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Wei W, Xu Q, Wu L, Gong G, Tian Y, Huang H, Li Z. Drug development and potential targets for Cushing's syndrome. Eur J Med Chem 2024; 270:116333. [PMID: 38569434 DOI: 10.1016/j.ejmech.2024.116333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
Cushing's syndrome (CS) is a complex disorder characterized by the excessive secretion of cortisol, with Cushing's disease (CD), particularly associated with pituitary tumors, exhibiting heightened morbidity and mortality. Although transsphenoidal pituitary surgery (TSS) stands as the primary treatment for CD, there is a crucial need to optimize patient prognosis. Current medical therapy serves as an adjunctive measure due to its unsatisfactory efficacy and unpredictable side effects. In this comprehensive review, we delve into recent advances in understanding the pathogenesis of CS and explore therapeutic options by conducting a critical analysis of potential drug targets and candidates. Additionally, we provide an overview of the design strategy employed in previously reported candidates, along with a summary of structure-activity relationship (SAR) analyses and their biological efficacy. This review aims to contribute valuable insights to the evolving landscape of CS research, shedding light on potential avenues for therapeutic development.
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Affiliation(s)
- Wei Wei
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Qianqian Xu
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Liuyi Wu
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Guangyue Gong
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Yucheng Tian
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Huidan Huang
- Center of Drug Screening & Evaluation, Wannan Medical College, Wuhu, Anhui, 241000, PR China.
| | - Zhiyu Li
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, PR China.
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Yang J, Zhu Q, Wu Y, Qu X, Liu H, Jiang B, Ge D, Song X. Utilization of macrocyclic peptides to target protein-protein interactions in cancer. Front Oncol 2022; 12:992171. [PMID: 36465350 PMCID: PMC9714258 DOI: 10.3389/fonc.2022.992171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/24/2022] [Indexed: 07/30/2023] Open
Abstract
Protein-protein interactions (PPIs) play vital roles in normal cellular processes. Dysregulated PPIs are involved in the process of various diseases, including cancer. Thus, these PPIs may serve as potential therapeutic targets in cancer treatment. However, despite rapid advances in small-molecule drugs and biologics, it is still hard to target PPIs, especially for those intracellular PPIs. Macrocyclic peptides have gained growing attention for their therapeutic properties in targeting dysregulated PPIs. Macrocyclic peptides have some unique features, such as moderate sizes, high selectivity, and high binding affinities, which make them good drug candidates. In addition, some oncology macrocyclic peptide drugs have been approved by the US Food and Drug Administration (FDA) for clinical use. Here, we reviewed the recent development of macrocyclic peptides in cancer treatment. The opportunities and challenges were also discussed to inspire new perspectives.
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Affiliation(s)
- Jiawen Yang
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
- Shanghai Clinical Research and Trial Center, Shanghai, China
| | - Qiaoliang Zhu
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yifan Wu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaojuan Qu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Haixia Liu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Biao Jiang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Di Ge
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoling Song
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
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3
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Börzsei R, Zsidó BZ, Bálint M, Helyes Z, Pintér E, Hetényi C. Exploration of Somatostatin Binding Mechanism to Somatostatin Receptor Subtype 4. Int J Mol Sci 2022; 23:ijms23136878. [PMID: 35805885 PMCID: PMC9266823 DOI: 10.3390/ijms23136878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 02/04/2023] Open
Abstract
Somatostatin (also named as growth hormone-inhibiting hormone or somatotropin release-inhibiting factor) is a regulatory peptide important for the proper functioning of the endocrine system, local inflammatory reactions, mood and motor coordination, and behavioral responses to stress. Somatostatin exerts its effects via binding to G-protein-coupled somatostatin receptors of which the fourth subtype (SSTR4) is a particularly important receptor mediating analgesic, anti-inflammatory, and anti-depressant effects without endocrine actions. Thus, SSTR4 agonists are promising drug candidates. Although the knowledge of the atomic resolution-binding modes of SST would be essential for drug development, experimental elucidation of the structures of SSTR4 and its complexes is still awaiting. In the present study, structures of the somatostatin–SSTR4 complex were produced using an unbiased, blind docking approach. Beyond the static structures, the binding mechanism of SST was also elucidated in the explicit water molecular dynamics (MD) calculations, and key binding modes (external, intermediate, and internal) were distinguished. The most important residues on both receptor and SST sides were identified. An energetic comparison of SST binding to SSTR4 and 2 offered a residue-level explanation of receptor subtype selectivity. The calculated structures show good agreement with available experimental results and indicate that somatostatin binding is realized via prerequisite binding modes and an induced fit mechanism. The identified binding modes and the corresponding key residues provide useful information for future drug design targeting SSTR4.
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Affiliation(s)
- Rita Börzsei
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Balázs Zoltán Zsidó
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Mónika Bálint
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
- Algonist Gmbh, 1030 Vienna, Austria
- PharmInVivo Ltd., 7624 Pécs, Hungary
| | - Erika Pintér
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
- Algonist Gmbh, 1030 Vienna, Austria
- PharmInVivo Ltd., 7624 Pécs, Hungary
| | - Csaba Hetényi
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (R.B.); (B.Z.Z.); (M.B.); (Z.H.); (E.P.)
- János Szentágothai Research Centre & Centre for Neuroscience, University of Pécs, 7624 Pécs, Hungary
- Correspondence:
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Slater O, Kontoyianni M. A computational study of somatostatin subtype-4 receptor agonist binding. SN APPLIED SCIENCES 2022. [DOI: 10.1007/s42452-022-04968-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
AbstractThe somatostatin subtype-4 receptor (sst4) is highly expressed in neocortical and hippocampal areas, which are affected by amyloid beta accumulation. Sst4 agonists enhance downstream activity of amyloid beta peptide catabolism through neprilysin and may slow the progression of Alzheimer’s disease (AD). Sst4 is a G protein coupled receptor (GPCR), the structure of which has yet to be resolved. A newly constructed sst4 homology model, along with a previously reported model-built sst4 receptor structure, were used in the present study to gain insights into binding requirements of sst4 agonists employing a set of compounds patented by Boehringer Ingelheim. Besides aiming at delineating binding at the macromolecular level of these recently disclosed compounds, our objectives included the generation of a quantitative structure-activity relationship (QSAR) global model to explore the relationship between chemical structure and affinity. Through the implementation of model building, docking, and QSAR, plausible correlations between structural properties and the binding affinity are established. This study sheds light on understanding binding requirements at the sst4 receptor.
Graphical abstract
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Neumann WL, Sandoval KE, Mobayen S, Minaeian M, Kukielski SG, Srabony KN, Frare R, Slater O, Farr SA, Niehoff ML, Hospital A, Kontoyianni M, Crider AM, Witt KA. Synthesis and structure-activity relationships of 3,4,5-trisubstituted-1,2,4-triazoles: high affinity and selective somatostatin receptor-4 agonists for Alzheimer's disease treatment. RSC Med Chem 2021; 12:1352-1365. [PMID: 34458738 DOI: 10.1039/d1md00044f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/14/2021] [Indexed: 12/23/2022] Open
Abstract
Somatostatin receptor-4 (SST4) is highly expressed in brain regions affiliated with learning and memory. SST4 agonist treatment may act to mitigate Alzheimer's disease (AD) pathology. An integrated approach to SST4 agonist lead optimization is presented herein. High affinity and selective agonists with biological efficacy were identified through iterative cycles of a structure-based design strategy encompassing computational methods, chemistry, and preclinical pharmacology. 1,2,4-Triazole derivatives of our previously reported hit (4) showed enhanced SST4 binding affinity, activity, and selectivity. Thirty-five compounds showed low nanomolar range SST4 binding affinity, 12 having a K i < 1 nM. These compounds showed >500-fold affinity for SST4 as compared to SST2A. SST4 activities were consistent with the respective SST4 binding affinities (EC50 < 10 nM for 34 compounds). Compound 208 (SST4 K i = 0.7 nM; EC50 = 2.5 nM; >600-fold selectivity over SST2A) display a favorable physiochemical profile, and was advanced to learning and memory behavior evaluations in the senescence accelerated mouse-prone 8 model of AD-related cognitive decline. Chronic administration enhanced learning with i.p. dosing (1 mg kg-1) compared to vehicle. Chronic administration enhanced memory with both i.p. (0.01, 0.1, 1 mg kg-1) and oral (0.01, 10 mg kg-1) dosing compared to vehicle. This study identified a novel series of SST4 agonists with high affinity, selectivity, and biological activity that may be useful in the treatment of AD.
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Affiliation(s)
- William L Neumann
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Karin E Sandoval
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Shirin Mobayen
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Mahsa Minaeian
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Stephen G Kukielski
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Khush N Srabony
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Rafael Frare
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Olivia Slater
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Susan A Farr
- Research and Development Service, VA Medical Center, Division of Geriatric Medicine, Saint Louis University School of Medicine 1402 South Grand Boulevard, M238 St Louis MO 63104 USA
| | - Michael L Niehoff
- Research and Development Service, VA Medical Center, Division of Geriatric Medicine, Saint Louis University School of Medicine 1402 South Grand Boulevard, M238 St Louis MO 63104 USA
| | - Audrey Hospital
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Maria Kontoyianni
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - A Michael Crider
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
| | - Ken A Witt
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville Edwardsville IL 62026 USA
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Duong Phu M, Bross S, Burkhalter MD, Philipp M. Limitations and opportunities in the pharmacotherapy of ciliopathies. Pharmacol Ther 2021; 225:107841. [PMID: 33771583 DOI: 10.1016/j.pharmthera.2021.107841] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/11/2021] [Indexed: 01/10/2023]
Abstract
Ciliopathies are a family of rather diverse conditions, which have been grouped based on the finding of altered or dysfunctional cilia, potentially motile, small cellular antennae extending from the surface of postmitotic cells. Cilia-related disorders include embryonically arising conditions such as Joubert, Usher or Kartagener syndrome, but also afflictions with a postnatal or even adult onset phenotype, i.e. autosomal dominant polycystic kidney disease. The majority of ciliopathies are syndromic rather than affecting only a single organ due to cilia being found on almost any cell in the human body. Overall ciliopathies are considered rare diseases. Despite that, pharmacological research and the strive to help these patients has led to enormous therapeutic advances in the last decade. In this review we discuss new treatment options for certain ciliopathies, give an outlook on promising future therapeutic strategies, but also highlight the limitations in the development of therapeutic approaches of ciliopathies.
