| 1. |
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| 2. |
- Altai, Mohamed, et al.
(författare)
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Order of amino acids in C-terminal cysteine-containing peptide-based chelators influences cellular processing and biodistribution of Tc-99m-labeled recombinant Affibody molecules
- 2012
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Ingår i: Amino Acids. - : Springer Science and Business Media LLC. - 0939-4451 .- 1438-2199. ; 42:5, s. 1975-1985
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules constitute a novel class of molecular display selected affinity proteins based on non-immunoglobulin scaffold. Preclinical investigations and pilot clinical data have demonstrated that Affibody molecules provide high contrast imaging of tumor-associated molecular targets shortly after injection. The use of cysteine-containing peptide-based chelators at the C-terminus of recombinant Affibody molecules enabled site-specific labeling with the radionuclide Tc-99m. Earlier studies have demonstrated that position, composition and the order of amino acids in peptide-based chelators influence labeling stability, cellular processing and biodistribution of Affibody molecules. To investigate the influence of the amino acid order, a series of anti-HER2 Affibody molecules, containing GSGC, GEGC and GKGC chelators have been prepared and characterized. The affinity to HER2, cellular processing of Tc-99m-labeled Affibody molecules and their biodistribution were investigated. These properties were compared with that of the previously studied Tc-99m-labeled Affibody molecules containing GGSC, GGEC and GGKC chelators. All variants displayed picomolar affinities to HER2. The substitution of a single amino acid in the chelator had an appreciable influence on the cellular processing of Tc-99m. The biodistribution of all Tc-99m-labeled Affibody molecules was in general comparable, with the main difference in uptake and retention of radioactivity in excretory organs. The hepatic accumulation of radioactivity was higher for the lysine-containing chelators and the renal retention of Tc-99m was significantly affected by the amino acid composition of chelators. The order of amino acids influenced renal uptake of some conjugates at 1 h after injection, but the difference decreased at later time points. Such information can be helpful for the development of other scaffold protein-based imaging and therapeutic radiolabeled conjugates.
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| 3. |
- Altai, Mohamed, et al.
(författare)
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Selection of an optimal cysteine-containing peptide-based chelator for labeling of affibody molecules with (188)Re.
- 2014
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 87, s. 519-28
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of (188)Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all (188)Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The (188)Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of (188)Re-ZHER2:V2 (3.1 ± 0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental (188)Re-ZHER2:2395 (172 ± 32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of (188)Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.
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| 4. |
- Altai, Mohamed, et al.
(författare)
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Selection of an optimal cysteine-containing peptide-based chelator for labeling of Affibody molecules with 188-Re
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 40:Suppl. 2, s. S219-S220
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1±0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172±32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.
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| 5. |
- Andersson, Jennie, et al.
(författare)
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Imaging of HER2 may improve the outcome of external irradiation therapy for prostate cancer patients
- 2015
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Ingår i: Oncology Letters. - : Spandidos Publications. - 1792-1074 .- 1792-1082. ; 9:2, s. 950-954
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer (PCa) is the most common type of cancer among males. Human epidermal growth factor receptor type 2 (HER2) expression in PCa has been reported by several studies and its involvement in the progression towards androgen-independent PCa has been discussed. External irradiation is one of the existing therapies, which has been demonstrated to be efficient in combination with androgen deprivation therapy for the treatment of advanced PCa. However, 20-40% of patients develop recurrent and more aggressive PCa within 10 years. The current study investigates the involvement of HER2 in survival and radioresistance in PCa cells and we hypothesized that, by monitoring HER2 expression, treatment may be personalized. The PCa cell lines, LNCap, PC3 and DU-145, received a 6 Gy single dose of external irradiation. The number of PC3 cells was not affected by a single dose of radiation, whereas a 5-fold decrease in cell number was detected in LNCap (P<0.00001) and DU-145 (P<0.0001) cells. The HER2 expression in PC3 exhibited a significant increase post irradiation, however, the expression was stable in the remaining cell lines. The administration of trastuzumab post-irradiation resulted in a 2-fold decrease in the PC3 cell number, while the drug did not demonstrate additional effects in LNCap and DU-145 cells, when compared with that of irradiation treatment alone. The results of the present study demonstrated that an increase in membranous HER2 expression in response to external irradiation may indicate cell radioresistance. Furthermore, imaging of HER2 expression prior to and following external irradiation may present a step towards personalized therapy in PCa.
