahoo.com.m [Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico); Rivero, I.A. [Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico); Instituto Tecnologico de Tijuana, Baja California (Mexico); Santos-Cuevas, C.L. [Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico); Universidad Autonoma del Estado de Mexico (Mexico); Sarmiento, J.I. [Instituto Tecnologico de Tijuana, Baja California (Mexico); Arteaga de Murphy, C. [Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran (Mexico); Ocampo-Garcia, B.E. [Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico); Garcia-Becerra, R.; Ordaz-Rosado, D. [Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran (Mexico)

    2010-12-15

    {sup 99m}Tc-HYNIC labeled Lys{sup 3}-bombesin has shown specific binding to gastrin-releasing peptide receptors (GRP-r) over-expressed in cancer cells. Click chemistry offers an innovative functionalization strategy for biomolecules such as bombesin. The aim of this research was to apply a click chemistry approach for [{sup 99m}Tc(CO){sub 3}] labeling of Lys{sup 3}-bombesin and to compare the in vitro MCF7 breast cancer cell uptake and biodistribution profile in mice with that of {sup 99m}Tc-EDDA/HYNIC-Lys{sup 3}-bombesin. The results suggest a higher lipophilicity for {sup 99m}Tc(CO){sub 3}-triazole-Lys{sup 3}-bombesin which explains its higher in vivo hepatobiliary elimination. Pancreas-to-blood ratio for {sup 99m}Tc(CO){sub 3}-triazole-Lys{sup 3}-bombesin was 4.46 at 3 h and both bombesin radiopharmaceuticals showed specific recognition for GRP receptors in MCF7 cancer cells. Click chemistry is a reliable approach for [{sup 99m}Tc(CO){sub 3}] labeling of Lys{sup 3}-bombesin.

  7. GLP1- and GIP-producing cells rarely overlap and differ by bombesin receptor-2 expression and responsiveness

    DEFF Research Database (Denmark)

    Svendsen, Berit; Pais, Ramona; Engelstoft, Maja S

    2016-01-01

    the secretion of both GLP1 and GIP, whereas bombesin/neuromedin C only stimulated GLP1 secretion. Expression analysis showed high expression of the bombesin 2 receptor in GLP1 positive cells, but no expression in GIP-positive cells. These data indicate both expressional and functional differences between...

  8. DOTA-PESIN, a DOTA-conjugated bombesin derivative designed for the imaging and targeted radionuclide treatment of bombesin receptor-positive tumours

    International Nuclear Information System (INIS)

    Zhang, Hanwen; Maecke, Helmut R.; Schuhmacher, Jochen; Eisenhut, Michael; Waser, Beatrice; Reubi, Jean Claude; Wild, Damian

    2007-01-01

    We aimed at designing and developing a novel bombesin analogue, DOTA-PEG 4 -BN(7-14) (DOTA-PESIN), with the goal of labelling it with 67/68 Ga and 177 Lu for diagnosis and radionuclide therapy of prostate and other human cancers overexpressing bombesin receptors. The 8-amino acid peptide bombesin (7-14) was coupled to the macrocyclic chelator DOTA via the spacer 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG 4 ). The conjugate was complexed with Ga(III) and Lu(III) salts. The GRP receptor affinity and the bombesin receptor subtype profile were determined in human tumour specimens expressing the three bombesin receptor subtypes. Internalisation and efflux studies were performed with the human GRP receptor cell line PC-3. Xenografted nude mice were used for biodistribution. [Ga III /Lu III ]-DOTA-PESIN showed good affinity to GRP and neuromedin B receptors but no affinity to BB3. [ 67 Ga/ 177 Lu]-DOTA-PESIN internalised rapidly into PC-3 cells whereas the efflux from PC-3 cells was relatively slow. In vivo experiments showed a high and specific tumour uptake and good retention of [ 67 Ga/ 177 Lu]-DOTA-PESIN. [ 67 Ga/ 177 Lu]-DOTA-PESIN highly accumulated in GRP receptor-expressing mouse pancreas. The uptake specificity was demonstrated by blocking tumour uptake and pancreas uptake. Fast clearance was found from blood and all non-target organs except the kidneys. High tumour-to-normal tissue ratios were achieved, which increased with time. PET imaging with [ 68 Ga]-DOTA-PESIN was successful in visualising the tumour at 1 h post injection. Planar scintigraphic imaging showed that the 177 Lu-labelled peptide remained in the tumour even 3 days post injection. The newly designed ligands have high potential with regard to PET and SPECT imaging with 68/67 Ga and targeted radionuclide therapy with 177 Lu. (orig.)

  9. Rhodium-105 Bombesin Analogs for Prostate Cancer Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Silvia S. Jurisson, PhD

    2005-12-31

    Over the period of this grant (11/01/2001 to 12/31/2005), the consistent and reproducible production of Rh-105, synthesis and evaluation of three new chelate systems based on hydroxymethyl phosphines, development of a new non-hydroxymethyl phosphine N{sub 2}P{sub 2} chelate system, conjugation of two of the chelates to the bombesin peptide analog BBN[7-14]NH{sub 2}, evaluation of the bombesin conjugates and their Rh-105 complexes for stability, cell binding affinity, and in vivo biodistribution in normal mice has been developed. The BBN analogs bind to GRP receptors that are overexpressed on PC-3 prostate tumor cells. A dedicated glove box is used for the separation and isolation of {sup 105}Rh from the target ({sup 104}Ru). All tubing/connections/valves from the point of the Cl{sub 2} tank are made of Teflon to minimize/eliminate the introduction of any metal into the process (e.g., iron from stainless steel corrosion). The separation of {sup 105}Rh produced from the enriched {sup 104}Ru target involves oxidation of the enriched {sup 104}Ru metal target to ruthenium tetroxide with chlorine gas and sodium hydroxide solution to generate hypochlorite in situ. The RuO4 is removed by distillation and the {sup 105}Rh remaining in the reaction vial is converted into {sup 105}Rh-chloride by acidification with hydrochloric acid and heating. The {sup 105}Rh production process has become reproducible over the past year to consistently make 10-30 mCi of {sup 105}Rh from 1-3 mg of an enriched (99.21%) {sup 104}Ru target. The process itself involves irradiation of the enriched {sup 104}Ru target in the core of the reactor (University of Missouri Research Reactor (MURR)) for one week to yield 16-40 mCi of {sup 105}Rh. The irradiated target is processed to separate the Rh-105 in high specific activity from the {sup 104}Ru target. The irradiated target is dissolved in NaOH (2M, 3 mL) by bubbling Cl{sub 2} gas through the solution (generating NaOCl in situ) to generate RuO{sub 4

  10. Validation of the production process of core-equipment HYNIC-Bombesin-Sn

    International Nuclear Information System (INIS)

    Rubio C, N. I.

    2008-01-01

    The validation process is establishing documented evidence that provides a high degree of assurance that a specific process consistently will produce a product that will meet specifications and quality attributes preset and, therefore, ensures the efficiency and effectiveness of a product. The radiopharmaceutical 99m Tc-HYNlC-Bombesin is part of the gastrin-releasing peptide (GRP) analogues of bombesin that are radiolabelled with technetium 99 metastable for molecular images obtention. Is obtained from freeze-dry formulations kits (core- equipment)) and has reported a very high stability in human serum, specific binding to receptors and rapid internalization. Biodistribution data in mice showed rapid blood clearance with predominant renal excretion and specific binding to tissues with positive response to GRP receptors. According to biokinetics studies performed on patients with breast cancer, breast show a marked asymmetry with increased uptake in neoplastic breast in healthy women and the uptake of radiopharmaceuticals is symmetrical in both breasts. No reported adverse reactions. In this paper, the prospective validation core-equipment HYNlC-Bombesin-Sn, which was shown consistently that the product meets the specifications and quality, attributes to preset from the obtained from the diagnostic radiopharmaceutical third generation: 99m Tc-HYNlC-Bombesin. The process was successfully validated and thereby ensuring the efficiency and effectiveness of this agent as a preliminary diagnostic for approval to be marketed. (Author)

  11. Bombesin-stimulated serum immunoreactive trypsin in the different diagnosis between endocrine and exocrine tumors of the pancreas

    International Nuclear Information System (INIS)

    Bonora, G.; De Giorgio, R.; Toni, R.; Fanti, M.P.; Cariani, G.; Vezzadini, P.

    1987-01-01

    Bombesin administration was recently found to induce a marked increase in circulating immunoreactive trypsin (IRT), whose magnitude seems to reflect the functional capacity of pancreatic acinar cell mass. The purpose of the present study was to assess the effect of bombesin infusion on serum IRT concentration in patients with endocrine or exocrine tumors of the pancreas. Fifteen patients with pancreatic endocrine tumor, 17 patients with pancreatic exocrine carcinoma and 15 healty subjects were investigated. Serum IRT was measured by radioimmunoassay before and for 120 minutes after the start of bombesin infusion (9 ng/kg/min over 30 min). The integrated serum IRT response to bombesin administration in patients with endocrine tumor of the pancreas did not differ significantly from controls, but were significantly higher than in patients with exocrine carcinoma. In the latter the integrated IRT responses to bombesin infusion in patients with endocrine tumor can probably be explained by small tumor size and/or little invasion of the glandular parenchyma, resulting in an undetectable impairment of exocrine pancreatic function. The very low IRT responses in patients with exocrine carcinoma could reflect the presence of severe pancreatic damage. The results suggest that this newly proposed bombesin test may be useful in the preoperative differential diagnosis between endocrine and exocrine tumors of the pancreas

  12. Pharmacology and selectivity of various natural and synthetic Bombesin related peptide agonists for human and rat bombesin receptors differs

    Science.gov (United States)

    Uehara, Hirotsugu; González, Nieves; Sancho, Veronica; Mantey, Samuel A.; Nuche-Berenguer, Bernardo; Pradhan, Tapas; Coy, David H.; Jensen, Robert T.

    2011-01-01

    The mammalian bombesin (Bn)-receptor family[gastrin-releasing peptide-receptor(GRPR-receptor), neuromedin B-receptor(NMB-receptor)], their natural ligands,GRP/NMB, as well as the related orphan-receptor,BRS-3, are widely-distributed, and frequently overexpressed by tumors. There is increased interest in agonists for this receptor family to explore their roles in physiological/pathophysiological processes, and for receptor-imaging/cytotoxicity in tumors. However, there is minimal data on human pharmacology of Bn-receptor agonists and most results are based on nonhuman receptor studies, particular rodent-receptors, which with other receptors frequently differ from human-receptors. To address this issue we compared hNMB/GRP-receptor affinities and potencies/efficacies of cell-activation(assessing phospholipase C activity) for 24 putative Bn-agonists(12-natural,12-synthetic) in four different cells with these receptors, containing native-receptors or receptors expressed at physiological densities, and compared the results to native rat-GRP-receptor-containing cells-(AR42J–cells) or rat-NMB-receptor cells(C6-glioblastoma cells). There were close correlations(r=0.92–99,psynthetic Bn-analogues containing β−alanine11 had high affinity for hBRS-3, but t also had high affinities/potencies for all GRP-/hNMB-receptor cells. There was no correlation between affinities for human-GRP-receptors and rat-GRP-receptors(r=0.131,p=0.54), but hNMB-receptor results correlated with rat-NMB-receptor(r=0.71, p<0.0001). These results elucidate the human- and rat-GRP-receptor pharmacophore for agonists differ markedly,whereas they do not for NMB-receptors, therefore potential GRP-receptor agonists for human studies(such as Bn-receptor-imaging/cytotoxicity) must be assessed on human-Bn-receptors. The current study provides affinities/potencies on a large number of potential agonists that might be useful for human studies. PMID:21729729

  13. Development of lutetium-labeled bombesin derivates: relationship between structure and diagnostic-therapeutic activity for prostate tumor

    International Nuclear Information System (INIS)

    Pujatti, Priscilla Brunelli

    2009-01-01

    Bombesin (BBN) receptors - in particular, the gastrin-releasing peptide (GRP) receptor peptide - have been shown to be massively over expressed in several human tumors types, including prostate cancer, and could be an alternative as target for its treatment by radionuclide therapy (RNT). A large number of BBN analogs had already been synthesized for this purpose and have shown to reduce tumor growth in mice. Nevertheless, most of the studied analogs exhibit high abdominal accumulation, especially in pancreas. This abdominal accumulation may represent a problem in clinical use of radiolabeled bombesin analogs probably due to serious side effects to patients. The goal of the present work was to radiolabel a novel series of bombesin derivatives with lutetium-177 and to evaluate the relationship between their structure and diagnostic-therapeutic activity for prostate tumor. The generic structure of studied peptides is DOTA-Phe-(Gly) n -BBN(6-14), where DOTA is the chelator, n is the number of glycine amino acids of Phe-(Gly) n spacer and BBN(6-14) is the bombesin sequence from the amino acid 6 to the amino acid 14. Preliminary studies were done to establish the ideal labeling conditions for obtaining the highest yield of labeled bombesin derivatives, determined by instant thin layer chromatography (ITLC-SG) and high performance liquid chromatography (HPLC). The stability of the preparations was evaluated either after storing at 2-8 degree C or incubation in human serum at 37 degree C and the partition coefficient was determined in n:octanol:water. In vivo studies were performed in both healthy Balb-c and Nude mice bearing PC-3 xenografts, in order to characterize the biological properties of labeled peptides. In vitro studies involved the evaluation of cold bombesin derivatives effect in PC-3 cells proliferation. Bombesin derivatives were successfully labeled with high yield at optimized conditions and exhibited high stability at 4 degree C. The analysis of the

  14. Optimization of the production process of hybrid and multivalent formulation Bombesin/RGD for the opportune detection of breast cancer

    International Nuclear Information System (INIS)

    Robles M, M.

    2013-01-01

    The radiopharmaceuticals of third generation are used in nuclear medicine to obtain images of specific molecular targets, and they are unique in their capacity to detect in vivo specific biochemical sites as receptors that are over-expressed in diverse illness. In cancer cells several types of receptors are over-expressed, as the integrin s α(v)β(3) and α(v)β(5) that specifically recognize the sequence RGD (Arginine-Glycin-Ac. Aspartic) and gastrin-releasing peptide that recognizes specifically to the peptide Lys 3 -Bombesin. The integrin s α(v)β(3) and α(v)β(5) are involved in the tumor angio genesis processes and the gastrin-releasing peptide is over-expressed in breast and prostate cancer. The molecular recognition of the specific receptors is the basis to be utilized as targets of the radiopharmaceuticals 99m Tc-HYNIC-Bombesin and 99m Tc-HYNIC-RGD. In this work was developed a lyophilized pharmaceutical formulation effective, stable and safe for the simultaneous obtaining of the radiopharmaceuticals 99m Tc-HYNIC-Bombesin ( 99m Tc-EDDA/HYNIC-Lys 3 -Bombesin) and 99m Tc-HYNIC-RGD ( 99m Tc EDDA/HYNIC-E-[c(RGDfK)] 2 ). Later on the production process of the product HYNIC-Bombesin/RGD-Sn was optimized using a factorial design and the formulation was transferred to the production plant of radiopharmaceuticals of the Instituto Nacional de Investigaciones Nucleares (ININ). The optimized formulation is described in the following chart: HYNIC-[Lys 3 ]-Bombesin - 12.5 μg; HYNIC-E-c[RGDfK] 2 - 12.5 μg; Stannous chloride (SnCl 2 ) - 20 μg; Ethylenediamine diacetic acid (EDDA) - 10 mg; N-tris(hydroxymethyl)methyl glycin (Tricine) - 20 mg; Mannitol - 50 mg. The production process was validated and were carried out the stability studies under refrigeration conditions. (Author)

  15. Bombesin peptide antagonist for target-selective delivery of liposomal doxorubicin on cancer cells.

    Science.gov (United States)

    Accardo, Antonella; Mansi, Rosalba; Salzano, Giuseppina; Morisco, Anna; Aurilio, Michela; Parisi, Antonio; Maione, Francesco; Cicala, Carla; Ziaco, Barbara; Tesauro, Diego; Aloj, Luigi; De Rosa, Giuseppe; Morelli, Giancarlo

    2012-11-21

    Purpose: This study addresses novel peptide modified liposomal doxorubicin to specifically target tissues overexpressing bombesin (BN) receptors. Methods: DOTA-(AEEA)(2)-peptides containing the [7-14]bombesin and the new BN-AA1 sequence have been synthesized to compare their binding properties and in serum stabilities. The amphiphilic peptide derivative (MonY-BN-AA1) containing BN-AA1, a hydrophobic moiety, polyethylenglycole (PEG), and diethylenetriaminepentaacetate (DTPA), has been synthesized. Liposomes have been obtained by mixing of MonY-BN-AA1 with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). Results: Both (111)In labeled peptide derivatives present nanomolar Kd to PC-3 cells. (177)Lu labeled peptide DOTA-(AEEA)(2)-BN-AA1 is very stable (half-life 414.1 h), while DOTA-(AEEA)(2)-BN, shows a half-life of 15.5 h. In vivo studies on the therapeutic efficacy of DSPC/MonY-BN-AA1/Dox in comparison to DSPC/MonY-BN/Dox, were performed in PC-3 xenograft bearing mice. Both formulations showed similar tumor growth inhibition (TGI) compared to control animals treated with non-targeted DSPC/Dox liposomes or saline solution. For DSPC/MonY-BN-AA1/Dox the maximum effect was observed 19 days after treatment. Conclusions: DSPC/MonY-BN-AA1/Dox nanovectors confirm the ability to selectively target and provide therapeutic efficacy in mice. The lack of receptor activation and possible acute biological side effects provided by using the AA1 antagonist bombesin sequence should provide safe working conditions for further development of this class of drug delivery vehicles.

  16. Molecular markers derived from bombesin for tumor diagnosis by SPECT and PET

    International Nuclear Information System (INIS)

    Pujatti, Priscilla Brunelli

    2012-01-01

    A high number of molecules have already been identified to have high affinity to some receptors overexpressed on tumour cells and the radiolabelling of those molecules offers the possibility of new compounds for tumour diagnosis and therapy by nuclear medicine. Among of those molecules, bombesin (BBN) has become focus of interest, as its BB 2 receptors are known to be overexpressed in prostate, breast, colon, pancreatic and lung tumour, as long as glioblastomas and neuroblastomas. BBN agonists and antagonists have already been described for this purpose and promising results were obtained in preclinical studies. However, most of them exhibited high abdominal accumulation, especially in pancreas and intestines, which can compromise diagnosis accuracy and cause serious adverse effects in therapy. In this context, the goal of the present work to radiolabel new BBN derivatives with 11 1In and 68 Ga and to evaluate their potential for BB 2 positive tumors diagnosis by single photon emission tomography (SPECT) and positron emission tomography (PET). The structure of studied peptides was Q-YG n -BBN(6-14), where Q is the chelator, n is the number of glycine aminoacids in the spacer YG n and BBN(6-14) is the original bombesin sequence from the aminoacid 6 to 14. The derivative in which the last aminoacid (methionine, Met) was replaced by norleucine (Nle) was also evaluated. The experimental evaluation of the bombesin derivatives was divided into four steps: computational studies, molecular markers for SPECT, molecular markers for PET and toxicological studies. The theoretical partition (log P) and distribution (log D) coefficients were calculated for all bombesin derivatives conjugated to DTPA (diethylenetriaminepentaacetic acid) and DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) chelators applying computational programmes. Bombesin derivatives for SPECT were developed by radiolabelling DTPA-conjugated bombesin derivatives with 111 In to determine the best

  17. A possible new target in lung-cancer cells: The orphan receptor, bombesin receptor subtype-3.

    Science.gov (United States)

    Moreno, Paola; Mantey, Samuel A; Lee, Suk H; Ramos-Álvarez, Irene; Moody, Terry W; Jensen, Robert T

    2018-03-01

    Human bombesin receptors, GRPR and NMBR, are two of the most frequently overexpressed G-protein-coupled-receptors by lung-cancers. Recently, GRPR/NMBR are receiving considerable attention because they act as growth factor receptors often in an autocrine manner in different lung-cancers, affect tumor angiogenesis, their inhibition increases the cytotoxic potency of tyrosine-kinase inhibitors reducing lung-cancer cellular resistance/survival and their overexpression can be used for sensitive tumor localization as well as to target cytotoxic agents to the cancer. The orphan BRS-3-receptor, because of homology is classified as a bombesin receptor but has received little attention, despite the fact that it is also reported in a number of studies in lung-cancer cells and has growth effects in these cells. To address its potential importance, in this study, we examined the frequency/relative quantitative expression of human BRS-3 compared to GRPR/NMBR and the effects of its activation on cell-signaling/growth in 13 different human lung-cancer cell-lines. Our results showed that BRS-3 receptor is expressed in 92% of the cell-lines and that it is functional in these cells, because its activation stimulates phospholipase-C with breakdown of phosphoinositides and changes in cytosolic calcium, stimulates ERK/MAPK and stimulates cell growth by EGFR transactivation in some, but not all, the lung-cancer cell-lines. These results suggest that human BRS-3, similar to GRPR/NMBR, is frequently ectopically-expressed by lung-cancer cells in which, it is functional, affecting cell signaling/growth. These results suggest that similar to GRPR/NMBR, BRS-3 should receive increased attention as possible approach for the development of novel treatments and/or diagnosis in lung-cancer. Published by Elsevier Inc.

  18. Comparative in vivo evaluation of two novel 99mTc labelled bombesin derivatives

    International Nuclear Information System (INIS)

    Gourni, Eleni; Bouziotis, Penelope; Zikos, Christos; Loudos, George; Xanthopoulos, Stavros; Fani, Melpomeni; Archimandritis, Spyridon C.; Varvarigou, Alexandra D.

    2006-01-01

    Bombesin (BN), a 14 amino acid peptide, is an analogue of human gastrin-releasing-peptide (GRP) that binds to GRP receptors (GRP-R) with high affinity and specificity. In addition to this physiological role, GRP, through its interaction with GRP-R, promotes tumour growth in a number of human cancer cell lines. The GRP receptors are over-expressed on a variety of human cancer cells. Aim of the present work is the study of two novels BN-like peptides, by investigating the radiochemical and radiopharmacological behaviour of their complexes with metals. The derivatives under study are: Gly-Gly-Cys-Aca-BN [2-14] where Aca: 6-amino-hexanoic acid. Pyroglutamic acid in the bombesin molecule has been replaced by the chemical group Gly-Gly-Cys-Aca, which bears an amino-acid combination capable of complexing a variety of radiometals. The other derivative under study is: Gly-Gly-Cys-Aca-BN [7-14]. This moiety of the peptide has been chosen because it has been proven to be a potent GRP agonist. The peptide derivatives were synthesized by SPPS, according to the Fmoc strategy and were identified by reverse phase high performance liquid chromatography (RP-HPLC). Radiolabelling with 99m Tc was performed via the precursor 99m Tc-gluconate. The stability of the radiolabelled species was examined with time. In vivo studies of the two 99m Tc-labelled derivatives were performed, comparatively, in normal mice, attention being focused on GRP receptor-bearing organs, and in experimentally induced prostate cancer models. Experimental tumours were imaged in a small field-of-view animal gamma camera

  19. Therapeutic Efficacy with Treatment-related Toxicities of {sup 177}Lu-labeled Bombesin Derivative for the Peptide Receptor Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Cheong; Cho, Eun Ha; Lee, So Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The gastrin-releasing peptide receptor (GRPR) has been shown to be overexpressed in many human tumours, including breast cancer, prostate cancer, small cell lung cancer, ovarian cancers, endometrial cancers, and gastrointestinal stromal tumors. In particular, GRPR expression is high in 83 % of invasive primary prostatic carcinomas. These results suggest that {sup 177}Lu-labeled bombesin derivative has promising characteristics as a novel nuclear medicine, especially for the treatment of GRPR over-expressing prostate tumors.

  20. Viability of D283 medulloblastoma cells treated with a histone deacetylase inhibitor combined with bombesin receptor antagonists.

    Science.gov (United States)

    Jaeger, Mariane; Ghisleni, Eduarda C; Fratini, Lívia; Brunetto, Algemir L; Gregianin, Lauro José; Brunetto, André T; Schwartsmann, Gilberto; de Farias, Caroline B; Roesler, Rafael

    2016-01-01

    Medulloblastoma (MB) comprises four distinct molecular subgroups, and survival remains particularly poor in patients with Group 3 tumors. Mutations and copy number variations result in altered epigenetic regulation of gene expression in Group 3 MB. Histone deacetylase inhibitors (HDACi) reduce proliferation, promote cell death and neuronal differentiation, and increase sensitivity to radiation and chemotherapy in experimental MB. Bombesin receptor antagonists potentiate the antiproliferative effects of HDACi in lung cancer cells and show promise as experimental therapies for several human cancers. Here, we examined the viability of D283 cells, which belong to Group 3 MB, treated with an HDACi alone or combined with bombesin receptor antagonists. D283 MB cells were treated with different doses of the HDACi sodium butyrate (NaB), the neuromedin B receptor (NMBR) antagonist BIM-23127, the gastrin releasing peptide receptor (GRPR) antagonist RC-3095, or combinations of NaB with each receptor antagonist. Cell viability was examined by cell counting. NaB alone or combined with receptor antagonists reduced cell viability at all doses tested. BIM-23127 alone did not affect cell viability, whereas RC-3095 at an intermediate dose significantly increased cell number. Although HDACi are promising agents to inhibit MB growth, the present results provide preliminary evidence that combining HDACi with bombesin receptor antagonists is not an effective strategy to improve the effects of HDACi against MB cells.

  1. PEG spacers of different length influence the biological profile of bombesin-based radiolabeled antagonists

    International Nuclear Information System (INIS)

    Jamous, Mazen; Tamma, Maria L.; Gourni, Eleni; Waser, Beatrice; Reubi, Jean C.; Maecke, Helmut R.; Mansi, Rosalba

    2014-01-01

    Introduction: The gastrin-releasing peptide receptor (GRPR) was shown to be expressed with high density on several types of cancers. Radiolabeled peptides for imaging and targeted radionuclide therapy have been developed. In this study, we evaluated the potential of statine-based bombesin antagonists, conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) through oligoethyleneglycol spacers, labeled with 177 Lu and we determined the effect of polyethyleneglycol (PEG) spacer length on in vitro and in vivo properties. Methods: The bombesin antagonists were synthesized on solid phase using Fmoc chemistry; the spacers Fmoc-dPEG x -OH (x = 2, 4, 6 and 12) and the DOTA(tBu) 3 were coupled using a standard procedure. The peptides were labeled with 177 Lu and evaluated in vitro (lipophilicity, serum stability, internalization and binding affinity assays). Biodistribution studies were performed in PC-3 tumor-bearing nude mice. Results: The solid-phase synthesis was straightforward with an overall yield ranging from 30% to 35% based on the first Fmoc cleavage. The hydrophilicity increased with spacer length (logD: − 1.95 vs − 2.22 of PEG 2 and PEG 12 analogs, respectively). There is a tendency of increased serum stability by increasing the spacer length (T 1/2 = 246 ± 4 and 584 ± 20 for PEG 2 and PEG 6 analogs, respectively) which seems to reverse with the PEG 12 analog. The IC 50 values are similar with the only significant difference of the PEG 12 analog. The 177 Lu-labeled PEG 4 and PEG 6 conjugates showed similar pharmacokinetic with high tumor uptake and excellent tumor-to-kidney ratios (7.8 and 9.7 at 4 h for the PEG 4 and PEG 6 derivatives, respectively). The pancreas uptake was relatively high at 1 h but it shows fast washout (0.46% ± 0.02% IA/g and 0.29% ± 0.08% IA/g already at 4 h). Conclusion: Among all the studied analogs the PEG 4 and PEG 6 showed significantly better properties. The very high tumor-to-non-target organ ratios, in

  2. Bombesin administration impairs memory and does not reverse memory deficit caused by sleep deprivation.

    Science.gov (United States)

    Ferreira, L B T; Oliveira, S L B; Raya, J; Esumi, L A; Hipolide, D C

    2017-07-28

    Sleep deprivation impairs performance in emotional memory tasks, however this effect on memory is not completely understood. Possible mechanisms may involve an alteration in neurotransmission systems, as shown by the fact that many drugs that modulate neural pathways can prevent memory impairment by sleep loss. Gastrin releasing peptide (GRP) is a neuropeptide that emerged as a regulatory molecule of emotional memory through the modulation of other neurotransmission systems. Thus, the present study addressed the effect of intraperitoneal (IP) administration of bombesin (BB) (2.5, 5.0 and 10.0μg/kg), a GRP agonist, on the performance of Wistar rats in a multiple trail inhibitory avoidance (MTIA) task, after sleep deprivation, using the modified multiple platforms method (MMPM). Sleep deprived animals exhibited acquisition and retention impairment that was not prevented by BB injection. In addition, non-sleep deprived animals treated with BB before and after the training session, but not before the test, have shown a retention deficit. In summary, BB did not improve the memory impairment by sleep loss and, under normal conditions, produced a memory consolidation deficit. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Does bombesin-like peptide mediate radiation-induced anorexia and satiety?

    International Nuclear Information System (INIS)

    Aalto, Y.; Franzen, L.; Henriksson, R.; Forsgren, S.; Kjoerell, U.; Funegaard, U.

    1999-01-01

    Bombesin (BN) and its mammalian counterpart gastrin-releasing peptide (GRP) act as neuroregulatory hormones and peripheral and central satiety-inducing agents. Previously, we demonstrated that irradiation induces an increase in the expression of BN/GRP in the innervation of the salivary glands in rats. We therefore carried out a study using radioimmunoassay (RIA) analysis and immunohistochemistry to examine whether saliva contains BN and whether irradiation affects the BN release to saliva in rats. Immunoreactivity for BN was detected not only in the innervation of the parenchyma but also in the duct cells and in the lumina of the ducts, suggesting entrance of BN into saliva. The RIA analysis confirmed that rat saliva contains a BN-like peptide. The observation shows that saliva contains this peptide but that there is no significant increase following the radiation schedule used. Nevertheless, the occurrence of an enhanced expression of BN in different peripheral tissues such as the salivary and laryngeal glands should be taken into consideration when discussing the clinically important problem of reduced food intake and anorexia in cancer patients. (orig.)

  4. Does bombesin-like peptide mediate radiation-induced anorexia and satiety?

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, Y.; Franzen, L.; Henriksson, R. [Umeaa Univ. (Sweden). Dept. of Oncology; Forsgren, S.; Kjoerell, U. [Umeaa Univ. (Sweden). Dept. of Anatomy; Funegaard, U. [Umeaa Univ. (Sweden). Dept. of Cardiology

    1999-07-01

    Bombesin (BN) and its mammalian counterpart gastrin-releasing peptide (GRP) act as neuroregulatory hormones and peripheral and central satiety-inducing agents. Previously, we demonstrated that irradiation induces an increase in the expression of BN/GRP in the innervation of the salivary glands in rats. We therefore carried out a study using radioimmunoassay (RIA) analysis and immunohistochemistry to examine whether saliva contains BN and whether irradiation affects the BN release to saliva in rats. Immunoreactivity for BN was detected not only in the innervation of the parenchyma but also in the duct cells and in the lumina of the ducts, suggesting entrance of BN into saliva. The RIA analysis confirmed that rat saliva contains a BN-like peptide. The observation shows that saliva contains this peptide but that there is no significant increase following the radiation schedule used. Nevertheless, the occurrence of an enhanced expression of BN in different peripheral tissues such as the salivary and laryngeal glands should be taken into consideration when discussing the clinically important problem of reduced food intake and anorexia in cancer patients. (orig.)

