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![NT-induced IP1 formation in cultured cells. A, effects of SR 142948A on IP1 formation induced by increasing concentrations of NT [10 (F), 100 (E) and 1000 nM (å)] in HT 29 cells. The results are expressed as a percentage of maximal NT response. Each point represents the mean S.E.M. of triplicate determinations. B, antagonism by SR 142948A (E) and SR 48692 (F) of NT-induced IP1 formation in h-NTR1-CHO cells. The results are expressed as a percentage of the effect of 10 nM NT. Each point represents the mean S.E.M. of three independent experiments performed in triplicate.](profile/Catherine-Labbe-Jullie/publication/14186841/figure/fig4/AS:601623416021020@1520449608680/NT-induced-IP1-formation-in-cultured-cells-A-effects-of-SR-142948A-on-IP1-formation.png)
NT-induced IP1 formation in cultured cells. A, effects of SR 142948A on IP1 formation induced by increasing concentrations of NT [10 (F), 100 (E) and 1000 nM (å)] in HT 29 cells. The results are expressed as a percentage of maximal NT response. Each point represents the mean S.E.M. of triplicate determinations. B, antagonism by SR 142948A (E) and SR 48692 (F) of NT-induced IP1 formation in h-NTR1-CHO cells. The results are expressed as a percentage of the effect of 10 nM NT. Each point represents the mean S.E.M. of three independent experiments performed in triplicate.
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![Fig. 2. Inhibition of the specific binding of [ 125 I-Tyr 3 ]NT to...](profile/Catherine-Labbe-Jullie/publication/14186841/figure/fig1/AS:601623416041493@1520449608633/Inhibition-of-the-specific-binding-of-125-I-Tyr-3-NT-to-h-NTR1CHO-cell-membranes-by_Q320.jpg)
![Fig. 3. Inhibition of [ 125 I-Tyr 3 ]NT specific binding to adult rat...](profile/Catherine-Labbe-Jullie/publication/14186841/figure/fig2/AS:601623416033289@1520449608649/Inhibition-of-125-I-Tyr-3-NT-specific-binding-to-adult-rat-brain-membranes-by-SR_Q320.jpg)
![Fig. 4. Inhibition by SR 142948A (F) and SR 48692 (f) of [ 3 H]SR 48692...](profile/Catherine-Labbe-Jullie/publication/14186841/figure/fig3/AS:601623416021018@1520449608664/Inhibition-by-SR-142948A-F-and-SR-48692-f-of-3-HSR-48692-specific-binding-to_Q320.jpg)
SR 142948A, 2-[[5-(2,6-dimethoxyphenyl)-1-(4-(N-(3-dimethylaminopropyl)-N-methylc arbamoyl)-2-isopropylphenyl)-1H-pyrazole3-carbonyl]amino] adamantane-2-carboxylic acid, hydrochloride, a new and extremely potent neurotensin (NT) receptor antagonist, has been characterized in comparison with SR 48692. This selective compound possesses nanomolar affi...
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Context 1
... mice (10 or multiples per group). SR 142948A (0.25-8 mg/kg) was administered p.o. (0.4 ml/20 g b.wt.) 1 hr before NT injection. Writh- ings were visually recorded between 5 and 15 min after PBQ injec- tion. Control animals received the corresponding vehicle. Statistical analysis was performed using ANOVA followed by Dunnett's t test. . 5B) with an IC 50 value of 9.7 1.7 nM, whereas SR 48692 was approximately 3-fold less effi- Vol. 280 cient in inhibiting this response (IC 50 value of 22.9 3.2 nM). In all of these experiments, SR 142948A alone (up to 1 M concentration) did not affect the basal level of IP1 (data not ...
Citations
... An ideal NTSR1 theranostic agent needs to have both high contrast and prominent-and-persistent tumor uptake. SR45398 was first developed as a nonpeptidic antagonist [34,35] that binds to NTSR1, which was later developed into SR142948A, a more efficient antagonist, showing nanomolar affinity with two binding sites of NTSR1 [36][37][38]. In the last decade, several PET imaging tracers have been synthesized based on analogs of SR142948A [39][40][41]. ...