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| 6. |
- Andersson, Jennie, et al.
(författare)
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In Vitro Therapy Modeling of HER2 Targeting Therapy in Disseminated Prostate Cancer
- 2014
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 45:5, s. 2153-2158
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer (PCa) is the most common cancer type among men. Treatments against advanced PCa are limited and in many cases only palliative. In a later, androgent independent, stage of PCa androgen receptors can be activated without interaction with ligand, i.e., by receptors of tyrosine kinase (RTK) family in the outlaw pathway. Human epidermal growth factor receptors HER2 and EGFR belong to RTK-family. HER2 is one of the main actors in the outlaw pathway with EGFR as the preferable heterodimerizing partner. We hypothesized that information on HER2 expression in advanced PCa could be useful for selection of patients for anti-RTK therapy and monitoring of therapy response. A panel of PCa cell lines (LNCap, PC3, DU-145) was subjected to a 8-week treatment using drugs influencing the RTK: trastuzumab (anti‑HER2), 17-DMAG (Hsp90 inhibitor), alone or in combination, and their HER2 and EGFR expressions were compared with non-treated cells. Treatment with trastuzumab decreased proliferation of LNCap and DU-145 cell lines, while 17-DMAG and trastuzumab/17‑DMAG combination affected all three cell lines. HER2 expression was significantly increased in PC3 cells, the most resistant cell line. On the contrary, in responding cells (LNCap and DU-145) HER2 expression decreased, accompanied by increased EGFR expression. However, additional treatment of cells with cetuximab (anti‑EGFR) did not give any additive effect to trastuzumab. In this study the response to anti-RTK therapy proved to vary between different PCa cell lines. We have demonstrated that RTK targeting treatments may affect the phenotypic profile of PCa tumor cells that correlates with therapy outcome. Observation of such changes during treatment could be used for monitoring and an improved therapy outcome.
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| 7. |
- Andersson, Ken G, et al.
(författare)
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Comparative evaluation of 111In-labeled NOTA‑conjugated affibody molecules for visualization of HER3 expression in malignant tumors
- 2015
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 34:2, s. 1042-8
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Tidskriftsartikel (refereegranskat)abstract
- Expression of human epidermal growth factor receptor type 3 (HER3) in malignant tumors has been associated with resistance to a variety of anticancer therapies. Several anti-HER3 monoclonal antibodies are currently under pre-clinical and clinical development aiming to overcome HER3-mediated resistance. Radionuclide molecular imaging of HER3 expression may improve treatment by allowing the selection of suitable patients for HER3-targeted therapy. Affibody molecules are a class of small (7kDa) high-affinity targeting proteins with appreciable potential as molecular imaging probes. In a recent study, we selected affibody molecules with affinity to HER3 at a low picomolar range. The aim of the present study was to develop an anti-HER3 affibody molecule suitable for labeling with radiometals. The HEHEHE-Z08698-NOTA and HEHEHE-Z08699-NOTA HER3-specific affibody molecules were labeled with indium‑111 (111In) and assessed invitro and invivo for imaging properties using single photon emission computed tomography (SPECT). Labeling of HEHEHE-Z08698-NOTA and HEHEHE-Z08699-NOTA with 111In provided stable conjugates. Invitro cell tests demonstrated specific binding of the two conjugates to HER3-expressing BT‑474 breast carcinoma cells. In mice bearing BT‑474 xenografts, the tumor uptake of the two conjugates was receptor‑specific. Direct invivo comparison of 111In-HEHEHE-Z08698-NOTA and 111In-HEHEHE-Z08699‑NOTA demonstrated that the two conjugates provided equal radioactivity uptake in tumors, although the tumor-to-blood ratio was improved for 111In-HEHEHE-Z08698-NOTA [12±3 vs. 8±1, 4h post injection (p.i.)] due to more efficient blood clearance. 111In-HEHEHE-Z08698-NOTA is a promising candidate for imaging of HER3-expression in malignant tumors using SPECT. Results of the present study indicate that this conjugate could be used for patient stratification for anti-HER3 therapy.
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| 8. |
- Bass, Tarek, et al.