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Affiliation(s)
- Max Duong Phu
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Stefan Bross
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Martin D Burkhalter
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Melanie Philipp
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany.
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Schorn S, Vogel T, Demir IE, Demir E, Safak O, Friess H, Ceyhan GO. Do somatostatin-analogues have the same impact on postoperative morbidity and pancreatic fistula in patients after pancreaticoduodenectomy and distal pancreatectomy? - A systematic review with meta-analysis of randomized-controlled trials. Pancreatology 2020; 20:1770-1778. [PMID: 33121847 DOI: 10.1016/j.pan.2020.10.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/22/2020] [Accepted: 10/14/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Postoperative pancreatic fistula/POPF is the most feared complication in pancreatic surgery. Although several systematic reviews investigated the impact of somatostatin analogues on POPF, no stratification was performed regarding type of pancreatic resection (pancreaticoduodenectomy/PD; distal pancreatectomy/DP) and different somatostatin analogues. METHODS This study was planed according to the Preferred-Reporting-Items-for-Systematic -Review-and-Meta-Analysis/PRISMA-guidelines. After screening databases for randomized controlled trials/RCT, studies were stratified into pancreatic resection techniques and data were pooled in meta-analyses containing subgroups of octreotide, somatostatin, lanreotide, pasireotide and vapreotide. RESULTS The meta-analysis of studies with a mixed cohort of patients after pancreatic resection revealed a protective effect of somatostatin analogues for morbidity (RR: 0.71, p < .00001) but not for mortality (RR: 1.07, = 0.78) or intra-abdominal abscesses (RR: 1.00, p = 1.00). Moreover, no effect was visible for mortality (RR: 1.57, p = .15), morbidity (RR: 0.87, p = .15) and intra-abdominal abscesses (RR: 0.92, p = .48) after PD. The meta-analysis of patients after PD revealed no impact of somatostatin analogues on POPF (RR: 0.87, p = .19) and clinically relevant POPF (RR: 0.69, p = .30). However, treatment with somatostatin analogues in the mixed cohort showed less POPF (RR: 0.60, p < .00001) and clinically relevant POPF (RR: 0.47, p = .02), which was also the case after DP (RR: 0.41, p = .03). CONCLUSION Somatostatin analogues did not affect POPF and clinically relevant POPF after PD, but seemed to be associated with less POPF after DP. As no sufficiently powered RCT could be identified by the systematic review, further RCTs are urgently needed to investigate the effect of somatostatin analogues after DP. STUDY REGISTRATION CRD42018099808.
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Affiliation(s)
- Stephan Schorn
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany.
| | - Thomas Vogel
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany
| | - Ihsan Ekin Demir
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany; Department of General Surgery, HPB-Unit, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Elke Demir
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany
| | - Okan Safak
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany
| | - Helmut Friess
- Technical University of Munich, School of Medicine, Klinikum Rechts der Isar, Department of Surgery, Germany
| | - Güralp Onur Ceyhan
- Department of General Surgery, HPB-Unit, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
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A new 68Ga-labeled somatostatin analog containing two iodo-amino acids for dual somatostatin receptor subtype 2 and 5 targeting. EJNMMI Res 2020; 10:90. [PMID: 32757150 PMCID: PMC7406630 DOI: 10.1186/s13550-020-00677-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/22/2020] [Indexed: 01/02/2023] Open
Abstract
Background Somatostatin receptor (SST) targeting, specifically of the subtype 2 (SST2), with radiolabeled somatostatin analogs, is established for imaging and treatment of neuroendocrine tumors. Owing to the concomitant and heterogeneous expression of several subtypes on the same tumor, analogs targeting more subtypes than SST2 potentially target a broader spectrum of tumors and/or increase the uptake of a given tumor. The analog ST8950 ((4-amino-3-iodo)-d-Phe-c[Cys-(3-iodo)-Tyr-d-Trp-Lys-Val-Cys]-Thr-NH2), bearing 2 iodo-amino acids, exhibits sub-nanomolar affinity to SST2 and SST5. We report herein the development and preclinical evaluation of DOTA-ST8950 labeled with 68Ga, for imaging SST2- and SST5-expressing tumors. Comparative in vitro and in vivo studies were performed with the de-iodinated DOTA-ST8951 ((4-amino)-d-Phe-c[Cys-Tyr-d-Trp-Lys-Val-Cys]-Thr-NH2) and with the reference compounds DOTA-TATE (SST2 selective) and DOTA-NOC (for SST2 and SST5). Results Compared with natGa-DOTA-NOC, natGa-DOTA-ST8950 exhibited higher affinity to SST2 and SST5 (IC50 (95%CI), nM = 0.32 (0.20–0.50) and 1.9 (1.1–3.1) vs 0.70 (0.50-0.96) and 3.4 (1.8-6.2), respectively), while natGa-DOTA-ST8951 lost affinity for both subtypes. natGa-DOTA-ST8950 had the same potency for inducing SST2-mediated cAMP accumulation as natGa-DOTA-TATE and slightly better than natGa-DOTA-NOC (EC50, nM = 0.46 (0.23–0.92) vs 0.47 (0.15–1.5) vs 0.59 (0.18–1.9), respectively). [67Ga]Ga-DOTA-ST8950 had a similar internalization rate as [67Ga]Ga-DOTA-NOC in SST2-expressing cells (12.4 ± 1.6% vs 16.6 ± 2.2%, at 4 h, p = 0.0586). In vivo, [68Ga]Ga-DOTA-ST8950 showed high and specific accumulation in SST2- and SST5-expressing tumors, comparable with [68Ga]Ga-DOTA-NOC (26 ± 8 vs 30 ± 8 %IA/g, p = 0.4630 for SST2 and 15 ± 6 vs 12 ± 5 %IA/g, p = 0.3282, for SST5, 1 h p.i.) and accumulation in the SST-positive tissues, the kidneys and the liver. PET/CT images of [68Ga]Ga-DOTA-ST8950, performed in a dual HEK-SST2 and HEK-SST5 tumor xenografted model, clearly visualized both tumors and illustrated high tumor-to-background contrast. Conclusions [68Ga]Ga-DOTA-ST8950 reveals its potential for PET imaging SST2- and SST5-expressing tumors. It compares favorably with the clinically used [68Ga]Ga-DOTA-NOC in terms of tumor uptake; however, its uptake in the liver remains a challenge for clinical translation. In addition, this study reveals the essential role of the iodo-substitutions in positions 1 and 3 of [68Ga]Ga-DOTA-ST8950 for maintaining affinity to SST2 and SST5, as the de-iodinated [68Ga]Ga-DOTA-ST8951 lost affinity for both receptor subtypes.
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Structural modifications of amino acid sequences of radiolabeled peptides for targeted tumor imaging. Bioorg Chem 2020; 99:103802. [DOI: 10.1016/j.bioorg.2020.103802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/19/2020] [Accepted: 03/25/2020] [Indexed: 12/18/2022]
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10
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The discovery of potent and stable short peptide FGFR1 antagonist for cancer therapy. Eur J Pharm Sci 2019; 143:105179. [PMID: 31841696 DOI: 10.1016/j.ejps.2019.105179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/16/2019] [Accepted: 12/07/2019] [Indexed: 11/22/2022]
Abstract
Fibroblast growth factor receptor 1 (FGFR1) is one of the attractive pharmaceutical targets for cancer therapy. The FGFR1 targeting antagonist peptides, especially of the short peptides harbouring only coding amino acid might highlights promising aspects for their higher affinity, specificity and lower adverse reactions. However, most of peptides inhibitors remain in preclinical research, likely associating with their instability and short half-life. In this study, we found a stable short peptide inhibitor P48 and speculated that its stability might be related to its non-linear spatial structure. In addition, P48 could target the extracellular immunoglobulin domain of FGFR1, and effectively block the particular signaling pathways of FGFR1, which lead to the inhibition of cancer proliferation, invasion in vitro and restraint of tumor growth in vivo. Together, this study provided a promising FGFR1 inhibitor with the potential to be developed as an antitumor drug.
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Ma C, Chen M, Chu W, Tao J, Kong D, Zhang M, Feng W. A Practical and Total Synthesis of Pasireotide: Synthesis of Cyclic Hexapeptide via a Three-Component Condensation. Molecules 2019; 24:molecules24112185. [PMID: 31212595 PMCID: PMC6600510 DOI: 10.3390/molecules24112185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/29/2019] [Accepted: 06/04/2019] [Indexed: 11/16/2022] Open
Abstract
Pasireotide is a multi-receptor ligand somatostatin analogue approved for medical treatment of Cushing’s disease and acromegaly. The liquid-phase total synthesis of pasireotide-a 18-membered cyclic hexapeptide-was achieved by the 3 + 2 + 1 strategy, and the Pro1-Phe6 peptide bond was selected as the final cyclization position. Two key fragments were simply synthesized using N,O-bis(trimethylsilyl)acetamide/N-hydroxysuccinimide ester (BSA/NHS) as coupling agents, and processes of the two key fragments were simple without any chromatographic purification. The current synthesis method is easily scalable and produces the target peptide with an overall yield of 15%.