Purpose
Accumulating evidence suggests that neurotensin (NTS) and neurotensin receptors (NTSRs) play key roles in lung cancer progression by triggering multiple oncogenic signaling pathways. This study aims to develop Cu-labeled neurotensin receptor 1 (NTSR1)-targeting agents with the potential for both imaging and therapeutic applications.
Method
A series of neurotensin receptor antagonists (NRAs) with variable propylamine (PA) linker length and different chelators were synthesized, including [⁶⁴Cu]Cu-CB-TE2A-iPA-NRA ([⁶⁴Cu]Cu-4a-c, i = 1, 2, 3), [⁶⁴Cu]Cu-NOTA-2PA-NRA ([⁶⁴Cu]Cu-4d), [⁶⁴Cu]Cu-DOTA-2PA-NRA ([⁶⁴Cu]Cu-4e, also known as [⁶⁴Cu]Cu-3BP-227), and [⁶⁴Cu]Cu-DOTA-VS-2PA-NRA ([⁶⁴Cu]Cu-4f). The series of small animal PET/CT were conducted in H1299 lung cancer model. The expression profile of NTSR1 was also confirmed by IHC using patient tissue samples.
Results
For most of the compounds studied, PET/CT showed prominent tumor uptake and high tumor-to-background contrast, but the tumor retention was strongly influenced by the chelators used. For previously reported 4e, [⁶⁴Cu]Cu-labeled derivative showed initial high tumor uptake accompanied by rapid tumor washout at 24 h. The newly developed [⁶⁴Cu]Cu-4d and [⁶⁴Cu]Cu-4f demonstrated good tumor uptake and tumor-to-background contrast at early time points, but were less promising in tumor retention. In contrast, our lead compound [⁶⁴Cu]Cu-4b demonstrated 9.57 ± 1.35, 9.44 ± 2.38 and 9.72 ± 4.89%ID/g tumor uptake at 4, 24, and 48 h p.i., respectively. Moderate liver uptake (11.97 ± 3.85, 9.80 ± 3.63, and 7.72 ± 4.68%ID/g at 4, 24, and 48 h p.i.) was observed with low uptake in most other organs. The PA linker was found to have a significant effect on drug distribution. Compared to [⁶⁴Cu]Cu-4b, [⁶⁴Cu]Cu-4a had a lower background, including a greatly reduced liver uptake, while the tumor uptake was only moderately reduced. Meanwhile, [⁶⁴Cu]Cu-4c showed increased uptake in both the tumor and the liver. The clinical relevance of NTSR1 was also demonstrated by the elevated tumor expression in patient tissue samples.
Conclusions
Through the side-by-side comparison, [⁶⁴Cu]Cu-4b was identified as the lead agent for further evaluation based on its high and sustained tumor uptake and moderate liver uptake. It can not only be used to efficiently detect NTSR1 expression in lung cancer (for diagnosis, patient screening, and treatment monitoring), but also has the great potential to treat NTSR-positive lesions once chelating to the beta emitter ⁶⁷Cu.
Graphical Abstract
... Neurotensin receptor 1 (NTSR1), a prototypical class A GPCR, plays a prominent role in the central nervous system and the periphery [3]. In the past 40 years, researchers have extensively developed small molecules and peptides to explore its biological functions [4][5][6][7][8][9]. These modulators, according to their biological effect, can be categorized into full agonists, partial agonists, and antagonists [10]. ...
... Furthermore, throughout decades of development of NTSR1 modulators, a ubiquitous phenomenon in the medicinal chemistry field has been that one single moiety difference in NTSR1 modulators can evoke distinct agonistic and antagonistic downstream signaling. For example, in full agonists SR12062 [8] and ML301 [10] and a partial agonist from the Research Triangle Institute (RTI) [6], substituting the leucine moiety for the adamantane moiety can transform the agonists into antagonists, like SR48692 [6] and SR-142948A [4]. Not fully interpreting the underlying mechanism of this phenomenon could inhibit drug discovery. ...