(författare)
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In vivo evaluation of a novel format of a bivalent HER3-targeting and albumin- binding therapeutic affibody construct
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of human epidermal growth factor receptor 3 (HER3) is involved in resistance to several therapies for malignant tumours. Currently, several anti-HER3 monoclonal antibodies are under clinical development. We introduce an alternative approach to HER3-targeted therapy based on engineered scaffold proteins, i.e. affibody molecules. We designed a small construct (22.5 kDa, denoted 3A3), consisting of two high-affinity anti-HER3 affibody molecules flanking an albumin-binding domain ABD, which was introduced for prolonged residence in circulation. In vitro, 3A3 efficiently inhibited growth of HER3-expressing BxPC-3 cells. Biodistribution in mice was measured using 3A3 that was site-specifically labelled with In-111 via a DOTA chelator. The residence time of In-111-DOTA-3A3 in blood was extended when compared with the monomeric affibody molecule. In-111-DOTA-3A3 accumulated specifically in HER3-expressing BxPC-3 xenografts in mice. However, In-111-DOTA-3A3 cleared more rapidly from blood than a size-matched control construct In-111-DOTA-TAT, most likely due to sequestering of 3A3 by mErbB3, the murine counterpart of HER3. Repeated dosing and increase of injected protein dose decreased uptake of In-111-DOTA-3A3 in mErbB3-expressing tissues. Encouragingly, growth of BxPC-3 xenografts in mice was delayed in an experimental (pilot-scale) therapy study using 3A3. We conclude that the 3A3 affibody format seems promising for treatment of HER3-overexpressing tumours.
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| 9. |
- Espes, Daniel, 1985-, et al.
(författare)
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Longitudinal Assessment of 11C-5-Hydroxytryptophan Uptake in Pancreas After Debut of Type 1 Diabetes
- 2021
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 70:4, s. 966-975
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Tidskriftsartikel (refereegranskat)abstract
- The longitudinal alterations of the pancreatic β-cell and islet mass in the progression of type 1 diabetes (T1D) are still poorly understood. The objective of this study was to repeatedly assess the endocrine volume and the morphology of the pancreas for up to 24 months after T1D diagnosis (n = 16), by 11C-5-hydroxytryptophan (11C-5-HTP) positron emission tomography (PET) and MRI. Study participants were examined four times by PET/MRI: at recruitment and then after 6, 12, and 24 months. Clinical examinations and assessment of β-cell function by a mixed-meal tolerance test and fasting blood samples were performed in connection with the imaging examination. Pancreas volume has a tendency to decrease from 50.2 ± 10.3 mL at T1D debut to 42.2 ± 14.6 mL after 24 months (P < 0.098). Pancreas uptake of 11C-5-HTP (e.g., the volume of the endocrine pancreas) did not decrease from T1D diagnosis (0.23 ± 0.10 % of injected dose) to 24-month follow-up, 0.21 ± 0.14% of injected dose, and exhibited low interindividual changes. Pancreas perfusion was unchanged from diagnosis to 24-month follow-up. The pancreas uptake of 11C-5-HTP correlated with the long-term metabolic control as estimated by HbA1c (P < 0.05). Our findings argue against a major destruction of β-cell or islet mass in the 2-year period after diagnosis of T1D.
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| 10. |
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| 11. |
- Mitran, Bogdan, et al.