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Affiliation(s)
- Chunying Ma
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Miao Chen
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Weiming Chu
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Jiayi Tao
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Delong Kong
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Mengmeng Zhang
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
| | - Wenhua Feng
- Department of New Drug Research and Development, Institute of Materia Medical, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
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Ligand design for somatostatin receptor isoforms 4 and 5. Eur J Med Chem 2019; 163:148-159. [DOI: 10.1016/j.ejmech.2018.11.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 12/14/2022]
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13
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Daryaei I, Sandoval K, Witt K, Kontoyianni M, Michael Crider A. Discovery of a 3,4,5-trisubstituted-1,2,4-triazole agonist with high affinity and selectivity at the somatostatin subtype-4 (sst 4) receptor. MEDCHEMCOMM 2018; 9:2083-2090. [PMID: 30746066 PMCID: PMC6336083 DOI: 10.1039/c8md00388b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/06/2018] [Indexed: 12/20/2022]
Abstract
A series of compounds containing a 1,2,4-triazole moiety were synthesized, targeting the somatostatin receptor subtype-4 (sst4). Compounds were developed in which the Phe6/Phe7/Phe11, Trp8, and Lys9 mimetic groups were interchanged at positions 3, 4, and 5 of the 1,2,4-triazole ring. The 1,2,4-triazoles containing an 2-(imidazol-4-yl)ethyl substituent at position-3 demonstrated moderate binding affinity at sst4. 1,2,4-Triazoles containing an (indol-3-yl)methyl substituent at position-5 lacked affinity at sst4. The 1,2,4-triazoles containing an aminopropyl group at position-4 showed enhanced binding affinity compared to the 3-position. One compound with an 3-(imidazol-4-yl)propyl group at position-4 (compound 44) imparted high affinity and selectivity at sst4 (sst2A = >10 000 nM; sst4 = 19 nM), acting as an agonist (EC50 = 6.8 nM). Docking 44 into a model-built structure of sst4 pointed to differences in its binding versus the other low-affinity compounds and was also in line with one of the two previously reported binding modes. A virtual screening (VS) experiment, employing two separate docking algorithms, was able to score 44 among the top-ranked poses. In summary, compound 44 represents a novel and promising lead structure towards the development of a clinically viable sst4 agonist for the treatment of conditions ranging from Alzheimer's disease to chronic pain.
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Affiliation(s)
- Iman Daryaei
- Department of Pharmaceutical Sciences , School of Pharmacy , Southern Illinois University Edwardsville , Edwardsville , IL , 62026-2000 USA .
- NuvOx Pharma , 1635 18th St , Tucson , AZ , 85719 USA
| | - Karin Sandoval
- Department of Pharmaceutical Sciences , School of Pharmacy , Southern Illinois University Edwardsville , Edwardsville , IL , 62026-2000 USA .
| | - Ken Witt
- Department of Pharmaceutical Sciences , School of Pharmacy , Southern Illinois University Edwardsville , Edwardsville , IL , 62026-2000 USA .
| | - Maria Kontoyianni
- Department of Pharmaceutical Sciences , School of Pharmacy , Southern Illinois University Edwardsville , Edwardsville , IL , 62026-2000 USA .
| | - A Michael Crider
- Department of Pharmaceutical Sciences , School of Pharmacy , Southern Illinois University Edwardsville , Edwardsville , IL , 62026-2000 USA .
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14
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Liu F, Liu T, Xu X, Guo X, Li N, Xiong C, Li C, Zhu H, Yang Z. Design, Synthesis, and Biological Evaluation of 68Ga-DOTA-PA1 for Lung Cancer: A Novel PET Tracer for Multiple Somatostatin Receptor Imaging. Mol Pharm 2018; 15:619-628. [PMID: 29278911 DOI: 10.1021/acs.molpharmaceut.7b00963] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Most of the radiolabeled somatostatin analogues (SSAs) are specific for subtype somatostatin receptor 2 (SSTR2). Lack of ligands targeting other subtypes of SSTRs, especially SSTR1, SSTR3, and SSTR5, limited their applications in tumors of low SSTR2 expression, including lung tumor. In this study, we aimed to design and synthesize a positron emission tomography (PET) radiotracer targeting multi-subtypes of SSTRs for PET imaging. PA1 peptide and its conjugate with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator or fluorescein isothiocyanate (FITC) at the N-terminal of the lysine position were synthesized. 68Ga was chelated to DOTA-PA1 to obtain 68Ga-DOTA-PA1 radiotracer. The stability, lipophilicity, binding affinity, and binding specificity of 68Ga-DOTA-PA1 and FITC-PA1 were evaluated by various in vitro experiments. Micro-PET imaging of 68Ga-DOTA-PA1 was performed in nude mice bearing A549 lung adenocarcinoma, as compared with 68Ga-DOTA-(Tyr3)-octreotate (68Ga-DOTA-TATE). Histological analysis of SSTR expression in A549 tumor tissues and human tumor tissues was conducted using immunofluorescence staining and immunohistochemical assay. 68Ga-DOTA-PA1 had high radiochemical yield and radiochemical purity of over 95% and 99%, respectively. The radiotracer was stable in vitro in different buffers over a 2 h incubation period. Cell uptake of 68Ga-DOTA-PA1 was 1.31-, 1.33-, and 1.90-fold that of 68Ga-DOTA-TATE, which has high binding affinity only for SSTR2, after 2 h incubation in H520, PG, and A549 lung cancer cell lines, respectively. Micro-PET images of 68Ga-DOTA-PA1 showed that the PET imaging signal correlated with the total expression of SSTRs, instead of SSTR2 only, which was measured by Western blotting and immunofluorescence analysis in mice bearing A549 tumors. In summary, a novel PET radiotracer, 68Ga-DOTA-PA1, targeting multi-subtypes of SSTRs, was successfully synthesized and was confirmed to be useful for PET imaging. It may have potential as a noninvasive PET radiotracer for imaging SSTR-positive tumors.
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Affiliation(s)
- Fei Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Teli Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Xiaoxia Xu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Xiaoyi Guo
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Nan Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Chiyi Xiong
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center , Houston, Texas 77030, United States
| | - Chun Li
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center , Houston, Texas 77030, United States
| | - Hua Zhu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute , Beijing 100142, P. R. China
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15
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Treppiedi D, Peverelli E, Giardino E, Ferrante E, Calebiro D, Spada A, Mantovani G. Somatostatin Receptor Type 2 (SSTR2) Internalization and Intracellular Trafficking in Pituitary GH-Secreting Adenomas: Role of Scaffold Proteins and Implications for Pharmacological Resistance. Horm Metab Res 2017; 49:259-268. [PMID: 27632151 DOI: 10.1055/s-0042-116025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractSomatostatin receptor type 2 (SSTR2), together with SSTR5, represents the main
target of medical treatment for growth hormone (GH)-secreting pituitary tumors,
since it is expressed in most of these tumors and exerts both antiproliferative
and cytostatic effects, and reduces hormone secretion, as well. However,
clinical practice indicates a great variability in the frequency and entity of
favorable responses of acromegalic patients to long-acting somatostatin
analogues (SSAs), but the molecular mechanisms regulating this pharmacological
resistance are not completely understood. So far, several potentially implied
mechanisms have been suggested, including impaired expression of SSTRs, or
post-receptor signal transduction alterations. More recently, new studies
exploited the molecular factors involved in SSTRs intracellular trafficking
regulation, this being a critical point for the modulation of the available
active G-coupled receptors (GPCRs) amount at the cell surface. In this respect,
the role of the scaffold proteins such as β-arrestins, and the cytoskeleton
protein Filamin A (FLNA), have become of relevant importance for GH-secreting
pituitary tumors. In fact, β-arrestins are linked to SSTR2 desensitization and
internalization, and FLNA is able to regulate SSTR2 trafficking and stability at
the plasma membrane. Therefore, the present review will summarize emerging
evidence highlighting the role of β-arrestins and FLNA, as possible novel
players in the modulation of agonist activated-SSTR2 receptor trafficking and
response in GH-secreting pituitary tumors.
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Affiliation(s)
- D Treppiedi
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Peverelli
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Giardino
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Ferrante
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - D Calebiro
- Institute of Pharmacology and Toxicology, University of Würzburg, and Rudolf Virchow Center, Bio-Imaging Center, Würzburg, Germany
| | - A Spada
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - G Mantovani
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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16
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Holland JP, Ferdani R, Anderson CJ, Lewis JS. Copper-64 Radiopharmaceuticals for Oncologic Imaging. PET Clin 2016; 4:49-67. [PMID: 27156895 DOI: 10.1016/j.cpet.2009.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The positron emitting radionuclide (64)Cu has a radioactive half-life of 12.7 hours. The decay characteristics of (64)Cu allow for PET images that are comparable in quality to those obtained using (18)F. Given the longer radioactive half-life of (64)Cu compared with (18)F and the versatility of copper chemistry, copper is an attractive alternative to the shorter-lived nuclides for PET imaging of peptides, antibodies, and small molecules that may require longer circulation times. This article discusses a number of copper radiopharmaceuticals, such as Cu-ATSM, that have been translated to the clinic and new developments in copper-based radiopharmaceuticals.