Small-molecule modulators of neurotensin receptor 1 (NTSR1), a class A G-protein-coupled receptor (GPCR), has emerged as promising therapeutic agent for psychiatric disorders and cancer. Interestingly, a chemical group substitution in NTSR1 modulators can launch different types of downstream regulation, highlighting the significance of deciphering the internal fine-tuning mechanism. Here, we conducted a synergistic application of a Gaussian accelerated molecular dynamics simulation, a conventional molecular dynamics simulation, and Markov state models (MSM) to investigate the underlying mechanism of 'driver chemical groups' of modulators triggering inverse signaling. The results indicated that the flexibility of the leucine moiety in NTSR1 agonists contributes to the inward displacement of TM7 through a loosely coupled allosteric pathway, while the rigidity of the adamantane moiety in NTSR1 antagonists leads to unfavorable downward transduction of agonistic signaling. Furthermore, we found that R3226.54, Y3196.51, F3537.42, R1483.32, S3567.45, and S3577.46 may play a key role in inducing the activation of NTSR1. Together, our findings not only highlight the ingenious signal transduction within class A GPCRs but also lay a foundation for the development of targeted drugs harboring different regulatory functions of NTSR1.
... SR-48692 and SR-142948A drugs display different activity spectra on NTRs [132,133]. However, both inhibit basal activity and antagonize NTR1-dependent activity (inverse agonism) [134]. ...
Harmful alcohol use is responsible for a group of disorders collectively named alcohol use disorders (AUDs), according to the DSM-5 classification. The damage induced by alcohol depends on the amount, time, and consumption patterns (continuous and heavy episodic drinking). It affects individual global well-being and social and familial environments with variable impact. Alcohol addiction manifests with different degrees of organ and mental health detriment for the individual, exhibiting two main traits: compulsive drinking and negative emotional states occurring at withdrawal, frequently causing relapse episodes. Numerous individual and living conditions, including the concomitant use of other psychoactive substances, lie in the complexity of AUD. Ethanol and its metabolites directly impact the tissues and may cause local damage or alter the homeostasis of brain neurotransmission, immunity scaffolding, or cell repair biochemical pathways. Brain modulator and neurotransmitter-assembled neurocircuitries govern reward, reinforcement, social interaction, and consumption of alcohol behaviors in an intertwined manner. Experimental evidence supports the participation of neurotensin (NT) in preclinical models of alcohol addiction. For example, NT neurons in the central nucleus of the amygdala projecting to the parabrachial nucleus strengthen alcohol consumption and preference. In addition, the levels of NT in the frontal cortex were found to be lower in rats bred to prefer alcohol to water in a free alcohol–water choice compared to wild-type animals. NT receptors 1 and 2 seem to be involved in alcohol consumption and alcohol effects in several models of knockout mice. This review aims to present an updated picture of the role of NT systems in alcohol addiction and the possible use of nonpeptide ligands modulating the activity of the NT system, applied to experimental animal models of harmful drinking behavior mimicking alcohol addiction leading to health ruin in humans.
... Since NTSR2 expression is regulated by inflammation, we investigated whether modulating NTSR activity with previously described agonists or antagonists could in turn regulate NTSR2 expression and glial cell inflammation. We used Levocabastine (Levo, NTSR2 agonist) (Coppola et al., 2008;Mazella et al., 1996;Richard et al., 2001), and SR142948A (SR, NTSR2 antagonist) (Gully et al., 1997;Kreitel et al., 2002;Schaeffer et al., 1998). Dual NTSR2/GFAP (Figure 8(a,b)), and NTSR2/Iba1 (Figure 8(c,d)) immunocytochemistry was carried out on primary glial cultures treated with NT, Levo, SR, LPS, LPS + NT, LPS + Levo, or LPS + SR for 24 h. ...
... SR142948A is a potent antagonist of both NTSR1 and NTSR2 (Dobner, 2005;Gully et al., 1997;Vita et al., 1998). Levocabastine acts as a NTSR2 agonist in mammals and amphibians (Coppola et al., 2008;Dong et al., 2015;Hwang et al., 2009;. ...
