scholarly journals Somatostatin receptors in gastroentero-pancreatic neuroendocrine tumours.

2003 ◽  
pp. 451-458 ◽  
Author(s):  
W W de Herder ◽  
L J Hofland ◽  
A J van der Lely ◽  
S W J Lamberts
Keyword(s):  
Neuroendocrine Tumours ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Carcinoid Tumours ◽  
High Affinity ◽  
Pancreatic Neuroendocrine Tumours ◽  
Predominant Expression ◽  
Somatostatin 14

Five somatostatin receptor (sst) subtype genes, sst(1), sst(2), sst(3), sst(4) and sst(5), have been cloned and characterised. The five sst subtypes all bind natural somatostatin-14 and somatostatin-28 with high affinity. Endocrine pancreatic and endocrine digestive tract tumours also express multiple sst subtypes, but sst(2) predominance is generally found. However, there is considerable variation in sst subtype expression between the different tumour types and among tumours of the same type. The predominant expression of sst(2) receptors on pancreatic endocrine or carcinoid tumours is essential for the control of hormonal hypersecretion by the octapeptide somatostatin analogues such as octreotide and lanreotide. Somatostatin and its octapeptide analogues are also able to inhibit proliferation of normal and tumour cells. The high density of sst(2) or sst(5) on pancreatic endocrine or carcinoid tumours further allows the use of radiolabelled somatostatin analogues for in vivo visualisation. The predominant expression of sst(2) receptors in these tumours and the efficiency of sst(2) receptors to undergo agonist-induced internalisation is also essential for the application of radiolabelled octapeptide somatostatin analogues. Currently, [(111)In-DTPA(0)]octreotide, [(90)Y-DOTA(0),Tyr(3)]octreotide, [(177)Lu-DOTA(0)Tyr(3)]octreotate, [(111)In-DOTA(0)]lanreotide and [(90)Y-DOTA(0)]lanreotide can be used for this purpose.

[111In-DTPA-D-Phe1]Octreotide scintigraphy in patients with carcinoid tumours: the predictive value for somatostatin analogue treatment

1994 ◽  
Vol 131 (6) ◽  
pp. 577-581 ◽  
Author(s):  
Eva Tiensuu Janson ◽  
Jan-Erik Westlin ◽  
Barbro Eriksson ◽  
Håkan Ahlström ◽  
Sten Nilsson ◽  
...  
Keyword(s):  
Predictive Value ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
University Hospital ◽  
Somatostatin Analogue ◽  
Carcinoid Tumours ◽  
Malignant Carcinoid ◽  
Receptor Scintigraphy ◽  
Octreotide Scintigraphy

Tiensuu Janson E, Westlin J-E, Eriksson B, Ahlström H, Nilsson S, Öberg K. [111In-DTPA-D-Phe1]Octrotide scintigraphy in patients with carcinoid tumours: the predictive value for somatostatin analogue treatment. Eur J Endocrinol 1994:131:577–81. ISSN 0804–4643 This study was performed to evaluate whether the presence or absence of somatostatin receptors in malignant carcinoid tumours detected by [111In-DTPA-D-Phe1]octreotide scintigraphy can be used to predict response to somatostatin analogue treatment. Thirty patients were investigated, 28 with midgut carcinoid tumours and two with foregut carcinoid tumours. Twenty-seven patients showed pathological uptake in tumour lesions at scintigraphy: of these, 22 responded to somatostatin analogue treatment using octreotide, somatuline or octastatin, while five patients failed to respond. None of the three patients displaying negative scintigraphic investigations responded to treatment with somatostatin analogues. These results show a good correlation between the somatostatin receptor status and the patients' ability to respond to somatostatin analogue treatment (p = 0.014). We conclude that somatostatin receptor scintigraphy using [111In-DTPA-D-Phe1]octreotide can be used to select patients with malignant carcinoid tumours suitable for somatostatin analogue treatment and exclude those that will not benefit from such medication. Eva Tiensuu Janson, Dept of Internal Medicine, University Hospital, S-751 85 Uppsala, Sweden

scholarly journals 177Lu-octreotate therapy for neuroendocrine tumours is enhanced by Hsp90 inhibition