  5. Breast cancer photothermal therapy based on gold nanorods targeted by covalently-coupled bombesin peptide

    Science.gov (United States)

    Heidari, Zahra; Salouti, Mojtaba; Sariri, Reyhaneh

    2015-05-01

    Photothermal therapy, a minimally invasive treatment method for killing cancers cells, has generated a great deal of interest. In an effort to improve treatment efficacy and reduce side effects, better targeting of photoabsorbers to tumors has become a new concept in the battle against cancer. In this study, a bombesin (BBN) analog that can bind to all gastrin-releasing peptide (GRP) receptor subtypes was bound covalently with gold nanorods (GNRs) using Nanothinks acid as a link. The BBN analog was also coated with poly(ethylene glycol) to increase its stability and biocompatibility. The interactions were confirmed by ultraviolet-visible and Fourier transform infrared spectroscopy. A methylthiazol tetrazolium assay showed no cytotoxicity of the PEGylated GNR-BBN conjugate. The cell binding and internalization studies showed high specificity and uptake of the GNR-BBN-PEG conjugate toward breast cancer cells of the T47D cell line. The in vitro study revealed destruction of the T47D cells exposed to the new photothermal agent combined with continuous-wave near-infrared laser irradiation. The biodistribution study showed significant accumulation of the conjugate in the tumor tissue of mice with breast cancer. The in vivo photothermal therapy showed the complete disappearance of xenographted breast tumors in the mouse model.

  6. Inhibition of serotonin release by bombesin-like peptides in rat hypothalamus in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Saporito, M.S.; Warwick, R.O. Jr.

    1989-01-01

    We investigated the activity of bombesin (BN), neuromedin-C (NM-C) and neuromedin-B (NM-B) on serotonin (5-HT) release and reuptake in rat hypothalamus (HYP) in vitro. BN and NM-C but not NM-B decreased K/sup +/ evoked /sup 3/H-5-HT release from superfused HYP slices by 25%. Bacitracin, a nonspecific peptidase inhibitor, reversed the inhibitory effect of BN on K/sup +/ evoked /sup 3/H-5-HT release. Phosphoramidon (PAN, 10 /mu/M) an endopeptidase 24.11 inhibitor, abolished the inhibitory effect of BN, but not NM-C, on K/sup +/ evoked /sup 3/H-5-HT release. The peptidyl dipeptidase A inhibitor enalaprilat (ENP, 10 /mu/M), enhanced both BN and NM-C inhibition of /sup 3/H-5-HT release. Bestatin (BST, 10 /mu/M) had no effect on BN or NM-C inhibitory activity on /sup 3/H-5-HT release. Neither BN, NM-C nor NM-B affected reuptake of /sup 3/H-5-HT into HYP synaptosomes alone or in combination with any of the peptidase inhibitors, nor did these peptides alter the ability of fluoxetine to inhibit /sup 3/H-5-HT uptake.

  7. AM-37 and ST-36 Are Small Molecule Bombesin Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Terry W. Moody

    2017-07-01

    Full Text Available While peptide antagonists for the gastrin-releasing peptide receptor (BB2R, neuromedin B receptor (BB1R, and bombesin (BB receptor subtype-3 (BRS-3 exist, there is a need to develop non-peptide small molecule inhibitors for all three BBR. The BB agonist (BA1 binds with high affinity to the BB1R, BB2R, and BRS-3. In this communication, small molecule BBR antagonists were evaluated using human lung cancer cells. AM-37 and ST-36 inhibited binding to human BB1R, BB2R, and BRS-3 with similar affinity (Ki = 1.4–10.8 µM. AM-13 and AM-14 were approximately an order of magnitude less potent than AM-37 and ST-36. The ability of BA1 to elevate cytosolic Ca2+ in human lung cancer cells transfected with BB1R, BB2R, and BRS-3 was antagonized by AM-37 and ST-36. BA1 increased tyrosine phosphorylation of the EGFR and ERK in lung cancer cells, which was blocked by AM-37 and ST-36. AM-37 and ST-36 reduced the growth of lung cancer cells that have BBR. The results indicate that AM-37 and ST-36 function as small molecule BB receptor antagonists.

  8. Early events elicited by Bombesin and structurally related peptides in quiescent Swiss 3T3 cells. I. Activation of protein kinase C and inhibition of epidermal growth factor binding

    International Nuclear Information System (INIS)

    Zachary, I.; Sinnett-Smith, J.W.; Rozengurt, E.

    1986-01-01

    Addition of bombesin to quiescent cultures of Swiss 3T3 cells caused a rapid increase in the phosphorylation of an M/sub r/ 80,000 cellular protein (designated 80k). The effect was both concentration and time dependent. The 80k phosphoproteins generated in response to bombesin and to phorbol 12,13-dibutyrate were identical as judged by one- and two-dimensional PAGE and by peptide mapping after partial proteolysis with Staphylococcus aureus V8 protease. In addition, prolonged pretreatment of 3T3 cells with phorbol 12,13-dibutyrate, which leads to the disappearance of protein kinase C activity, blocked the ability of bombesin to stimulate 80k. Bombesin also caused a rapid (1 min) inhibition of 125 I-labeled epidermal growth factor ( 125 I-EGF) binding to Swiss 3T3 cells. The inhibition was both concentration and temperature dependent and resulted from a marked decrease in the affinity of the EGF receptor for its ligand. These results strongly suggest that these responses are mediated by specific high-affinity receptors that recognize the peptides of the bombesin family in Swiss 3T3 cells. While an increase in cytosolic Ca 2+ concentration does not mediate the bombesin inhibition of 125 I-EGF binding, the activation of protein kinase C in intact Swiss 3T3 cells by peptides of the bombesin family may lead to rapid inhibition of the binding of 125 I-EGF to its cellular receptor

  9. Characterization of a bombesin receptor on Swiss mouse 3T3 cells by affinity cross-linking

    International Nuclear Information System (INIS)

    Sinnett-Smith, J.; Zachary, I.; Rozengurt, E.

    1988-01-01

    We have previously identified by chemical cross-linking a cell surface protein in Swiss 3T3 cells of apparent Mr 75,000-85,000, which may represent a major component of the receptor for peptides of the bombesin family in these cells. Because bombesin-like peptides may interact with other cell surface molecules, it was important to establish the correlation between receptor binding and functions of this complex and further characterize the Mr 75,000-85,000 cross-linked protein. Detailed time courses carried out at different temperatures demonstrated that the Mr 75,000-85,000 affinity-labelled band was the earliest cross-linked complex detected in Swiss 3T3 cells incubated with 125I-labelled gastrin-releasing peptide (125I-GRP). Furthermore, the ability of various nonradioactive bombesin agonists and antagonists to block the formation of the Mr 75,000-85,000 cross-linked complex correlated extremely well (r = 0.994) with the relative capacity of these peptides to inhibit 125I-GRP specific binding. Pretreatment with unlabelled GRP for up to 6 h caused only a slight decrease in both specific 125I-GRP binding and the affinity labelling of the Mr 75,000-85,000 protein. We also show that the cross-linked complex is a glycoprotein. First, solubilized affinity labelled Mr 75,000-85,000 complex applied to wheat germ lectin-sepharose columns was eluted by addition of 0.3 M N-acetyl-D-glucosamine. Second, treatment with endo-beta-N-acetylglucosaminidase F reduced the apparent molecular weight of the affinity-labelled band from 75,000-85,000 to 43,000, indicating the presence of N-linked oligosaccharide groups

  10. 177Lu-Dendrimer Conjugated to Folate and Bombesin with Gold Nanoparticles in the Dendritic Cavity: A Potential Theranostic Radiopharmaceutical

    Directory of Open Access Journals (Sweden)

    Héctor Mendoza-Nava

    2016-01-01

    Full Text Available 177Lu-labeled nanoparticles conjugated to biomolecules have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this research was to synthesize 177Lu-dendrimer(PAMAM-G4-folate-bombesin with gold nanoparticles (AuNPs in the dendritic cavity and to evaluate the radiopharmaceutical potential for targeted radiotherapy and the simultaneous detection of folate receptors (FRs and gastrin-releasing peptide receptors (GRPRs overexpressed in breast cancer cells. p-SCN-Benzyl-DOTA was conjugated in aqueous-basic medium to the dendrimer. The carboxylate groups of Lys1Lys3(DOTA-bombesin and folic acid were activated with HATU and also conjugated to the dendrimer. The conjugate was mixed with 1% HAuCl4 followed by the addition of NaBH4 and purified by ultrafiltration. Elemental analysis (EDS, particle size distribution (DLS, TEM analysis, UV-Vis, and infrared and fluorescence spectroscopies were performed. The conjugate was radiolabeled using 177LuCl3 or 68GaCl3 and analyzed by radio-HPLC. Studies confirmed the dendrimer functionalization with high radiochemical purity (>95%. Fluorescence results demonstrated that the presence of AuNPs in the dendritic cavity confers useful photophysical properties to the radiopharmaceutical for optical imaging. Preliminary binding studies in T47D breast cancer cells showed a specific cell uptake (41.15±2.72%. 177Lu-dendrimer(AuNP-folate-bombesin may be useful as an optical and nuclear imaging agent for breast tumors overexpressing GRPR and FRs, as well as for targeted radiotherapy.

  11. Comparative study of two different Bombesin derivates labeled with 111In and biodistribution in normal mice

    International Nuclear Information System (INIS)

    Oliveira, Ricardo S.; Alcarde, Lais F.; Correa, Beatriz L.; Massicano, Adriana V.F.; Couto, Renata M.; Mengatti, Jair; Araujo, Elaine B. de

    2013-01-01

    Nuclear medicine is a medical speciality that uses radioactive compounds (radiopharmaceuticals), consisting of a substrate and a radioactive isotope, for diagnostic. Among the peptides of interest for Nuclear Medicine, bombesin (BBN), a 14 amino acid neuropeptide analog of human gastrin-releasing peptide, is one of the highlights. This is a comparative study aiming to establish the best condition to radiolabel two BBN derivatives, (DTPA-Phe-Gly 5 -BBN (6-14) ) and (DTPA-Phe-Gly 2 -BBN (6-14 )) with 111-indium. Specific objectives of this study were evaluate a good condition of radiolabelling in search excellent specific activity the bombesin derivatives and determinate the biodistribution in health mice model. Ten micrograms (10μg) of the derivative DTPA-Phe-Gly2-BBN (6-14) was labeled with 18.5 MBq (0.5 mCi) of 111 InCl 3 at 25°C for different times (5, 15 and 30 minutes). The best condition was applied to peptide mass variation (10, 5, 2.5, 1, 0.5, 0.25 and 0.1 μg), keeping all other parameters fixed. Finally, the influence of 111 InCl 3 activity in the radiolabeling process (18.5, 37, 55.5, 74, 185 MBq) was evaluated. The best conditions were repeated for the second derivate, DTPA-Phe-Gly 5 -BBN (6-14 ). The radiochemical purity was assessed by thin layer chromatography (TLC), using 0.2 M EDTA pH 5 as solvent, and high performance liquid chromatography (HPLC) with a C18 column with linear gradient 10% A to 90% A (v/v) (A: 0,1% of TFA in CH3CN; B: 0,1% of TFA in H2O) at a flow rate of 1 mL/minute for 15 minutes. Considering the reaction time, the higher radiochemical purity was obtained when 10μg of the peptide was labeled with 18.5 MBq (0.5 mCi) of 111 In for 15 minutes at 25°C (97.33 ± 0.50%, n=3). In the mass variation study, the best results of radiochemical purity were obtained when 10 μg of the peptide was employed (97.69 ± 0.4%, n = 4). Finally, the maximum specific activity of the radiolabelled peptides was 1.85 MBq/ μg. The maximum specific

  12. Stress and eating: A dual role for bombesin-like peptides

    Directory of Open Access Journals (Sweden)

    Zul eMerali

    2013-10-01

    Full Text Available The current obesity ‘epidemic’ in the developed world is a major health concern; over half of adult Canadians are now classified as overweight or obese. Although the reasons for high obesity rates remain unknown, an important factor appears to be the role stressors play in overconsumption of food and weight gain. In this context, increased stressor exposure and/or perceived stress may influence eating behavior and food choices. Stress-induced anorexia is often noted in rats exposed to chronic stress (e.g. repeated restraint and access to standard Chow diet; associated reduced consumption and weight loss. However, if a similar stressor exposure takes place in the presence of palatable, calorie dense food, rats often consume an increase proportion of palatable food relative to Chow, leading to weight gain and obesity. In humans, a similar desire to eat palatable or ‘comfort’ foods has been noted under stressful situations; it is thought that this response may potentially be attributable to stress-buffering properties and/or through activation of reward pathways. The complex interplay between stress-induced anorexia and stress-induced obesity is discussed in terms of the overlapping circuitry and neurochemicals that mediate feeding, stress and reward pathways. In particular, this paper draws attention to the bombesin family of peptides (BBs initially shown to regulate food intake and subsequently shown to mediate stress response as well. Evidence is presented to support the hypothesis that BBs may be involved in stress-induced anorexia under certain conditions, but that the same peptides could also be involved in stress-induced obesity. This hypothesis is based on the unique distribution of BBs in key cortico-limbic brain regions involved in food regulation, reward, incentive salience and motivationally driven behavior.

  13. Stress and eating: a dual role for bombesin-like peptides.

    Science.gov (United States)

    Merali, Z; Graitson, S; Mackay, J C; Kent, P

    2013-01-01

    The current obesity "epidemic" in the developed world is a major health concern; over half of adult Canadians are now classified as overweight or obese. Although the reasons for high obesity rates remain unknown, an important factor appears to be the role stressors play in overconsumption of food and weight gain. In this context, increased stressor exposure and/or perceived stress may influence eating behavior and food choices. Stress-induced anorexia is often noted in rats exposed to chronic stress (e.g., repeated restraint) and access to standard Chow diet; associated reduced consumption and weight loss. However, if a similar stressor exposure takes place in the presence of palatable, calorie dense food, rats often consume an increase proportion of palatable food relative to Chow, leading to weight gain and obesity. In humans, a similar desire to eat palatable or "comfort" foods has been noted under stressful situations; it is thought that this response may potentially be attributable to stress-buffering properties and/or through activation of reward pathways. The complex interplay between stress-induced anorexia and stress-induced obesity is discussed in terms of the overlapping circuitry and neurochemicals that mediate feeding, stress and reward pathways. In particular, this paper draws attention to the bombesin family of peptides (BBs) initially shown to regulate food intake and subsequently shown to mediate stress response as well. Evidence is presented to support the hypothesis that BBs may be involved in stress-induced anorexia under certain conditions, but that the same peptides could also be involved in stress-induced obesity. This hypothesis is based on the unique distribution of BBs in key cortico-limbic brain regions involved in food regulation, reward, incentive salience and motivationally driven behavior.

  14. Preclinical evaluation of 111In-DOTA-Bombesin analogue for peptide receptor targeted imaging

    International Nuclear Information System (INIS)

    Salgueiro, C.; Castiglia, S.G. de; Tesan, F.; Salgueiro, M.J.

    2017-01-01

    Peptide receptors are very important targets for imaging and therapy. The bombesin family is becoming significant, in special the gastrine-releasing peptide receptor (GRPr) that has been found in Prostate and Breast tumors. The aim of this work is to label [DOTA-Pro1,Tyr4] BN with 111 InCl3 and study its efficacy in normal and tumor animals. Radiolabeling experiences were made to find the best peptide : radionuclide relationship. The radiochemical purity was determined by Sep-pak C18 cartridge (Waters) and ITLC-SG using 50mM EDTA in 0.1M ammonium acetate (pH 5.5) and 3.5%(v/v) ammonia/methanol 1:1. Gamma imaging studies were made 24 hs after injection of the product in control rats. On the other hand gamma imaging studies were made at 24 hs in tumor bearing nude mice too. The tumor was induced by subcutaneous injection of PC3 cells. For biodistribution studies animals were sacrificed and blood, pancreas, intestine, kidneys, liver, lungs, femoral muscle and tumor were analyzed. The results were expressed as %ID/g of tissue. Radiolabeling experiments allowed us to obtain an stable product with >95% of radiochemical purity and 5.78MBq/nmol of specific activity, with a ratio of 13μg peptide per In-111 mCi. The normal and tumor animals imaging show physiological uptake in kidneys and a biodistribution according to bibliography. A specific uptake is evidenced in tumor. Our results show a radiochemical stable compound for 48 hs and suitable for GRPr imaging. (authors) [es

  15. Validation of the production process of core-equipment HYNIC-Bombesin-Sn; Validacion del proceso de produccion del nucleo-equipo HYNIC-Bombesina-Sn

    Energy Technology Data Exchange (ETDEWEB)

    Rubio C, N. I. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2008-07-01

    The validation process is establishing documented evidence that provides a high degree of assurance that a specific process consistently will produce a product that will meet specifications and quality attributes preset and, therefore, ensures the efficiency and effectiveness of a product. The radiopharmaceutical {sup 99m}Tc-HYNlC-Bombesin is part of the gastrin-releasing peptide (GRP) analogues of bombesin that are radiolabelled with technetium 99 metastable for molecular images obtention. Is obtained from freeze-dry formulations kits (core- equipment)) and has reported a very high stability in human serum, specific binding to receptors and rapid internalization. Biodistribution data in mice showed rapid blood clearance with predominant renal excretion and specific binding to tissues with positive response to GRP receptors. According to biokinetics studies performed on patients with breast cancer, breast show a marked asymmetry with increased uptake in neoplastic breast in healthy women and the uptake of radiopharmaceuticals is symmetrical in both breasts. No reported adverse reactions. In this paper, the prospective validation core-equipment HYNlC-Bombesin-Sn, which was shown consistently that the product meets the specifications and quality, attributes to preset from the obtained from the diagnostic radiopharmaceutical third generation: {sup 99m}Tc-HYNlC-Bombesin. The process was successfully validated and thereby ensuring the efficiency and effectiveness of this agent as a preliminary diagnostic for approval to be marketed. (Author)

  16. Study of the optical and dosimetric properties of the nano conjugate 99mTc-EDDA/HYNIC-GGC-Au Np-Bombesin by effect of nano particle size

    International Nuclear Information System (INIS)

    Mendoza S, A. N.

    2011-01-01

    The receptors over-expressed on the surface of cancer cells represent promising targets for breast cancer diagnosis or therapy. The gastrin-releasing peptide receptor (GRP-r) is a seven-transmembrane G-protein coupled receptor that is over-expressed on primary prostate and breast cancer and lymph node metastases. Bombesin (Bn) is a tetradeca peptide that binds with high affinity to GRP-r. The strong, specific Bn-GRP-r binding is the basis for labelling Bn with radionuclides (i.e. 99m Tc, 111 In, 18 F) to obtain molecular images. The aim of this work was to develop 3 multifunctional systems of 99m Tc-labeled gold nanoparticles (Au Np) (5, 10 and 20 nm) conjugated to Lys 3 -Bombesin for GRP-receptor targeting in breast cancer. The systems were characterized by Tem and UV-Vis, IR, Raman, Fluorescence and XP spectroscopy. The 99m Tc-Au Np-Lys 3 -Bombesin multifunctional system (20 nm) shows in vitro and in vivo specific recognition for GRP-r and suitable properties to be used as a nuclear molecular imaging agent. Results also showed a specific Lys 3 -Bombesin binding to the gold surface and higher fluorescence intensity for the 20 nm system. The Nir bands observed in the 20 nm radio conjugate indicate potential for bio imaging as dual systems. (Author)

  17. The involvement of selected membrane transport mechanisms in the cellular uptake of 177Lu-labeled bombesin, somatostatin and gastrin analogues

    International Nuclear Information System (INIS)

    Volková, M.; Mandíková, J.; Lázníčková, A.; Lázníček, M.; Bárta, P.; Trejtnar, F.

    2015-01-01

    Introduction: Radiolabeled receptor-targeting peptides are a useful tool for the diagnostic imaging and radiotherapy of some malignancies. However, the retention of radioactivity in the kidney may result in renal radiotoxic injury. This study seeks to evaluate the role of endocytic receptor megalin, renal SLC influx transporters and fluid phase endocytosis (FPE) in the cellular accumulation of radiolabeled peptides. Methods: In vitro transport cellular studies using megalin ligands (RAP, albumin), fluid phase endocytosis (FPE) inhibitor rottlerin and low temperature were employed to evaluate the transport mechanisms of the peptides. Cells transfected with hOAT1 or hOCT2 were used to analyze the role of these SLC transporters. Somatostatin ( 177 Lu-DOTA-[Tyr 3 ]octreotate, 177 Lu-DOTA-[1-Nal 3 ]octreotide), gastrin ( 177 Lu-DOTA-sargastrin) and bombesin ( 177 Lu-DOTA-[Pro 1 ,Tyr 4 ]bombesin, 177 Lu-DOTA-[Lys 3 ]bombesin, 177 Lu-PCTA-[Lys 3 ]bombesin) analogues were involved in the study. Results: RAP, albumin and low temperature decreased the accumulation of all the studied peptides significantly. With one exception, rottlerin caused the concentration dependent inhibition of the cellular accumulation of the radiopeptides. No significant differences in the uptake of the peptides between the control cells and those transfected with hOAT1 or hOCT2 were observed. Conclusion: The study showed that active transport mechanisms are decisive for the cellular accumulation in all tested 177 Lu-labeled somatostatin, gastrin and bombesin analogues. Besides receptor-mediated endocytosis by megalin, FPE participates significantly in the uptake. The tested types of renal SLC transporters are not involved in this process

  18. The involvement of selected membrane transport mechanisms in the cellular uptake of (177)Lu-labeled bombesin, somatostatin and gastrin analogues.

    Science.gov (United States)

    Volková, M; Mandíková, J; Lázníčková, A; Lázníček, M; Bárta, P; Trejtnar, F

    2015-01-01

    Radiolabeled receptor-targeting peptides are a useful tool for the diagnostic imaging and radiotherapy of some malignancies. However, the retention of radioactivity in the kidney may result in renal radiotoxic injury. This study seeks to evaluate the role of endocytic receptor megalin, renal SLC influx transporters and fluid phase endocytosis (FPE) in the cellular accumulation of radiolabeled peptides. In vitro transport cellular studies using megalin ligands (RAP, albumin), fluid phase endocytosis (FPE) inhibitor rottlerin and low temperature were employed to evaluate the transport mechanisms of the peptides. Cells transfected with hOAT1 or hOCT2 were used to analyze the role of these SLC transporters. Somatostatin ((177)Lu-DOTA-[Tyr(3)]octreotate, (177)Lu-DOTA-[1-Nal(3)]octreotide), gastrin ((177)Lu-DOTA-sargastrin) and bombesin ((177)Lu-DOTA-[Pro(1),Tyr(4)]bombesin, (177)Lu-DOTA-[Lys(3)]bombesin, (177)Lu-PCTA-[Lys(3)]bombesin) analogues were involved in the study. RAP, albumin and low temperature decreased the accumulation of all the studied peptides significantly. With one exception, rottlerin caused the concentration dependent inhibition of the cellular accumulation of the radiopeptides. No significant differences in the uptake of the peptides between the control cells and those transfected with hOAT1 or hOCT2 were observed. The study showed that active transport mechanisms are decisive for the cellular accumulation in all tested (177)Lu-labeled somatostatin, gastrin and bombesin analogues. Besides receptor-mediated endocytosis by megalin, FPE participates significantly in the uptake. The tested types of renal SLC transporters are not involved in this process. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. 99mTc-Glu-c(RGDyK)-Bombesin SPECT Can Reduce Unnecessary Biopsy of Masses That Are BI-RADS Category 4 on Ultrasonography.

    Science.gov (United States)

    Ji, Tiefeng; Gao, Shi; Liu, Zhaofei; Xing, Hua; Zhao, Guoqing; Ma, Qingjie

    2016-08-01

    Masses that, on ultrasonography, are category 4 according to the Breast Imaging Reporting and Data System (BI-RADS) represent possible malignancy, and a biopsy is recommended. This study explored the value of (99m)Tc-Glu-c(RGDyK)-bombesin ((99m)Tc-RGD-bombesin) in reducing unnecessary biopsy of these masses. Ninety women with a BI-RADS 4 mass on ultrasonography were enrolled in this study to undergo breast SPECT using (99m)Tc-RGD-bombesin. The images were independently interpreted using qualitative visual and semiquantitative analyses. The final diagnosis was based on histopathologic examination of surgically excised or percutaneous biopsy specimens. Fractions of the samples were immunohistochemically analyzed to evaluate expression of integrin αvβ3 and gastrin-releasing peptide receptor (GRPR). The receptor-positive group was further divided into 3 subgroups (GRPR(+)/αvβ3 (+), GRPR(+)/αvβ3 (-), and αvβ3 (+)/GRPR(-)). Ninety-four masses (22 malignant and 72 benign) were confirmed by histopathologic examination. On qualitative analysis, 20 of the malignant masses showed high (99m)Tc-RGD-bombesin accumulation and 48 of the benign masses showed no (99m)Tc-RGD-bombesin accumulation. The optimal cutoff for qualitative analysis was a score of 2. Semiquantitative analysis revealed that 20 of the malignant masses and 16 of the benign masses had a relatively high tumor-to-normal-tissue ratio (T/N). The optimal cutoff was a T/N of 2.26. The mean T/N was higher for malignant masses than for benign masses (3.17 ± 0.86 vs. 1.89 ± 0.71, P 0.05). The areas under the receiver-operating-characteristic curves for the qualitative and semiquantitative analyses were 0.788 and 0.865, respectively, and the overall diagnostic performance did not significantly differ between these analyses (P > 0.05). (99m)Tc-RGD-bombesin SPECT can differentiate benign from malignant BI-RADS 4 masses with high specificity. Further study of the application of this test to clinical breast cancer

  20. Early events elicited by bombesin and structurally related peptides in quiescent Swiss 3T3 cells. II. Changes in Na+ and Ca2+ fluxes, Na+/K+ pump activity, and intracellular pH

    International Nuclear Information System (INIS)

    Mendoza, S.A.; Schneider, J.A.; Lopez-Rivas, A.; Sinnett-Smith, J.W.; Rozengurt, E.

    1986-01-01

    The amphibian tetradecapeptide, bombesin, and structurally related peptides caused a marked increase in ouabain-sensitive 86 Rb + uptake (a measure of Na + /K + pump activity) in quiescent Swiss 3T3 cells. This effect occurred within seconds after the addition of the peptide and appeared to be mediated by an increase in Na + entry into the cells. The effect of bombesin on Na + entry and Na + /K + pump activity was concentration dependent with half-maximal stimulation occurring at 0.3-0.4 nM. The structurally related peptides litorin, gastrin-releasing peptide, and neuromedin B also stimulated ouabain-sensitive 86 Rb + uptake; the relative potencies of these peptides in stimulating the Na + /K + pump were comparable to their potencies in increasing DNA synthesis. Bombesin increased Na + influx, at least in part, through an Na + /H + antiport. The peptide augmented intracellular pH and this effect was abolished in the absence of extracellular Na + . In addition to monovalent ion transport, bombesin and the structurally related peptides rapidly increased the efflux of 45 Ca 2+ from quiescent Swiss 3T3 cells. This Ca 2+ came from an intracellular pool and the efflux was associated with a 50% decrease in total intracellular Ca 2+ . The peptides also caused a rapid increase in cytosolic free calcium concentration. Prolonged pretreatment of Swiss 3T3 cells with phorbol dibutyrate, which causes a loss of protein kinase C activity, greatly decreased the stimulation of 86 Rb + uptake and Na + entry by bombesin implicating this phosphotransferase system in the mediation of part of these responses to bombesin. Since some activation of monovalent ion transport by bombesin was seen in phorbol dibutyrate-pretreated cells, it is likely that the peptide also stimulates monovalent ion transport by a second mechanism

  1. Development of a novel bombesin analog radiolabeled with Lutetium-177: in vivo evaluation of the biological properties in Balb-C mice

    International Nuclear Information System (INIS)

    Pujatti, Priscilla Brunelli; Barrio, Ofelia; Santos, Josefina da Silva; Mengatti, Jair; Araujo, Elaine Bortoleti de

    2008-01-01

    Bombesin (BBN), a 14-aminoacid amphibian peptide homologue of mammalian gastrin-releasing peptide (GRP), has demonstrated the ability to bind with high affinity and specificity to GRP receptor, which are overexpressed on a variety of human cancers. A large number of BBN analogs were synthesized for this purpose and have shown to reduce tumor growth in mice. However, most of the studied analogs exhibit high abdominal accumulation, specially in pancreas. This abdominal accumulation may represent a problem in clinical use of radiolabeled bombesin analogs probably due to serious side effects to patients. In this study we describe the results of radiolabeling with lutetium-177 ( 177 Lu) and in vivo biodistribution and pharmacokinetics studies in normal Balb-C mice of a novel bombesin analog (BBNp4) - DOTA-X-BBN(6-14), where X is a spacer of four aminoacids. This spacer was inserted between the chelator and the binding sequence in order to improve bombesin in vivo properties. BBNp4 was successfully labeled with high yield and kept stable for more than 96 hours at 4 deg C and 4 hours in human plasma. Data analysis obtained from the in vivo studies showed that the amount of BBNp4 present in plasma decreased rapidly and became almost undetectable at 60 min p.i., indicating rapid peptide excretion, which is performed mainly by renal pathway. In addition, biodistribution and single photon emission tomography showed low abdominal accumulation of 177 Lu-DOTA-X-BBN(6-14), indicating that this analog is a potential candidate for tumors target therapy. (author)

  2. Evaluation of {sup 99m}Tc-HYNIC-βAla-Bombesin{sub (7-14)} as an agent for pancreas tumor detection in mice

    Energy Technology Data Exchange (ETDEWEB)

    Carlesso, F.N.; Fuscaldi, L.L.; Araujo, R.S.; Teixeira, C.S.; Oliveira, M.C.; Fernandes, S.O.A.; Cassali, G.D.; Reis, D.C.; Barros, A.L.B.; Cardoso, V.N., E-mail: valbertcardoso@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2015-10-15

    Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using {sup 99m}Tc-HYNIC--βAla-Bombesin{sub (7-14)} as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that {sup 99m}Tc-HYNIC--βAla-Bombesin{sub (7-14)} uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that {sup 99m}Tc-HYNIC--βAla-Bombesin{sub (7-14)} may be useful for the detection of pancreatic adenocarcinoma. (author)

  3. Preparation of [In-111]-labeled-DTPA-bombesin conjugates at high specific activity and stability: Evaluation of labeling parameters and potential stabilizers

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, P.B., E-mail: pujatti.pb@gmail.com [Directory of Radiopharmacy, Nuclear and Energy Research Institute (IPEN/CNEN), Av. Prof. Lineu Prestes, 2242 - Cidade Universitaria da USP - Butanta, Sao Paulo - SP - Brazil - CEP: 05508-000 (Brazil); Massicano, A.V.F.; Mengatti, J.; Araujo, E.B. de [Directory of Radiopharmacy, Nuclear and Energy Research Institute (IPEN/CNEN), Av. Prof. Lineu Prestes, 2242 - Cidade Universitaria da USP - Butanta, Sao Paulo - SP - Brazil - CEP: 05508-000 (Brazil)

    2012-05-15

    The aim of the present work was to obtain stabilized high specific activity (HSA) {sup 111}In-labeled bombesin conjugates for preclinical evaluations. Parameters influencing the kinetics of labeling were investigated and the effect of stabilizers on HSA radiopeptides stability at room temperature were systematically categorized applying chromatography techniques. A SA of 174 GBq/{mu}mol was achieved with high radiochemical purity, but the labeled compounds exhibited low stability. The addition of stabilizers avoided their radiolysis and significantly increased their stability. - Highlights: Black-Right-Pointing-Pointer We aimed to obtain stabilized high specific activity (SA) {sup 111}In-labeled bombesin conjugates. Black-Right-Pointing-Pointer The effect of stabilizers on high SA radiopeptides stability were investigated. Black-Right-Pointing-Pointer A maximum specific activity of 174 GBq/{mu}mol was achieved. Black-Right-Pointing-Pointer The studied stabilizers significantly increased the stability of high SA radiopeptides. Black-Right-Pointing-Pointer These stabilized bombesin conjugates will be applied in preclinical studies.