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Affiliation(s)
- Jason P Holland
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Riccardo Ferdani
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Campus Box 8225, St. Louis, MO 63110, USA
| | - Carolyn J Anderson
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Campus Box 8225, St. Louis, MO 63110, USA
| | - Jason S Lewis
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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17
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Bronstein MD, Jallad RS. Pasireotide for treating acromegaly. Expert Opin Orphan Drugs 2016. [DOI: 10.1517/21678707.2016.1167593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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Lehmann A, Kliewer A, Günther T, Nagel F, Schulz S. Identification of Phosphorylation Sites Regulating sst3 Somatostatin Receptor Trafficking. Mol Endocrinol 2016; 30:645-59. [PMID: 27101376 DOI: 10.1210/me.2015-1244] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The human somatostatin receptor 3 (sst3) is expressed in about 50% of all neuroendocrine tumors and hence a promising target for multireceptor somatostatin analogs. The sst3 receptor is unique among ssts in that it exhibits a very long intracellular C-terminal tail containing a huge number of potential phosphate acceptor sites. Consequently, our knowledge about the functional role of the C-terminal tail in sst3 receptor regulation is very limited. Here, we have generated a series of phosphorylation-deficient mutants that enabled us to determine crucial sites for its agonist-induced β-arrestin mobilization, internalization, and down-regulation. Based on this information, we generated phosphosite-specific antibodies for C-terminal Ser(337)/Thr(341), Thr(348), and Ser(361) that enabled us to investigate the temporal patterns of sst3 phosphorylation and dephosphorylation. We found that the endogenous ligand somatostatin induced a rapid and robust phosphorylation that was completely blocked by the sst3 antagonist NVP-ACQ090. The stable somatostatin analogs pasireotide and octreotide promoted clearly less phosphorylation compared with somatostatin. We also show that sst3 phosphorylation occurred within seconds to minutes, whereas dephosphorylation of the sst3 receptor occurred at a considerable slower rate. In addition, we also identified G protein-coupled receptor kinases 2 and 3 and protein phosphatase 1α and 1β as key regulators of sst3 phosphorylation and dephosphorylation, respectively. Thus, we here define the C-terminal phosphorylation motif of the human sst3 receptor that regulates its agonist-promoted phosphorylation, β-arrestin recruitment, and internalization of this clinically relevant receptor.
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Affiliation(s)
- Andreas Lehmann
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Andrea Kliewer
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Falko Nagel
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
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19
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Sabatino G, Guryanov I, Rombecchi A, Zanon J, Ricci A, Cabri W, Papini AM, Rovero P. Production of peptides as generic drugs: a patent landscape of octreotide. Expert Opin Ther Pat 2016; 26:485-95. [DOI: 10.1517/13543776.2016.1158810] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Liu F, Zhu H, Li C, Lin X, Xiong C, Li C, Yang Z. Design and radio-synthesis of somatostatin receptors targeted 68Ga-DOTA-Benereotide for non-invasive PET imaging. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4241-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Shao GQ, Zhang NZ. Effect of somatostatin on expression of VEGF and bFGF in human gastric cancer xenografts in nude mice. Shijie Huaren Xiaohua Zazhi 2014; 22:5659-5664. [DOI: 10.11569/wcjd.v22.i36.5659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the effect of somatostatin on the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in subcutaneous xenografts derived from human gastric carcinoma SGC-7901 cells in nude mice.
METHODS: An animal model of human gastric cancer xenograft was established by subcutaneously implanting SGC-7901 cells in nude mice. Twenty-four nude mice were randomly divided into four groups and treated with normal saline (group A), octreotide (group B), high-dose somatostatin (group C) and low-dose somatostatin (group D) for three weeks, respectively. After treatment, the animals were killed to take the tumors. The expression of VEGF and bFGF was examined by immunohistochemistry and Western blot.
RESULTS: Immunohistochemical analysis indicated that the integral optical density (IOD)/area (/pix2) of VEGF in groups A-D were 0.644 ± 0.022, 0.549 ± 0.002, 0.345 ± 0.019 and 0.435 ± 0.018, respectively. The expression of VEGF protein in tumor tissue was significantly higher in group A than in the other three groups (P < 0.001). Compared with group B, the expression of VEGF was reduced more significantly in groups C and D (P < 0.001 for both). The IOD/area (/pix2) of bFGF in groups A-D were 0.723 ± 0.018, 0.558 ± 0.004, 0.288 ± 0.017 and 0.595 ± 0.011, respectively. The expression of bFGF protein in tumor tissue was significantly higher in group A than in the other three groups (P < 0.001). Compared with group B, the expression of bFGF was reduced more significantly only in group C (P < 0.001). Western blot analysis indicated that the relative expression of VEGF in groups A-D were 0.98 ± 0.02, 0.76 ± 0.02, 0.53 ± 0.01 and 0.53 ± 0.01, respectively. The relative expression of bFGF in groups A-D were 0.76 ± 0.02, 0.71 ± 0.02, 0.32 ± 0.01 and 0.51 ± 0.01, respectively. The expression of bFGF and VEGF protein was significantly higher in group A than in the other three groups (P < 0.001). Compared with group B, the expression of VEGF and bFGF was reduced more significantly in groups C and D (P < 0.001).
CONCLUSION: Somatostatin can down-regulate the expression of VEGF and bFGF in subcutaneous xenografts derived from human gastric carcinoma SGC-7901 cells in nude mice, and the effect is more obvious than that of octreotide.
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22
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Stevenazzi A, Marchini M, Sandrone G, Vergani B, Lattanzio M. Amino acidic scaffolds bearing unnatural side chains: An old idea generates new and versatile tools for the life sciences. Bioorg Med Chem Lett 2014; 24:5349-56. [DOI: 10.1016/j.bmcl.2014.10.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/26/2014] [Accepted: 10/02/2014] [Indexed: 11/16/2022]
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23
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Ermert P, Moehle K, Obrecht D. Macrocyclic Inhibitors of GPCR's, Integrins and Protein–Protein Interactions. MACROCYCLES IN DRUG DISCOVERY 2014. [DOI: 10.1039/9781782623113-00283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This chapter summarizes some highlights of macrocyclic drug discovery in the area of GPCRs, integrins, and protein–protein interactions spanning roughly the last 30 years. Several examples demonstrate that incorporation of pharmacophores derived from natural peptide ligands into the context of a constrained macrocycle (“lock of the bioactive conformation”) has proven a powerful approach for the discovery of potent and selective macrocyclic drugs. In addition, it will be shown that macrocycles, due to their semi-rigid nature, can exhibit unique properties that can be beneficially exploited by medicinal chemists. Macrocycles can adapt their conformation during binding to a flexible protein target surface (“induced fit”), and due to their size, can interact with larger protein interfaces (“hot spots”). Also, macrocycles can display favorable ADME properties well beyond the rule of 5 in particular exhibiting favorable cell penetrating properties and oral bioavailability.
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Affiliation(s)
- Philipp Ermert
- Polyphor Ltd Hegenheimermattweg 125 CH-4123 Allschwil Switzerland
| | - Kerstin Moehle
- University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Daniel Obrecht
- Polyphor Ltd Hegenheimermattweg 125 CH-4123 Allschwil Switzerland
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24
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Maina T, Cescato R, Waser B, Tatsi A, Kaloudi A, Krenning EP, de Jong M, Nock BA, Reubi JC. [111In-DOTA]LTT-SS28, a First Pansomatostatin Radioligand for in Vivo Targeting of Somatostatin Receptor-Positive Tumors. J Med Chem 2014; 57:6564-71. [DOI: 10.1021/jm500581d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Theodosia Maina
- Molecular
Radiopharmacy, INRASTES, National Center for Scientific Research “Demokritos”, GR-153 10 Athens, Greece
| | - Renzo Cescato
- Cell
Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, CH-3010 Berne, Switzerland
| | - Beatrice Waser
- Cell
Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, CH-3010 Berne, Switzerland
| | - Aikaterini Tatsi
- Molecular
Radiopharmacy, INRASTES, National Center for Scientific Research “Demokritos”, GR-153 10 Athens, Greece
| | - Aikaterini Kaloudi
- Molecular
Radiopharmacy, INRASTES, National Center for Scientific Research “Demokritos”, GR-153 10 Athens, Greece
| | - Eric P. Krenning
- Department
of Nuclear Medicine, Erasmus MC, 3015 CE Rotterdam, The Netherlands
| | - Marion de Jong
- Department
of Nuclear Medicine, Erasmus MC, 3015 CE Rotterdam, The Netherlands
- Department
of Radiology, Erasmus MC, 3015 CE Rotterdam, The Netherlands
| | - Berthold A. Nock
- Molecular
Radiopharmacy, INRASTES, National Center for Scientific Research “Demokritos”, GR-153 10 Athens, Greece
| | - Jean Claude Reubi
- Cell
Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, CH-3010 Berne, Switzerland
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25
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The effect of albumin fusion structure on the production and bioactivity of the somatostatin-28 fusion protein in Pichia pastoris. ACTA ACUST UNITED AC 2014; 41:997-1006. [DOI: 10.1007/s10295-014-1440-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 03/14/2014] [Indexed: 11/26/2022]
Abstract
Abstract
Somatostatin, a natural inhibitor of growth hormone (GH), and its analogs have been used in clinical settings for the treatment of acromegaly, gigantism, thyrotropinoma, and other carcinoid syndromes. However, natural somatostatin is limited for clinical usage because of its short half-life in vivo. Albumin fusion technology was used to construct long-acting fusion proteins and Pichia pastoris was used as an expression system. Three fusion proteins (SS28)2-HSA, (SS28)3-HSA, and HSA-(SS28)2, were constructed with different fusion copies of somatostatin-28 and fusion orientations. The expression level of (SS28)3-HSA was much lower than (SS28)2-HSA and HSA-(SS28)2 due to the additional fusion of the somatostatin-28 molecule. MALDI-TOF mass spectrometry revealed that severe degradation occurred in the fermentation process. Similar to the standard, somatostatin-14, all three fusion proteins were able to inhibit GH secretion in blood, with (SS28)2-HSA being the most effective one. A pharmacokinetics study showed that (SS28)2-HSA had a prolonged half-life of 2 h. These results showed that increasing the number of small protein copies fused to HSA may not be a suitable method for improving protein bioactivity.