2019 ◽  
Vol 26 (4) ◽  
pp. 437-449 ◽  
Author(s):  
Tobias Hofving ◽  
Viktor Sandblom ◽  
Yvonne Arvidsson ◽  
Emman Shubbar ◽  
Gülay Altiparmak ◽  
...  
Keyword(s):  
Neuroendocrine Tumours ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Xenograft Model ◽  
Progression Free Survival ◽  
Tumour Volume ◽  
Tumour Cells ◽  
Hsp90 Inhibition ◽  
Killing Effect

177Lu-octreotate is an FDA-approved radionuclide therapy for patients with gastroenteropancreatic neuroendocrine tumours (NETs) expressing somatostatin receptors. The 177Lu-octreotate therapy has shown promising results in clinical trials by prolonging progression-free survival, but complete responses are still uncommon. The aim of this study was to improve the 177Lu-octreotate therapy by means of combination therapy. To identify radiosensitising inhibitors, two cell lines, GOT1 and P-STS, derived from small intestinal neuroendocrine tumours (SINETs), were screened with 1224 inhibitors alone or in combination with external radiation. The screening revealed that inhibitors of Hsp90 can potentiate the tumour cell-killing effect of radiation in a synergistic fashion (GOT1; false discovery rate <3.2 × 10−11). The potential for Hsp90 inhibitor ganetespib to enhance the anti-tumour effect of 177Lu-octreotate in an in vivo setting was studied in the somatostatin receptor-expressing GOT1 xenograft model. The combination led to a larger decrease in tumour volume relative to monotherapies and the tumour-reducing effect was shown to be synergistic. Using patient-derived tumour cells from eight metastatic SINETs, we could show that ganetespib enhanced the effect of 177Lu-octreotate therapy for all investigated patient tumours. Levels of Hsp90 protein expression were evaluated in 767 SINETs from 379 patients. We found that Hsp90 expression was upregulated in tumour cells relative to tumour stroma in the vast majority of SINETs. We conclude that Hsp90 inhibitors enhance the tumour-killing effect of 177Lu-octreotate therapy synergistically in SINET tumour models and suggest that this potentially promising combination should be further evaluated.

scholarly journals Better way to image and manage Neuroendocrine Tumours: Role of 68Gallium DOTA-Peptide PET-CT scan

2018 ◽  
Vol 20 (2) ◽  
pp. 136
Author(s):  
Shankar Kumar Dey
Keyword(s):  
Molecular Imaging ◽  
Ct Scan ◽  
Significant Role ◽  
Neuroendocrine Tumours ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Pet Ct ◽  
Receptor Scintigraphy ◽  
Pet Ct Scan

<p>Neuroendocrine tumours (NETs) are special entity of neoplasms arising from nervous and endocrine systems and involving variety of organs. Over expression of somatostatin receptors is an unique characteristic of these tumours. This allows molecular imaging to play a significant role in evaluation of NETs using somatostatin analogues. <sup>111</sup> In Pentetreotide scintigraphy has been playing a significant role as molecular imaging of choice to locate the primary tumor, evaluate extent of disease and plan for surgical management. Recently <sup>68 </sup>Ga labelled peptides have emerged as promising PET tracers for scintigraphy of these tumours. Several recent studies have demonstrated the superiority of <sup>68</sup>Ga DOTA- Peptide PET-CT scan with a number of advantages over conventional somatostatin receptor scintigraphy.</p><p>Bangladesh J. Nuclear Med. 20(2): 136-142, July 2017</p>

scholarly journals Selection of the First 99mTc-Labelled Somatostatin Receptor Subtype 2 Antagonist for Clinical Translation—Preclinical Assessment of Two Optimized Candidates