  4. Early events elicited by bombesin and structurally related peptides in quiescent Swiss 3T3 cells. I. Activation of protein kinase C and inhibition of epidermal growth factor binding.

    Science.gov (United States)

    Zachary, I; Sinnett-Smith, J W; Rozengurt, E

    1986-06-01

    Addition of bombesin to quiescent cultures of Swiss 3T3 cells caused a rapid increase in the phosphorylation of an Mr 80,000 cellular protein (designated 80k). The effect was both concentration and time dependent; enhancement in 80k phosphorylation could be detected as early as 10 s after the addition of peptide. Recently, a rapid increase in the phosphorylation of an 80k cellular protein after treatment with phorbol esters or diacylglycerol has been shown to reflect the activation of protein kinase C in intact fibroblasts (Rozengurt, E., A. Rodriguez-Pena, and K. A. Smith, 1983, Proc. Natl. Acad. Sci. USA., 80:7244-7248; Rozengurt, E., A. Rodriguez-Pena, M. Coombs, and J. Sinnett-Smith, 1984, Proc. Natl. Acad. Sci. USA., 81:5748-5752). The 80k phosphoproteins generated in response to bombesin and to phorbol 12,13-dibutyrate were identical as judged by one- and two-dimensional PAGE and by peptide mapping after partial proteolysis with Staphylococcus aureus V8 protease. In addition, prolonged pretreatment of 3T3 cells with phorbol 12,13-dibutyrate, which leads to the disappearance of protein kinase C activity, blocked the ability of bombesin to stimulate 80k. Bombesin also caused a rapid (1 min) inhibition of 125I-labeled epidermal growth factor (125I-EGF) binding to Swiss 3T3 cells. The inhibition was both concentration and temperature dependent and resulted from a marked decrease in the affinity of the EGF receptor for its ligand. Peptides structurally related to bombesin, including gastrin-releasing peptide, also stimulated 80k phosphorylation and inhibited 125I-EGF binding; both effects were selectively blocked by a novel bombesin antagonist. These results strongly suggest that these responses are mediated by specific high-affinity receptors that recognize the peptides of the bombesin family in Swiss 3T3 cells. While an increase in cytosolic Ca2+ concentration does not mediate the bombesin inhibition of 125I-EGF binding, the activation of protein kinase C in

  5. Biokinetics and dosimetry of 99m Tc-EDDA/HYNIC-[Lys3]-bombesin in humans: imaging of GRP receptors

    International Nuclear Information System (INIS)

    Santos C, C.L.; Ferro F, G.; Murphy, C.A de; Cardena, E.; Pichardo R, P.

    2007-01-01

    Full text: Bombesin (BN) receptor subtype 2 (GRP-r) is over-expressed on various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently we reported the 99- mTc-EDDA/HYNIC-[Lys 3 ]-Bombesin ( 99m Tc-HYNIC-BN) complex as a new radiopharmaceutical with high stability in human serum, specific cell GRP-receptor binding and rapid internalization. The aim of this study was to evaluate the 99m Tc-HYNIC-BN biokinetics and dosimetry in 5-healthy and 3-breast cancer women. Whole-body images were acquired at 20, 90, 180 min and 24 h after 99m Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source' organs on each time frame. The same set of ROIs was used for all 8 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-BN time activity curves in each organ, to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed a rapid radiopharmaceutical blood clearance with predominantly renal excretion and minimal hepatobiliary elimination. 99m Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in breast cancer lesions and well differentiated from GRP-r expression in lungs and airways with normal GRP-r density (ratio 3:1). The equivalent doses for a study using 370 MBq were 7.38±1.68, 0.59±0.08, 2.07±0.60, 0.58±0.1, 0.75±0.09 and 0.43±0.07 mSv for kidneys, liver, lungs, ovaries, pancreas and red marrow respectively. The effective dose was 1.64±0.25 mSv which is comparable with the doses known for most of the 99m Tc radiopharmaceutical studies in nuclear medicine. (Author)

  6. Imaging of Gastrin-Releasing Peptide Receptor-Expressing Prostate Tumor using a {sup 68}Ga-Labeled Bombesin Analog

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Cheong; Dho, So Hee; Cho, Eun Ha; Lee, So Young; Kim, Soo Yong [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected. The imaging efficacy of {sup 68}Ga-DOTA-gluBBN was evaluated in the PC-3- peritoneal metastasized model. These results suggest that {sup 68}Ga-labeled bombesin derivative has promising characteristics as a novel nuclear medicine, especially for the imaging of GRPR over-expressing prostate tumors. A target for irradiation was produced using 99% Ni-62 metal power concentrate. Ni-62 target of 1 g was irradiated in MARIA reactor operated in Poland for 470 hours at neutron flux of 2.5 x 10{sup 14}n/cm{sup 2}s, and estimated production of Ni-63 was calculated. Irradiated Ni-63 pellets were dissolved in HCl solution, and Ni-63 coatings were deposited by DC electroplating at current density of 20 mA/cm{sup 2}.

  7. Biokinetics and dosimetry in patients of 99mTc-HYNIC-Lys3-Bombesin: images of GRP receptors

    International Nuclear Information System (INIS)

    Santos C, C. L.

    2007-01-01

    The bombesin (BN) receptor subtype 2 (GRP-r) is expressed in several normal human tissues and is over-expressed in various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently [ 99m Tc]EDDA/HYNIC-Lys 3 -bombesin ( 99m Tc-HYNIC-BN) was reported as a radiopharmaceutical with high stability in human serum, specific cell GRP-r binding and rapid cell internalization. The aim of this study was to evaluate the feasibility of using 99m Tc-HYNIC-BN to image GRP-r and to assess the radiopharmaceutical biokinetics and dosimetry in 4 breast cancer patients and in 7 healthy women. Methods: Whole-body images were acquired at 20, 90, 180 min and 24 h after 99m Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all 11 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-BN time-activity curves in each organ in order to calculate the total number of disintegrations (N) that occurred in the source regions, according with MIRD methodology. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Results: Images showed a rapid radiopharmaceutical blood clearance with renal excretion as predominant route. 99m Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in cancer mammary glands and well differentiated from the ubiquitous GRP-r expression in normal breast, lungs and airways. There was no statistically significant difference (p > 0.05) in the radiation absorbed doses between cancer patients and healthy women. The average equivalent doses (n=11) for a study using 740 MBq were 24.8 +- 8.8 mSv (kidneys), 7.3 +- 1.8 mSv (lungs), 6.5 +- 4.0 mSv (breast) 2.0 +- 0.3 mSv (pancreas), 1.6 +- 0.3 mSv (liver), 1.2 +- 0.2 mSv (ovaries) and 1.0 +- 0.2 mSv (red marrow). The mean effective dose

  8. Renal uptake and retention of radiolabeled somatostatin, bombesin, neurotensin, minigastrin and CCK analogues: species and gender differences

    International Nuclear Information System (INIS)

    Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Visser, Monique de; Rolleman, Edgar; Jong, Marion de

    2007-01-01

    Introduction: During therapy with radiolabeled peptides, the kidney is most often the critical organ. Newly developed peptides are evaluated preclinically in different animal models before their application in humans. In this study, the renal retention of several radiolabeled peptides was compared in male and female rats and mice. Methods: After intravenous injection of radiolabeled peptides [somatostatin, cholecystokinin (CCK), minigastrin, bombesin and neurotensin analogues], renal uptake was determined in both male and female Lewis rats and C57Bl mice. In addition, ex vivo autoradiography of renal sections was performed to localize accumulated radioactivity. Results: An equal distribution pattern of renal radioactivity was found for all peptides: high accumulation in the cortex, lower accumulation in the outer medulla and no radioactivity in the inner medulla of the kidneys. In both male rats and mice, an increasing renal uptake was found: [ 111 In-DTPA]CCK8 111 In-DTPA-Pro 1 ,Tyr 4 ]bombesin∼[ 111 In-DTPA] neurotensin 111 In-DTPA]octreotide 111 In-DTPA]MG0. Renal uptake of [ 111 In-DTPA]octreotide in rats showed no gender difference, and renal radioactivity was about constant over time. In mice, however, renal uptake in females was significantly higher than that in males and decreased rapidly over time in both genders. Moreover, renal radioactivity in female mice injected with [ 111 In-DTPA]octreotide showed a different localization pattern. Conclusions: Regarding the renal uptake of different radiolabeled peptides, both species showed the same ranking order. Similar to findings in patients, rats showed comparable and constant renal retention of radioactivity in both genders, in contrast to mice. Therefore, rats appear to be the more favorable species for the study of the renal retention of radioactivity

  9. In vitro and in vivo studies in Balb-c and nude mice of a new 177Lu-Bombesin analog developed for prostate tumor diagnosis and treatment

    International Nuclear Information System (INIS)

    Pujatti, Priscilla B.; Santos, Josefina S.; Couto, Renata M.; Araujo, Elaine B. de; Mengatti, Jair; Suzuki, Miriam F.

    2009-01-01

    In this work we describe the radiolabeling with 177 Lu and some properties of the novel bombesin analog BBNp6 - DOTA-X-BBN(6-14), where X is a spacer of six aminoacids. Bombesin (BBN) is an analog of human gastrin releasing peptide (GRP) isolated from the skin of the frog Bombina bombina in 1970. Development of radiolabeled BBN derivatives as agents for diagnostic imaging and systemic radiotherapy has increased considerable because of the observation that GRP receptors (GRPr) are over-expressed in a variety of human tumor cells, such as prostate tumor cells. 177 Lu-labeled peptides are attractive due to the excellent radiophysical properties and commercial availability of the radiometal. BBNp6 was labeled with high yield after reacting with 92.5 MBq of 177 LuCl3 at 90 deg C for 30 minutes and this mixture kept stable for more than 96 hours at 4 deg C and 1 hour in human plasma. In vivo studies showed a multicompartimental distribution model with fast blood clearance, mainly performed by renal pathway. In addition, 177 Lu-BBNp6 showed high affinity for PC-3 tumor xenografts, but not for pancreas and intestine (GRP positive tissues), suggesting its specificity and usefulness for prostate tumor treatment. Moreover, scintigraphic images showed that this derivative can also be a tool in this tumor diagnosis. So, BBNp6 is a promising radiopharmaceutical for prostate tumor imaging and treatment. (author)

  10. Molecular markers derived from bombesin for tumor diagnosis by SPECT and PET; Marcadores moleculares derivados da bombesina para diagnostico de tumores por SPECT e PET

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, Priscilla Brunelli

    2012-07-01

    A high number of molecules have already been identified to have high affinity to some receptors overexpressed on tumour cells and the radiolabelling of those molecules offers the possibility of new compounds for tumour diagnosis and therapy by nuclear medicine. Among of those molecules, bombesin (BBN) has become focus of interest, as its BB{sub 2} receptors are known to be overexpressed in prostate, breast, colon, pancreatic and lung tumour, as long as glioblastomas and neuroblastomas. BBN agonists and antagonists have already been described for this purpose and promising results were obtained in preclinical studies. However, most of them exhibited high abdominal accumulation, especially in pancreas and intestines, which can compromise diagnosis accuracy and cause serious adverse effects in therapy. In this context, the goal of the present work to radiolabel new BBN derivatives with {sup 11}1In and {sup 68}Ga and to evaluate their potential for BB{sub 2} positive tumors diagnosis by single photon emission tomography (SPECT) and positron emission tomography (PET). The structure of studied peptides was Q-YG{sub n}-BBN(6-14), where Q is the chelator, n is the number of glycine aminoacids in the spacer YG{sub n} and BBN(6-14) is the original bombesin sequence from the aminoacid 6 to 14. The derivative in which the last aminoacid (methionine, Met) was replaced by norleucine (Nle) was also evaluated. The experimental evaluation of the bombesin derivatives was divided into four steps: computational studies, molecular markers for SPECT, molecular markers for PET and toxicological studies. The theoretical partition (log P) and distribution (log D) coefficients were calculated for all bombesin derivatives conjugated to DTPA (diethylenetriaminepentaacetic acid) and DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) chelators applying computational programmes. Bombesin derivatives for SPECT were developed by radiolabelling DTPA-conjugated bombesin derivatives with

  11. Peptide-modified liposomes for selective targeting of bombesin receptors overexpressed by cancer cells: a potential theranostic agent

    Science.gov (United States)

    Accardo, Antonella; Salsano, Giuseppina; Morisco, Anna; Aurilio, Michela; Parisi, Antonio; Maione, Francesco; Cicala, Carla; Tesauro, Diego; Aloj, Luigi; De Rosa, Giuseppe; Morelli, Giancarlo

    2012-01-01

    Objectives Drug delivery systems consisting of liposomes displaying a cell surface receptor-targeting peptide are being developed to specifically deliver chemotherapeutic drugs to tumors overexpressing a target receptor. This study addresses novel liposome composition approaches to specifically target tissues overexpressing bombesin (BN) receptors. Methods A new amphiphilic peptide derivative (MonY-BN) containing the BN(7–14) peptide, the DTPA (diethylenetriaminepentaacetate) chelating agent, a hydrophobic moiety with two C18 alkyl chains, and polyethylene glycol spacers, has been synthesized by solid-phase methods. Liposomes have been generated by co-aggregation of MonY-BN with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). The structural and biological properties of these new target-selective drug-delivery systems have been characterized. Results Liposomes with a DSPC/MonY-BN (97/3 molar ratio) composition showed a diameter of 145.5 ± 31.5 nm and a polydispersity index of 0.20 ± 0.05. High doxorubicin (Dox) loading was obtained with the remote pH gradient method using citrate as the inner buffer. Specific binding to PC-3 cells of DSPC/MonY-BN liposomes was obtained (2.7% ± 0.3%, at 37°C), compared with peptide-free DSPC liposomes (1.4% ± 0.2% at 37°C). Incubation of cells with DSPC/ MonY-BN/Dox showed significantly lower cell survival compared with DSPC/Dox-treated cells, in the presence of 100 ng/mL and 300 ng/mL drug amounts, in cytotoxicity experiments. Intravenous treatment of PC-3 xenograft-bearing mice with DSPC/MonY-BN/Dox at 10 mg/kg Dox dose produced higher tumour growth inhibition (60%) compared with nonspecific DSPC/ Dox liposomes (36%) relative to control animals. Conclusion The structural and loading properties of DSPC/MonY-BN liposomes along with the observed in-vitro and in-vivo activity are encouraging for further development of this approach for target-specific cancer chemotherapy. PMID:22619538

  12. Exogenously administered bombesin and gastrin releasing peptide contract the female rat urethra in vivo and in vitro.

    Science.gov (United States)

    Radziszewski, Piotr; Crayton, Robert; Persson, Katarina; Andersson, Karl-Erik; Mattiasson, Anders

    2011-11-01

    Bombesin (BOM) and gastrin releasing peptide (GRP) have been located to the lower urinary tract. However, there is a paucity of data demonstrating the impact of these neuropeptides. The present study investigates the impact of BOM and GRP in the female Sprague-Dawley rats 225  g b.w. n = 37 urethras in vitro and in vivo. Intraurethral pressure was recorded by a catheter placed at the maximum pressure zone corresponding to the intrinsic urethral spincter. In vitro, the intraurethral pressure was measured in response to the administration of BOM and GRP and noradrenaline from perfused intact urethral/bladder preparations. In vivo, changes in intraurethral pressure were conducted in anesthetized subjects and compared with the basal intraurethral pressure and sham controls. In vitro, the increase in intraurethral pressure induced by BOM was 23.6 ± 3.2  cmH(2) O, exceeding the pressure evoked with NA by 10.7  cmH(2) O whereas GRP induced 10.7 ± 1.6  cmH(2) O, an increase of 3.3 cmH(2) O but less than the NA evoked intraurethral pressure by 2.2  cmH(2) O. Incubation with scopolamine (1 µM), phentolamine (1  µM), pancuronium (1  µM), and indomethacin (1  µM) did not produce any significant difference in the contractile responses to BOM or GRP. In vivo, the mean basal pressure was 22.9 ± 1.4  cmH(2) O. The intraurethral pressure evoked by BOM was 29.7  cmH(2) O (21.3  ±  1.3 to 51.0  ±  1.6  cmH(2) O), and for GRP, the evoked intraurethral pressure was 33.8  cmH(2) O (22.3  ±  1.9 to 56.2  ±  30  cmH(2) O). BOM and GRP may contribute to the control of continence by their contractile action on the sphincters of the lower urinary tract outflow region. Copyright © 2011 Wiley Periodicals, Inc.

  13. Co-administration of succinylated gelatine with a 99mTc-bombesin analogue, effects on pharmacokinetics and tumor uptake

    International Nuclear Information System (INIS)

    Liolios, Christos C.; Xanthopoulos, Stavros; Loudos, George; Varvarigou, Alexandra D.; Sivolapenko, Gregory B.

    2016-01-01

    The bombesin analogue, [ 99m Tc-GGC]-(Ornithine) 3 -BN(2-14), 99m Tc-BN-O, targeting gastrin releasing peptide receptors (GRPrs) on the surface of tumors, was pre-clinically investigated as potential imaging agent for single photon emission computed tomography (SPECT). In addition, the improvement of its pharmacokinetic profile (PK) was investigated through the co-administration of a succinylated gelatin plasma expander (Gelofusine), aiming to reduce its kidney accumulation and enhance its tumor-to-normal tissue contrast ratios. Biodistribution data were collected from normal mice and rats, and PC-3 tumor bearing mice, in reference to its PK, metabolism and tumor uptake. Imaging data were also collected from PC-3 tumor bearing mice. Biodistribution and imaging experiments showed that 99m Tc-BN-O was able to efficiently localize the tumor (5.23 and 7.00% ID/g at 30 and 60 min post injection, respectively), while at the same time it was rapidly cleared from the circulation through the kidneys. HPLC analysis of kidney samples, collected at 60 min p.i. from normal mice and rats, showed that the majority of radioactivity detected was due to intact peptide i.e. 56% for mice and 73% for rats. Co-administration of 99m Tc-BN-O with Gelo resulted in the reduction of kidney uptake in both animal models. The integrated area under the curve (AUC 30–60 min ) from the concentration–time plots of kidneys was decreased in both mice and rats by 25 and 50%, respectively. In PC-3 tumor bearing mice, an increase of tumor uptake (AUC tumor increased by 69%) was also observed with Gelo. An improvement in tumor-to-blood and tumor-to-normal tissue ratios was noted in all cases with the exception of the pancreas, which normally expresses GRPr. The results of this preclinical study may also be extended to other similar peptides, which are utilized in prostate cancer imaging and present similar PK profile.

  14. Comparison of [(11)C]Choline ([(11)C]CHO) and [(18)F]Bombesin (BAY 86-4367) as Imaging Probes for Prostate Cancer in a PC-3 Prostate Cancer Xenograft Model.

    Science.gov (United States)

    Schwarzenböck, Sarah Marie; Schmeja, Philipp; Kurth, Jens; Souvatzoglou, Michael; Nawroth, Roman; Treiber, Uwe; Kundt, Guenther; Berndt, Sandra; Graham, Keith; Senekowitsch-Schmidtke, Reingard; Schwaiger, Markus; Ziegler, Sibylle I; Dinkelborg, Ludger; Wester, Hans-Jürgen; Krause, Bernd Joachim

    2016-06-01

    Carbon-11- and fluorine-18-labeled choline derivatives are commonly used in prostate cancer imaging in the clinical setting for staging and re-staging of prostate cancer. Due to a limited detection rate of established positron emission tomography (PET) tracers, there is a clinical need for innovative tumor-specific PET compounds addressing new imaging targets. The aim of this study was to compare the properties of [(18)F]Bombesin (BAY 86-4367) as an innovative biomarker for prostate cancer imaging targeting the gastrin-releasing peptide receptor and [(11)C]Choline ([(11)C]CHO) in a human prostate tumor mouse xenograft model by small animal PET/X-ray computed tomography (CT). We carried out a dual-tracer small animal PET/CT study comparing [(18)F]Bombesin and [(11)C]CHO. The androgen-independent human prostate tumor cell line PC-3 was implanted subcutaneously in the flanks of nu/nu NMRI mice (n = 10) (PET/CT measurements of two [(11)C]Choline mice could not be analyzed due to technical reasons). [(18)F]Bombesin and [(11)C]CHO PET/CT imaging was performed about 3-4 weeks after the implantation of PC-3 cells on two separate days. After the intravenous tail vein injection of 14 MBq [(18)F]Bombesin and 37 MBq [(11)C]CHO, respectively, a dynamic study over 60 min was acquired in list mode using an Inveon animal PET/CT scanner (Siemens Medical Solutions). The sequence of [(18)F]Bombesin and [(11)C]CHO was randomized. Image analysis was performed using summed images as well as dynamic data. To calculate static and dynamic tumor-to-muscle (T/M), tumor-to-blood (T/B), liver-to-blood (L/B), and kidney-to-blood (K/B) ratios, 4 × 4 × 4 mm(3) volumes of interest (VOIs) of tumor, muscle (thigh), liver, kidney, and blood derived from transversal slices were used. The mean T/M ratio of [(18)F]Bombesin and [(11)C]CHO was 6.54 ± 2.49 and 1.35 ± 0.30, respectively. The mean T/B ratio was 1.83 ± 0.79 for [(18)F]Bombesin and 0.55 ± 0.10 for [(11)C

  15. BLOCKADE OF ROSTRAL VENTROLATERAL MEDULLA (RVLM BOMBESIN RECEPTOR TYPE 1 DECREASES BLOOD PRESSURE AND SYMPATHETIC ACTIVITY IN ANESTHETIZED SPONTANEOUSLY HYPERTENSIVE RATS

    Directory of Open Access Journals (Sweden)

    Izabella Silva De Jesus Pinto

    2016-06-01

    Full Text Available IIntrathecal injection of bombesin (BBS promoted hypertensive and sympathoexcitatory effects in normotensive (NT rats. However, the involvement of rostral ventrolateral medulla (RVLM in these responses is still unclear. In the present study, we investigated: (1 the effects of BBS injected bilaterally into RVLM on cardiorespiratory and sympathetic activity in NT and spontaneously hypertensive rats (SHR; (2 the contribution of RVLM bombesin type 1 receptors (BB1 to the maintenance of hypertension in SHR. Urethane-anesthetized rats (1.2 g · kg−1, i.v. were instrumented to record mean arterial pressure (MAP, diaphragm (DIA motor and renal sympathetic nerve activity (RSNA. In NT rats and SHR, BBS (0.3 mM nanoinjected into RVLM increased MAP (33.9 ± 6.6 mmHg and 37.1 ± 4.5 mmHg, respectively; p < 0.05 and RSNA (97.8 ± 12.9 % and 84.5 ± 18.1 %, respectively; p < 0.05. In SHR, BBS also increased DIA burst amplitude (115.3 ± 22.7 %; p < 0.05. BB1 receptors antagonist (BIM-23127; 3 mM reduced MAP (-19.9 ± 4.4 mmHg; p < 0.05 and RSNA (-17.7 ± 3.8 %; p < 0.05 in SHR, but not in NT rats (-2.5 ± 2.8 mmHg; -2.7 ± 5.6 %, respectively. These results show that BBS can evoke sympathoexcitatory and pressor responses by activating RVLM BB1 receptors. This pathway might be involved in the maintenance of high levels of arterial blood pressure in SHR.

  16. Inhibitory effect of juniperonic acid (Delta-5c,11c,14c,17c-20:4, omega-3) on bombesin-induced proliferation of Swiss 3T3 cells.

    Science.gov (United States)

    Morishige, Jun-ichi; Amano, Naoki; Hirano, Kaoru; Nishio, Hiroaki; Tanaka, Tamotsu; Satouchi, Kiyoshi

    2008-09-01

    Juniperonic acid (Delta-5c,11c,14c,17c-20:4, JA) is a polymethylene-interrupted (PMI) fatty acid that occurs in Biota orientalis. In this study, we found that JA has an antiproliferative activity. Swiss 3T3 cells were preloaded with fatty acids before stimulation with bombesin, a mitogenic neuropeptide, and proliferation of the cells was assessed by [(3)H]thymidine incorporation. Preloading of linoleic acid (Delta-9c,12c-18:2) significantly enhanced bombesin-induced proliferation. In contrast, preloading of eicosapentaenoic acid (Delta-5c,8c,11c,14c,17c-20:5, EPA) suppressed proliferation. Likewise, cells preloaded with JA showed a significantly curtailed response to bombesin. The antiproliferative potency of JA was equivalent to that of EPA. Sciadonic acid (Delta-5c,11c,14c-20:3), an omega-6 analogue of JA did not show antiproliferative activity, suggesting the importance of the omega-3 double bond rather than the PMI structure. The EPA-like activity of JA may be involved in the pharmaceutical activity of biota seeds, a psychoactive Chinese traditional medicine.

  17. Effect of the peptide Tat(49-57) on the bio-distribution and similar radiopharmaceuticals dosimetry of the bombesin

    International Nuclear Information System (INIS)

    Santos C, C. L.

    2011-01-01

    The gastrin-releasing peptide receptor (GRP-r) is over-expressed in prostate and breast cancer. 99m Tc-Bombesin ( 99m Tc-Bn) has been reported as a radiopharmaceutical with specific cell GRP-r binding. The HIV Tat(49-57)-derived peptide has been used to deliver a large variety of molecules to cell nuclei. New hybrid radiopharmaceuticals of type 99m Tc-N 2 S 2 -Tat(49-57)-Lys 3 -Bn ( 99m Tc-Tat-Bn) and 188 Re-N 2 S 2 -Tat(49-57)-Lys 3 -Bn ( 188 Re-Tat-Bn), would increase cell uptake and internalized in cancer cell nuclei could act as an effective system of targeted radiotherapy using Auger and internal conversion (I C) electron emissions near DNA. The aim of this research was to prepare and assess in vitro and in vivo uptake kinetics in cancer cells of 99m Tc/ 188 Re-Tat-Bn and the in vitro nucleus and cytoplasm internalization kinetics in GRP receptor-positive cancer cells as well as to evaluate the subcellular-level radiation absorbed dose associated with the observed effect on cancer cell DNA proliferation. Structures of N 2 S 2 -Tat-Bn and Tc/Re(O)N 2 S 2 -Tat-Bn were calculated by an Mm procedure. 99m Tc-Tat-Bn and 188 Re-Tat-Bn were synthesized and stability studies carried out by HPLC and I TLC-Sg analyses in serum and cysteine solutions. In vitro internalization was tested using human prostate cancer Pc 3 cells and breast carcinoma cell lines MDA-Mb 231 and MCF 7. Nuclei from cells were isolated using a nuclear extraction kit. Total disintegrations in each subcellular compartment were calculated by integration of experimental time activity kinetic curves. Nucleus internalization was corroborated by con focal microscopy images using immunofluorescent labelled Tat-Bn. Biodistribution was determined in Pc 3 tumor-bearing nude mice. The Penelope code was used to simulate and calculate the absorbed dose by contribution of β, Auger and I C electrons in the cytoplasm and nucleus using geometric models built from immunofluorescent cell images. A cell proliferation

  18. Fluorescence imaging of bombesin and transferrin receptor expression is comparable to 18F-FDG PET in early detection of sorafenib-induced changes in tumor metabolism.

    Directory of Open Access Journals (Sweden)

    Jen-Chieh Tseng

    noticeable changes in tumor size. For comparison, two FLI probes, BombesinRSense™ 680 (BRS-680 and Transferrin-Vivo™ 750 (TfV-750, were assessed for their potential in metabolic imaging. Metabolically active cancer cells are known to have elevated bombesin and transferrin receptor levels on the surface. In excellent agreement with PET imaging, the BRS-680 imaging showed 40% and 79% inhibition on days 2 and 3, respectively, and the TfV-750 imaging showed 65% inhibition on day 3. In both cases, no significant reduction in tumor volume or BLI signal was observed during the first 3 days of treatment. These results suggest that metabolic FLI has potential preclinical application as an additional method for detecting drug-induced metabolic changes in tumors.

  19. Biokinetics and dosimetry of {sup 99m} Tc-EDDA/HYNIC-[Lys{sup 3}]-bombesin in humans: imaging of GRP receptors

    Energy Technology Data Exchange (ETDEWEB)

    Santos C, C.L.; Ferro F, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Murphy, C.A de [INCMNSZ, 14000 Mexico D.F. (Mexico); Cardena, E.; Pichardo R, P. [Departamento de Medicina Nuclear, Oncologia Centro Medico Siglo XXI, Mexico D.F. (Mexico)

    2007-07-01

    Full text: Bombesin (BN) receptor subtype 2 (GRP-r) is over-expressed on various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently we reported the {sup 99-}mTc-EDDA/HYNIC-[Lys{sup 3}]-Bombesin ({sup 99m}Tc-HYNIC-BN) complex as a new radiopharmaceutical with high stability in human serum, specific cell GRP-receptor binding and rapid internalization. The aim of this study was to evaluate the {sup 99m}Tc-HYNIC-BN biokinetics and dosimetry in 5-healthy and 3-breast cancer women. Whole-body images were acquired at 20, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source' organs on each time frame. The same set of ROIs was used for all 8 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-BN time activity curves in each organ, to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed a rapid radiopharmaceutical blood clearance with predominantly renal excretion and minimal hepatobiliary elimination. {sup 99m}Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in breast cancer lesions and well differentiated from GRP-r expression in lungs and airways with normal GRP-r density (ratio 3:1). The equivalent doses for a study using 370 MBq were 7.38{+-}1.68, 0.59{+-}0.08, 2.07{+-}0.60, 0.58{+-}0.1, 0.75{+-}0.09 and 0.43{+-}0.07 mSv for kidneys, liver, lungs, ovaries, pancreas and red marrow respectively. The effective dose was 1.64{+-}0.25 mSv which is comparable with the doses known for most of the {sup 99m}Tc radiopharmaceutical studies in nuclear medicine. (Author)

  20. Synthesis and characterization of Bombesin-superparamagnetic iron oxide nanoparticles as a targeted contrast agent for imaging of breast cancer using MRI

    International Nuclear Information System (INIS)

    Jafari, Atefeh; Shayesteh, Saber Farjami; Salouti, Mojtaba; Heidari, Zahra; Rajabi, Ahmad Bitarafan; Boustani, Komail; Nahardani, Ali

    2015-01-01

    The targeted delivery of superparamagnetic iron oxide nanoparticles (SPIONs) as a contrast agent may facilitate their accumulation in cancer cells and enhance the sensitivity of MR imaging. In this study, SPIONs coated with dextran (DSPIONs) were conjugated with bombesin (BBN) to produce a targeting contrast agent for detection of breast cancer using MRI. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer analyses indicated the formation of dextran-coated superparamagnetic iron oxide nanoparticles with an average size of 6.0 ± 0.5 nm. Fourier transform infrared spectroscopy confirmed the conjugation of the BBN with the DSPIONs. A stability study proved the high optical stability of DSPION–BBN in human blood serum. DSPION–BBN biocompatibility was confirmed by cytotoxicity evaluation. A binding study showed the targeting ability of DSPION–BBN to bind to T47D breast cancer cells overexpressing gastrin-releasing peptide (GRP) receptors. T 2 -weighted and T 2 *-weighted color map MR images were acquired. The MRI study indicated that the DSPION–BBN possessed good diagnostic ability as a GRP-specific contrast agent, with appropriate signal reduction in T 2 *-weighted color map MR images in mice with breast tumors. (paper)

  1. Synthesis and characterization of Bombesin-superparamagnetic iron oxide nanoparticles as a targeted contrast agent for imaging of breast cancer using MRI

    Science.gov (United States)

    Jafari, Atefeh; Salouti, Mojtaba; Farjami Shayesteh, Saber; Heidari, Zahra; Bitarafan Rajabi, Ahmad; Boustani, Komail; Nahardani, Ali

    2015-02-01

    The targeted delivery of superparamagnetic iron oxide nanoparticles (SPIONs) as a contrast agent may facilitate their accumulation in cancer cells and enhance the sensitivity of MR imaging. In this study, SPIONs coated with dextran (DSPIONs) were conjugated with bombesin (BBN) to produce a targeting contrast agent for detection of breast cancer using MRI. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer analyses indicated the formation of dextran-coated superparamagnetic iron oxide nanoparticles with an average size of 6.0 ± 0.5 nm. Fourier transform infrared spectroscopy confirmed the conjugation of the BBN with the DSPIONs. A stability study proved the high optical stability of DSPION-BBN in human blood serum. DSPION-BBN biocompatibility was confirmed by cytotoxicity evaluation. A binding study showed the targeting ability of DSPION-BBN to bind to T47D breast cancer cells overexpressing gastrin-releasing peptide (GRP) receptors. T2-weighted and T2*-weighted color map MR images were acquired. The MRI study indicated that the DSPION-BBN possessed good diagnostic ability as a GRP-specific contrast agent, with appropriate signal reduction in T2*-weighted color map MR images in mice with breast tumors.