(författare)
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Affibody-mediated imaging of EGFR expression in prostate cancer using radiocobalt-labeled DOTA-Z(EGFR:2377)
- 2019
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 41:1, s. 534-542
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Tidskriftsartikel (refereegranskat)abstract
- The epidermal growth factor receptor (EGFR) is often overexpressed during prostate cancer (PCa) progression towards androgen-independence after hormone therapy, but the overexpression is lower than in other types of cancers. Despite the low expression, EGFR has emerged as a promising therapeutic target for patients with castration-resistant PCa. Non-invasive methods for determination of EGFR expression in PCa can serve for patient stratification and therapy response monitoring. Radionuclide imaging probes based on affibody molecules (7 kDa) provide high contrast imaging of cancer-associated molecular targets. We hypothesized that the anti-EGFR affibody molecule DOTA-Z(EGFR:2377) labeled with Co-55 (positron-emitter, T1/2=17.5 h) would enable imaging of EGFR expression in PCa xenografts. The human PCa cell line DU-145 was used for in vitro and in vivo experiments and Co-57 was used as a surrogate for Co-55 in the present study. Binding of Co-57-DOTA-Z(EGFR:2377) to EGFR-expressing xenografts was saturable with anti-EGFR monoclonal antibody cetuximab, which would motivate the use of this tracer for monitoring the receptor occupancy during treatment. A significant dose-dependent difference in radioactivity accumulation in tumors and normal organs was observed when the biodistribution was studied 3 h after the injection of 10 and 35 mu g of Co-57-DOTA-Z(EGFR:2377): At lower doses the tumor uptake was 2-fold higher although tumor-to-organ ratios were not altered. For clinically relevant organs for PCa, tumor-to-organ ratios increased with time, and at 24 h pi were 2.2 +/- 0.5 for colon, 7 +/- 2 for muscle, and 4.0 +/- 0.7 for bones. Small animal SPECT/CT images confirmed the capacity of radiocobalt labeled DOTA-Z(EGFR:2377) to visualize EGFR expression in PCa. In conclusion, the present study demonstrated the feasibility of using the radiocobalt labeled anti-EGFR affibody conjugate Z(EGFR:2377) as an imaging agent for in vivo visualization of low EGFR-expressing tumors, like PCa, and for monitoring of receptor occupancy during cetuximab therapy as well as the importance of optimal dosing in order to achieve higher sensitivity molecular imaging.
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| 12. |
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| 13. |
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| 14. |
- Orlova, Anna, 1960-, et al.
(författare)
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Evaluation of the Therapeutic Potential of a HER3-Binding Affibody Construct TAM-HER3 in Comparison with a Monoclonal Antibody, Seribantumab
- 2018
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Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 15:8, s. 3394-3403
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor type 3 (HER3) is recognized to be involved in resistance to HER targeting therapies. A number of HER3-targeting monoclonal antibodies are under clinical investigation as potential cancer therapeutics. Smaller high-affinity scaffold proteins are attractive non-Fc containing alternatives to antibodies. A previous study indicated that anti-HER3 affibody molecules could delay the growth of xenografted HER3-positive tumors. Here, we designed a second-generation HER3-targeting construct (TAM-HER3), containing two HER3-specific affibody molecules bridged by an albumin-binding domain (ABD) for extension of blood circulation. Receptor blocking activity was demonstrated in vitro. In mice bearing BxPC-3 xenografts, the therapeutic efficacy of TAM-HER3 was compared to the HER3-specific monoclonal antibody seribantumab (MM-121). TAM-HER3 inhibited heregulin-induced phosphorylation in a panel of HER3-expressing cancer cells and was found to be equally as potent as seribantumab in terms of therapeutic efficacy in vivo and with a similar safety profile. Median survival times were 60 days for TAM-HER3, 54 days for seribantumab, and 41 days for the control group. No pathological changes were observed in cytopathological examination. The multimeric HER3-binding affibody molecule in fusion to ABD seems promising for further evaluation as candidate therapeutics for treatment of HER3-overexpressing tumors.
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| 15. |
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| 16. |
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| 17. |
- Orlova, Anna, et al.
(författare)
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Imaging of HER3-expressing xenografts in mice using a Tc-99m(CO)(3)-HEHEHE-Z(HER3:08699) affibody molecule
- 2014
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 41:7, s. 1450-1459
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor type 3 (HER3) is a transmembrane receptor tyrosine kinase belonging to the HER (ErbB) receptor family. Membranous expression of HER3 is associated with trastuzumab resistance in breast cancer and the transition to androgen independence in prostate cancer. Imaging of HER3 expression in malignant tumors may provide important diagnostic information that can influence patient management. Affibody molecules with low picomolar affinity to HER3 were recently selected. The aim of this study was to investigate the feasibility of HER3 imaging using radiolabeled Affibody molecules. A HER3-binding Affibody molecule, Z(08699), with a HEHEHE-tag on N-terminus was labeled with Tc-99m(CO)(3) using an IsoLink kit. In vitro and in vivo binding specificity and the cellular processing of the labeled binder were evaluated. Biodistribution of Tc-99m(CO)(3)-HEHEHE-Z(08699) was studied over time in mice bearing HER3-expressing xenografts. HEHEHE-Z(08699) was labeled with Tc-99m(CO)(3) with an isolated yield of > 80 % and a purity of > 99 %. Binding of Tc-99m(CO)(3)-HEHEHE-Z(08699) was specific to BT474 and MCF7 (breast cancer), and LS174T (colon cancer) cells. Cellular processing showed rapid binding and relatively quick internalization of the receptor/Affibody molecule complex (70 % of cell-associated radioactivity was internalized after 24 h). The tumor targeting was receptor mediated and the excretion was predominantly renal. Receptor-mediated uptake was also found in the liver, lung, stomach, intestine, and salivary glands. At 4 h pi, tumor-to-blood ratios were 7 +/- 3 for BT474, and 6 +/- 2 for LS174T xenografts. LS174T tumors were visualized by microSPECT 4 h pi. The results of this study suggest the feasibility of HER3-imaging in malignant tumors using Affibody molecules.
