| 1. |
- Bernhardt, Peter, 1966, et al.
(författare)
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Effects of treatment with (177)Lu-DOTA-Tyr(3)-octreotate on uptake of subsequent injection in carcinoid-bearing nude mice.
- 2007
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Ingår i: Cancer biotherapy & radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1084-9785 .- 1557-8852. ; 22:5, s. 644-53
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to analyze the effect therapeutic injections of (177)Lu-DOTA(0)-Tyr(3)]-octreotate (DOTATATE) had on the tumor uptake of a subsequent injection with (111)In-DOTATATE in GOT1-bearing nude mice. METHODS AND MATERIALS: Nude mice, xenografted with the human midgut carcinoid, GOT1, were first intravenously injected with a curative (30 MBq) or a suboptimal (7.5 MBq) amount of (177)Lu-DOTATATE. At various intervals thereafter (4-13 days), a second injection with (111)In-DOTATATE (0.5 MBq) was given. One (1) day after the second injection, the animals were sacrificed, tumor tissues collected, the tumor (111)In and (177)Lu activity concentration determined, and tumor regression/cell density was recorded. RESULTS: In animals given curative amounts, the uptake of (111)In was lower than in untreated animals. On the other hand, a second late injection (3-13 days) after suboptimal amounts resulted in a twofold higher tumor activity concentration versus untreated animals. When the uptake of the curative injection was corrected for tumor cell density, which decreased from 66% to 4% over 2 weeks, an enhanced uptake per tumor cell was observed. The curative and suboptimal amounts resulted in a different uptake and retention of (177)Lu in tumors. The suboptimal amount resulted in a constant activity concentration, while the curative amount resulted in an increased activity concentration over time. CONCLUSIONS: Our results, as presented in this paper, describe how the second injection in a fractionation protocol will be affected by the first therapeutic amount. This new information might be useful in the optimization of radionuclide therapy.
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| 2. |
- Elf, Anna-Karin, et al.
(författare)
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Evaluation of sstr2 expression in si-nets and relation to overall survival after prrt
- 2021
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- (1) Purpose: Small intestinal neuroendocrine tumors (SI-NETs) often present with distant metastases at diagnosis. Peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogues is a systemic treatment that increases overall survival (OS) in SI-NET patients with stage IV disease. However, the treatment response after PRRT, which targets somatostatin receptor 2 (SSTR2), is variable and predictive factors have not been established. This exploratory study aims to evaluate if SSTR2 expression in SI-NETs could be used to predict OS after PRRT treatment. (2) Methods: Using a previously constructed Tissue Micro Array (TMA) we identified tissue samples from 42 patients that had received PRRT treatment during 2006–2017 at Sahlgrenska University hospital. Immunohistochemical expression of SSTR2, Ki-67 and neuroendocrine markers synaptophysin and Chromogranin A (CgA) were assessed. A retrospective estimation of177Lu-DOTATATE uptake in 33 patients was performed. Data regarding OS and non-surgical treatment after PRRT were collected. Another subgroup of 34 patients with paired samples from 3 tumor sites (primary tumor, lymph node and liver metastases) was identified in the TMA. The SSTR2 expression was assessed in corresponding tissue samples (n = 102). (3) Results: The patients were grouped into Low SSTR2 or High SSTR2 groups based upon on levels of SSTR2 expression. There was no significant difference in177Lu-DOTATATE uptake between the groups. The patients in the Low SSTR2 group had significantly longer OS after PRRT than the patients in the High SSTR2 group (p = 0.049). PRRT treated patients with low SSTR2 expression received less additional treatment compared with patients with high SSTR2 expression. SSTR2 expression did not vary between tumor sites but correlated within patients. (4) Conclusion: The results from the present study suggest that retrospective evaluation of SSTR2 expression in resected tumors cannot be used to predict OS after PRRT. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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| 3. |
- Elf, Anna-Karin, et al.
(författare)
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NAMPT inhibitor GMX1778 enhances the efficacy of 177Lu-DOTATATE treatment of neuroendocrine tumors.
- 2017
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 58:2, s. 288-292
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Tidskriftsartikel (refereegranskat)abstract
- Neuroendocrine tumors (NETs) can be treated by peptide receptor radionuclide therapy using radiolabeled somatostatin analogs. However, the efficacy of such treatment is low and needs to be optimized.To evaluate the potential radiosensitizing effects of NAMPT inhibition on (177)Lu-DOTATATE treatment in a NET model.Nude mice xenografted with the human NET cell line GOT1 were treated with semi-efficient doses of (177)Lu-DOTATATE (7,5 MBq, i.v.) and/or GMX1778 (100 mg/kg/week, p.o.).Median time to tumor progression (tumor volume larger than at day 0) was 3 days for controls, 7 days for single dose GMX1778, 28 days for single dose (177)Lu-DOTATATE and 35 days for 3 weekly doses of GMX1778. Combined treatment with (177)Lu-DOTATATE and GMX1778 x1 resulted in a median time to progression of 98 days. After (177)Lu-DOTATATE and 3 weekly doses of GMX1778 none of the tumors progressed within 120 days.The NAMPT inhibitor GMX1778 enhances the efficacy of (177)Lu-DOTATATE treatment and induces a prolonged antitumor response. Combinations of radiolabeled somatostatin analogs and radiosensitizing drugs should be further evaluated to optimize the efficacy of peptide receptor radionuclide therapy in NETs.