  2. Radiochemical and radiobiological assessment of a pyridyl-S-cysteine functionalized bombesin derivative labeled with the (99m)Tc(CO)3(+) core.

    Science.gov (United States)

    Bouziotis, Penelope; Gourni, Eleni; Patsis, George; Psimadas, Dimitrios; Zikos, Christos; Fani, Melpomeni; Xanthopoulos, Stavros; Loudos, George; Paravatou-Petsotas, Maria; Livaniou, Evangelia; Varvarigou, Alexandra D; Pirmettis, Ioannis; Papadopoulos, Minas

    2013-11-01

    Bombesin is a neuropeptide widely studied due to its ability to target various types of cancers. Technetium-99m on the other hand is ideal for diagnostic tumor targeting. The aim of the present study is the investigation of the coupling of the ligand (S)-(2-(2'-pyridyl)ethyl)-d,l-cysteine with the BN-peptide Gln-Arg-Leu-Gly-Asn-Gln-Trp-Ala-Val-Gly-His-Leu-Met(CONH2) through the spacer aminohexanoic acidand the labeling of the resulting derivative MBN with the synthon [M(CO)3(H2O)3](+) (M=(99m)Tc, Re). The peptide was synthesized according to the SPPS method, purified and characterized by ESI-MS. The new (99m)Tc-labeled biomolecule was stable in vitro, showed high affinity for the human GRP receptor expressed in PC3 cells and the rate of internalization was found to be time-dependent tissue distribution of the radiopeptide was evaluated in normal mice and in prostate cancer experimental models and significant radioactivity uptake was observed in the pancreas of normal mice as well as in PC3 tumors. Dynamic studies of the radiopeptide showed satisfactory tumor images. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. In vitro Evaluation of a Bombesin Antagonistic Analogue Conjugated with DOTA-Ala(SO{sub 3}H)-Aminooctanoyl for Targeting of the Gastrin-releasing Peptide Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Cheong; Cho, Eun Ha; Kim, Jin Joo; Lee, So Young; Choi, Sang Mu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    As Bombesin (BBS) binds with high affinity to GRPR, BBS derivatives have been labeled with various radionuclides such as {sup 99}mTc, {sup 111}In, {sup 90}Y, {sup 64}Cu, {sup 177}Lu, {sup 68}Ga, or {sup 18}F and have proved to be successful candidates for peptide receptor radiotherapy (PRRT). In this study, we employed Ala(SO{sub 3}H)-Aminooctanoyl as a linker of BBS antagonistic peptide sequence, Gln-Trp-Ala-Val-N methyl Gly-His-Statine-Leu-NH{sub 2}, with DOTA to prepare radiolabeled candidates for GRPR targeting. A DOTA-conjugated BBS antagonistic analogue was synthesized and radiolabeled with {sup 177}Lu, and in vitro characteristics on GRPR-overexpressing human prostate tumor cells were evaluated. In conclusion, a novel BBS antagonistic analogue, {sup 177}Lu-DOTA-sBBNA, is a promising candidate for the targeting of GRPR-over-expressing tumors. Further investigations to evaluate its in vivo characteristics and therapeutic efficacy are needed.

  4. Synthesis and evaluation of Lys1(α, γ-Folate)Lys3(177Lu-DOTA)-Bombesin(1-14) as a potential theranostic radiopharmaceutical for breast cancer

    International Nuclear Information System (INIS)

    Aranda L, L.; Ferro F, G.; Azorin V, E.; Ramirez, F. M.; Ocampo G, B.; Santos C, C.; Jimenez M, N.; Issac O, K.

    2015-10-01

    Full text: Lutetium-177 labeled hetero bivalent molecules that interact with different targets on tumor cells have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this work was to synthesize Lys 1 (α,γ-Folate)-Lys 3 ( 177 Lu-DOTA)-Bombesin (1-14) ( 177 LuFolate-Bn), as well as to assess its in vitro and in vivo potential for molecular imaging and targeted radiotherapy of breast tumors expressing folate receptors (Fr) and gastrin releasing peptide receptors (GRPR). Lys 1 Lys 3 (DOTA)-Bombesin (1-14) was conjugated to the terminal carboxylic group of the folic acid and the product purified by size-exclusion HPLC. Chemical characterization was carried out by UV-vis, Ft-IR spectroscopies and MALDI-TOF mass spectrometry. 177 Lu labeling was performed by reaction of 177 LuCl 3 with the Lys 1 (α,γ-Folate)-Lys 3 (DOTA)-Bombesin (Folate-Bn) conjugate. In vitro binding studies were carried out in T47D breast cancer cells (positive to Fr and GRPR). Biokinetic studies and micro-SPECT/CT images were obtained using athymic mice with T47D induced tumors. Spectroscopic studies and HPLC analyses indicated that the conjugate was obtained with high chemical and radiochemical purity (98 ± 1.3%). T47D-tumors were clearly visible with high contrast at 2 h after radiopharmaceutical administration. The 177 Lu-absorbed dose delivered to tumors was 23.9 ± 2.1 Gy (74 MBq, intravenously administered) 177 Lu-Folate-Bn demonstrated properties suitable as a theranostic radiopharmaceutical for breast tumors expressing Fr s and GRPR s. (Author)

  5. Synthesis and evaluation of Lys{sup 1}(α, γ-Folate)Lys{sup 3}({sup 177}Lu-DOTA)-Bombesin(1-14) as a potential theranostic radiopharmaceutical for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Aranda L, L.; Ferro F, G.; Azorin V, E.; Ramirez, F. M.; Ocampo G, B.; Santos C, C.; Jimenez M, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Issac O, K. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, 50180 Toluca, Estado de Mexico (Mexico)

    2015-10-15

    Full text: Lutetium-177 labeled hetero bivalent molecules that interact with different targets on tumor cells have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this work was to synthesize Lys{sup 1} (α,γ-Folate)-Lys{sup 3}({sup 177}Lu-DOTA)-Bombesin (1-14) ({sup 177}LuFolate-Bn), as well as to assess its in vitro and in vivo potential for molecular imaging and targeted radiotherapy of breast tumors expressing folate receptors (Fr) and gastrin releasing peptide receptors (GRPR). Lys{sup 1} Lys{sup 3} (DOTA)-Bombesin (1-14) was conjugated to the terminal carboxylic group of the folic acid and the product purified by size-exclusion HPLC. Chemical characterization was carried out by UV-vis, Ft-IR spectroscopies and MALDI-TOF mass spectrometry. {sup 177}Lu labeling was performed by reaction of {sup 177}LuCl{sub 3} with the Lys{sup 1} (α,γ-Folate)-Lys{sup 3} (DOTA)-Bombesin (Folate-Bn) conjugate. In vitro binding studies were carried out in T47D breast cancer cells (positive to Fr and GRPR). Biokinetic studies and micro-SPECT/CT images were obtained using athymic mice with T47D induced tumors. Spectroscopic studies and HPLC analyses indicated that the conjugate was obtained with high chemical and radiochemical purity (98 ± 1.3%). T47D-tumors were clearly visible with high contrast at 2 h after radiopharmaceutical administration. The {sup 177}Lu-absorbed dose delivered to tumors was 23.9 ± 2.1 Gy (74 MBq, intravenously administered) {sup 177}Lu-Folate-Bn demonstrated properties suitable as a theranostic radiopharmaceutical for breast tumors expressing Fr s and GRPR s. (Author)

  6. Study of the optical and dosimetric properties of the nano conjugate {sup 99m}Tc-EDDA/HYNIC-GGC-Au Np-Bombesin by effect of nano particle size; Estudio de las propiedades opticas y dosimetricas del nanoconjugado {sup 99m}Tc-EDDA/HYNIC-GGC-AUNP-Bombesina por efecto del tamano de nanoparticula

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza S, A. N.

    2011-07-01

    The receptors over-expressed on the surface of cancer cells represent promising targets for breast cancer diagnosis or therapy. The gastrin-releasing peptide receptor (GRP-r) is a seven-transmembrane G-protein coupled receptor that is over-expressed on primary prostate and breast cancer and lymph node metastases. Bombesin (Bn) is a tetradeca peptide that binds with high affinity to GRP-r. The strong, specific Bn-GRP-r binding is the basis for labelling Bn with radionuclides (i.e. {sup 99m}Tc, {sup 111}In, {sup 18}F) to obtain molecular images. The aim of this work was to develop 3 multifunctional systems of {sup 99m}Tc-labeled gold nanoparticles (Au Np) (5, 10 and 20 nm) conjugated to Lys{sup 3}-Bombesin for GRP-receptor targeting in breast cancer. The systems were characterized by Tem and UV-Vis, IR, Raman, Fluorescence and XP spectroscopy. The {sup 99m}Tc-Au Np-Lys{sup 3}-Bombesin multifunctional system (20 nm) shows in vitro and in vivo specific recognition for GRP-r and suitable properties to be used as a nuclear molecular imaging agent. Results also showed a specific Lys{sup 3}-Bombesin binding to the gold surface and higher fluorescence intensity for the 20 nm system. The Nir bands observed in the 20 nm radio conjugate indicate potential for bio imaging as dual systems. (Author)

  7. The Effect of Mini-PEG-Based Spacer Length on Binding and Pharmacokinetic Properties of a 68Ga-Labeled NOTA-Conjugated Antagonistic Analog of Bombesin

    Directory of Open Access Journals (Sweden)

    Zohreh Varasteh

    2014-07-01

    Full Text Available The overexpression of gastrin-releasing peptide receptor (GRPR in cancer can be used for peptide-receptor mediated radionuclide imaging and therapy. We have previously shown that an antagonist analog of bombesin RM26 conjugated to 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA via a diethyleneglycol (PEG2 spacer (NOTA-PEG2-RM26 and labeled with 68Ga can be used for imaging of GRPR-expressing tumors. In this study, we evaluated if a variation of mini-PEG spacer length can be used for optimization of targeting properties of the NOTA-conjugated RM26. A series of analogs with different PEG-length (n = 2, 3, 4, 6 was synthesized, radiolabeled and evaluated in vitro and in vivo. The IC50 values of natGa-NOTA-PEGn-RM26 (n = 2, 3, 4, 6 were 3.1 ± 0.2, 3.9 ± 0.3, 5.4 ± 0.4 and 5.8 ± 0.3 nM, respectively. In normal mice all conjugates demonstrated similar biodistribution pattern, however 68Ga-NOTA-PEG3-RM26 showed lower liver uptake. Biodistribution of 68Ga-NOTA-PEG3-RM26 was evaluated in nude mice bearing PC-3 (prostate cancer and BT-474 (breast cancer xenografts. High uptake in tumors (4.6 ± 0.6%ID/g and 2.8 ± 0.4%ID/g for PC-3 and BT-474 xenografts, respectively and high tumor-to-background ratios (tumor/blood of 44 ± 12 and 42 ± 5 for PC-3 and BT-474 xenografts, respectively were found already at 2 h p.i. of 68Ga-NOTA-PEG3-RM26. Results of this study suggest that variation in the length of the PEG spacer can be used for optimization of targeting properties of peptide-chelator conjugates. However, the influence of the mini-PEG length on biodistribution is minor when di-, tri-, tetra- and hexaethylene glycol are compared.

  8. Preclinical pharmacokinetic, biodistribution, imaging and therapeutic efficacy of 177Lu-Labeled glycated bombesin analogue for gastrin-releasing peptide receptor-positive prostate tumor targeting

    International Nuclear Information System (INIS)

    Lim, Jae Cheong; Cho, Eun Ha; Kim, Jin Joo; Choi, Sang Mu; Lee, So Young; Nam, Sung Soo; Park, Ul Jae; Park, Soo Hyun

    2015-01-01

    The gastrin-releasing peptide receptor (GRPR) has been shown to be overexpressed in many human tumors, including prostate, colon, gastric, breast, pancreatic, and small cell lung cancers. Because bombesin (BBS) binds to GRPR with high affinity, BBS derivatives have been labeled with various radionuclides and have been demonstrated to be successful candidates for peptide receptor radiotherapy (PRRT). The present study describes the in vitro and in vivo preclinical characteristics of 177 Lu-DOTA-Lys(glucose)-4 aminobenzoic acid-BBS 7-14 ( 177 Lu-DOTA-gluBBN) to prepare radiolabeled candidates for the treatment of GRPR-expressing prostate tumors. Methods: 177 Lu-DOTA-gluBBN was prepared as previously published [1]. Human prostate PC-3 tumor cells were used to determine the binding (Kd) retention and efflux of 177 Lu-DOTA-gluBBN. Pharmacokinetic, imaging, and radiotherapy studies were performed in PC-3 xenografted mice. Results: The Kd value of 177 Lu-DOTA-gluBBN was 0.63 nM, with a maximum binding capacity (Bmax) of 669.7 fmol/10 6 cells (4.04 × 10 5 GRPR/cell). During a 2-hr incubation, 90.1 ± 0.4% of the cell-associated radio-peptide was internalized, and 56.3 ± 7.1% of the internalized radio-peptide was externalized in vitro. High amounts of the radio-peptide were rapidly accumulated in a PC-3 tumor in vivo, and the % ID/g of the tumor was 12.42 ± 2.15 1 hr p.i. The radio-peptide was quickly cleared from the blood, yielding tumor-to-blood ratios of 39.22 ± 17.36 at 1 hr p.i. and 330.67 ± 131.23 at 24 hr p.i. In addition, 177 Lu-DOTA-gluBBN was clearly visualized in PC-3 tumors 1 hr p.i. and significantly inhibited the tumor growth (P < 0.05). Treatment-related toxicity in the pancreas and kidneys was not observed, except for slight glomerulopathy. Conclusions: The pharmacokinetic, imaging, and therapy studies suggest that this 177 Lu-DOTA-gluBBN has promising characteristics for application in nuclear medicine, namely, for the diagnosis and treatment of GRPR

  9. Comparative in vitro and in vivo evaluation of two 64Cu-labeled bombesin analogs in a mouse model of human prostate adenocarcinoma

    International Nuclear Information System (INIS)

    Yang, Y.-S.; Zhang Xianzhong; Xiong Zhengming; Chen Xiaoyuan

    2006-01-01

    Bombesin (BBN), an analog of human gastrin-releasing peptide (GRP), binds to the GRP receptor (GRPR) with high affinity and specificity. Overexpression of GRPR has been discovered in mostly androgen-independent human prostate tissues and, thus, provides a potential target for prostate cancer diagnosis and therapy. We have previously demonstrated the feasibility of the positron emission tomography (PET) imaging using 64 Cu-1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA)-[Lys 3 ]BBN to detect GRPR-positive prostate cancer. In this study, we compared the receptor affinity, metabolic stability, tumor-targeting efficacy, and pharmacokinetics of a truncated BBN analog 64 Cu-DOTA-Aca-BBN(7-14) with 64 Cu-DOTA-[Lys 3 ]BBN. Binding of each DOTA conjugate to GRPR on PC-3 and 22Rv1 prostate cancer cells was evaluated with competitive binding assay using 125 I-[Tyr 4 ]BBN as radioligand. In vivo pharmacokinetics was determined on male nude mice subcutaneously implanted with PC-3 cells. Dynamic microPET imaging was performed to evaluate the systemic distribution of the tracers. Metabolic stability of the tracers in blood, urine, tumor, liver and kidney was studied using high-performance liquid chromatography. The results showed that 125 I-[Tyr 4 ]BBN has a K d of 14.8±0.4 nM against PC-3 cells, and the receptor concentration on PC-3 cell surface is approximately 2.7±0.1x10 6 receptors per cell. The 50% inhibitory concentration value for DOTA-Aca-BBN(7-14) is 18.4±0.2 nM, and that for DOTA-[Lys 3 ]BBN is 2.2±0.5 nM. DOTA-[Lys 3 ]BBN shows a better tumor contrast and absolute tumor activity accumulation compared to DOTA-Aca-BBN(7-14). Studies on metabolic stability for both tracers on organ homogenates showed that 64 Cu-DOTA-[Lys 3 ]BBN is relatively stable. This study demonstrated that both tracers are suitable for targeted PET imaging to detect the expression of GRPR in prostate cancer, while 64 Cu-DOTA-[Lys 3 ]BBN may have a better potential for clinical

  10. Optimization of the production process of hybrid and multivalent formulation Bombesin/RGD for the opportune detection of breast cancer; Optimizacion del proceso de fabricacion de la formulacion hibrida y multivalente Bombesina/RGD para la deteccion oportuna de cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Robles M, M.

    2013-07-01

    The radiopharmaceuticals of third generation are used in nuclear medicine to obtain images of specific molecular targets, and they are unique in their capacity to detect in vivo specific biochemical sites as receptors that are over-expressed in diverse illness. In cancer cells several types of receptors are over-expressed, as the integrin s α(v)β(3) and α(v)β(5) that specifically recognize the sequence RGD (Arginine-Glycin-Ac. Aspartic) and gastrin-releasing peptide that recognizes specifically to the peptide Lys{sup 3}-Bombesin. The integrin s α(v)β(3) and α(v)β(5) are involved in the tumor angio genesis processes and the gastrin-releasing peptide is over-expressed in breast and prostate cancer. The molecular recognition of the specific receptors is the basis to be utilized as targets of the radiopharmaceuticals {sup 99m}Tc-HYNIC-Bombesin and {sup 99m}Tc-HYNIC-RGD. In this work was developed a lyophilized pharmaceutical formulation effective, stable and safe for the simultaneous obtaining of the radiopharmaceuticals {sup 99m}Tc-HYNIC-Bombesin ({sup 99m}Tc-EDDA/HYNIC-Lys{sup 3}-Bombesin) and {sup 99m}Tc-HYNIC-RGD ({sup 99m}Tc EDDA/HYNIC-E-[c(RGDfK)]{sub 2}). Later on the production process of the product HYNIC-Bombesin/RGD-Sn was optimized using a factorial design and the formulation was transferred to the production plant of radiopharmaceuticals of the Instituto Nacional de Investigaciones Nucleares (ININ). The optimized formulation is described in the following chart: HYNIC-[Lys{sup 3}]-Bombesin - 12.5 μg; HYNIC-E-c[RGDfK]{sub 2} - 12.5 μg; Stannous chloride (SnCl{sub 2}) - 20 μg; Ethylenediamine diacetic acid (EDDA) - 10 mg; N-tris(hydroxymethyl)methyl glycin (Tricine) - 20 mg; Mannitol - 50 mg. The production process was validated and were carried out the stability studies under refrigeration conditions. (Author)

  11. Synthesis and evaluation of Lys¹(α,γ-Folate)Lys³(¹⁷⁷Lu-DOTA)-Bombesin(1-14) as a potential theranostic radiopharmaceutical for breast cancer.

    Science.gov (United States)

    Aranda-Lara, Liliana; Ferro-Flores, Guillermina; Azorín-Vega, Erika; Ramírez, Flor de María; Jiménez-Mancilla, Nallely; Ocampo-García, Blanca; Santos-Cuevas, Clara; Isaac-Olivé, Keila

    2016-01-01

    The aim of this work was to synthesize Lys(1)(α,γ-Folate)-Lys(3)((177)Lu-DOTA)-Bombesin (1-14) ((177)Lu-Folate-BN), as well as to assess its potential for molecular imaging and targeted radiotherapy of breast tumors expressing folate receptors (FR) and gastrin-releasing peptide receptors (GRPR). Radiation absorbed doses of (177)Lu-Folate-BN (74 MBq, i.v.) estimated in athymic mice with T47D-induced breast tumors (positive to FR and GRPR), showed tumor doses of 23.9±2.1 Gy. T47D-tumors were clearly visible (Micro-SPECT/CT images). (177)Lu-Folate-BN demonstrated properties suitable as a theranostic radiopharmaceutical. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Comparative study on DOTA-derivatized bombesin analog labeled with 90Y and 177Lu: in vitro and in vivo evaluation

    International Nuclear Information System (INIS)

    Koumarianou, Eftychia; Mikolajczak, Renata; Pawlak, Dariusz; Zikos, Xhristos; Bouziotis, Pinelopi; Garnuszek, Piotr; Karczmarczyk, Urszula; Maurin, Michal; Archimandritis, Spyridon C.

    2009-01-01

    Introduction: The aim of the study was to compare in vitro and in vivo a novel DOTA-chelated bombesin (BN) analog of the amino acid sequence, QRLGNQWAVGHLM-CONH 2 (BN[2-14]NH 2 ), labeled with 90 Y and 177 Lu, for its potential use in targeted radiotherapy of tumors expressing gastrin releasing peptide (GRP) receptors. The same amino acid sequence, but with different chelator, referred as BN1.1 (Gly-Gly-Cys-Aca-QRLGNQWAVGHLM-CONH 2 ), has already been studied and reported; however, the DOTA-chelated one, suitable for labeling with M +3 type radiometals, was not yet described. Methods: The conditions for labeling of DOTA-BN[2-14]NH 2 with noncarrier added 90 Y and with 177 Lu [specific activity (SA), 15 Ci/mg Lu] were investigated and optimized to provide 90 Y-DOTA-BN[2-14]NH 2 and 177 Lu-DOTA-BN[2-14]NH 2 of high SA. The stability of the radiolabeled compounds in human serum was evaluated over a period of 24 h. The human prostate cancer cell line PC-3, known to express GRP receptors, was used for in vitro evaluation of radiolabeled peptide affinity to GRP receptors and for assessment of cytotoxicity of both nonlabeled and radiolabeled peptide. Biodistribution accompanied by receptor blocking was studied in normal Swiss mice. Results: 90 Y-DOTA-BN[2-14]NH 2 and 177 Lu-DOTA-BN[2-14]NH 2 were obtained with radiochemical yield >98% and high SA (67.3 GBq 90 Y/μmol and 33.6 GBq 177 Lu/μmol, respectively). They were stable when incubated in human serum for up to 24 h. The binding affinities of DOTA-BN[2-14]NH 2 and both nat Y- and nat Lu-labeled analogs to GRP receptors were high (IC 50 =1.78, 1.99, and 1.34 nM, respectively), especially for the nat Lu-DOTA-BN[2-14]NH 2 complex. The cytotoxicity study of DOTA-BN[2-14]NH 2 to PC-3 cells revealed an IC 50 =6300 nM after 72 h of exposition, while the labeled derivatives showed no significant cytotoxic effect. The internalization rate to PC-3 cells was more rapid for 177 Lu-labeled peptide (84.87%) than for the 90 Y

  13. Synthesis and evaluation of Lys1(α,γ-Folate)Lys3(177Lu-DOTA)-Bombesin(1-14) as a potential theranostic radiopharmaceutical for breast cancer

    International Nuclear Information System (INIS)

    Aranda-Lara, Liliana; Ferro-Flores, Guillermina; Azorín-Vega, Erika; Ramírez, Flor de María; Jiménez-Mancilla, Nallely; Ocampo-García, Blanca; Santos-Cuevas, Clara; Isaac-Olivé, Keila

    2016-01-01

    The aim of this work was to synthesize Lys 1 (α,γ-Folate)-Lys 3 ( 177 Lu-DOTA)-Bombesin (1-14) ( 177 Lu-Folate-BN), as well as to assess its potential for molecular imaging and targeted radiotherapy of breast tumors expressing folate receptors (FR) and gastrin-releasing peptide receptors (GRPR). Radiation absorbed doses of 177 Lu-Folate-BN (74 MBq, i.v.) estimated in athymic mice with T47D-induced breast tumors (positive to FR and GRPR), showed tumor doses of 23.9±2.1 Gy. T47D-tumors were clearly visible (Micro-SPECT/CT images). 177 Lu-Folate-BN demonstrated properties suitable as a theranostic radiopharmaceutical. - Highlights: • 177 Lu-Folate-BN improves recognition of breast cancer cells positive to FR and GRPR. • 177 Lu-Folate-BN shows theranostic (imaging and radiation therapy) properties. • The heterobivalent 177 Lu-Folate-BN tracer interacts with different targets on tumors.

  14. Biokinetics and dosimetry in patients of {sup 99m}Tc-HYNIC-Lys{sup 3}-Bombesin: images of GRP receptors; Biocinetica y dosimetria en humanos de {sup 99m}Tc-HYNIC-Lys{sup 3}-Bombesina: imagenes de receptores GRP

    Energy Technology Data Exchange (ETDEWEB)

    Santos C, C. L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2007-07-01

    The bombesin (BN) receptor subtype 2 (GRP-r) is expressed in several normal human tissues and is over-expressed in various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently [{sup 99m}Tc]EDDA/HYNIC-Lys{sup 3}-bombesin ({sup 99m}Tc-HYNIC-BN) was reported as a radiopharmaceutical with high stability in human serum, specific cell GRP-r binding and rapid cell internalization. The aim of this study was to evaluate the feasibility of using {sup 99m}Tc-HYNIC-BN to image GRP-r and to assess the radiopharmaceutical biokinetics and dosimetry in 4 breast cancer patients and in 7 healthy women. Methods: Whole-body images were acquired at 20, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all 11 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-BN time-activity curves in each organ in order to calculate the total number of disintegrations (N) that occurred in the source regions, according with MIRD methodology. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Results: Images showed a rapid radiopharmaceutical blood clearance with renal excretion as predominant route. {sup 99m}Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in cancer mammary glands and well differentiated from the ubiquitous GRP-r expression in normal breast, lungs and airways. There was no statistically significant difference (p > 0.05) in the radiation absorbed doses between cancer patients and healthy women. The average equivalent doses (n=11) for a study using 740 MBq were 24.8 +- 8.8 mSv (kidneys), 7.3 +- 1.8 mSv (lungs), 6.5 +- 4.0 mSv (breast) 2.0 +- 0.3 mSv (pancreas), 1.6 +- 0.3 mSv (liver), 1.2 +- 0.2 mSv (ovaries) and 1.0 +- 0.2 mSv (red

  15. In Vitro and In Vivo Evaluation of Alexa Fluor 680-Bombesin[7–14]NH2 Peptide Conjugate, a High-Affinity Fluorescent Probe with High Selectivity for the Gastrin-Releasing Peptide Receptor

    Directory of Open Access Journals (Sweden)

    Lixin Ma

    2007-05-01

    Full Text Available Gastrin-releasing peptide (GRP receptors are overexpressed on several types of human cancer cells, including breast, prostate, small cell lung, and pancreatic cancers. Bombesin (BBN, a 14–amino acid peptide that is an analogue of human GRP, binds to GRP receptors with very high affinity and specificity. The aim of this study was to develop a new fluorescent probe based on BBN having high tumor uptake and optimal pharmacokinetics for specific targeting and optical imaging of human breast cancer tissue. In this study, solid-phase peptide synthesis was used to produce H2N-glycylglycylglycine-BBN[7–14]NH2 peptide with the following general sequence: H2N-G-G-G-Q-W-A-V-G-H-L-M-(NH2. This conjugate was purified by reversed-phase high-performance liquid chromatography and characterized by electrospray-ionization mass spectra. The fluorescent probe Alexa Fluor 680-G-G-G-BBN[7–14]NH2 conjugate was prepared by reaction of Alexa Fluor 680 succinimidyl ester to H2N-G-G-G-BBN[7–14]NH2 in dimethylformamide (DMF. In vitro competitive binding assays, using 125I-Tyr4-BBN as the radiolabeling gold standard, demonstrated an inhibitory concentration 50% value of 7.7 ± 1.4 nM in human T-47D breast cancer cells. Confocal fluorescence microscopy images of Alexa Fluor 680-G-G-G-BBN[7–14]NH2 in human T-47D breast cancer cells indicated specific uptake, internalization, and receptor blocking of the fluorescent bioprobe in vitro. In vivo investigations in SCID mice bearing xenografted T-47D breast cancer lesions demonstrated the ability of this new conjugate to specifically target tumor tissue with high selectivity and affinity.

  16. In vitro and in vivo evaluation of Alexa Fluor 680-bombesin[7-14]NH2 peptide conjugate, a high-affinity fluorescent probe with high selectivity for the gastrin-releasing peptide receptor.

    Science.gov (United States)

    Ma, Lixin; Yu, Ping; Veerendra, Bhadrasetty; Rold, Tammy L; Retzloff, Lauren; Prasanphanich, Adam; Sieckman, Gary; Hoffman, Timothy J; Volkert, Wynn A; Smith, Charles J

    2007-01-01

    Gastrin-releasing peptide (GRP) receptors are overexpressed on several types of human cancer cells, including breast, prostate, small cell lung, and pancreatic cancers. Bombesin (BBN), a 14-amino acid peptide that is an analogue of human GRP, binds to GRP receptors with very high affinity and specificity. The aim of this study was to develop a new fluorescent probe based on BBN having high tumor uptake and optimal pharmacokinetics for specific targeting and optical imaging of human breast cancer tissue. In this study, solid-phase peptide synthesis was used to produce H(2)N-glycylglycylglycine-BBN[7-14]NH(2) peptide with the following general sequence: H(2)N-G-G-G-Q-W-A-V-G-H-L-M-(NH(2)). This conjugate was purified by reversed-phase high-performance liquid chromatography and characterized by electrospray-ionization mass spectra. The fluorescent probe Alexa Fluor 680-G-G-G-BBN[7-14]NH(2) conjugate was prepared by reaction of Alexa Fluor 680 succinimidyl ester to H(2)N-G-G-G-BBN[7-14]NH(2) in dimethylformamide (DMF). In vitro competitive binding assays, using (125)I-Tyr(4)-BBN as the radiolabeling gold standard, demonstrated an inhibitory concentration 50% value of 7.7 +/- 1.4 nM in human T-47D breast cancer cells. Confocal fluorescence microscopy images of Alexa Fluor 680-G-G-G-BBN[7-14]NH(2) in human T-47D breast cancer cells indicated specific uptake, internalization, and receptor blocking of the fluorescent bioprobe in vitro. In vivo investigations in SCID mice bearing xenografted T-47D breast cancer lesions demonstrated the ability of this new conjugate to specifically target tumor tissue with high selectivity and affinity.