Neurotensin (NT) acts as a primary neurotransmitter and neuromodulator in the CNS and has been involved in a number of CNS pathologies including epilepsy. NT mediates its central and peripheral effects by interacting with the NTSR1, NTSR2, and Sort1/NTSR3 receptor subtypes. To date, little is known about the precise expression of the NT receptors in brain neural cells and their regulation in pathology. In the present work, we studied the cellular distribution of the NTSR2 protein in the rat hippocampus and questioned whether its expression was modulated in conditions of neuroinflammation using a model of temporal lobe epilepsy induced by pilocarpine. This model is characterized by a rapid and intense inflammatory reaction with reactive gliosis in the hippocampus. We show that NTSR2 protein is expressed in hippocampal astrocytes and its expression increases together with astrocyte reactivity following induction of status epilepticus. NTSR2 immunoreactivity is also increased in astrocytes proximal to blood vessels and their end‐feet, and in endothelial cells. Proinflammatory factors such as IL1β and LPS induced NTSR2 mRNA and protein in cultured astroglial cells. Antagonizing NTSR2 with SR142948A decreased NTSR2 expression as well as astroglial reactivity. Together, our results suggest that NTSR2 is implicated in astroglial and gliovascular inflammation and that targeting the NTSR2 receptor may open new avenues in the regulation of neuroinflammation in CNS diseases. Epilepsy is associated with increased NTSR2 expression in astrocytes and endothelial cells. Proinflammatory factors induce NTSR2 in astroglia. Antagonizing NTSR2 downregulates NTSR2 expression and glial cell inflammation.
... 17, 18 After few years of optimization, they identified SR142948A, a drug candidate with nanomolar affinity and potency for neurotensin receptors. 19,20 Starting from the structure of SR142948A, a few radiotracers were developed for the diagnosis or therapy of neurotensin receptor-positive cancers. Such tracers present several advantages: in the absence of activation of receptor's signaling pathways, they produce no pharmacological effect; they often show better metabolic stability than peptides; 21, 22 and, their small size allows for a rapid biodistribution, with fast renal clearance. ...
... Antagonist activities were determined on a fluorescent assay measuring [Ca 2+ ] mobilization in CHO cells overexpressing human recombinant NTS1, upon stimulation by neurotensin (0.3 nM), in the presence of increasing concentrations of nat Ga-bisNODAGA-16 (Eurofins, France). 19 SR142948A was used as an internal control (IC50 = 23 nM; KB = 2.1 nM). Results are expressed as a percent inhibition of control agonist response. ...
... The chemically related nonpeptide ligands SR48692 (Meclinertant) and SR142948A were identified by industry-led efforts over two decades ago (13,14). These compounds competitively antagonize NTSmediated effects, such as tumor promotion in various cancers (15)(16)(17)(18). ...
Neurotensin receptor 1 (NTSR1) and related G protein–coupled receptors of the ghrelin family are clinically unexploited, and several mechanistic aspects of their activation and inactivation have remained unclear. Enabled by a new crystallization design, we present five new structures: apo-state NTSR1 as well as complexes with nonpeptide inverse agonists SR48692 and SR142948A, partial agonist RTI-3a, and the novel full agonist SRI-9829, providing structural rationales on how ligands modulate NTSR1. The inverse agonists favor a large extracellular opening of helices VI and VII, undescribed so far for NTSR1, causing a constriction of the intracellular portion. In contrast, the full and partial agonists induce a binding site contraction, and their efficacy correlates with the ability to mimic the binding mode of the endogenous agonist neurotensin. Providing evidence of helical and side-chain rearrangements modulating receptor activation, our structural and functional data expand the mechanistic understanding of NTSR1 and potentially other peptidergic receptors.
... (Scheme 4). [31,47] The non-peptide antagonist SR 142948A showed high affinity to the NTS1R (K i = 1.03 nM), [47] but lower affinity to NTS2R (K i = 74 nM). [37] ...
... (Scheme 4). [31,47] The non-peptide antagonist SR 142948A showed high affinity to the NTS1R (K i = 1.03 nM), [47] but lower affinity to NTS2R (K i = 74 nM). [37] ...