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| 18. |
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| 19. |
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| 20. |
- Rosestedt, Maria, et al.
(författare)
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Affibody-mediated PET imaging of HER3 expression in malignant tumours
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor 3(HER3) is involved in the progression of various cancers and in resistance to therapies targeting the HER family. In vivo imaging of HER3 expression would enable patient stratification for anti-HER3 immunotherapy. Key challenges with HER3-targeting are the relatively low expression in HER3-positive tumours and HER3 expression in normal tissues. The use of positron-emission tomography (PET) provides advantages of high resolution, sensitivity and quantification accuracy compared to SPECT. Affibody molecules, imaging probes based on a non-immunoglobulin scaffold, provide high imaging contrast shortly after injection. The aim of this study was to evaluate feasibility of PET imaging of HER3 expression using 68Ga-labeled affibody molecules. The anti-HER3 affibody molecule HEHEHE-Z08698-NOTA was successfully labelled with 68Ga with high yield, purity and stability. The agent bound specifically to HER3-expressing cancer cells in vitro and in vivo. At 3 h pi, uptake of 68Ga-HEHEHE-Z08698-NOTA was significantly higher in xenografts with high HER3 expression (BT474, BxPC-3) than in xenografts with low HER3 expression (A431). In xenografts with high expression, tumour-to-blood ratios were >20, tumour-to-muscle >15, and tumour-to-bone >7. HER3-positive xenografts were visualised using microPET 3 h pi. In conclusion, PET imaging of HER3 expression is feasible using 68Ga-HEHEHE-Z08698-NOTA shortly after administration.
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| 21. |
- Rosestedt, Maria
(författare)
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Affibody Molecules for HER3-targeted Theranostics of Malignant Tumours
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The HER3 receptor plays a strong role in disease progression and resistance to therapies in several cancer types. Due to its endogenous expression and low overexpression in malignant tumours, it is a particularly challenging target. The primary aim of this thesis project was to develop, evaluate and characterize affibody molecules for theranostic applications in HER3-expressing malignant tumours.Paper I investigated the in vivo targeting properties and therapeutic efficacy of a bivalent affibody construct fused with an albumin binding domain, ZHER3-ABD-ZHER3. This construct could slow down the growth of HER3-expressing tumour xenografts without causing health problems or side effects in mice.Paper II compared the in vitro and in vivo properties of two HER3-targeting affibody molecules (Z08698 and Z08699) to select an imaging probe for HER3 diagnostics. While the two constructs had similar properties, Z08698 demonstrated better blood clearance and better radioactivity retention in tumours.Paper III and IV present the development of a HER3 imaging probe for PET using gallium and cobalt isotopes. We demonstrated that imaging of HER3 expression could be obtained as soon as 3 h pi using gallium-68. Additionally, we demonstrated that affibody molecules labelled with a neutral cobalt-NOTA complex had a lower radioactivity uptake in the liver than molecules radiolabelled with a positive gallium-NOTA complex. Imaging contrast increased over time. As the dose of the injected protein increased, the activity uptake in normal organs decreased, whereas the tumour uptake remained the same, which improved the imaging contrast and allowed discrimination between xenografts with high and low HER3 expression. This modification did not influence tumour activity uptake.Paper V presents the HER3-targeting affibody molecule trimer as a tool to block hepatic uptake in order to increase the imaging contrast in the liver. The trimer demonstrated its ability to bind to endogenous receptors in the liver, which decreased the hepatic uptake of the radiolabelled monomer. This phenomenon enabled the monomer to pass the liver barrier, which increased tumour radioactivity uptake and improved imaging contrast.