  17. Optimization, biological evaluation and microPET imaging of copper-64-labeled bombesin agonists, [64Cu-NO2A-(X)-BBN(7-14)NH2], in a prostate tumor xenografted mouse model

    International Nuclear Information System (INIS)

    Lane, Stephanie R.; Nanda, Prasanta; Rold, Tammy L.; Sieckman, Gary L.; Figueroa, Said D.; Hoffman, Timothy J.; Jurisson, Silvia S.; Smith, Charles J.

    2010-01-01

    Gastrin-releasing peptide receptors (GRPr) are a member of the bombesin (BBN) receptor family. GRPr are expressed in high numbers on specific human cancers, including human prostate cancer. Therefore, copper-64 ( 64 Cu) radiolabeled BBN(7-14)NH 2 conjugates could have potential for diagnosis of human prostate cancer via positron-emission tomography (PET). The aim of this study was to produce [ 64 Cu-NO2A-(X)-BBN(7-14)NH 2 ] conjugates for prostate cancer imaging, where X=pharmacokinetic modifier (beta-alanine, 5-aminovaleric acid, 6-aminohexanoic acid, 8-aminooctanoic acid, 9-aminonanoic acid or para-aminobenzoic acid) and NO2A=1,4,7-triazacyclononane-1,4-diacetic acid [a derivative of NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid)]. Methods: [(X)-BBN(7-14)NH 2 ] Conjugates were synthesized by solid-phase peptide synthesis (SPPS), after which NOTA was added via manual conjugation. The new peptide conjugates were radiolabeled with 64 Cu radionuclide. The receptor-binding affinity was determined in human prostate PC-3 cells, and tumor-targeting efficacy was determined in PC-3 tumor-bearing severely combined immunodeficient (SCID) mice. Whole-body maximum intensity microPET/CT images of PC-3 tumor-bearing SCID mice were obtained 18 h postinjection (pi). Results: Competitive binding assays in PC-3 cells indicated high receptor-binding affinity for the [NO2A-(X)-BBN(7-14)NH 2 ] and [ nat Cu-NO2A-(X)-BBN(7-14)NH 2 ] conjugates. In vivo biodistribution studies of the [ 64 Cu-NO2A-(X)-BBN(7-14)NH 2 ] conjugates at 1, 4 and 24 h pi showed very high uptake of the tracer in GRPr-positive tissue with little accumulation and retention in nontarget tissues. High-quality, high-contrast microPET images were obtained, with xenografted tumors being clearly visible at 18 h pi. Conclusions: NO2A chelator sufficiently stabilizes copper(II) radiometal under in vivo conditions, producing conjugates with very high uptake and retention in targeted GRPr. Preclinical evaluation of these

  18. Bombesin and Neurotensin Receptor Targeting Using Radiolabeled Peptide Analogs

    NARCIS (Netherlands)

    M. de Visser (Monique)

    2007-01-01

    textabstractSomatostatin receptor-targeting peptides are widely used for imaging and therapy of neuroendocrine tumors. Peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumor patients with radiolabeled somatostatin analogs has resulted in symptomatic improvement, prolonged survival and

  19. Bombesin-like peptide mediates lung injury in a baboon model of bronchopulmonary dysplasia

    NARCIS (Netherlands)

    Sunday, ME; Yoder, BA; Cuttitta, F; Haley, KJ; Emanuel, RL

    1998-01-01

    The etiology of bronchopulmonary dysplasia (BPD), a chronic lung disease of infants surviving respiratory distress syndrome, remains fundamentally enigmatic. BPD is decreasing in severity but continues to be a major problem in pediatric medicine, being especially prevalent among very premature

  20. Localization of receptors for bombesin-like peptides in the rat brain

    International Nuclear Information System (INIS)

    Moody, T.W.; Getz, R.; O'Donohue, T.L.; Rosenstein, J.M.

    1988-01-01

    BN-like peptides and receptors are present in discrete areas of the mammalian brain. By radioimmunoassay, endogenous BN/GRP, neuromedin B, and ranatensin-like peptides are present in the rat brain. High-to-moderate concentrations of BN/GRP are present in the rat hypothalamus and thalamus, whereas moderate-to-high densities of neuromedin B and ranatensin-like peptides are present in the olfactory bulb and hippocampus, as well as in the hypothalamus and thalamus. While the distribution of neuromedin B and ranatensin-like peptides appears similar, it is distinct from that of BN/GRP. When released from CNS neurons, these peptides may interact with receptors for BN-like peptides. BN, GRP, ranatensin, and neuromedin B inhibit specific [ 125 I-Tyr4]BN binding with high affinity. By use of in vitro autoradiographic techniques to detect binding of [ 125 I-Tyr4]BN to receptors for BN-like peptides, high grain densities were found in the olfactory bulb and tubercle, the nucleus accumbens, the suprachiasmatic and paraventricular nucleus of the hypothalamus, the central medial and paraventricular thalamic nuclei, the hippocampus, the dentate gyrus, and the amygdala of the rat brain. Some of these receptors may be biologically active and mediate the biological effects of BN-like peptides. For example, when BN is directly injected into the nucleus accumbens, pronounced grooming results and the effects caused by BN are reversed by spantide and [D-Phe12]BN. Thus, the putative BN receptor antagonists may serve as useful agents to investigate the biological significance of BN-like peptides in the CNS

  1. High contrast pet imaging of GRPR expression in prostate cancer using cobalt-labeled bombesin antagonist RM26

    DEFF Research Database (Denmark)

    Mitran, Bogdan; Thisgaard, Helge; Rosenström, Ulrika

    2017-01-01

    ) and 1000 (24 h pi).The favorable biodistribution of cobalt-labeled NOTA-PEG2-RM26 translated into high contrast preclinical PET/CT (using55Co) and SPECT/CT (using57Co) images of PC-3 xenografts.The initial biological results suggest that55Co-NOTA-PEG2-RM26 is a promising tracer for PET visualization...

  2. 68Ga Bombesin PET/MRI in Patients with Biochemically Recurrent Prostate Cancer and Noncontributory Conventional Imaging

    Science.gov (United States)

    2017-10-01

    prostate cancer (PCa). Methods: We enrolled 15 men with biochemically recurrent PCa from May to Sep 2017, 63-79 year-old (mean± standard deviation (SD...code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 9 Table of Contents Page 1. Introduction...1. Attard G, Parker C, Eeles RA, et al. (2016) Prostate cancer. Lancet 387:70-82. 2. Siegel RL, Miller KD, Jemal A (2016) Cancer statistics , 2016. CA

  3. Preclinical Evaluation of a Novel In-111-Labeled Bombesin Homodimer for Improved Imaging of GRPR-Positive Prostate Cancer

    NARCIS (Netherlands)

    Carlucci, G.; Ananias, H. J. K.; Yu, Z.; Hoving, H. D.; Helfrich, W.; Dierckx, R. A. J. O.; Liu, S.; de Jong, I. J.; Elsinga, P. H.

    Rational-designed multimerization of targeting ligands can be used to improve kinetic and thermodynamic properties. Multimeric targeting ligands may be produced by tethering multiple identical or two or more monomeric ligands of different binding specificities. Consequently, multimeric ligands may

  4. Molecular basis for agonism in the BB3 receptor: an epitope located on the interface of transmembrane-III, -VI, and -VII

    DEFF Research Database (Denmark)

    Gbahou, F; Holst, B; Schwartz, T W

    2010-01-01

    Epitopes determining the agonist property of two structurally distinct selective ligands for the human bombesin receptor subtype 3 (BB3), [D-Tyr6,(R)-Apa11,Phe13, Nle14]-bombesin(6-14) (Pep-1) and Ac-Phe-Trp-Ala-His(TauBzl)-Nip-Gly-Arg-NH2 (Pep-2), were mapped through systematic mutagenesis...

  5. Primitive neuroectodermal tumors of the central nervous system. Patterns of expression of neuroendocrine markers, and all classes of intermediate filament proteins.

    NARCIS (Netherlands)

    Gould, V E; Jansson, D S; Molenaar, W M; Rorke, L B; Trojanowski, J Q; Lee, V M; Packer, R J; Franke, W W

    1990-01-01

    Snap-frozen samples from 22 primitive neuroectodermal tumors (PNETs) primary in the central nervous system were studied with antibodies to synaptophysin, bombesin, somatostatin, substance P, vasoactive intestinal polypeptide, all classes of intermediate filaments, and desmoplakins I and II. Frozen

  6. Coexistence of neuropeptides in hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J

    1983-01-01

    Using a technique for simultaneous visualisation of two antigens in one section, oxytocin-like immunoreactivity has been found to coexist with bombesin-like immunoreactivity in neurons of the basal disk, gastric region and tentacles of hydra. Neurons with oxytocin-like immunoreactivity in peduncle...... and hypostome, on the other hand, have little or no bombesin-like material. Oxytocin-like immunoreactivity never coexists with FMRFamide-immunoreactivity. The neurons with oxytocin- and FMRFamide-like immunoreactivity, however, are often found to be closely intermingled. The results show that coexistence......, as well as non-coexistence, of neuropeptides is a phylogenetically old principle....

  7. Structure-activity relationship study towards non-peptidic positron emission tomography (PET) radiotracer for gastrin releasing peptide receptors : Development of [F-18] (S)-3-(1H-indol-3-yl)-N-[1-[5-(2-fluoroethoxy) pyridin-2-yl]cyclohexylmethyl]-2-methyl-2-[3-(4-nitrophenyl)ureido]propionamide

    NARCIS (Netherlands)

    Lacivita, Enza; Lucente, Ermelinda; Kwizera, Chantal; Farinha Antunes, Ines; Niso, Mauro; De Giorgio, Paola; Perrone, Roberto; Colabufo, Nicola A.; Elsinga, Philip H.; Leopoldo, Marcello

    2017-01-01

    Gastrin-releasing peptide receptors (GRP-Rs, also known as bombesin 2 receptors) are overexpressed in a variety of human cancers, including prostate cancer, and therefore they represent a promising target for in vivo imaging of tumors using positron emission tomography (PET). Structural

  8. Insulin-like synergistic stimulation of DNA synthesis in Swiss 3T3 cells by the BSC-1 cell-derived growth inhibitor related to transforming growth factor type β

    International Nuclear Information System (INIS)

    Brown, K.D.; Holley, R.W.

    1987-01-01

    A cell growth inhibitor (GI), purified from BSC-1 cell-conditioned medium, has little if any effect on DNA synthesis when added alone to monolayer cultures of quiescent Swiss mouse 3T3 cells in serum-free medium. However, the inhibitor, which is closely related to transforming growth factor type β (TGF-β), exhibits a pronounced synergistic stimulation of DNA synthesis in combination with certain peptide (bombesin, vasopressin) or polypeptide (platelet-derived growth factor) mitogens. 125 I-EGF binding was measured and the efflux of 45 Ca 2+ was measured in response to mitogen stimulation. A similar synergistic response has been demonstrated for TGF-β purified from human platelets. In the presence of 3 nM bombesin, a half-maximal stimulation of DNA synthesis was obtained at a GI concentration of approximately 60 pg/ml, with a maximal response at approximately 600 pg/ml. The synergistic interactions demonstrated by GI or TGF-β in stimulating Swiss 3T3 cells closely resemble those previously shown for insulin, and the authors have observed that GI does not synergize with insulin to stimulate DNA synthesis in these cells. Like insulin, and in contrast to bombesin, vasopressin, and platelet-derived growth factor, GI does not activate cellular inositolphospholipid hydrolysis, calcium mobilization, or cross-regulation of epidermal growth factor receptor affinity. These results raise the possibility that the biochemical pathways activated by GI/TGF-β and insulin converge at a post-receptor stage

  9. Unsupported platinum nanoparticles as effective sensors of neurotransmitters and possible drug curriers

    Science.gov (United States)

    Tąta, Agnieszka; Gralec, Barbara; Proniewicz, Edyta

    2018-03-01

    Herein, surface-enhanced Raman scattering (SERS) activity of positively charged unsupported platinum nanoparticles (PtNPs) with ∼12 nm size and narrow size distribution, in an aqueous solution, towards neurotransmitters was monitored at 785 nm excitation wavelength. The pure PtNPs were synthetized by polyol method. Their morphology and structure were checked by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) measurements. As a neurotransmitter bombesin (BN), which exhibits autocrine effect on the growth of normal and tumour tissues, and its fragments from the C-terminal end: BN13-14, BN12-14, BN11-14, BN10-14, BN9-14, and BN8-14 (X-14 fragments of the BN amino acid sequence) were chosen. The collected spectra were interpreted and discussed. This is to determine the adsorption mode of bombesin onto the PtNPs surface and changes in this mode as a result of the bombesin backbone shortening from the N-terminal end. This is important from the point of using PtNPs as potential BN carrier into the cancerous tissue and antitumor drug.

  10. Towards cancer cell-specific phototoxic organometallic rhenium(I) complexes.

    Science.gov (United States)

    Leonidova, Anna; Pierroz, Vanessa; Rubbiani, Riccardo; Heier, Jakob; Ferrari, Stefano; Gasser, Gilles

    2014-03-21

    Over the recent years, several Re(I) organometallic compounds have been shown to be toxic to various cancer cell lines. However, these compounds lacked sufficient selectivity towards cancer tissues to be used as novel chemotherapeutic agents. In this study, we probe the potential of two known N,N-bis(quinolinoyl) Re(I) tricarbonyl complex derivatives, namely Re(I) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-4-butane-1-amine (Re-NH₂) and Re(I) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-5-valeric acid (Re-COOH), as photodynamic therapy (PDT) photosensitizers. Re-NH₂ and Re-COOH proved to be excellent singlet oxygen generators in a lipophilic environment with quantum yields of about 75%. Furthermore, we envisaged to improve the selectivity of Re-COOH via conjugation to two types of peptides, namely a nuclear localization signal (NLS) and a derivative of the neuropeptide bombesin, to form Re-NLS and Re-Bombesin, respectively. Fluorescent microscopy on cervical cancer cells (HeLa) showed that the conjugation of Re-COOH to NLS significantly enhanced the compound's accumulation into the cell nucleus and more specifically into its nucleoli. Importantly, in view of PDT applications, the cytotoxicity of the Re complexes and their bioconjugates increased significantly upon light irradiation. In particular, Re-Bombesin was found to be at least 20-fold more toxic after light irradiation. DNA photo-cleavage studies demonstrated that all compounds damaged DNA via singlet oxygen and, to a minor extent, superoxide production.

  11. Phenotypic imaging and gallium-68 radiolabeled peptides: Beyond the somatostatin analogs;Imagerie phenotypique et peptides radiomarques au gallium-68: au-dela des analogues de la somatostatine

    Energy Technology Data Exchange (ETDEWEB)

    Couturier, O.; Lacoeuille, F.; Lefebvre, C.; Hindre, F.; Vervueren, L.; Bouchet, F.; Le Jeune, J.J. [Universite d' Angers, Service de medecine nucleaire universitaire, 49 - Angers (France); Universite d' Angers, Inserm U646, 49 - Angers (France); Hustinx, R. [Departement de medecine nucleaire universitaire, domaine universitaire du Sart Tilman, Liege (Belgium)

    2010-05-15

    Receptor targeting with radiolabeled peptides has become very important in nuclear oncology in the past few years. The most frequently used peptides in the clinic are analogs of somatostatin. However, other radiolabeled analogs have also been developed and assessed in vitro and in vivo and some of them are already in clinical use. For instance, radiolabeled analogs of alpha-melanocyte-stimulating hormone (alpha-M.S.H.), neurotensin, vasoactive intestinal peptide (VIP), bombesin (B.N.), substance P (S.P.), cholecystokinin (C.C.K.), integrin. This review focuses on gallium-68 radiolabeled peptides developed for PET imaging, except for somatostatin analogs, which are discussed in another article. (authors)

  12. FMRFamide immunoreactivity in the nervous system of the medusa Polyorchis penicillatus

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Spencer, A N

    1984-01-01

    with several antisera to oxytocin/vasopressin and bombesin/gastrin-releasing peptide. The morphology and location of most FMRFamide-immunoreactive neurons in Polyorchis coincides with two identified neuronal systems, which have been recently discovered from neurophysiological studies....... immunoreactivity was found in neurons of the ectodermal nerve nets of the manubrium and tentacles, in neurons of the sensory epithelium, and in neurons at the periphery of the sphincter muscle. Strong immunoreactivity was also present in processes and perikarya of the whole outer nerve ring, in the ocellar nerves...

  13. Bronchial carcinoid tumors metastatic to the sella turcica and review of the literature.

    Science.gov (United States)

    Moshkin, Olga; Rotondo, Fabio; Scheithauer, Bernd W; Soares, Mark; Coire, Claire; Smyth, Harley S; Goth, Miklos; Horvath, Eva; Kovacs, Kalman

    2012-06-01

    We review here the literature on neuroendocrine neoplasms metastatic to the pituitary and present an example of the disease. Metastasis of bronchial carcinoid tumors to the sellar region are rare. Herein, we describe the case of a 63-year-old woman who presented with constant cough and headaches. She had previously been operated for carcinoid tumor of the lung. During the preoperative investigation, a CT scan of the head revealed a sellar mass. Six months after a left lower lobectomy, the sellar lesion was removed by transsphenoidal surgery. The two tumors were evaluated by histology, immunohistochemistry and electron microscopy. Both showed identical morphologic features, those of carcinoid tumor. Immunohistochemistry revealed immunoreactivity for the endocrine markers, synaptophysin and chromogranin, as well as CD-56, serotonin, bombesin and vascular endothelial growth factor. The sellar neoplasm showed nuclear immunopositivity for thyroid transcription factor-1, supporting the diagnosis of a metastatic bronchial carcinoid tumor. In conclusion, this is the first report of a serotonin- and bombesin-immunopositive atypical bronchial carcinoid tumor metastatic to the sella.

  14. Interactions of Gastrointestinal Peptides: Ghrelin and Its Anorexigenic Antagonists

    Directory of Open Access Journals (Sweden)

    Anna-Sophia Wisser

    2010-01-01

    Full Text Available Food intake behaviour and energy homeostasis are strongly regulated by a complex system of humoral factors and nerval structures constituting the brain-gut-axis. To date the only known peripherally produced and centrally acting peptide that stimulates food intake is ghrelin, which is mainly synthesized in the stomach. Recent data indicate that the orexigenic effect of ghrelin might be influenced by other gastrointestinal peptides such as cholecystokinin (CCK, bombesin, desacyl ghrelin, peptide YY (PYY, as well as glucagon-like peptide (GLP. Therefore, we will review on the interactions of ghrelin with several gastrointestinal factors known to be involved in appetite regulation in order to elucidate the interdependency of peripheral orexigenic and anorexigenic peptides in the control of appetite.

  15. Theranostic Prospects of Gastrin-Releasing Peptide Receptor-Radioantagonists in Oncology.

    Science.gov (United States)

    Maina, Theodosia; Nock, Berthold A; Kulkarni, Harshad; Singh, Aviral; Baum, Richard P

    2017-07-01

    Gastrin-releasing peptide receptors (GRPRs) represent attractive targets for cancer diagnosis and therapy owing to their overexpression in widespread human tumors. Bombesin (BBN) analogues coupled to suitable chelators for stable radiometal binding have been proposed for diagnostic imaging and radionuclide therapy (theranostics) of GRPR-positive tumors. Recently, interest has shifted from BBN-like receptor agonists to GRPR-radioantagonists, because radioantagonists do not induce adverse effects after injection to patients and display superior pharmacokinetic in vivo profiles. Thus, they seem more advantageous for clinical use compared to agonists. Newer developments highlighting the theranostic potential of GRPR-radioantagonists in cancer patient management are presented herein. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Radiolabeled peptides in the diagnosis and therapy of oncological diseases

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Ronald E. E-mail: weiner@adp.uchc.edu; Thakur, Mathew L

    2002-11-01

    There has been an exponential growth in the development of radiolabeled peptides for diagnostic and therapeutic applications in oncology. Peptides have fast clearance, rapid tissue penetration, low antigenicity and can be produced easily and inexpensively. However, peptides have problems with in vivo catabolism, unwanted physiological effects, and chelate attachment. The approved {sup 111}In-DTPA-OctreoScan, a somatostatin receptor binder, is well established for diagnosis of neuroendocrine tumors. NeoTect, an approved, {sup 99m}Tc-labeled, somatostatin-receptor-binding analogue has good specificity for lung cancer detection. The receptors for Vasoactive Intestinal Peptide, Cholecystokinin-B/gastrin, Bombesin, Epidermal Growth Factor, and Alpha Melanocyte Stimulating Hormone and the Integrin, {alpha}{sub v}{beta}{sub 3}, are under active investigation as targets. Octreotide and its analogues labeled with {sup 111}In, {sup 90}Y, {sup 64}Cu or {sup 177}Lu are under study for the treatment of patients with promising results.

  17. Laboratory methods to evaluate therapeutic radiopharmaceuticals

    International Nuclear Information System (INIS)

    Arteaga de Murphy, C.; Rodriguez-Cortes, J.; Pedraza-Lopez, M.; Ramirez-Iglesias, MT.; Ferro-Flores, G.

    2007-01-01

    The overall aim of this coordinated research project was to develop in vivo and in vitro laboratory methods to evaluate therapeutic radiopharmaceuticals. Towards this end, the laboratory methods used in this study are described in detail. Two peptides - an 8 amino acid minigastrin analogue and octreotate - were labelled with 177 Lu. Bombesin was labelled with 99 mTc, and its diagnostic utility was proven. For comparison, 99 mTc-TOC was used. The cell lines used in this study were AR42J cells, which overexpress somatostatin receptors found in neuroendocrine cancers, and PC3 cells, which overexpress gastric releasing peptide receptors (GRP-r) found in human prostate and breast cancers. The animal model chosen was athymic mice with implanted dorsal tumours of pathologically confirmed cell cancers. The methodology described for labelling, quality control, and in vitro and in vivo assays can be easily used with other radionuclides and other peptides of interest. (author)

  18. Involvement of the mitogen-activated protein (MAP kinase signalling pathway in host cell invasion by Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Robert-Gangneux F.

    2000-06-01

    Full Text Available Little is known about signalling in Toxoplasma gondii, but it is likely that protein kinases might play a key role in the parasite proliferation, differentiation and probably invasion. We previously characterized Mitogen-Activated Protein (MAP kinases in T. gondii lysates. In this study, cultured cells were tested for their susceptibility to Toxoplasma gondii infection after tachyzoite pretreatment with drugs interfering with AMP kinase activation pathways. Protein kinases inhibitors, i.e. genistein, R031-8220 and PD098059, reduced tachyzoite infectivity by 38 ± 4.5 %, 85.5 ± 9 % and 56 ± 10 %, respectively. Conversely, protein kinases activators, i.e. bombesin and PMA, markedly increased infectivity (by 202 ± 37 % and 258 ± 14 %, respectively. These results suggest that signalling pathways involving PKC and AAAP kinases play a role in host cell invasion by Toxoplasma.

  19. The Nutrient-Responsive Hormone CCHamide-2 Controls Growth by Regulating Insulin-like Peptides in the Brain of Drosophila melanogaster.

    Science.gov (United States)

    Sano, Hiroko; Nakamura, Akira; Texada, Michael J; Truman, James W; Ishimoto, Hiroshi; Kamikouchi, Azusa; Nibu, Yutaka; Kume, Kazuhiko; Ida, Takanori; Kojima, Masayasu

    2015-05-01

    The coordination of growth with nutritional status is essential for proper development and physiology. Nutritional information is mostly perceived by peripheral organs before being relayed to the brain, which modulates physiological responses. Hormonal signaling ensures this organ-to-organ communication, and the failure of endocrine regulation in humans can cause diseases including obesity and diabetes. In Drosophila melanogaster, the fat body (adipose tissue) has been suggested to play an important role in coupling growth with nutritional status. Here, we show that the peripheral tissue-derived peptide hormone CCHamide-2 (CCHa2) acts as a nutrient-dependent regulator of Drosophila insulin-like peptides (Dilps). A BAC-based transgenic reporter revealed strong expression of CCHa2 receptor (CCHa2-R) in insulin-producing cells (IPCs) in the brain. Calcium imaging of brain explants and IPC-specific CCHa2-R knockdown demonstrated that peripheral-tissue derived CCHa2 directly activates IPCs. Interestingly, genetic disruption of either CCHa2 or CCHa2-R caused almost identical defects in larval growth and developmental timing. Consistent with these phenotypes, the expression of dilp5, and the release of both Dilp2 and Dilp5, were severely reduced. Furthermore, transcription of CCHa2 is altered in response to nutritional levels, particularly of glucose. These findings demonstrate that CCHa2 and CCHa2-R form a direct link between peripheral tissues and the brain, and that this pathway is essential for the coordination of systemic growth with nutritional availability. A mammalian homologue of CCHa2-R, Bombesin receptor subtype-3 (Brs3), is an orphan receptor that is expressed in the islet β-cells; however, the role of Brs3 in insulin regulation remains elusive. Our genetic approach in Drosophila melanogaster provides the first evidence, to our knowledge, that bombesin receptor signaling with its endogenous ligand promotes insulin production.

  20. Neurotransmitters and putative neuromodulators in the gut of Anguilla anguilla (L.. Localizations in the enteric nervous and endocrine systems

    Directory of Open Access Journals (Sweden)

    A Veggetti

    2009-12-01

    Full Text Available The gut of silver eels (Anguilla anguilla L. was investigated in order to describe both the cholinergic and adrenergic intramural innervations, and the localization of possible accessory neuromediators. Histochemical reactions for the demonstration of nicotinamide adenine dinucleotide phosphate, reduced form-(NADPH-diaphorase and acetylcholinesterese (AChEase were performed, as well as the immunohistochemical testing of tyrosine hydroxylase, met-enkephalin, substance P, calcitonin gene-related peptide (CGRP, bombesin, vasoactive intestinal peptide (VIP, neuropeptide Y (NPY, somatostatin, cholecystokinin-octapeptide (CCK-8, serotonin, cholineacetyltransferase. The results evidenced a different pattern in comparison with other vertebrates, namely mammals, and with other fish. Both NADPH-diaphorase and AChEase activities were histochemically detected all along the gut in the myenteric plexus, the inner musculature and the propria-submucosa. Tyrosine hydroxylase immunoreactivity was observed in the intestinal tract only, both in the myenteric plexus and in the inner musculature. Several neuropeptides (metenkephalin, CGRP, bombesin, substance P, VIP, NPY, somatostatin were, in addition, detected in the intramural innervation; some of them also in epithelial cells of the diffuse endocrine system (met-enkephalin, substance P, NPY, somatostatin. Serotonin was only present in endocrine cells. Tyrosine hydroxylase immunoreactivity was present in localizations to those of similar NADPHdiaphorase- reactivity, and in the same nerve bundles in which substance P- and CGRP-likeimmunoreactivities were detectable in the intestinal tract. In addition, NADPH-diaphorase-reactive neurons showed an anatomical relationship with AChEase-reactive nerve terminals, and a similar relationship existed between the latter and substance P-like immunoreactivity.

  1. In vivo evaluation of biosensors volumetric bio-distribution for measurement of metabolic activity by X-ray correlation, fluorescence, Cerenkov image and radioisotope

    International Nuclear Information System (INIS)

    Ramirez N, G. J.

    2016-01-01

    The aim of this study was to characterize the in vivo volumetric distribution of three folate based biosensors by different imaging modalities (X-ray, fluorescence, Cerenkov luminescence and radioisotopic imaging) through the development of a tri dimensional (3D) image reconstruction algorithm. The preclinical and multimodal Xtreme imaging system, with a Multimodal Animal Rotation System (Mars), was used to acquire bidimensional (2D) images, which were processed to obtain the 3D reconstruction. Images of mice at different times (biosensor distribution) were simultaneously obtained from the four imaging modalities. The filtered backprojection and inverse Radon transformation were used as main image-processing techniques. In the first instance, the algorithm developed in Mat lab was able to reconstruct in the 3D form the skeleton of the mice under study. Subsequently, the algorithm was able to get the volumetric profiles of 99m Tc-Folate-Bombesin (radioisotopic image), 177 Lu-Folate-Bombesin (Cerenkov image), and FolateRSense 680 (fluorescence image) in the tumors and kidneys of the mice. No significant differences were detected between the volumetric quantifications using the standard measurement techniques and the quantifications obtained with the proposal made in this study, nor between the volumetric uptakes in the structures of interest. With the structures reconstructed in the 3D form, the fusion of anatomical (as the skeleton) and functional structures derived from the images of the biosensors uptake was achieved The imaging 3D reconstruction algorithm can be easily extrapolated to different 2D acquisition-type images. This characteristic flexibility of the algorithm developed in this study is an advantage in comparison to similar reconstruction methods. (Author)

  2. Peptide conjugated polymeric nanoparticles as a carrier for targeted delivery of docetaxel.

    Science.gov (United States)

    Kulhari, Hitesh; Pooja, Deep; Shrivastava, Shweta; V G M, Naidu; Sistla, Ramakrishna

    2014-05-01

    The aim of this research work was to develop Bombesin peptide (BBN) conjugated, docetaxel loaded nanocarrier for the treatment of breast cancer. Docetaxel loaded nanoparticles (DNP) were prepared by solvent evaporation method using sodium cholate as surfactant. BBN was conjugated to DNP surface through covalent bonding. Both DNP and BBN conjugated DNP (BDNP) were characterized by various techniques such as dynamic light scattering, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and thermogravimetric analysis. The particle diameter and zeta potential of BDNP were 136±3.95 nm and -10.8±2.7 mV, respectively. The change in surface charge and FTIR studies confirmed the formation of amide linkage between BBN and DNP. AFM analysis showed that nanoparticles were spherical in shapes. In nanoparticles, docetaxel was present in its amorphous form as confirmed by DSC and PXRD analysis and was stable during the thermal studies. The formulations showed the sustained release of DTX over the period of 120 h. During cellular toxicity assay in gastrin releasing peptide receptor positive breast cancer cells (MDA-MB-231), BDNP were found to be 12 times more toxic than pure DTX and Taxotere. The IC50 value for DTX, Taxotere, DNP and BDNP was >375, >375, 142.23 and 35.53 ng/ml, respectively. The above studies showed that Bombesin conjugated nanocarrier system could be a promising carrier for active targeting of anticancer drugs in GRP receptor over expressing cancer cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. In vivo evaluation of biosensors volumetric bio-distribution for measurement of metabolic activity by X-ray correlation, fluorescence, Cerenkov image and radioisotope; Evaluacion in vivo de la biodistribucion volumetrica de biosensores para medicion de la actividad metabolica por correlacion de rayos X, fluorescencia, imagen Cerenkov y radioisotopica

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez N, G. J.