... antagonist SR 142948A. [47] Based on the synthesis pathway of Dr. C. Lang, [85] Dr. A. Banerjee replaced the tertiary amide-moiety of the diphenylpyrazole by an alkyne-moiety (Scheme 9). [86] Scheme 9: Dr. A. Banerjee derivatized the NTS1R antagonist SR 142948A by introducing an alkynemoiety to obtain pyrazole ABN461. ...
In this thesis, the syntheses of two sets of bivalent ligands, which are supposed to address possible D3-NTS1 receptor heteromers, are presented: 2-(tert-Butyl)-4-(piperazin-1-yl)-6-(trifluoromethyl)pyrimidine attached to a lipophilic appendage was chosen as D3R-pharmacophore (NMP-120P). This moiety was added to a varying number of PEG(6)-spacer units. The applicability of the addition to the PEG(6)-spacers by amide bond formation was confirmed by determination of the binding properties of compound PGG131 which mimics the spacer-expanded D3R pharmacophore of the bivalent ligands. Ligand PGG131 showed only slight deviation in binding affinity to D3R, but a loss in selectivity compared to D2R. Replacement of the carboxylic acid-moiety of compound NMP-120P by a primary amide (PGG232), sulfonamide (PGG233) or nitrile (PGG236) resulted in ligands which showed similar binding properties to D2-like receptors as compound NMP-120P. Beside the bivalent ligands, a set of compounds targeting the dopamine D3 receptor were synthesized and tested in radio ligand binding assays for their binding properties to D2-like receptors by the biological section of our group. The binding assays revealed the influence of replacing the trifluoromethyl-moiety of ligand PGG79 with a difluoromethyl-moiety (PGG132) or with a carbonyl-moiety (PGG173) in case of affinity to D2-like receptors.
... With wild-type rNTR1, GTP exchange activity is very low if the receptor is present in the apo form or bound to the small molecule antagonist SR142948 (SR) [12] , and highly elevated in complex with the native agonist peptide neurotensin (NT1), as expected for a functional GPCR with low basal activity (black bars). The rNTR1 variant TM86V with fewer mutations, which has not been subjected to such a rigorous selection pressure as HTGH4, shows an increased basal activity but can still be stimulated in an agonist-dependent manner (red bars). ...
... (b) ESI-MS confirms the correct number of four attached -S-13 CH3 labels in the case of HTGH4. (c) CD-detected thermal stability analysis of 13 C-MMTS-labelled rNTR1 variants in complex with the agonist NT1 or the small molecule antagonist SR [12] in DDM micelles. ...
G protein‐coupled receptors (GPCRs) are key players in mediating signal transduction across the cell membrane. However, due to their intrinsic instability, many GPCRs are not suitable for structural investigations. Various approaches have been developed in recent years to remedy this situation, ranging from the use of more native membrane mimetics to protein‐stabilization methods. The latter approach typically results in GPCRs that contain various numbers of mutations. However, probing the functionality of such variants by in vitro and in vivo assays is often time consuming. In addition, to validate the suitability of such GPCRs for structural investigations, an assessment of their conformation state is required. NMR spectroscopy has been proven to be suitable to probe the conformation state of GPCRs in solution. Here, by using chemical labeling with an isotope‐labeled methyl probe, we show that the activity and the conformation state of stabilized neurotensin receptor 1 variants obtained from directed evolution can be efficiently assayed in 2D NMR experiments. This strategy enables the quantification of the active and inactive conformation states and the derivation of an estimation of the basal as well as agonist‐induced activity of the receptor. Furthermore, this assay can be used as a readout when re‐introducing agonist‐dependent signaling into a highly stabilized, and thus rigidified, receptor by mutagenesis. This approach will be useful in cases where low production yields do not permit the addition of labeled compounds to the growth medium and where 1D NMR spectra of selectively ¹⁹F‐labeled receptors are not sufficient to resolve signal overlap for a more detailed analysis.
... 73,88 The aim was to develop neurotensin receptor antagonists with an improved metabolic stability, less side effects compared to the already evaluated agonists, and an increased tumor uptake. The 112,113 The evaluation of both compounds demonstrated their potential to be used for NTS-mediated diseases as both SR48692 and SR142948A displayed no intrinsic agonist activity, oral bioavailability, long duration of action, and good brain access. 113 SR142948A, however, demonstrated a wider spectrum of activity compared to SR48692. ...