2020 ◽  
Vol 14 (1) ◽  
pp. 19
Author(s):  
Melpomeni Fani ◽  
Viktoria Weingaertner ◽  
Petra Kolenc Peitl ◽  
Rosalba Mansi ◽  
Raghuvir H. Gaonkar ◽  
...  
Keyword(s):  
Protein Binding ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Preclinical Study ◽  
Clinical Translation ◽  
Hek293 Cells ◽  
Neuroendocrine Neoplasms ◽  
Receptor Subtype ◽  
Selection Of

Recently, radiolabelled antagonists targeting somatostatin receptors subtype 2 (SST2) in neuroendocrine neoplasms demonstrated certain superior properties over agonists. Within the ERA-PerMED project “TECANT” two 99mTc-Tetramine (N4)-derivatized SST2 antagonists (TECANT-1 and TECANT-2) were studied for the selection of the best candidate for clinical translation. Receptor-affinity, internalization and dissociation studies were performed in human embryonic kidney-293 (HEK293) cells transfected with the human SST2 (HEK-SST2). Log D, protein binding and stability in human serum were assessed. Biodistribution and SPECT/CT studies were carried out in nude mice bearing HEK-SST2 xenografts, together with dosimetric estimations from mouse-to-man. [99mTc]Tc-TECANT-1 showed higher hydrophilicity and lower protein binding than [99mTc]-TECANT-2, while stability was comparable. Both radiotracers revealed similar binding affinity, while [99mTc]Tc-TECANT-1 had higher cellular uptake (>50%, at 2 h/37 °C) and lower dissociation rate (<30%, at 2 h/37 °C). In vivo, [99mTc]Tc-TECANT-1 showed lower blood values, kidney and muscles uptake, whereas tumour uptake was comparable to [99mTc]Tc-TECANT-2. SPECT/CT imaging confirmed the biodistribution results, providing the best tumour-to-background image contrast for [99mTc]Tc-TECANT-1 at 4 h post-injection (p.i.). The estimated radiation dose amounted to approximately 6 µSv/MBq for both radiotracers. This preclinical study provided the basis of selection of [99mTc]Tc-TECANT-1 for clinical translation of the first 99mTc-based SST2 antagonist.

Pancreatic endocrine disorders and multiple endocrine neoplasia

2020 ◽  
pp. 2449-2463
Author(s):  
B. Khoo ◽  
T.M. Tan ◽  
S.R. Bloom
Keyword(s):  
Kinase Inhibitors ◽  
Neuroendocrine Tumours ◽  
Mammalian Target Of Rapamycin ◽  
Peptide Receptor Radionuclide Therapy ◽  
Mtor Inhibitors ◽  
Somatostatin Analogues ◽  
Endocrine Disorders ◽  
Pancreatic Neuroendocrine Tumours ◽  
Islet Cell Tumours ◽  
Cancer Syndromes

Pancreatic neuroendocrine tumours (islet-cell tumours) are rare and usually sporadic, but they may be associated with complex familial endocrine cancer syndromes. Recognized types of pancreatic neuroendocrine tumours are those that are non-functioning (often advanced at diagnosis and presenting with mass effects due to the absence of symptoms attributable to hormone hypersecretion), insulinoma (the most frequent type), and others including gastrinoma, VIPoma, and glucagonoma. The following should be considered in addition to the symptomatic treatments: surgical resection—the only curative treatment, but not possible in many cases; tyrosine kinase inhibitors which inhibit specific kinases involved in tumour cell proliferation, growth, and angiogenesis; mammalian Target of Rapamycin (mTOR) inhibitors; peptide-receptor radionuclide therapy (radiolabelled somatostatin analogues).

scholarly journals Treatment of Advanced Hepatocellular Carcinoma with Somatostatin Analogues: A Review of the Literature