    2016-07-01

    The aim of this study was to characterize the in vivo volumetric distribution of three folate based biosensors by different imaging modalities (X-ray, fluorescence, Cerenkov luminescence and radioisotopic imaging) through the development of a tri dimensional (3D) image reconstruction algorithm. The preclinical and multimodal Xtreme imaging system, with a Multimodal Animal Rotation System (Mars), was used to acquire bidimensional (2D) images, which were processed to obtain the 3D reconstruction. Images of mice at different times (biosensor distribution) were simultaneously obtained from the four imaging modalities. The filtered backprojection and inverse Radon transformation were used as main image-processing techniques. In the first instance, the algorithm developed in Mat lab was able to reconstruct in the 3D form the skeleton of the mice under study. Subsequently, the algorithm was able to get the volumetric profiles of {sup 99m}Tc-Folate-Bombesin (radioisotopic image), {sup 177}Lu-Folate-Bombesin (Cerenkov image), and FolateRSense 680 (fluorescence image) in the tumors and kidneys of the mice. No significant differences were detected between the volumetric quantifications using the standard measurement techniques and the quantifications obtained with the proposal made in this study, nor between the volumetric uptakes in the structures of interest. With the structures reconstructed in the 3D form, the fusion of anatomical (as the skeleton) and functional structures derived from the images of the biosensors uptake was achieved The imaging 3D reconstruction algorithm can be easily extrapolated to different 2D acquisition-type images. This characteristic flexibility of the algorithm developed in this study is an advantage in comparison to similar reconstruction methods. (Author)

  4. Preparation of the radiopharmaceutical {sup 99m} Tc-HYNIC-[Lys{sup 3}]-BN; Preparacion del radiofarmaco {sup 99m} Tc-HYNIC-[Lys{sup 3}]-BN

    Energy Technology Data Exchange (ETDEWEB)

    Conde S, E. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, 50000 Toluca, Estado de Mexico (Mexico)

    2007-07-01

    In accordance with their design, the radiopharmaceuticals can be divided in three generations. The radiopharmaceuticals of third generation are used in nuclear medicine to obtain images of specific molecular targets, and they are only in their capacity to detect in vivo such specific biochemical places as receivers and enzymes. The receivers of regulator peptides are over expressed in numerous carcinogenic cells. Those receivers have been used as molecular targets of radiolabelled peptides to locate cancerous tumors. The small peptide bombesin (BN, 14 amino acids) it was isolated of the frog skin and it belongs to a wide neuropeptides group with many biological functions. The equivalent human is the liberator peptide of the gastrin (GRP, 27 amino acids) and his receivers (r-GRP) that are on expressed in the membranes of the tumor cells. The receiving subtype 2 of bombesin (receiving GRP) it is on expressed in several human tumors including breast, prostate, lung cells and pancreatic cancer. Some radiopharmaceuticals similar of BN has been developed that were prepared to be used in nuclear medicine for the detection of wicked tumors and to evidence prostate cancers, breast and of lymphatic nodules. A technique was developed to allow the conjugation of HYNIC-[Lys3]-BN that allowed to obtain this product with a high purity. The identity was determined by HPLC chromatography. It was necessary the validation of the method and the HPLC system, to assure that the results were reliable. Linearity, specificity, accuracy and precision parameters were analyzed, that are those required by the Mexican pharmacopoeia for chromatographic methods. With this conjugated a formulation for lyophilized kits were analyzed, with the purpose of obtaining a radiochemical purity, after the labelled one with {sup 99m}Tc, bigger to 95%; the components used in the nucleus-equipment should favor the conjugation of the {sup 99m}Tc by means of a ligands exchange between the tricine and the

  5. Preparation of the radiopharmaceutical 99m Tc-HYNIC-[Lys3]-BN

    International Nuclear Information System (INIS)

    Conde S, E.

    2007-01-01

    In accordance with their design, the radiopharmaceuticals can be divided in three generations. The radiopharmaceuticals of third generation are used in nuclear medicine to obtain images of specific molecular targets, and they are only in their capacity to detect in vivo such specific biochemical places as receivers and enzymes. The receivers of regulator peptides are over expressed in numerous carcinogenic cells. Those receivers have been used as molecular targets of radiolabelled peptides to locate cancerous tumors. The small peptide bombesin (BN, 14 amino acids) it was isolated of the frog skin and it belongs to a wide neuropeptides group with many biological functions. The equivalent human is the liberator peptide of the gastrin (GRP, 27 amino acids) and his receivers (r-GRP) that are on expressed in the membranes of the tumor cells. The receiving subtype 2 of bombesin (receiving GRP) it is on expressed in several human tumors including breast, prostate, lung cells and pancreatic cancer. Some radiopharmaceuticals similar of BN has been developed that were prepared to be used in nuclear medicine for the detection of wicked tumors and to evidence prostate cancers, breast and of lymphatic nodules. A technique was developed to allow the conjugation of HYNIC-[Lys3]-BN that allowed to obtain this product with a high purity. The identity was determined by HPLC chromatography. It was necessary the validation of the method and the HPLC system, to assure that the results were reliable. Linearity, specificity, accuracy and precision parameters were analyzed, that are those required by the Mexican pharmacopoeia for chromatographic methods. With this conjugated a formulation for lyophilized kits were analyzed, with the purpose of obtaining a radiochemical purity, after the labelled one with 99m Tc, bigger to 95%; the components used in the nucleus-equipment should favor the conjugation of the 99m Tc by means of a ligands exchange between the tricine and the

  6. Absorbed dose at subcellular level by Monte Carlo simulation for a {sup 99m}Tc-peptide with nuclear internalization

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L.; Ferro F, G. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Santos C, C. L., E-mail: leticia.rojas@inin.gob.m [Universidad Autonoma del Estado de Mexico, Paseo Tollocan esquina Paseo Colon s/n, Toluca 50120, Estado de Mexico (Mexico)

    2010-10-15

    The utility of radiolabeled peptides for the early and specific diagnosis of cancer is being investigated around the world. Recent investigations have demonstrated the specificity of {sup 99m}Tc-bombesin conjugates to target breast and prostate cancer cells. The novel idea of adding the Tat (49-57) peptide to the radiopharmaceutical in order to penetrate the cell nucleus is a new proposal for therapy at cellular level. {sup 99m}Tc radionuclide produces Auger energy of 0.9 keV/decay and internal conversion electron energy of 15.4 keV/decay, which represent 11.4% of the total {sup 99m}Tc energy released per decay. It is expected that the dose delivered at specific microscopic levels in cancer cells induce a therapeutic effect. The aim of this research was to assess in vitro internalization kinetics in breast and prostate cancer cells of {sup 99m}Tc-Tat(49-57)-bombesin and to evaluate the radiation absorbed dose at subcellular level simulating the electron transport. The pen main program from the 2006 version of the Penelope code was used to simulate and calculate the absorbed dose by Auger and internal conversion electron contribution in the membrane, cytoplasm and nucleus of Pc-3 prostate cancer and MCF7 and MDA human breast cancer cell lines. Nuclear data were obtained from the 2002 BNM-LNHB {sup 99m}Tc decay scheme. The spatial distribution of the absorbed doses to the membrane, cytoplasm and nucleus were calculated using a geometric model built from real images of cancer cells. The elemental cell composition was taken from the literature. The biokinetic data were obtained evaluating total disintegrations in each subcellular compartment by integration of the time-activity curves acquired from experimental data. Results showed that 61, 63 and 46% of total disintegrations per cell-bound {sup 99m}Tc-Tat-Bn activity unit occurred in the nucleus of Pc-3, MCF7 and MDA-MB231 respectively. {sup 99m}Tc--Tat-Bn absorbed doses were 1.78, 5.76 and 2.59 Gy/Bq in the nucleus of

  7. Calculus of spatial distribution of absorbed dose to cellular level by Monte Carlo simulation for a radio-labelled peptide with {sup 188}Re and with nuclear internalization : preliminary results; Calculo de la distribucion espacial de dosis absorbida a nivel celular por simulacion Monte Carlo para un peptido radiomarcado con {sup 188}Re y con internalizacion nuclear : resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Santos C, C. L. [Universidad Autonoma del Estado de Mexico, Paseo Tollocan y Jesus Carranza, Toluca 50120, Estado de Mexico (Mexico)], e-mail: leticia.rojas@inin.gob.mx

    2009-10-15

    The {sup 188}Re is a radionuclide of radiation gamma emitter, useful in obtaining of gamma-graphic images, but it is also emitter of beta radiations and Auger electrons. A bio-molecule directed to a specific receptor of a cancer cell labeled with a emitter radionuclide of beta particles and Auger electrons, as the {sup 188}Re-Tat-Bombesin, it has the potential to be used in radiotherapy of molecular targets for its capacity to penetrate to cellular nucleus. In this system, the radiation dose is distributed in way located at microscopic levels in sub cellular specific places, where Auger emissions contributes of significant way in absorbed dose. The cellular dosimetry is realized in most of cases, using analytic or semi analytical methods, for example the cellular MIRD methodology. However, it is required to complement these calculations simulating the electrons transport and considering experimental bio kinetics data. Therefore, in this work preliminary results are presented of dosimetric calculation to sub cellular level for {sup 188}Re-Tat-Bombesin by Monte Carlo simulation, using the 2008 version of PENELOPE: PENEASY code. The spatial distribution of absorbed dose in membrane, cytoplasm and nucleus, was calculated with geometry of a cell of 10 {mu}m of diameter, a nucleus of 2 {mu}m of ratio and membrane of 0.2 {mu}m of thickness, considering elementary constitution for each cellular compartment proposal in literature. The total number of disintegrations at sub cellular level was evaluated integrating the activity in function of time starting from experimental bio kinetics data in mamma cancer cells MDA-MB231. The preliminary results show that 46.4% of total disintegrations for unit of captured activity by cell occurs in nucleus, 38.4% in membrane and 15.2% in cytoplasm. The due absorbed dose to Auger electrons for 1 Bq of {sup 188}Re located in cellular membrane were respectively of 1.32E-1 and 1.43E-1 Gy in cytoplasm and nucleus. (Author)

  8. Convergent signalling in the action of integrins, neuropeptides, growth factors and oncogenes.

    Science.gov (United States)

    Rozengurt, E

    1995-01-01

    These findings have important implications for signal transduction and cell regulation. Most obviously, they suggest that tyrosine phosphorylation of a novel type of tyrosine kinase p125FAK is a point of convergence in the action of integrins, oncogenic forms of pp60src, mitogenic neuropeptides and growth factors (Fig. 3). One inference is that the signal transduction pathways initiated by these diverse groups of molecules have, at least in part, similar consequences for cellular function. The notion of convergence is reinforced by the striking similarity in the overall pattern of tyrosine phosphorylation produced through these different pathways. It is tempting to speculate that p125FAK, paxillin and p130 are components in a common programme of phosphorylation events stimulated by integrins, mitogenic neuropeptides and growth factors. The localization of p125FAK to focal adhesions is clearly consistent with a role for this protein as a junction point in the transduction of signals that regulate cell substrate adhesion and ultimately cell motility and cell shape, as suggested in Fig. 3. The existence of distinct pathways leading to p125FAK phosphorylation raises the possibility of synergistic interactions between integrins and G protein coupled receptors. In fact, integrin mediated p125FAK tyrosine phosphorylation appears to be mediated by a PKC dependent pathway (Vuori and Ruoslathi, 1993). By contrast, bombesin and LPA induce tyrosine phosphorylation of p125FAK and paxillin through a PKC independent pathway (Sinnett-Smith et al, 1993; Zachary et al, 1993; Seufferlein and Rozengurt, 1994). It is possible that tyrosine phosphorylation of p125FAK by bombesin, LPA and pp60v-src bypasses and perhaps mimics the phosphorylation caused by integrin activation. Further experimental work will be required to elucidate whether integrins and neuropeptides increase the autophosphorylation of Tyr-397 in p125FAK, as has been recently demonstrated in src-transformed cells

  9. Effect of endogenous cholecystokinin on the course of acute pancreatitis in rats.

    Science.gov (United States)

    Jia, Dongmei; Yamamoto, Mitsuyoshi; Otsuki, Makoto

    2015-07-07

    To examine the effects of pancreatic rest, stimulation and rest/stimulation on the natural course of recovery after acute pancreatitis. Acute hemorrhagic pancreatitis (AP) was induced in male rats by intraductal infusion of 40 μL/100 g body weight of 3% sodium taurocholate. All rats took food ad libitum. At 24 h after induction of AP, rats were divided into four groups: control (AP-C), pancreas rest (AP-R), stimulation (AP-S), and rest/stimulation (AP-R/S). Rats in the AP-C, AP-R and AP-S groups received oral administration of 2 mL/kg body weight saline, cholecystokinin (CCK)-1 receptor antagonist, and endogenous CCK release stimulant, respectively, twice daily for 10 d, while those in the AP-R/S group received twice daily CCK-1 receptor antagonist for the first 5 d followed by twice daily CCK release stimulant for 5 d. Rats without any treatment were used as control group (Control). Biochemical and histological changes in the pancreas, and secretory function were evaluated on day 12 at 24 h after the last treatment. Feeding ad libitum (AP-C) delayed biochemical, histological and functional recovery from AP. In AP-C rats, bombesin-stimulated pancreatic secretory function and HOMA-β-cell score were significantly lower than those in other groups of rats. In AP-R rats, protein per DNA ratio and pancreatic exocrine secretory function were significantly low compared with those in Control rats. In AP-S and AP-R/S rats, the above parameters recovered to the Control levels. Bombesin-stimulated pancreatic exocrine response in AP-R/S rats was higher than in AP-S rats and almost returned to control levels. In the pancreas of AP-C rats, destruction of pancreatic acini, marked infiltration of inflammatory cells, and strong expression of α-smooth muscle actin, tumor necrosis factor-α and interleukin-1β were seen. Pancreatic rest reversed these histological alterations, but not atrophy of pancreatic acini and mild infiltration of inflammatory cells. In AP-S and AP-R/S rats

  10. Paul Scherrer Institut Scientific Report 2001. Volume II: Life Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Jaussi, R.; Gschwend, B. (eds.)

    2002-03-01

    The IMR group investigated some new approaches to tumour therapy. Several candidate molecules for targeting the tumour vasculature have been identified and are being produced for in vivo studies in tumour-bearing mice. The liposome technology is well established in this group and the goal is to produce suitably tagged liposomes for delivering a variety of cytotoxic agents to tumours. The Centre for Radiopharmaceutical Science, a joint venture with the ETH Zurich and the University of Zurich, pursues a number of projects that should eventually lead to novel radiopharmaceuticals for tumour diagnosis and therapy. Functionally, these radioactive drugs consist of a tumour targeting part, a radionuclide and a linking moiety, which stably connects the two. Optimisation of the components and their combination in terms of in vitro and in vivo properties as well as the efficient large-scale production of promising candidates for eventual first clinical trials is a demanding task. The major emphasis is still on using antibodies, antibody derivatives or peptides as tumour targeting vehicles. In collaboration with the Queens Medical Centre Nottingham, the first patients were treated with a {sup 67}Cu labelled antibody targeting bladder carcinomas. When completed, these studies should give us important information on the usefulness of {sup 67}Cu as a therapeutic radionuclide. Neuropeptides such as neurotensin and bombesin are promising starting points for tumour targeting as their receptors are over expressed on certain tumour cells. Presently, the efforts concentrate on preparing for further clinical studies with neurotensin derivatives (diagnosis of pancreatic tumours using {sup 99m}Tc) and further improving the stability and pharmacological properties of bombesin derivatives. In both these projects the ultimate goal is to label the optimised compounds with {sup 186}Re, a therapeutic radionuclide that can be attached in the stable tricarbonyl form which is easily accessible by

  11. Gut hormones in Salamandra salamandra. An immunocytochemical and electron microscopic investigation.

    Science.gov (United States)

    Buchan, A M; Polak, J M; Pearse, A G

    1980-01-01

    Histological, cytochemical and immunocytochemical methods were used in light and electron microscopical studies to demonstrate the presence of a neuroendocrine system in the gut of the urodele, Salamandra salamandra. Cytochemical stains capable of detecting peptide-producing endocrine cells demonstrate cells reacting with Masson's silver (argentaffin) method, Grimelius' argyrophil silver method, masked metachromasia method and the lead haematoxylin stain. Using antisera raised to a variety of mammalian gut peptides, cells containing bombesin-, gastrin-, somatostatin-, substance P- and glucagon-like immunoreactivity were indentified; vasoactive intestinal polypeptide- and substance P-like immunoreactivities were found in nerve fibres in the submucous and myenteric plexus. No immunoreactivity was detected from motilin, gastric inhibitory polypeptide, cholecystokinin or secretin. The ultrastructure of the immunoreactive cells and nerves was revealed by the semithin/thin method. All the cells indentified contained numerous electrondense secretory granules, which varied in their characteristic morphological structure from one cell type to another. The evidence collected in this study indicates that a complex neuroendocrine system regulating gut function is present in this amphibian and may have developed prior to the emergence of the phylum.

  12. Identification and characterisation in vitro of cells with a non-SCLC cell-like phenotype derived from a continuous SCLC cell line.

    Science.gov (United States)

    Khan, M Z; Freshney, R I; Murray, A M; Merry, S; Plumb, J A; McNicol, A M

    1991-01-01

    Two adherent sublines, H69V and H69VZ, have been isolated from the classic SCLC cell line NCI-H69. Significant morphological differences were observed between the parental and the derivative cell lines. While NCI-H69 grew as densely packed free floating cellular aggregates the derivative lines grew as a monolayer of epithelioid cells. The growth rates of both the derivative lines were faster than the parental line with doubling times closer to non-SCLC cell lines in the derivative lines. Both H69V and H69VZ either express very low levels or do not express neuroendocrine cell markers including L-dopa-decarboxylase (DDC), creatine kinase-BB isoenzyme (CK-BB), bombesin-like immunoreactivity (BLI), neuron specific enolase (NSE), and neurosecretory type dense core granules (DGCs), compared to the parental cell line. All the lines stained positive for epithelial markers such as CAM5.2. LDH isoenzyme and chromosome analyses confirmed the human origin of all the cell lines. Therefore, it appears that cell line NCI-H69 contains stem cell subpopulation capable of generating cells of both small and non-small cell like phenotypes.

  13. New Insights in the Design of Bioactive Peptides and Chelating Agents for Imaging and Therapy in Oncology

    Directory of Open Access Journals (Sweden)

    Anna Lucia Tornesello

    2017-08-01

    Full Text Available Many synthetic peptides have been developed for diagnosis and therapy of human cancers based on their ability to target specific receptors on cancer cell surface or to penetrate the cell membrane. Chemical modifications of amino acid chains have significantly improved the biological activity, the stability and efficacy of peptide analogues currently employed as anticancer drugs or as molecular imaging tracers. The stability of somatostatin, integrins and bombesin analogues in the human body have been significantly increased by cyclization and/or insertion of non-natural amino acids in the peptide sequences. Moreover, the overall pharmacokinetic properties of such analogues and others (including cholecystokinin, vasoactive intestinal peptide and neurotensin analogues have been improved by PEGylation and glycosylation. Furthermore, conjugation of those peptide analogues to new linkers and bifunctional chelators (such as AAZTA, TETA, TRAP, NOPO etc., produced radiolabeled moieties with increased half life and higher binding affinity to the cognate receptors. This review describes the most important and recent chemical modifications introduced in the amino acid sequences as well as linkers and new bifunctional chelators which have significantly improved the specificity and sensitivity of peptides used in oncologic diagnosis and therapy.

  14. Receptor binding peptides for target-selective delivery of nanoparticles encapsulated drugs.

    Science.gov (United States)

    Accardo, Antonella; Aloj, Luigi; Aurilio, Michela; Morelli, Giancarlo; Tesauro, Diego

    2014-01-01

    Active targeting by means of drug encapsulated nanoparticles decorated with targeting bioactive moieties represents the next frontier in drug delivery; it reduces drug side effects and increases the therapeutic index. Peptides, based on their chemical and biological properties, could have a prevalent role to direct drug encapsulated nanoparticles, such as liposomes, micelles, or hard nanoparticles, toward the tumor tissues. A considerable number of molecular targets for peptides are either exclusively expressed or overexpressed on both cancer vasculature and cancer cells. They can be classified into three wide categories: integrins; growth factor receptors (GFRs); and G-protein coupled receptors (GPCRs). Therapeutic agents based on nanovectors decorated with peptides targeting membrane receptors belonging to the GPCR family overexpressed by cancer cells are reviewed in this article. The most studied targeting membrane receptors are considered: somatostatin receptors; cholecystokinin receptors; receptors associated with the Bombesin like peptides family; luteinizing hormone-releasing hormone receptors; and neurotensin receptors. Nanovectors of different sizes and shapes (micelles, liposomes, or hard nanoparticles) loaded with doxorubicin or other cytotoxic drugs and externally functionalized with natural or synthetic peptides are able to target the overexpressed receptors and are described based on their formulation and in vitro and in vivo behaviors.

  15. Exendin-4, a new peptide from Heloderma suspectum venom, potentiates cholecystokinin-induced amylase release from rat pancreatic acini.

    Science.gov (United States)

    Malhotra, R; Singh, L; Eng, J; Raufman, J P

    1992-09-22

    We examined the actions of exendin-4, a new peptide isolated from Heloderma suspectum venom, on dispersed acini from rat pancreas. Exendin-4 caused a 3-fold increase in cAMP but did not alter cellular calcium concentration. Exendin-4-induced increases in cAMP were inhibited by an exendin-receptor antagonist, exendin (9-39)NH2, but not by VIP-receptor antagonists. Whereas up to 1 microM exendin-4 alone did not alter amylase release, potentiation of enzyme release was observed when the peptide (greater than 30 pM) was combined with cholecystokinin. Potentiation of amylase release was also observed when exendin-4 was combined with carbamylcholine, bombesin or a calcium ionophore, A23187. These results indicate that stimulation of exendin receptors on rat pancreatic acini causes an increase in cellular cAMP. Although this increase in cAMP alone does not result in amylase release, combination of exendin-4 with agents that increase cell calcium results in potentiation of amylase release.

  16. Effects of organic solvent and cationic additive on capillary electrophoresis of peptides

    International Nuclear Information System (INIS)

    Surugau, L.N.; Bergstrom, Ed T.

    2008-01-01

    Capillary electrophoresis (CE) of nine peptides namely, bradykinin, bradykinin fragment 1-5, substance P, Arg 8 -vasopressin, luteinizing hormone-releasing hormone (LHRH), bombesin, leucine-enkephalin, methionine-enkephalin and oxytocin were carried out using 0.5 % and 1.0 % formic acid (FA) as the separation buffers, added with acetonitrile (ACN) and triethylamine (TEA) as an additive at low pH. The electrophoretic behaviour of these peptides was examined at different concentration of TEA (0, 10, 20, 30, 40 and 50 mM), and ACN (30, 40, 50, 60, 70 %) at their respective measured final pH. The results showed that all nine peptides were fully resolved with addition of 10 - 20 mM TEA. Peak efficiency was improved significantly by increasing TEA concentration up to 40 mM where 800 000 m -1 was obtained. Without TEA, the closely related enkephalins were co-migrating. Interestingly, by addition of as little as 5 mM TEA has sufficient to separate them almost at baseline. Increasing ACN to 40 % has shortened the analysis time by ca. 1 min. However, further increase of ACN can cause peak broadening and current instability. (author)

  17. Effects of organic solvent and cationic additive on capillary electrophoresis of peptides

    International Nuclear Information System (INIS)

    Surugau, L.N.; Bergstrom, E.T.

    2008-01-01

    Capillary electrophoresis (CE) of nine peptides namely, bradykinin, bradykinin fragment 1-5, substance P, Arg 8 -vasopressin, luteinizing hormone-releasing hormone (LHRH), bombesin, leucine-enkephalin, methionine-enkephalin and oxytocin were carried out using 0.5 % and 1.0 % formic acid (FA) as the separation buffers, added with acetonitrile (ACN) and triethylamine (TEA) as an additive at low pH. The electrophoretic behavior of these peptides was examined at different concentration of TEA (0, 10, 20, 30, 40 and 50 mM), and ACN (30, 40, 50, 60, 70 %) at their respective measured final pH. The results showed that all nine peptides were fully resolved with addition of 10-20 mM TEA. Peak efficiency was improved significantly by increasing TEA concentration up to 40 mM where 800 000 m -1 was obtained. Without TEA, the closely related enkephalins were co-migrating. Interestingly, by addition of as little as 5 mM TEA has sufficient to separate them almost at baseline. Increasing ACN to 40 % has shortened the analysis time by ca. 1 min. However, further increase of ACN can cause peak broadening and current instability. (author)

  18. More α Than β for Prostate Cancer?

    International Nuclear Information System (INIS)

    Fendler, Wolfgang P.; Cutler, Cathy

    2017-01-01

    Radionuclide therapy for prostate cancer started more than 70 y ago (1). Nuclear medicine has since evolved considerably to provide a multitude of new imaging and therapy options. The past decade witnessed an unprecedented expansion of radioligands for prostate cancer. Milestones include the first α-emitter for treatment of symptomatic bone metastases (2) and theranostic vectors directed at the prostate-specific membrane antigen (PSMA) or bombesin receptor (3–5). However, current radionuclide therapies are applied at a late stage of the disease aiming at palliation. Despite recent advances for treatment of metastatic prostate cancer, cure remains an unmet need of the 21st century. Cancer spreads early and develops slowly as submillimeter occult lesions. Lesions grow at distant sites and become detectable only when significant morphologic or metabolic alterations have formed, often years to decades after the initial spread (6). Effective ablation of small metastases is critical for cure and presents a specific challenge for β-emitting radionuclide therapy. Millimeter-range β-particles deliver insufficient amounts of radiation to millimeter-size tumor lesions, as energy deposition extends and dilutes beyond lesion boundaries (Fig. 1). α-radiation, because of its micrometer range, targets millimeter-size tumor volumes at higher relative yield (Fig. 1). Further evidence points to a superior biologic effectiveness for α-therapy based on high-linear-energy transfer resulting in frequent double-strand DNA breaks (7). However, are basic advantages of α-therapy associated with a clinical benefit?

  19. Conformational Dynamics of the Focal Adhesion Targeting Domain Control Specific Functions of Focal Adhesion Kinase in Cells

    KAUST Repository

    Kadaré, Gress

    2015-01-02

    Focal adhesion (FA) kinase (FAK) regulates cell survival and motility by transducing signals from membrane receptors. The C-terminal FA targeting (FAT) domain of FAK fulfils multiple functions, including recruitment to FAs through paxillin binding. Phosphorylation of FAT on Tyr925 facilitates FA disassembly and connects to the MAPK pathway through Grb2 association, but requires dissociation of the first helix (H1) of the four-helix bundle of FAT. We investigated the importance of H1 opening in cells by comparing the properties of FAK molecules containing wild-type or mutated FAT with impaired or facilitated H1 openings. These mutations did not alter the activation of FAK, but selectively affected its cellular functions, including self-association, Tyr925 phosphorylation, paxillin binding, and FA targeting and turnover. Phosphorylation of Tyr861, located between the kinase and FAT domains, was also enhanced by the mutation that opened the FAT bundle. Similarly phosphorylation of Ser910 by ERK in response to bombesin was increased by FAT opening. Although FAK molecules with the mutation favoring FAT opening were poorly recruited at FAs, they efficiently restored FA turnover and cell shape in FAK-deficient cells. In contrast, the mutation preventing H1 opening markedly impaired FAK function. Our data support the biological importance of conformational dynamics of the FAT domain and its functional interactions with other parts of the molecule.

  20. Transient disruption of fear-related memory by post-retrieval inactivation of gastrin-releasing peptide or N-methyl-D-aspartate receptors in the hippocampus.

    Science.gov (United States)

    Luft, Tatiana; Amaral, Olavo B; Schwartsmann, Gilberto; Roesler, Rafael

    2008-02-01

    Molecular accounts of memory consolidation suggest that new learning generates persistent synaptic modifications through activation of an extensive set of neuronal receptors and intracellular signal transduction pathways, accompanied by RNA and protein synthesis. This traditional cellular consolidation theory has been challenged by evidence that reactivation of a previously consolidated memory might render this memory again susceptible to disruption by amnesic treatments, a process generally referred to as reconsolidation. Current evidence indicates that reconsolidation can be disrupted by administration of a variety of pharmacological agents after memory reactivation. Previous studies have indicated that the gastrin-releasing preferring type of bombesin receptor (GRPR) and the N-methyl-D-aspartate glutamate receptor (NMDAR) in the rat hippocampus are involved in consolidation of inhibitory avoidance (IA), a fear-related memory task. We show here that blockade of hippocampal GRPRs or NMDARs after memory reactivation temporarily disrupts memory retention. Post-retrieval intra-hippocampal infusion of the GRPR antagonist RC-3095 or the NMDAR antagonist aminophosphonopentanoic acid (AP5) produced an impairment of IA performance tested 2 days after training in rats. However, this impairment was transient and recovered to levels of control rats in a subsequent test 3 days after training. The drug effects were only present after memory reactivation and not in its absence. These findings provide evidence that GRPR or NMDAR inactivation after retrieval can impair fear memory.

  1. Long-term high-soybean oil feeding alters regulation of body temperature in rats.

    Science.gov (United States)

    Tsushima, Hiromi; Yamada, Kazuyo; Miyazawa, Daisuke; Mori, Mayumi; Hashimoto, Yoko; Ohkubo, Takeshi; Hibino, Hidehiko; Okuyama, Harumi

    2014-01-01

    We investigated whether body temperature (BT) regulatory mechanisms are influenced by dietary fatty acids (FA). Male Wistar rats were fed a high-fat diet containing fish oil (HFD), soybean oil (HSD) or lard (HLD). At the 20-week intervention, the BT of the HSD and HLD groups were lower than that of the normal diet (ND) group in the light and dark periods. The intracerebroventricular injections of interleukin-1β and bombesin in the HSD group induced greater hyperthermia and weaker hypothermia, respectively, than in the ND group. The HSD differentially affected BT under both physiological and pharmacological conditions. In the hypothalamus, the ratio of n-6/n-3 FAs was higher in the HSD group compared with the ND group. DNA microarrays revealed increased expression of thyroid-stimulating hormone β-subunit, and decreased expression of several genes in the hypothalamus of the HSD group compared with the ND group. The HSD feeding increased several adipokine concentrations in the plasma. However, there were no adipokines or gene expressions that changed in only the HSD and HLD groups showing significant hypothermia under the physiological condition. These findings suggested that long-term HSD intake produces abnormal BT regulation. It is less likely that adipokines or proteins/peptides are involved in abnormal BT regulation under the physiological conditions after HSD feeding.

  2. Automated synthesis, characterization and biological evaluation of [{sup 68}Ga]Ga-AMBA, and the synthesis and characterization of {sup nat}Ga-AMBA and [{sup 67}Ga]Ga-AMBA

    Energy Technology Data Exchange (ETDEWEB)

    Cagnolini, Aldo; Chen Jianqing; Ramos, Kimberly; Marie Skedzielewski, Tina; Lantry, Laura E.; Nunn, Adrian D.; Swenson, Rolf E. [Ernst Felder Laboratories, Bracco Research USA Inc., 305 College Road East, Princeton, NJ 08540 (United States); Linder, Karen E., E-mail: karen.e.linder@gmail.co [Ernst Felder Laboratories, Bracco Research USA Inc., 305 College Road East, Princeton, NJ 08540 (United States)

    2010-12-15

    Ga-AMBA (Ga-DO3A-CH{sub 2}CO-G-[4-aminobenzoyl]-QWAVGHLM-NH{sub 2}) is a bombesin-like agonist with high affinity for gastrin releasing peptide receptors (GRP-R). Syntheses for {sup nat}Ga-AMBA, [{sup 67}Ga]Ga-AMBA and [{sup 68}Ga]Ga-AMBA were developed. The preparation of HPLC-purified and Sep-Pak purified [{sup 68}Ga]Ga-AMBA were fully automated, using the built-in radiodetector of the Tracerlab FX F-N synthesizer to monitor fractionated {sup 68}Ge/{sup 68}Ga generator elution and purification. The total synthesis time, including the fractional elution of the generator, was 20 min for Sep-Pak purified material and 40 min for HPLC-purified [{sup 68}Ga]Ga-AMBA. Both [{sup 67}Ga]Ga-AMBA and [{sup 177}Lu]Lu-AMBA showed comparable high affinity for GRP-R in the human prostate cancer cell line PC-3 in vitro (k{sub D}=0.46{+-}0.07; 0.44{+-}0.08 nM), high internalization (78; 77%) and low efflux from cells at 2 h (2.4{+-}0.7; 2.9{+-}1.8%). Biodistribution results in PC-3 tumor-bearing male nude mice showed comparable uptake for [{sup 177}Lu]Lu-, [{sup 111}In]In-, [{sup 67}Ga]Ga- and [{sup 68}Ga]Ga-AMBA.