... The 112,113 The evaluation of both compounds demonstrated their potential to be used for NTS-mediated diseases as both SR48692 and SR142948A displayed no intrinsic agonist activity, oral bioavailability, long duration of action, and good brain access. 113 SR142948A, however, demonstrated a wider spectrum of activity compared to SR48692. 113 The aim of these compounds was the evaluation of potential interactions between neurotensin and other neurotransmitters in the brain. ...
... 113 SR142948A, however, demonstrated a wider spectrum of activity compared to SR48692. 113 The aim of these compounds was the evaluation of potential interactions between neurotensin and other neurotransmitters in the brain. 114,115 During in vivo evaluation it was demonstrated that SR48692 produced anxiolytic, anti-addictive and memory-impairing effects. ...
Pancreatic adenocarcinoma is the third leading cause of cancer related death in the U.S. with a 5-year survival rate of only 3 %. Novel radiopharmaceuticals for imaging, staging, and endoradiotherapy are therefore required to improve the quality of life of these patients. Safe and effective radiotracers require a high tumor uptake along with a low uptake in non-target tissues. Visualization of tumor lesions is as important as a high tumor uptake and a long tumor retention of a potential radiotherapeutic agent. Already evaluated NTS1 agonists showed some major disadvantages, including low metabolic stability and high kidney uptake that can lead to renal damages. Therefore, NTS1 antagonists could be valuable candidates to improve the characteristics of these tracers. The first aim of this thesis was the preclinical evaluation of four NTS1 antagonists for the potential use for imaging and endoradiotherapy of NTS1-positive tumors. For this purpose the DOTA-conjugated labeling precursors FAUC 468, CL 156, ABN 550, and ABN 596 were either labeled with 68Ga or 177Lu. All four radiotracers bound with high affinity to the neurotensin receptor 1 (NTS1) that is overexpressed in various tumor types, but only rarely expressed in healthy tissue. In vitro studies were performed to study the internalization, externalization, and saturation binding characteristics of the radioligands. High cell uptake along with a long retention time are favorable characteristics that were shown for all four radioligands. The uptake was comparable with 77 – 82 % internalized tracer (after 240 min), but the externalized fraction was 2 - 4× higher for the hydroxylated compounds ABN 550 and ABN 596. Furthermore, the metabolic stability was determined to prove the advantage of antagonists over agonists. All 177Lu-labeled compounds showed values of > 95 % intact tracer in vitro after an incubation period of 96 h in plasma. Small animal µPET imaging studies were performed to investigate if the hydroxylation in the linker of ABN 550 and ABN 596 showed significant influence on tumor visualization and retention, background uptake and blood plasma binding. For this purpose, AsPC-1 tumor bearing mice were intravenously injected with the respective 68Ga-labeled radiotracer and PET imaging was performed at 1 h and 2 h p.i., resulting in a clear visualization of the tumor. Blocking experiments were performed to confirm receptor-specificity. In an additional approach, the biodistribution of 68Ga- and 177Lu-labeled compounds in AsPC-1 tumor bearing mice was studied. In vivo biodistribution studies performed with the 68Ga-labeled radiotracers showed high uptake in the NTS1-positive tumors for all four tracers. The blood uptake in biodistribution studies was 2 – 3-fold increased for the hydroxylated derivatives, indicating a higher background, suggesting non-specific binding, being disadvantageous for diagnostic purposes. In vivo studies using the 177Lu-labeled compounds also displayed the increased blood uptake for the hydroxylated compounds. The highest uptake was seen for the NTS1 receptor-positive tumor, whereas the uptake in excretion organs was low. The highest tumor uptake of 177Lu-labeled compounds was observed for [177Lu]Lu-CL 162 (34 ± 2 % ID/g; 24 h p.i.), whereas [177Lu]Lu-FAUC 469 showed the longest retention of the radiopharmaceuticals in the tumor over an observation period of 7 