2019 ◽  
Vol 20 (19) ◽  
pp. 4811
Author(s):  
Hendrik Reynaert ◽  
Isabelle Colle
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Cancer ◽  
Current Knowledge ◽  
Primary Liver Cancer ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Receptor Expression ◽  
Surrounding Tissue ◽  
Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma, one of the most dreaded complications of cirrhosis, is a frequent cancer with high mortality. Early primary liver cancer can be treated by surgery or ablation techniques, but advanced hepatocellular carcinoma remains a challenge for clinicians. Most of these patients have underlying cirrhosis, which complicates or even precludes treatment. Therefore, efficacious treatments without major side effects are welcomed. Initial results of treatment of advanced hepatocellular carcinoma with somatostatin analogues were promising, but subsequent trials have resulted in conflicting outcomes. This might be explained by different patient populations, differences in dosage and type of treatment and differences in somatostatin receptor expression in the tumor or surrounding tissue. It has been shown that the expression of somatostatin receptors in the tumor might be of importance to select patients who could benefit from treatment with somatostatin analogues. Moreover, somatostatin receptor expression in hepatocellular carcinoma has been shown to correlate with recurrence, prognosis, and survival. In this review, we will summarize the available data on treatment of primary liver cancer with somatostatin analogues and analyze the current knowledge of somatostatin receptor expression in hepatocellular carcinoma and its possible clinical impact.

Novel insights in somatostatin receptor physiology

2007 ◽  
Vol 156 (suppl_1) ◽  
pp. S3-S11 ◽  
Author(s):  
Giovanni Tulipano ◽  
Stefan Schulz
Keyword(s):  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogs ◽  
Receptor Subtypes ◽  
Ligand Complex ◽  
Endosomal Sorting ◽  
Intracellular Vesicle ◽  
Molecular Events ◽  
Somatostatin Receptor Subtypes

The experimental data reviewed in the present paper deal with the molecular events underlying the agonist-dependent regulation of the distinct somatostatin receptor subtypes and may suggest important clues about the clinical use of somatostatin analogs with different pattern of receptor specificity for the in vivo targeting of tumoral somatostatin receptors. Somatostatin receptor subtypes are characterized by differential β-arrestin trafficking and endosomal sorting upon agonist binding due, at least in part, to the differences in their C-terminal tails. Moreover, the subcellular expression pattern of somatostatin receptor subtypes and their activity in response to agonist treatment are affected by intracellular complements, such as proteins involved in intracellular vesicle trafficking. Different somatostatin analogs may induce distinct conformations of the receptor/ligand complex, preferentially coupled to either receptor signaling or receptor endocytosis.

scholarly journals Somatostatin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Corinne Bosquet ◽  
Justo P. Castaño ◽  
Zsolt Csaba ◽  
Micheal Culler ◽  
Pascal Dournaud ◽  
...  
Keyword(s):  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
The Body ◽  
Physiological Effects ◽  
Endogenous Ligand ◽  
Endogenous Ligands ◽  
Inhibiting Factor ◽  
Wide Range ◽  
Somatostatin 14

Somatostatin (somatotropin release inhibiting factor) is an abundant neuropeptide, which acts on five subtypes of somatostatin receptor (SST1-SST5; nomenclature as agreed by the NC-IUPHAR Subcommittee on Somatostatin Receptors [89]). Activation of these receptors produces a wide range of physiological effects throughout the body including the inhibition of secretion of many hormones. Endogenous ligands for these receptors are somatostatin-14 (SRIF-14) and somatostatin-28 (SRIF-28). cortistatin-14 has also been suggested to be an endogenous ligand for somatostatin receptors [56].

scholarly journals Sequence of therapy and survival in patients with advanced pancreatic neuroendocrine tumours