  3. A solvent resistant lab-on-chip platform for radiochemistry applications.

    Science.gov (United States)

    Rensch, Christian; Lindner, Simon; Salvamoser, Ruben; Leidner, Stephanie; Böld, Christoph; Samper, Victor; Taylor, David; Baller, Marko; Riese, Stefan; Bartenstein, Peter; Wängler, Carmen; Wängler, Björn

    2014-07-21

    The application of microfluidics to the synthesis of Positron Emission Tomography (PET) tracers has been explored for more than a decade. Microfluidic benefits such as superior temperature control have been successfully applied to PET tracer synthesis. However, the design of a compact microfluidic platform capable of executing a complete PET tracer synthesis workflow while maintaining prospects for commercialization remains a significant challenge. This study uses an integral system design approach to tackle commercialization challenges such as the material to process compatibility with a path towards cost effective lab-on-chip mass manufacturing from the start. It integrates all functional elements required for a simple PET tracer synthesis into one compact radiochemistry platform. For the lab-on-chip this includes the integration of on-chip valves, on-chip solid phase extraction (SPE), on-chip reactors and a reversible fluid interface while maintaining compatibility with all process chemicals, temperatures and chip mass manufacturing techniques. For the radiochemistry device it includes an automated chip-machine interface enabling one-move connection of all valve actuators and fluid connectors. A vial-based reagent supply as well as methods to transfer reagents efficiently from the vials to the chip has been integrated. After validation of all those functional elements, the microfluidic platform was exemplarily employed for the automated synthesis of a Gastrin-releasing peptide receptor (GRP-R) binding the PEGylated Bombesin BN(7-14)-derivative ([(18)F]PESIN) based PET tracer.

  4. Evaluation of the internalization kinetics of the radiopharmaceutical {sup 99m}Tc-N{sub 2}S{sub 2}-Tat(49-57)Lys{sup 3}-Bn with diagnostic purposes, using comet assay; Evaluacion de la cinetica de internalizacion del radiofarmaco {sup 99m}Tc-N{sub 2}S{sub 2}-TAT(49-57)Lys{sup 3}-BN con fines diagnosticos, empleando ensayo cometa

    Energy Technology Data Exchange (ETDEWEB)

    Luna G, M. A.

    2011-07-01

    Gastrin-rea leasing peptide receptors (GRP-r) are over expressed in breast and prostate cancer cells. Bombesin (Bn) binds specifically and strongly to GRP-r and this is the base for to label the Bn with radionuclides by gamma rays. Tat (49-57) is a peptide that across the cell membrane easily so that, when it is conjugated to different proteins, it can works as a Trojan horse, facilitating the drug internalization to the cells. The radiopharmaceutical {sup 99m}Tc-N{sub 2}S{sub 2}-Tat(49-57)-Lys{sup 3}-Bn was prepared for diagnosis and therapy at early stage of breast cancer. The objective of this study was to determine the role of Tat in the internalization kinetics of radiopharmaceuticals measured by DNA damage induced by means of comet assay. Human lymphocytes were treated with the following protocols: a) Tat-Bn, b) {sup 99m}Tc-Bn, or c) {sup 99m}Tc-N{sub 2}S{sub 2}-Tat(49-57)-Lys{sup 3}-Bn, also an untreated group was conformed. The internalization was evaluated at 0, 5, 10, 15, 30 and 60 min after exposure with three repetitions each one, and for radiopharmaceuticals with 2.9, 6.6, 9.0 and 14.8 MBq activities. DNA damage was scored in 100 cells per time and treatment, as tail length and tail moment. A Kruskal-Wallis variance analysis with p{<=} 0.05 was applied for comparison between treatments. The results showed that the damage caused by {sup 99m}Tc-N{sub 2}S{sub 2}-Tat(49-57)-Lys{sup 3}-Bn is significantly higher than that caused by {sup 99m}Tc-Bn and Tat-Bn, showing that Tat favors the internalization of the radiopharmaceutical. (Author)

  5. Effects of Enteromyxum scophthalmi experimental infection on the neuroendocrine system of turbot, Scophthalmus maximus (L.).

    Science.gov (United States)

    Losada, A P; Bermúdez, R; Faílde, L D; Di Giancamillo, A; Domeneghini, C; Quiroga, M I

    2014-10-01

    Enteromyxum scophthalmi is an intestinal myxosporean parasite responsible for serious outbreaks in turbot Scophthalmus maximus (L.) culture, in North-western Spain. The disease affects the digestive tract, provokes severe catarrhal enteritis, emaciation and high rates of mortality. The digestive parasitization triggers a response with the coordinate participation of immune and neuroendocrine systems through the action of peptides released by enteroendocrine cells and present in nervous elements, acting as neuro-immune modulators. The present study was designed to assess the response of the turbot neuroendocrine system against E. scophthalmi infection. Immunohistochemical tests were applied to sections of the gastrointestinal tract of uninfected and E. scophthalmi-infected turbot to characterize the presence of bombesin (BOM), glucagon (GLUC), somatostatin (SOM), leu-enkephalin (LEU) and met-enkephalin (MET). The occurrence of E. scophthalmi in the turbot gastrointestinal tract increased the number of enteroendocrine cells immunoreactive to SOM, LEU and MET. On the other hand, BOM and GLUC immunoreactive cells were less numerous in the gastrointestinal tract of the parasitized turbot. Scarce immunoreactivity to BOM, GLUC and SOM was observed in nerve fibres and neurons of the myenteric plexus of control and infected fish. The results indicate that E. scophthalmi infection in turbot induced changes in the neuroendocrine system, with the diminution of the anorexigenic peptides BOM and GLUC; the increase of enkephalins, related to pro-inflammatory processes; and the increase of SOM, which may cause inhibitory effects on the immune response, constituting a compensatory mechanism to the exacerbated response observed in E. scophthalmi-infected turbot. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Cancer therapy with alpha-emitters labeled peptides.

    Science.gov (United States)

    Dadachova, Ekaterina

    2010-05-01

    Actively targeted alpha-particles offer specific tumor cell killing action with less collateral damage to surrounding normal tissues than beta-emitters. During the last decade, radiolabeled peptides that bind to different receptors on the tumors have been investigated as potential therapeutic agents both in the preclinical and clinical settings. Advantages of radiolabeled peptides over antibodies include relatively straightforward chemical synthesis, versatility, easier radiolabeling, rapid clearance from the circulation, faster penetration and more uniform distribution into tissues, and less immunogenicity. Rapid internalization of the radiolabeled peptides with equally rapid re-expression of the cell surface target is a highly desirable property that enhances the total delivery of these radionuclides into malignant sites. Peptides, such as octreotide, alpha-melanocyte-stimulating hormone analogues, arginine-glycine-aspartic acid-containing peptides, bombesin derivatives, and others may all be feasible for use with alpha-emitters. The on-going preclinical work has primarily concentrated on octreotide and octreotate analogues labeled with Bismuth-213 and Astatine-211. In addition, alpha-melanocyte-stimulating hormone analogue has been labeled with Lead-212/Bismuth-212 in vivo generator and demonstrated the encouraging therapeutic efficacy in treatment of experimental melanoma. Obstacles that continue to obstruct widespread acceptance of alpha-emitter-labeled peptides are primarily the supply of these radionuclides and concerns about potential kidney toxicity. New sources and methods for production of these medically valuable radionuclides and better understanding of mechanisms related to the peptide renal uptake and clearance should speed up the introduction of alpha-emitter-labeled peptides into the clinic. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Central ventilatory and cardiovascular actions of trout gastrin-releasing peptide (GRP in the unanesthetized trout

    Directory of Open Access Journals (Sweden)

    Jean-Claude Le Mével

    2013-07-01

    Gastrin-releasing peptide (GRP, a neuropeptide initially isolated from porcine stomach, shares sequence similarity with bombesin. GRP and its receptors are present in the brains and peripheral tissues of several species of teleost fish, but little is known about the ventilatory and cardiovascular effects of this peptide in these vertebrates. The goal of this study was to compare the central and peripheral actions of picomolar doses of trout GRP on ventilatory and cardiovascular variables in the unanesthetized rainbow trout. Compared to vehicle, intracerebroventricular (ICV injection of GRP (1–50 pmol significantly elevated the ventilation rate (ƒV and the ventilation amplitude (VAMP, and consequently the total ventilation (VTOT. The maximum hyperventilatory effect of GRP (VTOT: +225%, observed at a dose of 50 pmol, was mostly due to its stimulatory action on VAMP (+170% rather than ƒV (+20%. In addition, ICV GRP (50 pmol produced a significant increase in mean dorsal aortic blood pressure (PDA (+35% and in heart rate (ƒH (+25%. Intra-arterial injections of GRP (5–100 pmol were without sustained effect on the ventilatory variables but produced sporadic and transient increases in ventilatory movement at doses of 50 and 100 pmol. At these doses, GRP elevated PDA by +20% but only the 50 pmol dose significantly increased HR (+15%. In conclusion, our study suggests that endogenous GRP within the brain of the trout may act as a potent neurotransmitter and/or neuromodulator in the regulation of cardio-ventilatory functions. In the periphery, endogenous GRP may act as locally-acting and/or circulating neurohormone with an involvement in vasoregulatory mechanisms.

  8. Characterization of atrial natriuretic peptide degradation by cell-surface peptidase activity on endothelial cells

    Science.gov (United States)

    Frost, S. J.; Whitson, P. A.

    1993-01-01

    Atrial natriuretic peptide (ANP) is a fluid-regulating peptide hormone that promotes vasorelaxation, natriuresis, and diuresis. The mechanisms for the release of ANP and for its clearance from the circulation play important roles in modulating its biological effects. Recently, we have reported that the cell surface of an endothelial cell line, CPA47, could degrade 125I-ANP in the presence of EDTA. In this study, we have characterized this degradation of 125I-ANP. The kinetics of ANP degradation by the surface of CPA47 cells were first order, with a Km of 320 +/- 60 nM and Vmax of 35 +/- 14 pmol of ANP degraded/10 min/10(5) cells at pH 7.4. ANP is degraded by the surface of CPA47 cells over a broad pH range from 7.0-8.5. Potato carboxypeptidase inhibitor and bestatin inhibited 125I-ANP degradation, suggesting that this degradative activity on the surface of CPA47 cells has exopeptidase characteristics. The selectivity of CPA47 cell-surface degradation of ANP was demonstrated when 125I-ANP degradation was inhibited in the presence of neuropeptide Y and angiotensin I and II but not bradykinin, bombesin, endothelin-1, or substance P. The C-terminal amino acids phe26 and tyr28 were deduced to be important for ANP interaction with the cell-surface peptidase(s) based on comparison of the IC50 of various ANP analogues and other natriuretic peptides for the inhibition of ANP degradation. These data suggest that a newly characterized divalent cation-independent exopeptidase(s) that selectively recognizes ANP and some other vasoactive peptides exists on the surface of endothelial cells.

  9. Feeding and the rhodopsin family G-Protein Coupled Receptors (GPCRs in nematodes and arthropods

    Directory of Open Access Journals (Sweden)

    Joao Carlos dos Reis Cardoso

    2012-12-01

    Full Text Available In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologues of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster, suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologues of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  10. Feeding and the rhodopsin family g-protein coupled receptors in nematodes and arthropods.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Fonseca, Vera G; Power, Deborah M

    2012-01-01

    In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  11. Immunocytochemical survey of the neuroepithelial endocrine system in the respiratory tract of the Tokyo salamander, Hynobius nebulosus tokyoensis TAgo.

    Science.gov (United States)

    Gomi, T; Kikuchi, Y; Adriaensen, D; Timmermans, J P; De Groodt-Lasseel, M H; Kimura, A; Naruse, H; Ishikawa, Y; Kishi, K; Scheuermann, D W

    1994-12-01

    The epithelial lining of the respiratory tract of urodeles has been shown to harbor an innervated system of neuroepithelial endocrine (NEE) cells. Even between phylogenetically closely related species, large differences have been reported in the appearance and chemical coding of the NEE system. Although urodeles are well suited for the purpose, none of the prior studies have provided an immunocytochemical survey of the NEE system in all parts of the respiratory tract. In the present study, many bioactive substances and a general marker were immunocytochemically demonstrated in serial sections of the entire respiratory tract of the Tokyo salamander, Hynobius nebulosus tokyoensis, a species in which neuroepithelial bodies (NEBs) were previously characterized at the electron microscopic level. In the current study, serotonin-immunoreactive solitary NEE cells were observed in variable numbers in the larynx, in all parts of the trachea, and in areas of the lungs covered with ciliomucous epithelium. Serotonin-containing NEBs, however, were detected in small cranial areas of the lung only. Solitary NEE cells were seen in the trachea and lungs of H. nebulosus tokyoensis by immunocytochemical staining for somatostatin, calcitonin, calcitonin gene-related peptide, and bombesin, but the number, localization, and appearance of the labeled NEE cells differed considerably. Only calcitonin-like immunoreactivity was also noted in some NEB-like cell clusters in the cranial parts of the lungs. Unlike many other vertebrates, neuron specific enolase was found to be a poor marker for the NEE system in the salamander species used in this investigation. It may be concluded that the NEE system of H. nebulosus tokyoensis contains at least five different bioactive substances.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Changes in the neuromodulators of the diffuse endocrine system of the alimentary canal of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), naturally infected with Eubothrium crassum (Cestoda).

    Science.gov (United States)

    Bosi, G; Shinn, A P; Giari, L; Simoni, E; Pironi, F; Dezfuli, B S

    2005-12-01

    A histopathological and immunohistochemical study on the intestines of 45 specimens of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), from Loch Awe, Scotland, revealed a number of cellular deviations in individuals naturally infected with the pseudophyllidean cestode Eubothrium crassum (Bloch, 1779). Twenty-five individuals (55.5%) were infected with an average worm burden of 18.84 +/- 4.06 (mean +/- SE) cestodes per host (range, 2-80 worms; total 471 worms). The cestodes, measuring an average 8.23 +/- 1.10 cm (mean +/- SE; range, 5.3-13.0 cm) in length, were found attached by their scolices to the mucosal lining of the distal portion of the pyloric caeca. Within the caeca, the strobila evoked a mild catarrhal enteritis, namely an enhanced mucus production with epithelial cellular desquamation, a leucocytic infiltration of the lamina propria-submucosa and vacuolization of the intestinal epithelial cells. Eosinophilic granular cells of the stratum granulosum exhibited granular depletion, while within the catarrh, the presence of a high number of rodlet cells was noticed. Immunohistochemically, the occurrence of E. crassum caused a significant reduction in the number of bombesin-, gastrin-releasing peptide and glucagon-like immunoreactive endocrine cells, but an increase in the relative densities of endocrine cells containing cholecystokinin-8- and gastrin-like substances. There were, however, no significant differences in the number of endocrine cells that were immunoreactive to secretin, neuropeptide Y and peptide histidine-isoleucine antisera in the digestive tracts of either the infected or non-infected O. mykiss.

  13. Evaluation of the internalization kinetics of the radiopharmaceutical 99mTc-N2S2-Tat(49-57)Lys3-Bn with diagnostic purposes, using comet assay

    International Nuclear Information System (INIS)

    Luna G, M. A.

    2011-01-01

    Gastrin-rea leasing peptide receptors (GRP-r) are over expressed in breast and prostate cancer cells. Bombesin (Bn) binds specifically and strongly to GRP-r and this is the base for to label the Bn with radionuclides by gamma rays. Tat (49-57) is a peptide that across the cell membrane easily so that, when it is conjugated to different proteins, it can works as a Trojan horse, facilitating the drug internalization to the cells. The radiopharmaceutical 99m Tc-N 2 S 2 -Tat(49-57)-Lys 3 -Bn was prepared for diagnosis and therapy at early stage of breast cancer. The objective of this study was to determine the role of Tat in the internalization kinetics of radiopharmaceuticals measured by DNA damage induced by means of comet assay. Human lymphocytes were treated with the following protocols: a) Tat-Bn, b) 99m Tc-Bn, or c) 99m Tc-N 2 S 2 -Tat(49-57)-Lys 3 -Bn, also an untreated group was conformed. The internalization was evaluated at 0, 5, 10, 15, 30 and 60 min after exposure with three repetitions each one, and for radiopharmaceuticals with 2.9, 6.6, 9.0 and 14.8 MBq activities. DNA damage was scored in 100 cells per time and treatment, as tail length and tail moment. A Kruskal-Wallis variance analysis with p≤ 0.05 was applied for comparison between treatments. The results showed that the damage caused by 99m Tc-N 2 S 2 -Tat(49-57)-Lys 3 -Bn is significantly higher than that caused by 99m Tc-Bn and Tat-Bn, showing that Tat favors the internalization of the radiopharmaceutical. (Author)

  14. Dehydroepiandrosterone inhibits intracellular calcium release in beta-cells by a plasma membrane-dependent mechanism.

    Science.gov (United States)

    Liu, Dongmin; Ren, Min; Bing, Xinyu; Stotts, Corey; Deorah, Sundeep; Love-Homan, Laurie; Dillon, Joseph S

    2006-08-01

    Both dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) affect glucose stimulated insulin secretion, though their cellular mechanisms of action are not well characterized. We tested the hypothesis that human physiological concentrations of DHEA alter insulin secretion by an action initiated at the plasma membrane of beta-cells. DHEA alone had no effect on intracellular calcium concentration ([Ca(2+)](i)) in a rat beta-cell line (INS-1). However, it caused an immediate and dose-dependent inhibition of carbachol-induced Ca(2+) release from intracellular stores, with a 25% inhibition at zero. One nanometer DHEA. DHEA also inhibited the Ca(2+) mobilizing effect of bombesin (29% decrease), but did not inhibit the influx of extracellular Ca(2+) evoked by glyburide (100 microM) or glucose (15 mM). The steroids (androstenedione, 17-alpha-hydroxypregnenolone, and DHEAS) had no inhibitory effect on carbachol-induced intracellular Ca(2+) release. The action of DHEA depended on a signal initiated at the plasma membrane, since membrane impermeant DHEA-BSA complexes also inhibited the carbachol effect on [Ca(2+)](i) (39% decrease). The inhibition of carbachol-induced Ca(2+) release by DHEA was blocked by pertussis toxin (PTX). DHEA also inhibited the carbachol induction of phosphoinositide generation, with a maximal inhibition at 0.1 nM DHEA. Furthermore, DHEA inhibited insulin secretion induced by carbachol in INS-1 cells by 25%, and in human pancreatic islets by 53%. Taken together, this is the first report showing that human physiological concentrations of DHEA decrease agonist-induced Ca(2+) release by a rapid, non-genomic mechanism in INS-1 cells. Furthermore, these data provide evidence consistent with the existence of a specific plasma membrane DHEA receptor, mediating this signal transduction pathway by pertussis toxin-sensitive G-proteins.

  15. Regulation of feeding behavior and food intake by appetite-regulating peptides in wild-type and growth hormone-transgenic coho salmon.

    Science.gov (United States)

    White, Samantha L; Volkoff, Helene; Devlin, Robert H

    2016-08-01

    Survival, competition, growth and reproductive success in fishes are highly dependent on food intake, food availability and feeding behavior and are all influenced by a complex set of metabolic and neuroendocrine mechanisms. Overexpression of growth hormone (GH) in transgenic fish can result in greatly enhanced growth rates, feed conversion, feeding motivation and food intake. The objectives of this study were to compare seasonal feeding behavior of non-transgenic wild-type (NT) and GH-transgenic (T) coho salmon (Oncorhynchus kisutch), and to examine the effects of intraperitoneal injections of the appetite-regulating peptides cholecystokinin (CCK-8), bombesin (BBS), glucagon-like peptide-1 (GLP-1), and alpha-melanocyte-stimulating hormone (α-MSH) on feeding behavior. T salmon fed consistently across all seasons, whereas NT dramatically reduced their food intake in winter, indicating the seasonal regulation of appetite can be altered by overexpression of GH in T fish. Intraperitoneal injections of CCK-8 and BBS caused a significant and rapid decrease in food intake for both genotypes. Treatment with either GLP-1 or α-MSH resulted in a significant suppression of food intake for NT but had no effect in T coho salmon. The differential response of T and NT fish to α-MSH is consistent with the melanocortin-4 receptor system being a significant pathway by which GH acts to stimulate appetite. Taken together, these results suggest that chronically increased levels of GH alter feeding regulatory pathways to different extents for individual peptides, and that altered feeding behavior in transgenic coho salmon may arise, in part, from changes in sensitivity to peripheral appetite-regulating signals. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Current status and perspectives in peptide receptor radiation therapy.

    Science.gov (United States)

    Ansquer, Catherine; Kraeber-Bodéré, Françoise; Chatal, Jean François

    2009-01-01

    Regulatory peptide receptors are overexpressed in numerous human cancers. The specific receptor binding property of peptides can be exploited by their labelling with a radionuclide and their use as carriers to guide the radioactivity to the tissues expressing their specific receptors. During the past decade, radiolabelled receptor-binding peptides have emerged as an important class of radiopharmaceuticals for tumour diagnosis and therapy. The first and most successful imaging agents to date are somatostatin analogues which are routinely used for somatostatin receptor scintigraphy. Peptide receptor radionuclide therapy (PRRT) with (90)Y-DOTA-octreotide and (177)Lu-DOTA-octreotate in neuroendocrine tumours (NETs) results in symptomatic improvement, prolonged survival, and enhanced quality of life. The results in terms of tumour regression are very encouraging with few and mostly mild side effects when patients are carefully selected and kidney protective agents are given. Nevertheless much profit can be gained from improving the available receptor-targeting strategies and developing new strategies. In this review, the current state of clinical use of radiolabelled peptides for diagnosis and therapy of NETs is presented. In addition, potential directions for optimization and future developments are discussed. These include the optimization of peptide analogues or derivatives, increasing the access and binding on specific receptors on the tumour sites, increasing radiotoxicity profile and multimodality strategies. Other peptides such as minigastrin, glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), bombesin (BN)/gastrin-releasing peptide (GRP), substance P, neurotensin (NT), neuropeptide Y (NPY) and RGD peptides are promising for PRRT and currently under preclinical and clinical development.

  17. Characteristics of the spontaneous gastric endocrine tumor of mastomys

    International Nuclear Information System (INIS)

    Modlin, I.M.; Zucker, K.A.; Zdon, M.J.; Sussman, J.; Adrian, T.E.

    1988-01-01

    Mastomys is a rodent which has been reported to develop spontaneous antral endocrine tumors with acid hypersecretion and duodenal ulceration. This study documents the establishment of a breeding colony and the characterization of the tumors and their possible secretagogues. Parietal cell secretory characteristics were studied using isolated gastric glands (IGG) of both normal (n = 5) and tumor-bearing animals. Tumors (n = 6) and control gastric tissue samples were examined by light transmission microscopy and immunohistochemistry. Gastrin was measured by radioimmunoassay in both plasma and tissue. IGG were prepared by collagenase dispersion and acid sequestration assessed by [ 14 C]AP accumulation. Secretory mechanisms of this species were identified by establishment of a histamine dose-response curve and use of 8-bromo-cAMP. Receptor and proton pump inhibitions were assessed using cimetidine (10(-5)M) and the H/K ATPase inhibitor omeprazole (10(-5]. Both reduced [ 14 C]AP accumulation significantly (P less than 0.05). 8-Bromo-cAMP and histamine significantly stimulated [ 14 C]AP accumulation (P less than 0.05). Although parietal cells were substantially increased in tumor animals as compared to controls, the physiological parameters of acid secretion appeared normal in both and were comparable to other species which have been studied. Tumors were Grimelius positive and contained diffuse electron-dense granules. Immunohistochemistry was negative for gastrin, bombesin, serotonin, neuron-specific enolase, calcitonin, and pancreatic polypeptide. Tumor histamine-like immunoreactivity was, however, positive. Normal stomach contained 1001 +/- 185 compared to less than 0.5 pmole/g gastrin in tumors. Plasma gastrin was normal in both groups (29 +/- 5) as compared to 26 +/- 8 pmole/liter

  18. Induction of phenotypic changes in SCLC cell lines in vitro by hexamethylene bisacetamide, sodium butyrate, and cyclic AMP.

    Science.gov (United States)

    Khan, M Z; Freshney, R I; McNicol, A M; Murray, A M

    1993-06-01

    Hexamethylene bisacetamide (HMBA), sodium butyrate (NaBt), and cyclic AMP (cAMP) have been shown to induce differentiation, which may regulate tumour growth differently from conventional cytotoxic drugs. It was the intention in the present study to determine whether alterations could be induced in the phenotype of small cell lung cancer (SCLC) cell lines with HMBA, NaBt and cAMP, and whether these alterations would correlate with reduced growth in vivo, implying a phenotypic shift from malignancy towards differentiation. The cell lines were NCI-H69, H187 and H128. The activity of dopa decarboxylase (DDC), the BB isozyme of creatine kinase (CK-BB), the synthesis of bombesin-like peptide (BLI), and the presence of neurone specific enolase (NSE) and chromogranin were used as markers of the small cell phenotype. Clonogenicity in suspension in agar, and growth as xenografts in nude mice, were used as malignancy-associated properties. Cell proliferation in vitro was determined by cell counting and growth curve analysis. HMBA, NaBt and cAMP were found to be reversibly cytostatic in liquid culture and pre-exposure reduced the cloning efficiency in agar by 60%-80%. Growth as xenografts was inhibited (three- to five-fold increase in the tumour doubling time), most significantly by NaBt. Effects of phenotypic markers were more complex. The most significant were a two-fold reduction in DDC with NaBt and HMBA, a 50% increase in CK-BB with cAMP, and a 70%-100% increase in secreted BLI with HMBA and cAMP, in NCI-H69 cells. No significant effects were seen on NSE and chromogranin. There was little sign of an interaction with adriamycin and vincristine, although a slight increase was observed in the ID50 of VP-16 following treatment with cAMP. NaBt, HMBA and cAMP were cytostatic and inhibited tumour growth, but there was no coordinated response in marker expression that would confirm phenotypic alteration indicative of differentiation. The problem of defining differentiation in

  19. The effect of macrocyclic chelators on the targeting properties of the 68Ga-labeled gastrin releasing peptide receptor antagonist PEG2-RM26

    International Nuclear Information System (INIS)

    Varasteh, Zohreh; Mitran, Bogdan; Rosenström, Ulrika; Velikyan, Irina; Rosestedt, Maria; Lindeberg, Gunnar; Sörensen, Jens; Larhed, Mats; Tolmachev, Vladimir; Orlova, Anna

    2015-01-01

    Introduction: Overexpression of gastrin-releasing peptide receptors (GRPR) has been reported in several cancers. Bombesin (BN) analogs are short peptides with a high affinity for GRPR. Different BN analogs were evaluated for radionuclide imaging and therapy of GRPR-expressing tumors. We have previously investigated an antagonistic analog of BN (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 , RM26) conjugated to NOTA via a PEG 2 spacer (NOTA-PEG 2 -RM26) labeled with 68 Ga, 111 In and Al 18 F. 68 Ga-labeled NOTA-PEG 2 -RM26 showed high tumor-to-organ ratios. Methods: The influence of different macrocyclic chelators (NOTA, NODAGA, DOTA and DOTAGA) on the targeting properties of 68 Ga-labeled PEG 2 -RM26 was studied in vitro and in vivo. Results: All conjugates were labeled with generator-produced 68 Ga with high yields and demonstrated high stability and specific binding to GRPR. The IC 50 values of nat Ga-X-PEG 2 -RM26 (X = NOTA, DOTA, NODAGA, DOTAGA) were 2.3 ± 0.2, 3.0 ± 0.3, 2.9 ± 0.3 and 10.0 ± 0.6 nM, respectively. The internalization of the conjugates by PC-3 cells was low. However, the DOTA-conjugated analog demonstrated a higher internalization rate compared to other analogs. GRPR-specific uptake was found in receptor-positive normal tissues and PC-3 xenografts for all conjugates. The biodistribution of the conjugates was influenced by the choice of the chelator moiety. Although all radiotracers cleared rapidly from the blood, [ 68 Ga]Ga-NOTA-PEG 2 -RM26 showed significantly lower uptake in lung, muscle and bone compared to the other analogs. The uptake in tumors (5.40 ± 1.04 %ID/g at 2 h p.i.) and the tumor-to-organ ratios (25 ± 3, 157 ± 23 and 39 ± 4 for blood, muscle and bone, respectively) were significantly higher for the NOTA-conjugate than the other analogs. Conclusions: Chelators had a clear influence on the biodistribution and targeting properties of 68 Ga-labeled antagonistic BN analogs. Positively charged [ 68 Ga]Ga-NOTA-PEG 2 -RM26 provided

  20. The EndoC-βH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates.

    Science.gov (United States)

    Tsonkova, Violeta Georgieva; Sand, Fredrik Wolfhagen; Wolf, Xenia Asbæk; Grunnet, Lars Groth; Kirstine Ringgaard, Anna; Ingvorsen, Camilla; Winkel, Louise; Kalisz, Mark; Dalgaard, Kevin; Bruun, Christine; Fels, Johannes Josef; Helgstrand, Charlotte; Hastrup, Sven; Öberg, Fredrik Kryh; Vernet, Erik; Sandrini, Michael Paolo Bastner; Shaw, Allan Christian; Jessen, Carsten; Grønborg, Mads; Hald, Jacob; Willenbrock, Hanni; Madsen, Dennis; Wernersson, Rasmus; Hansson, Lena; Jensen, Jan Nygaard; Plesner, Annette; Alanentalo, Tomas; Petersen, Maja Borup Kjær; Grapin-Botton, Anne; Honoré, Christian; Ahnfelt-Rønne, Jonas; Hecksher-Sørensen, Jacob; Ravassard, Philippe; Madsen, Ole D; Rescan, Claude; Frogne, Thomas

    2018-02-01

    To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. Transplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins. Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate. By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation. ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. Overall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active

  1. Prospective Evaluation of 68Ga-RM2 PET/MRI in Patients with Biochemical Recurrence of Prostate Cancer and Negative Findings on Conventional Imaging.

    Science.gov (United States)

    Minamimoto, Ryogo; Sonni, Ida; Hancock, Steven; Vasanawala, Shreyas; Loening, Andreas; Gambhir, Sanjiv S; Iagaru, Andrei

    2018-05-01

    68 Ga-labeled DOTA-4-amino-1-carboxymethyl-piperidine-d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 ( 68 Ga-RM2) is a synthetic bombesin receptor antagonist that targets gastrin-releasing peptide receptor (GRPr). GRPr proteins are highly overexpressed in several human tumors, including prostate cancer (PCa). We present data from the use of 68 Ga-RM2 in patients with biochemical recurrence (BCR) of PCa and negative findings on conventional imaging. Methods: We enrolled 32 men with BCR of PCa, who were 59-83 y old (mean ± SD, 68.7 ± 6.4 y). Imaging started at 40-69 min (mean, 50.5 ± 6.8 min) after injection of 133.2-151.7 MBq (mean, 140.6 ± 7.4 MBq) of 68 Ga-RM2 using a time-of-flight-enabled simultaneous PET/MRI scanner. T1-weighted, T2-weighted, and diffusion-weighted images were acquired. Results: All patients had a rising level of prostate-specific antigen (PSA) (range, 0.3-119.0 ng/mL; mean, 10.1 ± 21.3 ng/mL) and negative findings on conventional imaging (CT or MRI, and a 99m Tc-methylene diphosphonate bone scan) before enrollment. The observed 68 Ga-RM2 PET detection rate was 71.8%. 68 Ga-RM2 PET identified recurrent PCa in 23 of the 32 participants, whereas the simultaneous MRI scan identified findings compatible with recurrent PCa in 11 of the 32 patients. PSA velocity was 0.32 ± 0.59 ng/mL/y (range, 0.04-1.9 ng/mL/y) in patients with negative PET findings and 2.51 ± 2.16 ng/mL/y (range, 0.13-8.68 ng/mL/y) in patients with positive PET findings ( P = 0.006). Conclusion: 68 Ga-RM2 PET can be used for assessment of GRPr expression in patients with BCR of PCa. High uptake in multiple areas compatible with cancer lesions suggests that 68 Ga-RM2 is a promising PET radiopharmaceutical for localization of disease in patients with BCR of PCa and negative findings on conventional imaging. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

  2. Multiple sources of 1,2-diacylglycerol in isolated rat pancreatic acini stimulated by cholecystokinin. Involvement of phosphatidylinositol bisphosphate and phosphatidylcholine hydrolysis

    International Nuclear Information System (INIS)

    Matozaki, T.; Williams, J.A.