d p.i.. Furthermore, it was investigated whether [177Lu]Lu-FAUC 469 or [177Lu]Lu-CL 162 are promising candidates for endoradiotherapy. Therefore, the following approaches were studied over 112 days in AsPC-1 tumor-bearing nude mice: i) application of a single-dose of 25 MBq [177Lu]Lu-CL 162, ii) application of a single-dose of 25 MBq [177Lu]Lu-FAUC 469, and iii) application of a multiple-dose of 2×25 MBq [177Lu]Lu-FAUC 469 on day 0 and day 10. To determine angiogenesis and hypoxia in the tumor tissue, PET imaging with [68Ga]Ga-NODAGA-RGD and [18F]F-FAZA was performed over the first 28 days of endoradiotherapy. To detect potential toxic effects of the injected radiotracers on kidney and liver tissue, the respective tissues were collected on the day of euthanasia of the mice and stained with HE and Masson-Goldner. The kidney function was checked by measuring the blood plasma parameters blood urea nitrogen and creatinine. Moreover, liver functional data were evaluated by measuring the ALT content in the blood. [177Lu]Lu-FAUC 469 administration resulted in reduced tumor growth and prolonged survival of treated animals compared to control animals. Most promising results were obtained after multiple-dose administration leading to 33 % (n = 2) “cured” animals. No negative effects were confirmed in either histological and clinical chemistry evaluation. The long-term toxicity effects of [177Lu]Lu-FAUC 469 were studied in healthy mice over 50 weeks. Hence, the single-dose administration of 25 MBq [177Lu]Lu-FAUC 469 was compared with a two-dose administration of 2×25 MBq [177Lu]Lu-FAUC 469. After a time period of 9, 22, and 50 weeks, 2 - 3 animals of each group were sacrificed and kidneys and livers were evaluated for toxic effects using histological analysis. The body weight was comparable for all groups, no signs of unease were detected for any animal. The histological analyses and the determination of blood plasma parameters, including glucose, blood urea nitrogen, creatinine, and ALT, did not reveal any signs of liver and tissue damage. The next approach was the translation of the most promising candidate [177Lu]Lu-FAUC 469 from “bench to bedside”. In order to translate the radiopharmaceutical in the clinical routine of the University Hospital Erlangen, the preclinical evaluation was followed by the GMP compliant validation of the production of [177Lu]Lu-FAUC 469 in the GMP radiopharmacy of the nuclear medicine. The validation of a GMP-compliant quality control was essential prior to the administration of the finally formulated radiopharmaceutical to a patient. This procedure included the assessment of radiochemical and chemical purity, the determination of impurities, sterility, endotoxin content and pH value. During the evaluation of 177Lu-labeled FAUC 469, the feasibility of preparing the radiopharmaceutical according to GMP guidelines was demonstrated. The production process was validated and proven to be robust and reproducible. In conclusion, we were able to fulfill the step from “bench to bedside” for [177Lu]Lu-FAUC 469. [177Lu]Lu-FAUC 469 was the most promising candidate to be evaluated in further in vivo studies, showing a reduced tumor growth, a prolonged survival, and no toxic influence. Therefore, first-in-human studies with [177Lu]Lu-FAUC 469 are currently ongoing to discover whether the promising characteristics of [177Lu]Lu-FAUC 469 in mice can be translated to patients suffering from pancreatic adenocarcinoma.
... Le SR 48692, antagoniste non peptidique du NTSR1, qui passe la barrière hémato-encéphalique, a été développé dans le cadre de la schizophrénie. Comparé à la NTS, le SR 48692 a une affinité inférieure pour le NTSR2 que pour le NTSR1 (Gully et al., 1997) (Figure 17). ...
... La contribution du complexe NTS/NTSR1 dans la stimulation de la croissance tumorale a été rapportée dans plusieurs études en profitant d'antagonistes NTSR1 spécifiques, SR48692 et SR142948A (Gully et al., 1997). Une diminution d'au moins 50 % dans le volume et le poids de la tumeur a été observée chez les xénogreffes de cellules cancéreuses du colon lorsque des animaux ont été traités quotidiennement avec un antagoniste NTSR1 (Maoret et al., 1999, Moody et al., 2001, Liu et al., 2017. ...