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| 22. |
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| 23. |
- Rosestedt, Maria, et al.
(författare)
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Evaluation of a radiocobalt-labelled affibody molecule for imaging of human epidermal growth factor receptor 3 expression
- 2017
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 51:6, s. 1765-1774
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Tidskriftsartikel (refereegranskat)abstract
- The human epidermal growth factor receptor 3 (HER3) is involved in the development of cancer resistance towards tyrosine kinase-Targeted therapies. Several HER3-Targeting therapeutics are currently under clinical evaluation. Non-invasive imaging of HER3 expression could improve patient management. Affibody molecules are small engineered scaffold proteins demonstrating superior properties as targeting probes for molecular imaging compared with monoclonal antibodies. Feasibility of in vivo HER3 imaging using affibody molecules has been previously demonstrated. Preclinical studies have shown that the contrast when imaging using anti-HER3 affibody molecules can be improved over time. We aim to develop an agent for PET imaging of HER3 expression using the long-lived positron-emitting radionuclide cobalt-55 (55Co) (T1/2=17.5 h). A long-lived cobalt isotope 57Co was used as a surrogate for 55Co in this study. The anti-HER3 affibody molecule HEHEHE-ZHER3-NOTA was labelled with radiocobalt with high yield, purity and stability. Biodistribution of 57Co-HEHEHE-ZHER3-NOTA was measured in mice bearing DU145 (prostate carcinoma) and LS174T (colorectal carcinoma) xenografts at 3 and 24 h post injection (p.i.). Tumour-To-blood ratios significantly increased between 3 and 24 h p.i. (p<0.05). At 24 h p.i., tumour-To-blood ratios were 6 for DU145 and 8 for LS174T xenografts, respectively. HER3-expressing xenografts were clearly visualized in a preclinical imaging setting already 3 h p.i., and contrast further improved at 24 h p.i. In conclusion, the radiocobalt-labelled anti-HER3 affibody molecule, HEHEHE-ZHER3-NOTA, is a promising tracer for imaging of HER3 expression in tumours.
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| 24. |
- Rosestedt, Maria, et al.
(författare)
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Improved contrast of affibody-mediated imaging of HER3 expression in mouse xenograft model through co-injection of a trivalent affibody for in vivo blocking of hepatic uptake
- 2019
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor type 3 (HER3) plays a crucial role in the progression of many cancer types. In vivo radionuclide imaging could be a reliable method for repetitive detection of HER3-expression in tumors. The main challenge of HER3-imaging is the low expression in tumors together with endogenous receptor expression in normal tissues, particularly the liver. A HER3-targeting affibody molecule labeled with radiocobalt via a NOTA chelator [Co-57]Co-NOTA-Z(08699) has demonstrated the most favorable biodistribution profile with the lowest unspecific hepatic uptake and high activity uptake in tumors. We hypothesized that specific uptake of labeled affibody monomer might be selectively blocked in the liver but not in tumors by a co-injection of non-labeled corresponding trivalent affibody (Z(08699))(3). Biodistribution of [Co-57]Co-NOTA-Z(08699) and [In-111]ln-DOTA-(Z(08699))(3) was studied in BxPC-3 xenografted mice. [Co-57]Co-NOTA-Z(08699) was co-injected with unlabeled trivalent affibody DOTA-(Z(08699))(3) at different monomer:trimer molar ratios. HER3-expression in xenografts was imaged using [Co-57]Co-NOTA-Z(08699) and [Co-57]Co-NOTA-Z(08699): DOTA-(Z(08699))(3). Hepatic activity uptake of [Co-57] Co-NOTA-Z(08699): DOTA-(Z(08699))(3) decreased with increasing monomer:trimer molar ratio. The tumor activity uptake and tumor-to-liver ratios were the highest for the 1:3 ratio. SPECT/CT images confirmed the biodistribution data. Imaging of HER3 expression can be improved by co-injection of a radiolabeled monomeric affi body-based imaging probe together with a trivalent affibody.
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| 25. |
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| 26. |
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| 27. |
- Rosestedt, Maria, et al.