2020 ◽  
Vol 27 (4) ◽  
Author(s):  
E. S. Tsang ◽  
J.M. Loree ◽  
C. Speers ◽  
H.F. Kennecke
Keyword(s):  
Neuroendocrine Tumours ◽  
Progression Free Survival ◽  
Somatostatin Analogues ◽  
Treatment Modalities ◽  
Primary Role ◽  
First Line ◽  
Optimal Sequence ◽  
Systemic Treatments ◽  
Pancreatic Neuroendocrine Tumours ◽  
Line Of Therapy

Background Pancreatic neuroendocrine tumours (pnets) often present as advanced disease. The optimal sequence of therapy is unknown. Methods Sequential patients with advanced pnets referred to BC Cancer between 2000 and 2013 who received 1 or more treatment modalities were reviewed, and treatment patterns, progression-free survival (pfs), and overall survival (os) were characterized. Systemic treatments included chemotherapy, small-molecule therapy, and peptide receptor radiotherapy. Results In 66 cases of advanced pnets, median patient age was 61.2 years (25%–75% interquartile range: 50.8–66.2 years), and men constituted 47% of the group. First-line therapies were surgery (36%), chemotherapy (33%), and somatostatin analogues (32%). Compared with first-line systemic therapy, surgery in the first line was associated with increased pfs and os (20.6 months vs. 6.3 months and 100.3 months vs. 30.5 months respectively, p < 0.05). In 42 patients (64%) who received more than 1 line of therapy, no difference in os or pfs between second-line therapies was observed. Conclusions Our results confirm the primary role of surgery for advanced pnets. New systemic treatments will further increase options.

scholarly journals CUX1—Transcriptional Master Regulator of Tumor Progression in Pancreatic Neuroendocrine Tumors

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1957
Author(s):  
Sebastian Krug ◽  
Julia Weissbach ◽  
Annika Blank ◽  
Aurel Perren ◽  
Johannes Haybaeck ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mouse Model ◽  
Neuroendocrine Tumours ◽  
Tumour Progression ◽  
Free Survival ◽  
Treatment Naïve ◽  
Pancreatic Neuroendocrine Tumours ◽  
The Impact

Recently, we identified the homeodomain transcription factor Cut homeobox 1 (CUX1) as mediator of tumour de-differentiation and metastatic behaviour in human insulinoma patients. In insulinomas, CUX1 enhanced tumour progression by stimulating proliferation and angiogenesis in vitro and in vivo. In patients with non-functional pancreatic neuroendocrine tumours (PanNET), however, the impact of CUX1 remains to be elucidated. Here, we analysed CUX1 expression in two large independent cohorts (n = 43 and n = 141 tissues) of non-functional treatment-naïve and pre-treated PanNET patients, as well as in the RIP1Tag2 mouse model of pancreatic neuroendocrine tumours. To further assess the functional role of CUX1, expression profiling of DNA damage-, proliferation- and apoptosis-associated genes was performed in CUX1-overexpressing Bon-1 cells. Validation of differentially regulated genes was performed in Bon-1 and QGP1 cells with knock-down and overexpression strategies. CUX1 expression assessed by a predefined immunoreactivity score (IRS) was significantly associated with shorter progression-free survival (PFS) of pre-treated PanNET patients (23 vs. 8 months; p = 0.005). In treatment-naïve patients, CUX1 was negatively correlated with grading and recurrence-free survival (mRFS of 39 versus 8 months; p = 0.022). In both groups, high CUX1 levels indicated a metastatic phenotype. Functionally, CUX1 upregulated expression of caspases and death associated protein kinase 1 (DAPK1), known as mediators of tumour progression and resistance to cytotoxic drugs. This was also confirmed in both cell lines and human tissues. In the RIP1Tag2 mouse model, CUX1 expression was associated with advanced tumour stage and resistance to apoptosis. In summary, we identified the transcription factor CUX1 as mediator of tumour progression in non-functional PanNET in vitro and in vivo, indicating that the CUX1-dependent signalling network is a promising target for future therapeutic intervention.

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