Le récepteur de haute affinité 1 (NTSR1) et son agoniste, la neurotensine (NTS), sont corrélés avec l’agressivité tumorale dans la plupart des tumeurs solides, y compris les cancers hormono-dépendants. Comme l’endomètre et l’ovaire sont également soumis à une régulation hormonale, nous avons évalué la contribution de NTS/NTSR1 à la carcinogenèse de l’endomètre et de l’ovaire. L’expression du récepteur de la neurotensine 1 (NTSR1) et la méthylation du promoteur NTSR1 (HM450) ont été analysées dans 385 cas de carcinome de l’endomètre du Cancer Genome Atlas (TCGA). De plus, à partir d’une série de 100 carcinomes de l’endomètre et de 66 échantillons d’endomètre bénin, l’expression de NTS et NTSR1 a été évalué par immunohistochimie. La série TCGA d’adénocarcinomes ovariens séreux de haut grade et une série de 46 tissus ovariens ont également été analysés. Dans la série TCGA de carcinomes de l’endomètre, le taux d’ARN messager de NTSR1 (ARNm) était négativement corrélé avec la survie globale (SG) et la survie sans progression (SSP) (p = 0,0012 et p = 0,0116, respectivement), et positivement corrélé avec le grade (p = 0,0008). En incluant seulement les carcinomes endométrioïdes, le niveau d’ARNm de NTSR1 était également négativement corrélé avec la SG (log-rank:p < 0.0001) et la SSP (log-rank: p = 0.002). Une forte expression d’ARNm de NTSR1 était significativement associée à une perte de méthylation du promoteur NTSR1. L’expression immunohistochimique de NTS et NTSR1 était significativement augmentée dans l’adénocarcinome (n = 100), par rapport à l’endomètre bénin (p <0,001). L’expression de NTSR1 était positivement corrélée avec le grade (p = 0,004). Une forte expression du NTSR1 cytoplasmique était significativement corrélée avec une SG et une SSP plus courtes (p < 0,001 et p = 0,001, respectivement). Cette corrélation restait significative en excluant les sous-types non-endométrioïdes (p = 0,04 et p = 0,02, respectivement). En analyse multivariée, l’expression de NTSR1 était un facteur de mauvais pronostic indépendant (p = 0,004). Nos résultats indiquent également la présence d’une corrélation positive entre l’expression du marqueur de prolifération MCM6 et le grade histologique dans le sous-type endométrioïde (grade I, 66,7 %, grade II, 75,3 %, grade III, 81,4 %, p <0,001) et une corrélation inverse à la SG et à la SSP (p = 0,02 pour les deux). Dans la cohorte TCGA, les analyses de Cox univariées et multivariées (p = 0,003 et p = 0,03, respectivement) ont révélé que les z-scores élevés de l’ARNm de MCM6 étaient associés à une SG réduite. Ces associations étaient absentes pour Ki-67. Il n’y avait pas de corrélation significative entre NTSR1 et MCM6 ou Ki-67. Dans l’adénocarcinome de l’ovaire, la NTS et NTSR1 ont été détectés dans 72 % et 74 % des cancers de l’ovaire, respectivement. En outre, dans la grande série d’adénocarcinomes ovariens séreux de haut grade, l’ARNm de NTSR1 s’est avéré être en corrélation avec des stades plus élevés et la résistance au platine (p = 0.02). Ceci est concordant avec les résultats expérimentaux montrant que l’antagoniste très spécifique de NTSR1, le SR48692, a augmenté la réponse au carboplatine dans les cellules cancéreuses de l’ovaire et les tumeurs expérimentales induites. Lorsque le SR48692 est combiné avec du carboplatine, une augmentation majeure des dommages à l’ADN induits par le platine et de la mort cellulaire, ainsi qu’une diminution de la croissance tumorale, a été notée. La surexpression de NTSR1 est un facteur de mauvais pronostic dans les cancers de l’endomètre et de l’ovaire, mettant en évidence la contribution de NTS dans la progression du cancer et ses utilisations en tant que marqueur pronostique, et en tant que cible thérapeutique potentielle. L’ajout d’un inhibiteur de NTSR1 en association avec une thérapie à base de sel de platine pourrait améliorer la réponse au traitement