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26
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Lehmann A, Kliewer A, Schütz D, Nagel F, Stumm R, Schulz S. Carboxyl-terminal multi-site phosphorylation regulates internalization and desensitization of the human sst2 somatostatin receptor. Mol Cell Endocrinol 2014; 387:44-51. [PMID: 24565897 DOI: 10.1016/j.mce.2014.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 02/16/2014] [Accepted: 02/16/2014] [Indexed: 01/25/2023]
Abstract
The somatostatin receptor 2 (sst2) is the pharmacological target of somatostatin analogs that are widely used in the diagnosis and treatment of human neuroendocrine tumors. We have recently shown that the stable somatostatin analogs octreotide and pasireotide (SOM230) stimulate distinct patterns of sst2 receptor phosphorylation and internalization. Like somatostatin, octreotide promotes the phosphorylation of at least six carboxyl-terminal serine and threonine residues namely S341, S343, T353, T354, T356 and T359, which in turn leads to a robust receptor endocytosis. Unlike somatostatin, pasireotide stimulates a selective phosphorylation of S341 and S343 of the human sst2 receptor followed by a partial receptor internalization. Here, we show that exchange of S341 and S343 by alanine is sufficient to block pasireotide-driven internalization, whereas mutation of T353, T354, T356 and T359 to alanine is required to strongly inhibited both octreotide- and somatostatin-induced internalization. Yet, combined mutation of T353, T354, T356 and T359 is not sufficient to prevent somatostatin-driven β-arrestin mobilization and receptor desensitization. Replacement of all fourteen carboxyl-terminal serine and threonine residues by alanine completely abrogates sst2 receptor internalization and β-arrestin mobilization in HEK293 cells. Together, our findings demonstrate for the first time that agonist-selective sst2 receptor internalization is regulated by multi-site phosphorylation of its carboxyl-terminal tail.
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Affiliation(s)
- Andreas Lehmann
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany
| | - Andrea Kliewer
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany
| | - Dagmar Schütz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany
| | - Falko Nagel
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany
| | - Ralf Stumm
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, 07747 Jena, Germany.
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27
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Synthetic approaches to the 2012 new drugs. Bioorg Med Chem 2014; 22:2005-32. [DOI: 10.1016/j.bmc.2014.02.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 12/19/2022]
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28
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Peng Y, Deng L, Ding Y, Chen Q, Wu Y, Yang M, Wang Y, Fu Q. Comparative study of somatostatin-human serum albumin fusion proteins and natural somatostatin on receptor binding, internalization and activation. PLoS One 2014; 9:e89932. [PMID: 24587133 PMCID: PMC3937410 DOI: 10.1371/journal.pone.0089932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/25/2014] [Indexed: 01/08/2023] Open
Abstract
Albumin fusion technology, the combination of small molecular proteins or peptides with human serum albumin (HSA), is an effective method for improving the medicinal values of natural small molecular proteins or peptides. However, comparative studies between HSA-fusion proteins or peptides and the parent small molecules in biological and molecular mechanisms are less reported. In this study, we examined the binding property of two novel somatostatin-HSA fusion proteins, (SST14)2-HSA and (SST28)2-HSA, to human SSTRs in stably expressing SSTR1-5 HEK 293 cells; observed the regulation of receptor internalization and internalized receptor recycling; and detected the receptors activation of HSA fusion proteins in stably expressing SSTR2- and SSTR3-EGFP cells. We showed that both somatostatin-HSA fusion proteins had high affinity to all five SSTRs, stimulated the ERK1/2 phosphorylation and persistently inhibited the accumulation of forskolin-stimulated cAMP in SSTR2- and SSTR3-expressing cells; but were less potent than the synthetic somatostatin-14 (SST-14). Our experiments also showed that somatostatin-HSA fusion proteins did not induce the receptors internalization; rather, they accelerated the recycling of the internalized receptors induced by SST-14 to the plasma membrane. Our results indicated that somatostatin-HSA fusion proteins, different from SST-14, exhibit some particular properties in binding, regulating, and activating somatostatin receptors.
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Affiliation(s)
- Ying Peng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Lili Deng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Yuedi Ding
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Quancheng Chen
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Yu Wu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
| | - Meilin Yang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yaping Wang
- Wuxi Second People’s Hospital of Nanjing Medical University, Wuxi, Jiangsu, China
- * E-mail: (YW); (QF)
| | - Qiang Fu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, China
- * E-mail: (YW); (QF)
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Wang JW, Li Y, Mao ZG, Hu B, Jiang XB, Song BB, Wang X, Zhu YH, Wang HJ. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas. Patient Prefer Adherence 2014; 8:43-51. [PMID: 24421637 PMCID: PMC3888346 DOI: 10.2147/ppa.s53930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4-6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits.
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Affiliation(s)
- Ji-wen Wang
- Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, People’s Republic of China
- Key Laboratory of Pituitary Adenoma in Guangdong Province, People’s Republic of China
| | - Ying Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, People’s Republic of China
| | - Zhi-gang Mao
- Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, People’s Republic of China
- Key Laboratory of Pituitary Adenoma in Guangdong Province, People’s Republic of China
| | - Bin Hu
- Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, People’s Republic of China
- Key Laboratory of Pituitary Adenoma in Guangdong Province, People’s Republic of China
| | - Xiao-bing Jiang
- Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, People’s Republic of China
- Key Laboratory of Pituitary Adenoma in Guangdong Province, People’s Republic of China
| | - Bing-bing Song
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Xin Wang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Yong-hong Zhu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People’s Republic of China
- Yong-hong Zhu, Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, No. 74, Zhongshan Road 2, Guangzhou 510080, People’s Republic of China, Email
| | - Hai-jun Wang
- Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, People’s Republic of China
- Key Laboratory of Pituitary Adenoma in Guangdong Province, People’s Republic of China
- Correspondence: Hai-jun Wang; Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan Road 2, Guangzhou 510080, People’s Republic of China, Email
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Chinezu L, Vasiljevic A, Jouanneau E, François P, Borda A, Trouillas J, Raverot G. Expression of somatostatin receptors, SSTR2A and SSTR5, in 108 endocrine pituitary tumors using immunohistochemical detection with new specific monoclonal antibodies. Hum Pathol 2014; 45:71-7. [DOI: 10.1016/j.humpath.2013.08.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 08/02/2013] [Accepted: 08/02/2013] [Indexed: 11/28/2022]
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Martín-Gago P, Aragón E, Gomez-Caminals M, Fernández-Carneado J, Ramón R, Martin-Malpartida P, Verdaguer X, López-Ruiz P, Colás B, Cortes MA, Ponsati B, Macias MJ, Riera A. Insights into structure-activity relationships of somatostatin analogs containing mesitylalanine. Molecules 2013; 18:14564-84. [PMID: 24287991 PMCID: PMC6270305 DOI: 10.3390/molecules181214564] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/29/2022] Open
Abstract
The non-natural amino acid mesitylalanine (2,4,6-trimethyl-L-phenylalanine; Msa) has an electron-richer and a more conformationally restricted side-chain than that of its natural phenylalanine counterpart. Taking these properties into account, we have synthesized ten somatostatin analogs containing Msa residues in different key positions to modify the intrinsic conformational flexibility of the natural hormone. We have measured the binding affinity of these analogs and correlated it with the main conformations they populate in solution. NMR and computational analysis revealed that analogs containing one Msa residue were conformationally more restricted than somatostatin under similar experimental conditions. Furthermore, we were able to characterize the presence of a hairpin at the pharmacophore region and a non-covalent interaction between aromatic residues 6 and 11. In all cases, the inclusion of a D-Trp in the eighth position further stabilized the main conformation. Some of these peptides bound selectively to one or two somatostatin receptors with similar or even higher affinity than the natural hormone. However, we also found that multiple incorporations of Msa residues increased the life span of the peptides in serum but with a loss of conformational rigidity and binding affinity.
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Affiliation(s)
- Pablo Martín-Gago
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Eric Aragón
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Marc Gomez-Caminals
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Jimena Fernández-Carneado
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Rosario Ramón
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
| | - Pau Martin-Malpartida
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Xavier Verdaguer
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
| | - Pilar López-Ruiz
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - Begoña Colás
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - María Alicia Cortes
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - Berta Ponsati
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Maria J. Macias
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys, 23, Barcelona 08010, Spain
- Authors to whom correspondence should be addressed; E-Mails: (M.J.M.); (A.R.); Tel.: +34-934-037-189 (M.J.M.); Fax: +34-934-047-095 (M.J.M.); Tel. +34-934-047-093 (A.R.); Fax: +34-934-047-095 (A.R)
| | - Antoni Riera
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
- Authors to whom correspondence should be addressed; E-Mails: (M.J.M.); (A.R.); Tel.: +34-934-037-189 (M.J.M.); Fax: +34-934-047-095 (M.J.M.); Tel. +34-934-047-093 (A.R.); Fax: +34-934-047-095 (A.R)
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Lesma G, Cecchi R, Cagnotto A, Gobbi M, Meneghetti F, Musolino M, Sacchetti A, Silvani A. Tetrahydro-β-carboline-based spirocyclic lactam as type II' β-turn: application to the synthesis and biological evaluation of somatostatine mimetics. J Org Chem 2013; 78:2600-10. [PMID: 23409740 DOI: 10.1021/jo302737j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The synthesis of novel spirocyclic lactams, embodying D-tryptophan (Trp) amino acid as the central core and acting as peptidomimetics, is presented. It relies on the strategic combination of Seebach's self-reproduction of chirality chemistry and Pictet-Spengler condensation as key steps. Investigation of the conformational behavior by molecular modeling, X-ray crystallography, and NMR and IR spectroscopies suggests very stable and highly predictable type II' β-turn conformations for all compounds. Relying on this feature, we also pursued their application to two potential mimetics of the hormone somatostatin, a pharmaceutically relevant natural peptide, which contains a Trp-based type II' β-turn pharmacophore.