    1989-01-01

    Changes in the cellular content of 1,2-diacylglycerol (DAG) in isolated rat pancreatic acini in response to agonist stimulation were studied using a sensitive mass assay. When acini were stimulated by 10 nM COOH-terminal cholecystokinin-octapeptide (CCK8), the increase in DAG was biphasic, consisting of an early peak at 5 s and a second, larger, gradual increase that was maximal by 15 min. The basal level of DAG in acini was 1.04 nmol/mg of protein, which was increased to 1.24 nmol/mg of protein at 5 s and 2.76 nmol/mg of protein at 30 min. In comparison, the increase in DAG stimulated by 30 pM CCK8, a submaximal concentration for amylase release, was monophasic, increasing without an early peak but sustained to 60 min. Other Ca2+-mobilizing secretagogues such as carbamylcholine and bombesin increased DAG in acini, whereas vasoactive intestinal peptide, which acts to increase cAMP, had no effect. Phorbol ester and Ca2+ ionophore also stimulated DAG production. Analysis of the mass level of inositol 1,4,5-trisphosphate (1,4,5-IP3) showed that the generation of 1,4,5-IP3 stimulated by 10 nM CCK8 peaked at 5 s, a finding consistent with the early peak of DAG. The basal level was 4.7 pmol/mg of protein, which was increased to 144.6 pmol/mg of protein at 5 s by 10 nM CCK8. The levels of 1,4,5-IP3 then returned toward basal in contrast to the gradual and sustained increase of DAG. The dose dependencies of 1,4,5-IP3 and DAG formation at 5 s with respect to CCK8 were almost identical. This suggests that phosphatidylinositol 4,5-bisphosphate hydrolysis is a major source of the early increase in DAG but not of the sustained increase in DAG. Therefore, a possible contribution of phosphatidylcholine hydrolysis to DAG formation was examined utilizing acini prelabeled with [3H]choline. CCK8 (1 nM) maximally increased [3H]choline metabolite release by 133% of control at 30 min

  3. Evaluation the influence of Polyethylene glycol in circulation and biodistribution of pH-sensitive liposomes, radiolabeled with Technetium 99m in experimental models

    International Nuclear Information System (INIS)

    Nunes, Shirleide Santos

    2016-01-01

    Liposomes are lipid vesicles widely studied throughout the world as nanocarriers for different substances. The hydrophilic polymer polyethylene glycol (PEG) might be added onto the surface of liposomes to prolong the circulation time by reducing the opsonization of the vesicles, leading to a reduced uptake by the mononuclear phagocyte system (MPS). Several studies claim that the molecular weight of the PEG, as well as combination of different types of PEG with different molecular weights may alter the pharmacokinetics of the liposome. Therefore, the purpose of this study was to evaluate the influence of molecular weight and PEG combinations with different chain sizes in the pharmacokinetics and biodistribution of pH-sensitive liposomes containing 99m Tc-HYNIC-βAla-Bombesin complex (7-14 ) in tumor models (4T1 and Ehrlich). Eight liposomal formulations were prepared, the results showed that the liposomes exhibited adequate chemical and physical-chemical properties, such as mean diameter less than 300nm, monodisperse populations, neutral zeta potential, and encapsulation content of 26.4 to 38.7%. The images obtained by transmission electron cryomicroscopy (cryo-TEM) allowed visualization of unilamellar vesicles with an average diameter of 90 nm. There was no difference in blood half-life (T1/2), thereby for the composition of liposomes used in this study, PEG did not increase blood circulation time. Biodistribution studies and scintigraphic images showed high uptake by organs of the SMF, liver and spleen. The PEG2000 formulation showed higher concentration in blood. Liposomes with DSPE, PEG2000 or PEG1000 / 5000 showed higher uptake in the tumor compared to the contralateral muscle, but there was no statistical difference between the formulations when tumor-to-muscle ratio, obtained in the biodistribution studies or scintigraphic images, was analyzed. The results suggest that for this specific formulation, the addition of PEG was not efficient for increasing the

  4. New molecular targets for treatment of peptic ulcer disease.

    Science.gov (United States)

    Lehmann, Frank; Hildebrand, Pius; Beglinger, Christoph

    2003-01-01

    Most patients with peptic ulcer disease are currently treated with proton pump inhibitors or histamine H(2) receptor antagonists. The long-term use of these compounds has been associated with two potential problems. Firstly, proton pump inhibitors may induce enterochromaffin-like (ECL) cell hyperplasia. Secondly, ulcers may relapse despite maintenance therapy with histamine H(2) antagonists. This has been the rationale for the development of new antisecretory agents, including antagonists against gastrin and gastrin releasing peptide (GRP), as well as ligands to histamine H(3) receptors. Several potent, high affinity cholecystokinin (CCK)-2 receptor antagonists have recently been identified such as L-365260, YM-022, RP-73870, S-0509, spiroglumide and itriglumide (CR-2945). Current data suggest that they all have antisecretory and anti-ulcer effects. In addition to reducing acid production, CCK-2 receptor antagonists may possibly also accelerate gastric emptying, a combination of functions which could potentially be beneficial in patients with functional dyspepsia. Receptors for bombesin and its mammalian counterpart GRP have been localised in the brain, spinal cord and enteric nerve fibres of the gut as well as on secretory cells and smooth muscle cells of the intestinal tract. Current data clearly indicate that endogenous GRP is involved in the regulation of basal and postprandial acid secretion. However, at this stage it is not clear whether GRP agonists or GRP antagonists can be developed into useful drugs. The peptide has a wide range of biological effects and it is likely that analogues of GRP or antagonists of the peptide affect not only gastric acid secretion but also induce considerable side effects. Histamine plays a central role in the stimulation of acid secretion. After their detection in the brain, H(3) receptors have been identified in a variety of tissues including perivascular nerve terminals, enteric ganglia of the ileum and lung, and ECL cells

  5. SU-E-I-82: PET Radiopharmaceuticals for Prostate Cancer Imaging: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, F [Delfin Farmacos e Derivados Ltda, Lauro De Freitas, Bahia (Brazil); Escola Bahiana de Medicina e Saude Publica, Salvador, Bahia (Brazil); Silva, D da [Delfin Farmacos e Derivados Ltda, Lauro De Freitas, Bahia (Brazil); Rodrigues, L [Escola Bahiana de Medicina e Saude Publica, Salvador, Bahia (Brazil)

    2015-06-15

    Purpose: The aim of this work was to review new and clinical practice PET radiopharmaceuticals for prostate cancer imaging. Methods: PET radiopharmaceuticals were reviewed on the main databases. Availability, dosimetry, accuracy and limitations were considered. Results: The following radioisotopes with respective physical half-life and mean positron energy were found: {sup 18}F (109,7 min, 249,8 keV), {sup 89}Zr (78,4 hs, 395,5 keV), {sup 11}C (20,4 min, 385,7 keV) and {sup 68}Ga (67,8 min, 836 keV). {sup 68}Ga was the only one not produced by cyclotron. Radiopharmaceuticals uptake by glucose metabolism ({sup 18}F-FDG), lipogenesis ({sup 11}C-Choline and {sup 11}C-Acetate), amino acid transport (Anti-{sup 18}F-FACBC), bone matrix ({sup 18}F-NaF), prostatespecific membrane antigen ({sup 68}Ga-PSMA and {sup 89}Zr-J591), CXCR receptors ({sup 89}Ga-Pentixafor), adrenal receptors ({sup 18}F-FDHT) and gastrin release peptide receptor (bombesin analogue). Most of radiopharmaceuticals are urinary excretion, so bladder is the critical organ. 11C-choline (pancreas), Anti-{sup 18}FFACBC (liver) and {sup 18}F-FBDC (stomach wall) are the exception. Higher effective dose was seen {sup 18}F-NaF (27 μSv/MBq) while the lowest was {sup 11}CAcetate (3,5 μSv/MBq). Conclusion: Even though {sup 18}F-FDG has a large availability its high urinary excretion and poor uptake to slow growing disease offers weak results for prostate cancer. Better accuracy is obtained when {sup 18}F-NaF is used for bone metastatic investigation although physicians tend to choose bone scintigraphy probably due to its cost and practice. Many guidelines in oncology consider {sup 11}C or {sup 18}F labeled with Choline the gold standard for biochemical relapse after radical treatment. Local, lymph node and distant metastatic relapse can be evaluated at same time with this radiopharmaceutical. There is no consensus over bigger urinary excretion for {sup 18}F labeling. Anti-{sup 18}F-FACBC, {sup 68}Ga-PSMA and {sup

  6. Evaluation the influence of Polyethylene glycol in circulation and biodistribution of pH-sensitive liposomes, radiolabeled with Technetium 99m in experimental models; Avaliacao da influencia do polietilenoglicol na circulacao e biodistribuicao de lipossomas pH-sensiveis, radiomarcados com Tecnecio 99m em modelos experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Shirleide Santos

    2016-07-01

    Liposomes are lipid vesicles widely studied throughout the world as nanocarriers for different substances. The hydrophilic polymer polyethylene glycol (PEG) might be added onto the surface of liposomes to prolong the circulation time by reducing the opsonization of the vesicles, leading to a reduced uptake by the mononuclear phagocyte system (MPS). Several studies claim that the molecular weight of the PEG, as well as combination of different types of PEG with different molecular weights may alter the pharmacokinetics of the liposome. Therefore, the purpose of this study was to evaluate the influence of molecular weight and PEG combinations with different chain sizes in the pharmacokinetics and biodistribution of pH-sensitive liposomes containing {sup 99m}Tc-HYNIC-βAla-Bombesin complex (7-14 ) in tumor models (4T1 and Ehrlich). Eight liposomal formulations were prepared, the results showed that the liposomes exhibited adequate chemical and physical-chemical properties, such as mean diameter less than 300nm, monodisperse populations, neutral zeta potential, and encapsulation content of 26.4 to 38.7%. The images obtained by transmission electron cryomicroscopy (cryo-TEM) allowed visualization of unilamellar vesicles with an average diameter of 90 nm. There was no difference in blood half-life (T1/2), thereby for the composition of liposomes used in this study, PEG did not increase blood circulation time. Biodistribution studies and scintigraphic images showed high uptake by organs of the SMF, liver and spleen. The PEG2000 formulation showed higher concentration in blood. Liposomes with DSPE, PEG2000 or PEG1000 / 5000 showed higher uptake in the tumor compared to the contralateral muscle, but there was no statistical difference between the formulations when tumor-to-muscle ratio, obtained in the biodistribution studies or scintigraphic images, was analyzed. The results suggest that for this specific formulation, the addition of PEG was not efficient for increasing

  7. SU-E-I-82: PET Radiopharmaceuticals for Prostate Cancer Imaging: A Review

    International Nuclear Information System (INIS)

    Fernandes, F; Silva, D da; Rodrigues, L

    2015-01-01

    Purpose: The aim of this work was to review new and clinical practice PET radiopharmaceuticals for prostate cancer imaging. Methods: PET radiopharmaceuticals were reviewed on the main databases. Availability, dosimetry, accuracy and limitations were considered. Results: The following radioisotopes with respective physical half-life and mean positron energy were found: 18 F (109,7 min, 249,8 keV), 89 Zr (78,4 hs, 395,5 keV), 11 C (20,4 min, 385,7 keV) and 68 Ga (67,8 min, 836 keV). 68 Ga was the only one not produced by cyclotron. Radiopharmaceuticals uptake by glucose metabolism ( 18 F-FDG), lipogenesis ( 11 C-Choline and 11 C-Acetate), amino acid transport (Anti- 18 F-FACBC), bone matrix ( 18 F-NaF), prostatespecific membrane antigen ( 68 Ga-PSMA and 89 Zr-J591), CXCR receptors ( 89 Ga-Pentixafor), adrenal receptors ( 18 F-FDHT) and gastrin release peptide receptor (bombesin analogue). Most of radiopharmaceuticals are urinary excretion, so bladder is the critical organ. 11C-choline (pancreas), Anti- 18 FFACBC (liver) and 18 F-FBDC (stomach wall) are the exception. Higher effective dose was seen 18 F-NaF (27 μSv/MBq) while the lowest was 11 CAcetate (3,5 μSv/MBq). Conclusion: Even though 18 F-FDG has a large availability its high urinary excretion and poor uptake to slow growing disease offers weak results for prostate cancer. Better accuracy is obtained when 18 F-NaF is used for bone metastatic investigation although physicians tend to choose bone scintigraphy probably due to its cost and practice. Many guidelines in oncology consider 11 C or 18 F labeled with Choline the gold standard for biochemical relapse after radical treatment. Local, lymph node and distant metastatic relapse can be evaluated at same time with this radiopharmaceutical. There is no consensus over bigger urinary excretion for 18 F labeling. Anti- 18 F-FACBC, 68 Ga-PSMA and 68 Ga-Pentixafor are demonstrating good results but more researches are needed. While PSMA imaging seems to be

  8. Radio-peptides targeting g-protein coupled receptors in cancer: from bench to bed

    International Nuclear Information System (INIS)

    Maecke, H.R.

    2015-01-01

    Full text of publication follows. In the development of targeted imaging and therapy agents the most important challenge and prerequisite is to identify and validate the molecular targets of any disease. The targets should be specific, relevant, easily accessible and highly expressed. In addition they should have no or at least very low expression in normal tissue. Among the many drug targets is the large family of G-protein coupled receptors (GPCRs). It is the most important family of marketed drugs and the basic accomplishments in the field were recognised by the award of the recent Nobel price in chemistry. GPCRs also play a role in cancer. Several of these receptors are massively over-expressed in different human tumors such as neuroendocrine tumors (over-expression of the somatostatin receptor family), prostate and breast tumors (bombesin receptor family), brain tumors (NK1 receptor) etc.. This allows to develop (nuclear, MRI, optical) probes for imaging and potentially targeted therapy (theragnostics). Natural ligands targeting GPCRs are often peptides. They need to be modified for metabolic stability, modified for labeling with radio-metals (conjugation of bifunctional chelators) or radio-halogens (prosthetic groups). Preserved biological integrity after modification and labeling needs to be assured, long retention times in the tumor is important, conferred by internalisation. Radio-metal labeling in particular needs to be reasonably fast and the radio metal complexes have to show high stability with regard to radio-metal release. These prerequisites will be discussed for somatostatin receptor based radio-peptides in particular. For a successful clinical application preclinical imaging and biodistribution in adequate animal models are mandatory. New tracers for positron emission tomography (PET) and single photon emission computed tomography (SPECT) will be presented for neuroendocrine tumors and prostate cancer. In particular radiolabeled antagonists will

  9. Development of a specific radiopharmaceutical based on gold nanoparticles functionalized with HYNIC-peptide/mannose for the sentinel lymph node detection in breast cancer; Desarrollo de un radiofarmaco especifico basado en nanoparticulas de oro funcionalizadas con HYNIC-peptido/manosa para la deteccion de ganglio centinela en cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Ocampo G, B. E.

    2012-07-01

    ) which was retained during 24 h with minimal kidney accumulation (0.98 {+-} 0.10% Id) and negligible uptake in all other tissues. In order to design a pharmaceutical formulation for the instant preparation of stable m ultimeric systems with target-specific molecular recognition based on gold nanoparticles, a freeze-dried kit formulation of {sup 99m}Tc-ethylenediamine-N, N-diacetic acid (EDDA)/hydrazino nicotinyl (HYNIC)-Tyr{sup 3}-octreotide ({sup 99m}Tc-EDDA/HYNIC-TOC, previously approved by the Mexican Ministry of Health) (vial 1) and a second vial containing 1.5 ml of Au-Np solution plus 10 {mu}L of thiol-mannose, Lys{sup 3}-bombesin, or cyclo[Arg-Gly-Asp-D-Phe-Lys-(Cys)] (c[RGDfK(C)] (approximately 285 molecules per Au-Np) (vial 2) were prepared. M ultimeric radiopharmaceuticals prepared from kit showed a radiochemical purity of 96 {+-} 2%. The far-infrared spectra showed a characteristic band at 279 {+-} 1 cm{sup -1}, which was assigned to the Au-S bond. UV-Vis and XP S also indicated that the Au-Np were functionalized with peptides or mannose. Radiopharmaceuticals showed specific recognition for receptors expressed in cancer cells or rat liver cells. Micro-SPECT/CT images showed clear tumour uptake and lymph node accumulation. The kit demonstrated excellent stability during storage at 4 C for 6 months. This study demonstrated that {sup 99m}Tc-Au-Np-mannose remains within the first lymph node during 24 h and therefore might be useful as a target-specific radiopharmaceutical for SLND using 1-day or 2-day conventional protocols. Likewise, m ultimeric systems of {sup 99m}Tc-Au-Np-mannose, {sup 99m}Tc-Au-Np-RGD and {sup 99m}Tc-Au-Np-Lys{sup 3}-bombesin prepared from kits exhibited properties suitable as target-specific agents for molecular imaging of tumours and sentinel lymph node. (Author)

  10. Development of a specific radiopharmaceutical based on gold nanoparticles functionalized with HYNIC-peptide/mannose for the sentinel lymph node detection in breast cancer

    International Nuclear Information System (INIS)

    Ocampo G, B. E.

    2012-01-01

    minimal kidney accumulation (0.98 ± 0.10% Id) and negligible uptake in all other tissues. In order to design a pharmaceutical formulation for the instant preparation of stable m ultimeric systems with target-specific molecular recognition based on gold nanoparticles, a freeze-dried kit formulation of 99m Tc-ethylenediamine-N, N-diacetic acid (EDDA)/hydrazino nicotinyl (HYNIC)-Tyr 3 -octreotide ( 99m Tc-EDDA/HYNIC-TOC, previously approved by the Mexican Ministry of Health) (vial 1) and a second vial containing 1.5 ml of Au-Np solution plus 10 μL of thiol-mannose, Lys 3 -bombesin, or cyclo[Arg-Gly-Asp-D-Phe-Lys-(Cys)] (c[RGDfK(C)] (approximately 285 molecules per Au-Np) (vial 2) were prepared. M ultimeric radiopharmaceuticals prepared from kit showed a radiochemical purity of 96 ± 2%. The far-infrared spectra showed a characteristic band at 279 ± 1 cm -1 , which was assigned to the Au-S bond. UV-Vis and XP S also indicated that the Au-Np were functionalized with peptides or mannose. Radiopharmaceuticals showed specific recognition for receptors expressed in cancer cells or rat liver cells. Micro-SPECT/CT images showed clear tumour uptake and lymph node accumulation. The kit demonstrated excellent stability during storage at 4 C for 6 months. This study demonstrated that 99m Tc-Au-Np-mannose remains within the first lymph node during 24 h and therefore might be useful as a target-specific radiopharmaceutical for SLND using 1-day or 2-day conventional protocols. Likewise, m ultimeric systems of 99m Tc-Au-Np-mannose, 99m Tc-Au-Np-RGD and 99m Tc-Au-Np-Lys 3 -bombesin prepared from kits exhibited properties suitable as target-specific agents for molecular imaging of tumours and sentinel lymph node. (Author)

  11. Use of 99mTc-HYNIC-βAla-Bombesina(7-14) peptide for the identification of prostate tumor, LNCaP line, in an experimental model

    International Nuclear Information System (INIS)

    Fuscaldi, Leonardo Lima

    2012-01-01

    Prostate cancer is one of the most prevalent tumors in men, showing high mortality rates. Current diagnostic methods are not able to identify early prostate carcinoma, often resulting in a late diagnosis with established metastasis. Thus, there is by the scientific community an incessant search for diagnostic methods for early assessment of prostate cancer, facilitating the treatment and increasing the chances of cure. In this context, nuclear medicine provides a diagnostic method which can detect tumors at an early stage, because it is based on biochemical and physiological changes of the tissue, such as overexpression of gastrin releasing peptide receptors (GRPr's) by prostate cancer cells. Bombesin, a tetradecapeptide isolated from the frog Bombina bombina, has a high affinity for the GRPr's, since it is analogous to gastrin releasing peptide. Therefore, this study aims to prepare the complex 99m Tc-HYNIC-βAla-Bombesina (7-14) and use it for the identification of prostate tumor, LNCaP line, in an experimental model. For in vitro assays, aliquots of 0.026 MBq of the radiopeptide were incubated with 2x10 6 LNCaP cells in a water bath at 37 deg C, for 1 and 4 hours, with and without prior addition of cold peptide (n=3). Prostate tumors were induced into the upper right flank of male BALB/c nude mice by subcutaneous injection of 5x106 LNCaP cells resuspended in 150 μL of Matrigel:RPMI-1640 medium (1:1). Biodistribution profile (n=5) and scintigraphic images (n=3) were obtained at 1 and 4 hours after intravenous injection of 7.4 MBq of 99m Tc-HYNIC-βAla-Bombesina (7-14) . To assess this, healthy male BALB/c mice and tumor-bearing male BALB/c nude mice with 15, 20 and 25 days of tumor development were used. In vitro study results showed that the fraction of the radiopeptide which bound to LNCaP cells was 2.08 +- 0.30% (1 hour) and 2.44 +- 0.18% (4 hours). From the percentage which was bound, the internalized fractions were 25.64 +- 3.14% (1 hour) and 25.27 +- 2

  12. Compartmental analysis to predict biodistribution in radiopharmaceutical design studies

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marina F.; Pujatti, Priscilla B.; Araujo, Elaine B.; Mesquita, Carlos H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: mflima@ipen.br

    2009-07-01

    The use of compartmental analysis allows the mathematical separation of tissues and organs to determinate the concentration of activity in each fraction of interest. Although the radiochemical purity must observe Pharmacopoeia specification (values upper 95%), very lower contains of free radionuclides could contribute significantly as dose in the neighborhood organs and make tumor up take studies not viable in case of radiopharmaceutical on the basis of labeled peptides. Animal studies with a product of Lutetium-177 labeled Bombesin derivative ({sup 177}Lu-BBNP) developed in IPEN-CNEN/SP and free Lutetium-177 developed in CNEA/EZEIZA was used to show how subtract free {sup 177}Lu contribution over {sup 177}Lu-BBNP to estimate the radiopharmaceutical potential as diagnosis or therapy agent. The first approach of the studies included the knowledge of chemical kinetics and mimetism of the Lutetium and the possible targets of the diagnosis/therapy to choose the possible models to apply over the sampling standard methods used in experimental works. A model with only one physical compartment (whole body) and one chemical compartment ({sup 177}Lu-BBNP) generated with the compartmental analysis protocol ANACOMP showed high differences between experimental and theoretical values over 2.5 hours, in spite of the concentration of activity had been in a good statistics rang of measurement. The values used in this work were residence time from three different kinds of study with free {sup 177}Lu: whole body, average excretion and maximum excretion as a chemical compartment. Activity concentration values as time function in measurements of total whole body and activity measurement in samples of blood with projection to total circulating blood volume with {sup 177}Lu-BBNP. Considering the two sources of data in the same modeling a better consistence was obtained. The next step was the statistic treatment of biodistribution and dosimetry in mice (Balb C) considering three chemical

  13. Multi-functional system of radiotherapy and thermal phototherapy for tumors that over-express receptors of the gastrin releasing peptide; Sistema multifuncional de radioterapia y fototerapia termica para tumores que sobre-expresan receptores del peptido liberador de gastrina

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez M, N. P.

    2014-07-01

    The aim of this research was to prepare and characterize a multifunctional system of {sup 177}Lu and {sup 99m}Tc-labelled gold nanoparticles conjugated to Tat(49 57)-Lys{sup 3} bombesin ({sup 177}Lu/{sup 99m}Tc- AuNP-Tat-Bn) and to evaluate the radiation absorbed dose in GRP receptor positive PC3 tumours induced in mice (human prostate cancer cells), as well as to evaluate the thermal effect produced by the multifunctional system in PC3 cancer cells. The preparation of the system involved the conjugation of Bn-Tat, DOTA-GGC and HYNICTOC peptides to AuNP of 20 nm or 5 nm in diameter. The radiolabeling of the system with {sup 99m}Tc was carried out through the ligand HYNIC-TOC and with the {sup 177}Lu through DOTA-GGC. The functionalization of peptides to AuNP, was accomplished through a spontaneous reaction of thiol groups. The system was characterized by spectroscopic techniques while radiochemical purity was determined by size-exclusion molecular chromatography and ultrafiltration. Various internalization trials and non-specific binding were tested to demonstrate the affinity of the system to PC3 cells. The thermal effect was evaluated incubating the system into PC3 cells and irradiating it with a Nd:YAG pulsed laser beam and monitoring the temperature; after irradiation, cell viability was measured. In the evaluation of absorbed dose in mice with induced tumours, the system was administered intratumorally and later, mice were sacrificed, relevant organs and tumor were extracted, activity was quantified and radiopharmaceutical models were obtained for each organ and tumor to be used in the accumulated activity and absorbed dose calculation by the MIRD methodology. Finally, to establish the system location at cellular level, fluorescent images of the system incubated in PC3 cells were acquired with an epi fluorescent microscope. Tem, UV-Vis, XP S and Far-IR spectroscopy techniques demonstrated that AuNPs were functionalized with peptides through interactions with

  14. 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?

    International Nuclear Information System (INIS)

    Koumarianou, E.; Loktionova, N.S.; Fellner, M.; Roesch, F.; Thews, O.; Pawlak, D.; Archimandritis, S.C.; Mikolajczak, R.

    2012-01-01

    Aim: 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. Methods: 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. Results: The affinity to GRP receptors in the PC-3 cell line was higher for nat Ga-DOTA-BN[2-14]NH 2 (IC 50 (nM)=0.85±0.06) than that of nat Sc-DOTA-BN[2-14]NH 2 (IC 50 (nM)=6.49±0.13). The internalization rate of 68 Ga labeled DOTA-BN[2-14]NH 2 was slower than that of 44 Sc, but their final internalization percents were comparable. 68 Ga-DOTA-BN[2-14]NH 2 was externalized faster than 44 Sc-DOTA-BN[2-14]NH 2 . The biodistribution of 44 Sc-DOTA-BN[2-14]NH 2 and 68 Ga-DOTA-BN[2-14]NH 2 in normal rats revealed a higher uptake in target organs and tissues of the first one while both excreted mainly through urinary tract. In microPET images both tracers were accumulated in the tumor with similar uptake patterns. Conclusions: Despite the differences in the receptor affinity both the 68 Ga- and the 44 Sc-labeled DOTA-BN[2-14]NH 2 tracers showed comparable distribution and similar time constants of uptake and elimination. Moreover no differences in tumor accumulation (neither in the overall uptake nor in the dynamics) were observed from the microPet imaging. From that perspective the use of either 44 Sc or 68 Ga for detecting tumors with GRP receptors is equivalent. - Highlights: ► In vitro and in vivo evaluation of 44 Sc- and 68 Ga-DOTA-BN[2-14]NH 2 in reference to published

  15. Multi-functional system of radiotherapy and thermal phototherapy for tumors that over-express receptors of the gastrin releasing peptide

    International Nuclear Information System (INIS)

    Jimenez M, N. P.

    2014-01-01

    The aim of this research was to prepare and characterize a multifunctional system of 177 Lu and 99m Tc-labelled gold nanoparticles conjugated to Tat(49 57)-Lys 3 bombesin ( 177 Lu/ 99m Tc- AuNP-Tat-Bn) and to evaluate the radiation absorbed dose in GRP receptor positive PC3 tumours induced in mice (human prostate cancer cells), as well as to evaluate the thermal effect produced by the multifunctional system in PC3 cancer cells. The preparation of the system involved the conjugation of Bn-Tat, DOTA-GGC and HYNICTOC peptides to AuNP of 20 nm or 5 nm in diameter. The radiolabeling of the system with 99m Tc was carried out through the ligand HYNIC-TOC and with the 177 Lu through DOTA-GGC. The functionalization of peptides to AuNP, was accomplished through a spontaneous reaction of thiol groups. The system was characterized by spectroscopic techniques while radiochemical purity was determined by size-exclusion molecular chromatography and ultrafiltration. Various internalization trials and non-specific binding were tested to demonstrate the affinity of the system to PC3 cells. The thermal effect was evaluated incubating the system into PC3 cells and irradiating it with a Nd:YAG pulsed laser beam and monitoring the temperature; after irradiation, cell viability was measured. In the evaluation of absorbed dose in mice with induced tumours, the system was administered intratumorally and later, mice were sacrificed, relevant organs and tumor were extracted, activity was quantified and radiopharmaceutical models were obtained for each organ and tumor to be used in the accumulated activity and absorbed dose calculation by the MIRD methodology. Finally, to establish the system location at cellular level, fluorescent images of the system incubated in PC3 cells were acquired with an epi fluorescent microscope. Tem, UV-Vis, XP S and Far-IR spectroscopy techniques demonstrated that AuNPs were functionalized with peptides through interactions with the -Sh groups. The radiochemical

  16. Production and Clinical Applications of Radiopharmaceuticals and Medical Radioisotopes in Iran.

    Science.gov (United States)

    Jalilian, Amir Reza; Beiki, Davood; Hassanzadeh-Rad, Arman; Eftekhari, Arash; Geramifar, Parham; Eftekhari, Mohammad

    2016-07-01

    During past 3 decades, nuclear medicine has flourished as vibrant and independent medical specialty in Iran. Since that time, more than 200 nuclear physicians have been trained and now practicing in nearly 158 centers throughout the country. In the same period, Tc-99m generators and variety of cold kits for conventional nuclear medicine were locally produced for the first time. Local production has continued to mature in robust manner while fulfilling international standards. To meet the ever-growing demand at the national level and with international achievements in mind, work for production of other Tc-99m-based peptides such as ubiquicidin, bombesin, octreotide, and more recently a kit formulation for Tc-99m TRODAT-1 for clinical use was introduced. Other than the Tehran Research Reactor, the oldest facility active in production of medical radioisotopes, there is one commercial and three hospital-based cyclotrons currently operational in the country. I-131 has been one of the oldest radioisotope produced in Iran and traditionally used for treatment of thyrotoxicosis and differentiated thyroid carcinoma. Since 2009, (131)I-meta-iodobenzylguanidine has been locally available for diagnostic applications. Gallium-67 citrate, thallium-201 thallous chloride, and Indium-111 in the form of DTPA and Oxine are among the early cyclotron-produced tracers available in Iran for about 2 decades. Rb-81/Kr-81m generator has been available for pulmonary ventilation studies since 1996. Experimental production of PET radiopharmaceuticals began in 1998. This work has culminated with development and optimization of the high-scale production line of (18)F-FDG shortly after installation of PET/CT scanner in 2012. In the field of therapy, other than the use of old timers such as I-131 and different forms of P-32, there has been quite a significant advancement in production and application of therapeutic radiopharmaceuticals in recent years. Application of (131)I