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| 4. |
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| 5. |
- Forssell-Aronsson, Eva, 1961, et al.
(författare)
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Aspects on radionuclide therapy in malignant pheochromocytomas.
- 2006
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923. ; 1073, s. 498-504
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Tidskriftsartikel (refereegranskat)abstract
- Malignant pheochromocytomas/paragangliomas (PCs/PGs) often have distant metastases to the skeleton, liver, and lungs. Radionuclide therapy is valuable for treatment of disseminated tumor disease and could be used as adjuvant therapy after surgery. Patients with local and/or distant metastases of PC/PG should be investigated preoperatively by scintigraphy using both 123I-MIBG and 111In-DTPA-D-Phe1-octreotide, to evaluate the possibilities for radionuclide therapy (i.e., a dosimetric estimation of radiation dose to the tumor tissue versus critical normal tissues). Individual patient dose-planning should be performed. For patients in whom positive therapeutic effects are anticipated radionuclide therapy can be applied. Therapy with both 131I-MIBG and 177Lu-octreotate might be favorable in individual patients with lesions visualized by both metaiodobenzylguanidine (MIBG) and octreotide scintigraphy with enhanced therapeutic effects and reduced side effects.
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| 6. |
- Forssell-Aronsson, Eva, 1961, et al.
(författare)
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Biodistribution data from 100 patients i.v. injected with 111In-DTPA-D-Phe1-octreotide
- 2004
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Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 43:5, s. 436-42
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to obtain accurate data on the biodistribution of 111In-DTPA-D-Phe1-octreotide in tumour and normal tissues to facilitate dosimetric evaluations. Patients with carcinoid tumours, medullary thyroid carcinoma (MTC), differentiated thyroid tumours, endocrine pancreatic tumour (EPT), breast carcinoma, and various other tumour types were i.v. injected with 111In-DTPA-D-Phe-1-octreotide. Tumour and normal tissue samples were collected during surgery 1-35 days later, and the 111In activity concentration determined. Results showed large inter- and intra-individual variations. The 111In concentration was in general higher in carcinoids and some EPT (range 0.33-77% IA/kg) than in MTC and other tumours (0.017-7.8% IA/kg). Tumour-to-blood ratios (T/B) higher than 100 were found in most patients with carcinoids, EPT, renal carcinoma, and neuroendocrine carcinoma (max value 1500), while T/B was below 80 in most other tumours. Normal-tissue-to-blood ratios were in general < or = 10 but higher values were found in liver, kidneys, and spleen. The results presented are important for dosimetric calculations, when radiolabelled octreotide is used for diagnostic or therapeutic purposes.
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| 7. |
- Johanson, Viktor, 1958, et al.
(författare)
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A transplantable human medullary thyroid carcinoma as a model for RET tyrosine kinase-driven tumorigenesis
- 2007
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Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 14:2, s. 433-444
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Tidskriftsartikel (refereegranskat)abstract
- Hereditary medullary thyroid carcinoma (MTC) is caused by germline mutations in the RET proto-oncogene, resulting in constitutive activation of the RET tyrosine kinase. A substantial proportion of sporadic MTCs also have RET mutations, making the RET tyrosine kinase a potential therapeutic target in MTC. We have established a transplantable MTC in nude mice from a sporadic human MTC carrying a RET C634R mutation. Transplanted tumors had an exponential growth rate with an approximate doubling time of about 3 weeks, and expressed a neuroendocrine phenotype characteristic of MTC, e.g., expression of calcitonin, chromogranin A (CgA), synaptophysin, synaptic vesicle protein 2 (SV2), vesicular monoamine transporter-1 and -2, carcinoembryonic antigen, cytokeratin 8/18, epithelial cadherin, and neural cell adhesion molecule. Plasma calcitonin and CgA levels were elevated in tumor-bearing mice and correlated with tumor size. Cytogenetic analysis, including spectral karyotyping, confirmed the human origin of the xenografted tumors and demonstrated an abnormal, near triploid karyotype. Treatment of tumor-bearing nude mice with the tyrosine kinase inhibitor ZD6474, which specifically inhibits RET, epidermal growth factor receptor (EGFR), and vascular endothelium growth factor receptor (VEGFR) tyrosine kinases, resulted in a dose-dependent inhibition of tumor growth. Oral ZD6474 given once daily (250 mg/kg, 5 days/week) reduced tumor volume to 11% when compared with controls after 4 weeks. Our results show that this transplantable MTC, designated GOT2, represents a novel and useful model for studies of MTC and RET tyrosine kinase-dependent tumor growth.