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Affiliation(s)
- Giordano Lesma
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy
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Petrich A, Mann A, Kliewer A, Nagel F, Strigli A, Märtens JC, Pöll F, Schulz S. Phosphorylation of threonine 333 regulates trafficking of the human sst5 somatostatin receptor. Mol Endocrinol 2013; 27:671-82. [PMID: 23418396 DOI: 10.1210/me.2012-1329] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The frequent overexpression of the somatostatin receptors sst2 and sst5 in neuroendocrine tumors provides the molecular basis for therapeutic application of novel multireceptor somatostatin analogs. Although the phosphorylation of the carboxyl-terminal region of the sst2 receptor has been studied in detail, little is known about the agonist-induced regulation of the human sst5 receptor. Here, we have generated phosphosite-specific antibodies for the carboxyl-terminal threonines 333 (T333) and 347 (T347), which enabled us to selectively detect either the T333-phosphorylated or the T347-phosphorylated form of sst5. We show that agonist-mediated phosphorylation occurs at T333, whereas T347 is constitutively phosphorylated in the absence of agonist. We further demonstrate that the multireceptor somatostatin analog pasireotide and the sst5-selective ligand L-817,818 but not octreotide or KE108 were able to promote a detectable T333 phosphorylation. Interestingly, BIM-23268 was the only sst5 agonist that was able to stimulate T333 phosphorylation to the same extent as natural somatostatin. Agonist-induced T333 phosphorylation was dose-dependent and selectively mediated by G protein-coupled receptor kinase 2. Similar to that observed for the sst2 receptor, phosphorylation of sst5 occurred within seconds. However, unlike that seen for the sst2 receptor, dephosphorylation and recycling of sst5 were rapidly completed within minutes. We also identify protein phosphatase 1γ as G protein-coupled receptor phosphatase for the sst5 receptor. Together, we provide direct evidence for agonist-selective phosphorylation of carboxyl-terminal T333. In addition, we identify G protein-coupled receptor kinase 2-mediated phosphorylation and protein phosphatase 1γ-mediated dephosphorylation of T333 as key regulators of rapid internalization and recycling of the human sst5 receptor.
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Affiliation(s)
- Aline Petrich
- Department of Pharmacology and Toxicology, Jena University Hospital–Friedrich Schiller University Jena, Drackendorfer Strasse 1, D-07749 Jena, Germany
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Kliewer A, Mann A, Petrich A, Pöll F, Schulz S. A transplantable phosphorylation probe for direct assessment of G protein-coupled receptor activation. PLoS One 2012; 7:e39458. [PMID: 22745760 PMCID: PMC3383726 DOI: 10.1371/journal.pone.0039458] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/21/2012] [Indexed: 12/12/2022] Open
Abstract
The newly developed multireceptor somatostatin analogs pasireotide (SOM230), octreotide and somatoprim (DG3173) have primarily been characterized according to their binding profiles. However, their ability to activate individual somatostatin receptor subtypes (sst) has not been directly assessed so far. Here, we transplanted the carboxyl-terminal phosphorylation motif of the sst(2) receptor to other somatostatin receptors and assessed receptor activation using a set of three phosphosite-specific antibodies. Our comparative analysis revealed unexpected efficacy profiles for pasireotide, octreotide and somatoprim. Pasireotide was able to activate sst(3) and sst(5) receptors but was only a partial agonist at the sst(2) receptor. Octreotide exhibited potent agonistic properties at the sst(2) receptor but produced very little sst(5) receptor activation. Like octreotide, somatoprim was a full agonist at the sst(2) receptor. Unlike octreotide, somatoprim was also a potent agonist at the sst(5) receptor. Together, we propose the application of a phosphorylation probe for direct assessment of G protein-coupled receptor activation and demonstrate its utility in the pharmacological characterization of novel somatostatin analogs.
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Affiliation(s)
- Andrea Kliewer
- Department of Pharmacology and Toxicology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Anika Mann
- Department of Pharmacology and Toxicology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Aline Petrich
- Department of Pharmacology and Toxicology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Florian Pöll
- Department of Pharmacology and Toxicology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Stefan Schulz
- Department of Pharmacology and Toxicology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- * E-mail: .
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Cozzi R, Attanasio R. Octreotide long-acting repeatable for acromegaly. Expert Rev Clin Pharmacol 2012; 5:125-43. [PMID: 22390555 DOI: 10.1586/ecp.12.4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Acromegaly remains a therapeutic challenge for the endocrinologist. Among the available therapeutic options, octreotide long-acting repeatable (Sandostatin(®) LAR(®), Novartis) plays a chief role, both as a primary therapy and as an adjuvant treatment after unsuccessful surgery. A plethora of papers and a meta-analysis have demonstrated its efficacy in: control of clinical picture; achievement of safe growth hormone and normal age-matched IGF-I levels (both factors associated with restoration of normal life expectancy) in 60-70% of patients; control of tumor volume (with real shrinkage in over half of cases); and halt or reversal of most acromegaly-associated comorbidities. Treatment is well tolerated in most patients and can be safely prolonged for many years if required.
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Affiliation(s)
- Renato Cozzi
- Division of Endocrinology, Ospedale Niguarda, Via Canonica 81, I-20154 Milan, Italy.
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Golor G, Hu K, Ruffin M, Buchelt A, Bouillaud E, Wang Y, Maldonado M. A first-in-man study to evaluate the safety, tolerability, and pharmacokinetics of pasireotide (SOM230), a multireceptor-targeted somatostatin analog, in healthy volunteers. DRUG DESIGN DEVELOPMENT AND THERAPY 2012; 6:71-9. [PMID: 22573933 PMCID: PMC3346155 DOI: 10.2147/dddt.s29125] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Pasireotide (SOM230) is a multireceptor-targeted somatostatin analog with high binding affinity for four of the five somatostatin receptor subtypes (sst1,2,3 and sst5), and potential clinical activity in several neuroendocrine and oncologic conditions, including acromegaly, Cushing’s disease, and neuroendocrine tumors (NET). This manuscript reports the first-in-man dose-escalation study of pasireotide, evaluating its safety, tolerability, and pharmacokinetics (PK) in healthy male volunteers. A single dose of pasireotide 1–1200 μg was administered subcutaneously in four to eight subjects per dose level, with two additional subjects per cohort administered placebo. PK and safety evaluations were carried out over 7 days post-dose. Growth hormone (GH) suppression was evaluated using a GH-releasing hormone stimulation test on Day –1 and Day 1 at 3–5 hours post-injection. Seventy-two subjects completed the study. Pasireotide was well tolerated with no serious adverse events observed at any dose. Transient elevations in blood glucose levels were observed 2–6 hours after administration of pasireotide at doses between 200 μg and 1200 μg, but this resolved without intervention by 23 hours post-dosing. The maximum tolerable dose was not established within the tested range. Pasireotide demonstrated a favorable PK profile with fast absorption (tmax: 0.25–0.5 hours), low clearance (CL/F: 8–13 L/hour), long effective elimination half-life (mean t½,β: 7–11 hours), and a proportional dose-exposure relationship. GH suppression of 79%–96% was observed at single pasireotide doses between 200 μg and 1200 μg. In conclusion, pasireotide demonstrated favorable safety, tolerability, and PK profiles, as well as promising activity in suppressing the release of GH. The efficacy and safety of pasireotide is currently being evaluated in patients with acromegaly, Cushing’s disease, NET, and various non-neuroendocrine disorders.
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Affiliation(s)
- Georg Golor
- Parexel International GmbH, Berlin, Germany.
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Liu Z, Crider AM, Ansbro D, Hayes C, Kontoyianni M. A structure-based approach to understanding somatostatin receptor-4 agonism (sst4). J Chem Inf Model 2011; 52:171-86. [PMID: 22148589 DOI: 10.1021/ci200375j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
It has been reported that somatostatin receptor subtypes 4 and 5 would be high-impact templates for homology modeling if their 3D structures became available. We have generated a homology model of the somatostatin receptor subtype 4 (sst4), using the newest active state β(2) adrenoreceptor crystal structure, and subsequently docked a variety of agonists into the model-built receptor to elucidate the binding modes of reported agonists. Using experimental restraints, we were able to explain observed activity profiles. We propose two binding modes that can consistently explain findings for high-affinity agonists and reason why certain structures display low affinities for the receptor.
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Affiliation(s)
- Zhaomin Liu
- Department of Chemistry, Southern Illinois University Edwardsville, Edwardsville, Illinois 62026, USA
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Abstract
Somatostatin analogs (SA) are widely used in acromegaly, either as first-line or adjuvant treatment after surgery. First-line treatment with these drugs is generally used in the patients with macroadenomas or in those with clinical conditions so severe as to prevent unsafe reactions during anesthesia. Generally, the response to SA takes into account both control of GH and IGF-I excess, with consequent improvement of clinical symptoms directly related to GH and IGF-I excess, and tumor shrinkage. This latter effect is more prominent in the patients treated first-line and bearing large macroadenomas, but it is also observed in patients with microadenomas, even with little clinical implication. Predictors of response are patients' gender, age, initial GH and IGF-I levels, and tumor mass, as well as adequate expression of somatostatin receptor types 2 and 5, those with the highest affinity for octreotide and lanreotide. Only sporadic cases of somatostatin receptor gene mutation or impaired signaling pathways have been described in GH-secreting tumors so far. The response to SA also depends on treatment duration and dosage of the drug used, so that a definition of resistance based on short-term treatments using low doses of long-acting SA is limited. Current data suggest that response to these drugs is better analyzed taking together biochemical and tumoral effects because only the absence of both responses might be considered as a poor response or resistance. This latter evidence seems to occur in 25% of treated patients after 12 months of currently available long-acting SA.
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Affiliation(s)
- Annamaria Colao
- Department of Clinical and Molecular Endocrinology and Oncology, University “Federico II,” Naples, Italy.
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Kleinberg DL, Ameri P, Singh B. Pasireotide, an IGF-I action inhibitor, prevents growth hormone and estradiol-induced mammary hyperplasia. Pituitary 2011; 14:44-52. [PMID: 20890664 DOI: 10.1007/s11102-010-0257-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mammary hyperplasia increases breast cancer risk. Tamoxifen prevents breast cancer in women with atypical hyperplasia, but has serious side effects. As estradiol action requires IGF-I, direct inhibition of IGF-I action theoretically might be an efficacious alternative to tamoxifen. After hypophysectomy and oophorectomy, 21-day-old female rats were treated with GH and E₂. After 7 days all terminal end buds (TEBs) and 75% of ducts became hyperplastic. Co-treatment with pasireotide, a somatostatin analog that blocks GH secretion and IGF-I action in the mammary gland, prevented hormone-induced hyperplasia. The number and size of TEBs and moderately or floridly hyperplastic ducts was reduced by pasireotide (P < 0.01). In contrast, the same concentration of octreotide, which has a more selective somatostatin receptor subtype binding profile, was less effective than pasireotide. Tamoxifen inhibited hyperplasia when used alone with GH + E₂, but did not add to the inhibitory effect of pasireotide when the two treatments were combined. Both pasireotide and tamoxifen acted via the IGF-I receptor signaling pathway and both were found to inhibit mammary cell proliferation and stimulate apoptosis. The number of epithelial cells expressing phosphorylated insulin receptor substrate (IRS)-1 in response to GH and E₂ was reduced by pasireotide, as was staining intensity. These results support the concept that IGF-I inhibition, in this case by pasireotide, inhibits E₂ and GH-induced mammary hyperplasia. As tamoxifen did not further increase the inhibitory effect of pasireotide, the peptide appears to be at least as effective as tamoxifen in preventing GH + E₂-induced mammary hyperplasia.
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Affiliation(s)
- David L Kleinberg
- The Bunnie Joan Sachs Laboratory and Neuroendocrine Unit, Department of Medicine (Division of Endocrinology), New York University School of Medicine, New York, NY, USA.
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Nagel F, Doll C, Pöll F, Kliewer A, Schröder H, Schulz S. Structural determinants of agonist-selective signaling at the sst(2A) somatostatin receptor. Mol Endocrinol 2011; 25:859-66. [PMID: 21330405 DOI: 10.1210/me.2010-0407] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The clinically used somatostatin (SS-14) analogs octreotide and pasireotide (SOM230) stimulate distinct species-specific patterns of sst(2A) somatostatin receptor phosphorylation and internalization. Like SS-14, octreotide promotes the phosphorylation of at least six carboxyl-terminal serine and threonine residues, namely S341, S343, T353, T354, T356, and T359, which in turn leads to a robust endocytosis of both rat and human sst(2A) receptors. Unlike SS-14, pasireotide fails to induce any substantial phosphorylation or internalization of the rat sst(2A) receptor. Nevertheless, pasireotide is able to stimulate a selective phosphorylation of S341 and S343 of the human sst(2A) receptor followed by a clearly detectable receptor sequestration. Here, we show that transplantation of amino acids 1-180 of the human sst(2A) receptor to the rat sst(2A) receptor facilitates pasireotide-induced internalization. Conversely, construction of a rat-human sst(2A) chimera conferred resistance to pasireotide-induced internalization. We then created a series of site-directed mutants leading to the identification of amino acids 27, 30, 163, and 164 that when exchanged to their human counterparts facilitated pasireotide-driven S341/S343 phosphorylation and internalization of the rat sst(2A) receptor. Exchange of these amino acids to their rat counterparts completely blocked the pasireotide-mediated internalization of the human sst(2A) receptor. Notably, octreotide and SS-14 stimulated a full phosphorylation and internalization of all mutant sst(2A) receptors tested. Together, these findings suggest that pasireotide activates the sst(2A) receptor via a molecular switch that is structurally and functionally distinct from that turned on during octreotide-driven sst(2A) activation.
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Affiliation(s)
- Falko Nagel
- Department of Pharmacology and Toxicology, University Hospital Jena, Friedrich Schiller University, Drackendorfer Strasse 1, D-07747 Jena, Germany
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Lupp A, Hunder A, Petrich A, Nagel F, Doll C, Schulz S. Reassessment of sst(5) somatostatin receptor expression in normal and neoplastic human tissues using the novel rabbit monoclonal antibody UMB-4. Neuroendocrinology 2011; 94:255-64. [PMID: 21952553 DOI: 10.1159/000329876] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 05/31/2011] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The frequent overexpression of somatostatin receptors (sst) in neuroendocrine tumors provides the molecular basis for the diagnostic and therapeutic application of stable somatostatin analogs. Whereas octreotide acts mainly via the sst(2) receptor, the novel pan-somatostatin analog pasireotide exhibits particular high affinity for the sst(5) receptor. To determine whether a patient is a candidate for octreotide or pasireotide therapy, it is important to evaluate the somatostatin receptor status. However, so far highly specific rabbit monoclonal antibodies have been developed for the sst(2) receptor only (clone UMB-1). METHODS Here, we have extensively characterized a novel rabbit monoclonal antibody for the human sst(5) receptor (clone UMB-4). In a comparative immunohistochemical study, the expression of sst(5) and sst(2) receptors was assessed using UMB-4 and UMB-1, respectively. RESULTS Western blot experiments unequivocally demonstrated that UMB-4 selectively detected its cognate sst(5) receptor and did not cross-react with other proteins present in crude tissue homogenates. UMB-4 yielded a highly effective immunostaining of distinct cell populations in formalin-fixed, paraffin-embedded human tissues with a predominance of plasma membrane staining. In the pituitary, sst(5) was present on all growth hormone (GH)- and adrenocorticotropin hormone (ACTH)-producing cells whereas sst(2) was only observed on a subpopulation of GH-positive cells. Consequently, sst(5) was detectable on the majority of GH and ACTH adenomas. In contrast, sst(2) was only seen on GH but not on ACTH adenomas. CONCLUSIONS The rabbit monoclonal antibodies UMB-4 and UMB-1 will facilitate the assessment of the somatostatin receptor status of human tumors during routine histopathological examinations.
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Affiliation(s)
- Amelie Lupp
- Department of Pharmacology and Toxicology, University Hospital, Friedrich Schiller University, Jena, Germany
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Waser B, Cescato R, Tamma ML, Maecke HR, Reubi JC. Absence of somatostatin SST2 receptor internalization in vivo after intravenous SOM230 application in the AR42J animal tumor model. Eur J Pharmacol 2010; 644:257-62. [DOI: 10.1016/j.ejphar.2010.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 07/01/2010] [Accepted: 07/09/2010] [Indexed: 12/19/2022]
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Di Cianni A, Carotenuto A, Brancaccio D, Novellino E, Reubi JC, Beetschen K, Papini AM, Ginanneschi M. Novel Octreotide Dicarba-analogues with High Affinity and Different Selectivity for Somatostatin Receptors. J Med Chem 2010; 53:6188-97. [DOI: 10.1021/jm1005868] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Alessandra Di Cianni
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
| | - Alfonso Carotenuto
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Diego Brancaccio
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Ettore Novellino
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Jean Claude Reubi
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Karin Beetschen
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Anna Maria Papini
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
| | - Mauro Ginanneschi
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
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Ovadia O, Greenberg S, Laufer B, Gilon C, Hoffman A, Kessler H. Improvement of drug-like properties of peptides: the somatostatin paradigm. Expert Opin Drug Discov 2010; 5:655-71. [DOI: 10.1517/17460441.2010.493935] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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van der Hoek J, Lamberts SWJ, Hofland LJ. The somatostatin receptor subtype 5 in neuroendocrine tumours. Expert Opin Investig Drugs 2010; 19:385-99. [PMID: 20151855 DOI: 10.1517/13543781003604710] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD In recent years, scientific work has been intensified to unravel new (patho-) physiological insights, particularly regarding the functional role of somatostatin (SRIF) receptor subtype 5 (sst) and the development of novel sst(5)-targeted SRIF analogues, in order to broaden medical therapeutic opportunities in patients suffering from neuroendocrine diseases. AREAS COVERED IN THIS REVIEW The scope of this review is primarily focused upon recent insights in sst(5)-receptor physiology, novel sst(5)-targeted treatment options predominantly directed towards pituitary adenomas, and gastroenteropancreatic neuroendocrine tumours. WHAT THE READER WILL GAIN An understanding of the potential that novel sst(5)-targeted SRIF analogues might have in the medical treatment of Cushing's disease and acromegaly, as demonstrated by translational research, based on pathophysiological data combined with results from clinical trials. TAKE HOME MESSAGE The role of targeting sst(5) in gastroenteropancreatic neuroendocrine tumours remains to be established. The sst(5) subtype might function as sst(2) modulator in terms of receptor internalization and desensitization, and seems less important compared with sst(2)-preferring SRIF analogues in the regulation of human insulin secretion by the pancreas. Finally, absence of sst(5) in corticotroph adenomas could be related to tumour aggressiveness in Cushing's disease.