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| 8. |
- Johanson, Viktor, 1958, et al.
(författare)
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Antitumoural effects of the pyridyl cyanoguanidine CHS 828 on three different types of neuroendocrine tumours xenografted to nude mice
- 2005
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 82:3-4, s. 171-6
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Tidskriftsartikel (refereegranskat)abstract
- CHS 828, a cyanoguanidine with potent experimental antitumoural activity, inhibits activation of nuclear factor-kappaB. In the present study, marked antitumoural activity of peroral CHS 828 was shown against three different human neuroendocrine tumours, midgut carcinoid (GOT1), pancreatic carcinoid (BON), and medullary thyroid carcinoma (GOT2), transplanted in nude mice. Our results indicate that CHS 828 can be a candidate drug for treatment of neuroendocrine tumours.
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| 9. |
- Kölby, Lars, 1963, et al.
(författare)
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A transplantable human carcinoid as model for somatostatin receptor-mediated and amine transporter-mediated radionuclide uptake.
- 2001
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Ingår i: The American journal of pathology. - 0002-9440. ; 158:2, s. 745-55
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Tidskriftsartikel (refereegranskat)abstract
- A human midgut carcinoid tumor was successfully transplanted into nude mice and propagated for five consecutive generations (30 months) with well-preserved phenotype. Tumor cells in nude mice expressed identical neuroendocrine markers as the original tumor, including somatostatin receptors (somatostatin receptors 1 to 5) and vesicular monoamine transporters (VMAT1 and VMAT2). Because of the expression of somatostatin receptors and VMAT1 and VMAT2 the grafted tumors could be visualized scintigraphically using the somatostatin analogue 111In-octreotide and the catecholamine analogue 123I-metaiodobenzylguanidine. The biokinetics of the somatostatin analogue 111In-octreotide in the tumors was studied and showed a high retention 7 days after administration. Cell cultures were re-established from transplanted tumors. Immunocytochemical and ultrastructural studies confirmed the neuroendocrine differentiation. The human origin of transplanted tumor cells was confirmed by cytogenetic and fluorescence it situ hybridization analyses. Spontaneous secretion of serotonin and its metabolite, 5-hydroxyindole acetic acid, from tumor cells was demonstrated. The tumor cells increased their [Ca2+]i in response to beta-adrenoceptor stimulation (isoproterenol) and K+-depolarization. All somatostatin receptor subtypes could be demonstrated in cultured cells. This human transplantable carcinoid tumor, designated GOT1, grafted to nude mice, will give unique possibilities for studies of somatostatin receptor- and VMAT-mediated radionuclide uptake as well as for studies of secretory mechanisms.
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| 10. |
- Kölby, Lars, 1963, et al.
(författare)
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Can quantification of VMAT and SSTR expression be helpful for planning radionuclide therapy of malignant pheochromocytomas?
- 2006
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923. ; 1073, s. 491-7
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Tidskriftsartikel (refereegranskat)abstract
- Tumor-specific uptake of the radio-iodinated norepinephrine analogue meta-iodobenzylguanidine (MIBG) or uptake of radiolabeled somatostatin analogues via somatostatin receptors (SSTRs) are possibilities to diagnose and treat malignant pheochromocytomas/paragangliomas (PCs/PGs). The aims of this study were to investigate the quantitative expression of vesicular monoamine transporters (VMAT 1, 2) and all five SSTRs in malignant pheochromocytoma/paraganglioma (PC/PG) to evaluate the possibilities for tumor-specific radionuclide therapy. High scintigraphic 123I-MIBG uptake was found in two malignant PGs with high VMAT expression (500-730 copies of VMAT 1, 1,500-1,700 copies of VMAT 2 per 1,000 beta-actin), while no 123I-MIBG uptake was found in the malignant PG with low VMAT expression (330 copies of VMAT 1, 350 copies of VMAT 2 per 1,000 beta-actin). The two patients with high VMAT expression and high 123I-MIBG uptake were treated with 131I-MIBG (2-3x8 GBq). In vitro, the VMAT antagonist, reserpine, and the membrane pump inhibitor, clomipramine, inhibited the uptake of 123I-MIBG into tumor cells equally well (48% and 53% reduction respectively, P<0.001). SSTR2 was the most abundant receptor subtype, but in the two malignant PGs its expression was only 110-260 copies/1,000 beta-actin. The transporters at the cell membrane and in the vesicular membrane both appear to be of importance for the uptake of 123I-MIBG into malignant PC/PG. Quantitative determination of VMAT expression may be helpful in selecting patients suitable for radionuclide therapy with 131I-MIBG. The present data indicate that SSTR-mediated radionuclide therapy will not be effective treatment of malignant PC/PG.
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