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Affiliation(s)
- Joost van der Hoek
- Department of Internal Medicine, Division of Endocrinology, Room Ee530b, Erasmus MC, Dr Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
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Msaouel P, Galanis E, Koutsilieris M. Somatostatin and somatostatin receptors: implications for neoplastic growth and cancer biology. Expert Opin Investig Drugs 2010; 18:1297-316. [PMID: 19678799 DOI: 10.1517/13543780903176399] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Somatostatin agonists (SM-As) are capable of achieving durable symptomatic relief and significant clinical responses in certain tumours. Herein, we review the diverse direct and indirect mechanisms of antineoplastic activity elicited by SM-As as well as the hurdles that complicate their use as monotherapies in a broader range of malignancies. Emphasis is placed on recent clinical attempts to neutralise the IGF-mediated survival factor effects in the bone metastasis microenvironment in advanced prostate cancer. The first clinical trials of this 'anti-survival factor manipulation' strategy utilised the ability of SM-As to suppress the growth hormone-dependent liver-derived IGF-I bioavailability in combination with other drugs, such as dexamethasone, zolendronate and oestrogens, acting systemically and at the bone metastasis microenvironment. These regimens restored androgen ablation responsiveness in stage D3 prostate cancer patients and successfully produced objective clinical responses while only mild toxicities were observed. Furthermore, we focus on the preclinical experimental data of a targeted SM-A coupled to the super-potent doxorubicin derivative AN-201. The resulting conjugate (AN-238) has shown increased antitumour potency with a favourable toxicity profile. The potential use of novel SM-As as anticancer drugs is discussed in relation to data suggesting other direct and indirect treatment approaches pertaining to the somatostatin system.
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Affiliation(s)
- Pavlos Msaouel
- National & Kapodistrian University of Athens, Medical School, Department of Experimental Physiology, 75 Micras Asias St, Goudi-Athens 11527, Greece
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Pöll F, Lehmann D, Illing S, Ginj M, Jacobs S, Lupp A, Stumm R, Schulz S. Pasireotide and octreotide stimulate distinct patterns of sst2A somatostatin receptor phosphorylation. Mol Endocrinol 2010; 24:436-46. [PMID: 20051480 DOI: 10.1210/me.2009-0315] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Pasireotide (SOM230) is currently under clinical evaluation as a successor compound to octreotide for the treatment of acromegaly, Cushing's disease, and carcinoid tumors. Whereas octreotide acts primarily via the sst(2A) somatostatin receptor, pasireotide was designed to exhibit octreotide-like sst(2A) activity combined with enhanced binding to other somatostatin receptor subtypes. In the present study, we used phophosite-specific antibodies to examine agonist-induced phosphorylation of the rat sst(2A) receptor. We show that somatostatin and octreotide stimulate the complete phosphorylation of a cluster of four threonine residues within the cytoplasmic (353)TTETQRT(359) motif in a variety of cultured cell lines in vitro as well as in intact animals in vivo. This phosphorylation was mediated by G protein-coupled receptor kinases (GRK) 2 and 3 and followed by rapid cointernalization of the receptor and ss-arrestin into the same endocytic vesicles. In contrast, pasireotide failed to promote substantial phosphorylation and internalization of the rat sst(2A) receptor. In the presence of octreotide or SS-14, SOM230 showed partial agonist behavior, inhibiting phosphorylation, and internalization of sst(2A). Upon overexpression of GRK2 or GRK3, pasireotide stimulated selective phosphorylation of Thr356 and Thr359 but not of Thr353 or Thr354 within the (353)TTETQRT(359) motif. Pasireotide-mediated phosphorylation led to the formation of relatively unstable beta-arrestin-sst(2A) complexes that dissociated at or near the plasma membrane. Thus, octreotide and pasireotide are equally active in inducing classical G protein-dependent signaling via the sst(2A) somatostatin receptor. Yet, we find that they promote strikingly different patterns of sst(2A) receptor phosphorylation and, hence, stimulate functionally distinct pools of beta-arrestin.
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Affiliation(s)
- Florian Pöll
- Department of Pharmacology and Toxicology, Friedrich-Schiller-University, Drackendorfer Strasse 1, D-07747 Jena, Germany
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Cescato R, Loesch KA, Waser B, Mäcke HR, Rivier JE, Reubi JC, Schonbrunn A. Agonist-biased signaling at the sst2A receptor: the multi-somatostatin analogs KE108 and SOM230 activate and antagonize distinct signaling pathways. Mol Endocrinol 2009; 24:240-9. [PMID: 19910453 DOI: 10.1210/me.2009-0321] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Somatostatin analogs that activate the somatostatin subtype 2A (sst2A) receptor are used to treat neuroendocrine cancers because they inhibit tumor secretion and growth. Recently, new analogs capable of activating multiple somatostatin receptor subtypes have been developed to increase tumor responsiveness. We tested two such multi-somatostatin analogs for functional selectivity at the sst2A receptor: SOM230, which activates sst1, sst2, sst3, and sst5 receptors, and KE108, which activates all sst receptor subtypes. Both compounds are reported to act as full agonists at their target sst receptors. In sst2A-expressing HEK293 cells, somatostatin inhibited cAMP production, stimulated intracellular calcium accumulation, and increased ERK phosphorylation. SOM230 and KE108 were also potent inhibitors of cAMP accumulation, as expected. However, they antagonized somatostatin stimulation of intracellular calcium and behaved as partial agonists/antagonists for ERK phosphorylation. In pancreatic AR42J cells, which express sst2A receptors endogenously, SOM230 and KE108 were both full agonists for cAMP inhibition. However, although somatostatin increased intracellular calcium and ERK phosphorylation, SOM230 and KE108 again antagonized these effects. Distinct mechanisms were involved in sst2A receptor signaling in AR42J cells; pertussis toxin pretreatment blocked somatostatin inhibition of cAMP accumulation but not the stimulation of intracellular calcium and ERK phosphorylation. Our results demonstrate that SOM230 and KE108 behave as agonists for inhibition of adenylyl cyclase but antagonize somatostatin's actions on intracellular calcium and ERK phosphorylation. Thus, SOM230 and KE108 are not somatostatin mimics, and their functional selectivity at sst2A receptors must be considered in clinical applications where it may have important consequences for therapy.
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Affiliation(s)
- Renzo Cescato
- Division of Cell Biology, Institute of Pathology, University of Berne, Berne, Switzerland
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Ben-Shlomo A, Schmid H, Wawrowsky K, Pichurin O, Hubina E, Chesnokova V, Liu NA, Culler M, Melmed S. Differential ligand-mediated pituitary somatostatin receptor subtype signaling: implications for corticotroph tumor therapy. J Clin Endocrinol Metab 2009; 94:4342-50. [PMID: 19820006 DOI: 10.1210/jc.2009-1311] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Pituitary targeted pharmacotherapy for Cushing's disease is challenging and ineffective. Unlike octreotide and lanreotide, the multisomatostatin receptor (SST) analog pasireotide that exhibits SST5 greater than SST2 binding affinity offers potential for treating Cushing's disease. Because corticotroph cells express SST5 more abundantly than SST2, pasireotide likely exerts superior corticotroph action mainly through SST5. However, there is no direct evidence for this assumption, and moreover, the ligand effect on corticotroph SST2 is not known. RESULTS We used AtT20 mouse pituitary corticotroph tumor cells stably overexpressing SST2 or SST5 and TtT/GF mouse pituitary folliculostellate cells stably or transiently expressing SST receptors to examine ligand-receptor activation by SST2- and SST5-selective agonists. We show that pasireotide was more potent than either octreotide or somatostatin-14 in mouse corticotroph cells. Pasireotide potency is not affected by SST2 abundance, SST2 antagonist treatment, or octreotide cotreatment in SST2-overexpressing cells. Pasireotide also does not induce SST2 internalization and attenuates octreotide or SRIF14-induced SST2 internalization only at superphysiological dose ranges. In contrast, octreotide attenuates pasireotide potency in SST5-overexpressing cells. Moreover, short exposure to pasireotide causes prolonged inhibition of forskolin or CRH-induced cAMP accumulation, in contrast to somatostatin-14- and SST2-selective agonists that induced postwithdrawal cAMP rebound. Long-term pasireotide signaling effects are enhanced by SST5 overexpression. CONCLUSION The results indicate that SST5 determines short- and long-term enhanced pasireotide action in corticotroph cells, whereas the ligand action on SST2 is negligible.
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Affiliation(s)
- Anat Ben-Shlomo
- Department of Medicine, Pituitary Center, Cedars SinaiMedical Center, Los Angeles, California 90048, USA
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Fu Q, Berbée M, Boerma M, Wang J, Schmid HA, Hauer-Jensen M. The somatostatin analog SOM230 (pasireotide) ameliorates injury of the intestinal mucosa and increases survival after total-body irradiation by inhibiting exocrine pancreatic secretion. Radiat Res 2009; 171:698-707. [PMID: 19580476 DOI: 10.1667/rr1685.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Somatostatin analogs ameliorate intestinal injury after localized irradiation. This study investigated whether SOM230, a novel, metabolically stable analog with broad receptor affinity, reduces intestinal injury and lethality in mice exposed to total-body irradiation (TBI). Male CD2F1 mice were exposed to 7-15 Gy TBI. Twice-daily administration of SOM230 (1, 4 or 10 mg/kg per day) or vehicle was started either 2 days before or 4 h after TBI and continued for either 14 or 21 days. Parameters of intestinal and hematopoietic radiation injury, bacterial translocation, and circulating cytokine levels were assessed. Animal survival was monitored for up to 30 days. SOM230 increased survival (P < 0.001) and prolonged survival time (P < 0.001) whether administration was initiated before or after TBI. There was no benefit from administration for 21 compared to 14 days. The survival benefit of SOM230 was completely reversed by co-administration of pancreatic enzymes (P = 0.009). Consistent with the presumed non-cytoprotective mechanism of action, SOM230 did not influence hematopoietic injury or intestinal crypt lethality. However, SOM230 preserved mucosal surface area (P < 0.001) and reduced bacterial translocation in a dose-dependent manner (P < 0.001). Circulating IL-12 levels were reduced in SOM230-treated mice (P = 0.007). No toxicity from SOM230 was observed. SOM230 enhances animal survival whether administration begins before or after TBI; i.e., it is effective both as a protector and as a mitigator. The mechanism likely involves reduction of intraluminal pancreatic enzymes. Because of its efficacy and favorable safety profile, SOM230 is a promising countermeasure against radiation and should undergo further development.
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Affiliation(s)
- Qiang Fu
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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