(författare)
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Radiolabelling and positron emission tomography imaging of a high-affinity peptide binder to collagen type 1
- 2021
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Ingår i: Nuclear Medicine and Biology. - : Elsevier. - 0969-8051 .- 1872-9614. ; 93, s. 54-62
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionPathological formation of fibrosis, is an important feature in many diseases. Fibrosis in liver and pancreas has been associated to metabolic disease including type 1 and 2 diabetes. The current methods for detecting and diagnosing fibrosis are either invasive, or their sensitivity to detect fibrosis in early stage is limited. Therefore, it is crucial to develop non-invasive methods to detect, stage and study the molecular processes that drive the pathology of liver fibrosis. The peptide LRELHLNNN was previously identified as a selective binder to collagen type I with an affinity of 170 nM. Radiolabelled LRELHLNNN thus constitute a potential PET tracer for fibrosis.MethodLRELHLNNN was conjugated to a DOTA/NOTA moiety via a PEG2-linker. DOTA-PEG2-LRELHLNNN was labelled with Gallium-68 and NOTA- PEG2-LRELHLNNN with aluminium fluoride-18. Biodistribution of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN was performed in healthy rats ex vivo and in vivo. The 68Ga-labelled analogue was evaluated in a mouse model of liver fibrosis by PET/MRI-imaging. The human predicted dosimetry of the tracers was extrapolated from rat ex vivo biodistribution studies at 10, 20, 40, 60, 120, 180 min (only fluoride-18) post-injection.ResultsThe peptides were successfully radiolabelled with gallium-68 and aluminium fluoride-18, respectively. The biodistribution of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN was favorable showing rapid clearance and low background binding in organs where fibrosis may develop. Binding of [68Ga]Ga-DOTA-PEG2-LRELHLNNN to fibrotic liver was higher than surrounding tissues in mice with induced hepatic fibrosis. However, the binding was in the range of SUV 0.3, indicating limited targeting of the tracer to liver. The extrapolated human predicted dosimetric profiles of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN were beneficial, potentially allowing at least three PET examinations annually.ConclusionsWe describe the modification, radiolabelling and evaluation of the collagen type I binding peptide LRELHLNNN. The resulting radiotracer analogues demonstrated suitable biodistribution and dosimetry. [68Ga]Ga-DOTA-PEG2-LRELHLNNN exhibited binding to hepatic fibrotic lesions and is a promising tool for PET imaging of fibrosis.Advances in knowledgeValidation of a new collagen targeting PET tracer.Implications for patient careEarly, non-invasive diagnosis and stratification of fibrosis in order to improve the diagnosis, staging and treatment of patients with diseases involving fibrosis.
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| 28. |
- Varasteh, Zohreh, et al.
(författare)
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The effect of macrocyclic chelators on the targeting properties of the 68Ga-labeled gastrin releasing peptide receptor antagonist PEG2-RM26
- 2015
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 42:5, s. 446-454
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionOverexpression of gastrin-releasing peptide receptors (GRPR) has been reported in several cancers. Bombesin (BN) analogs are short peptides with a high affinity for GRPR. Different BN analogs were evaluated for radionuclide imaging and therapy of GRPR-expressing tumors. We have previously investigated an antagonistic analog of BN (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2, RM26) conjugated to NOTA via a PEG2 spacer (NOTA-PEG2-RM26) labeled with 68Ga, 111In and Al18F. 68Ga-labeled NOTA-PEG2-RM26 showed high tumor-to-organ ratios.MethodsThe influence of different macrocyclic chelators (NOTA, NODAGA, DOTA and DOTAGA) on the targeting properties of 68Ga-labeled PEG2-RM26 was studied in vitro and in vivo.ResultsAll conjugates were labeled with generator-produced 68Ga with high yields and demonstrated high stability and specific binding to GRPR. The IC50 values of natGa-X-PEG2-RM26 (X = NOTA, DOTA, NODAGA, DOTAGA) were 2.3 ± 0.2, 3.0 ± 0.3, 2.9 ± 0.3 and 10.0 ± 0.6 nM, respectively. The internalization of the conjugates by PC-3 cells was low. However, the DOTA-conjugated analog demonstrated a higher internalization rate compared to other analogs. GRPR-specific uptake was found in receptor-positive normal tissues and PC-3 xenografts for all conjugates. The biodistribution of the conjugates was influenced by the choice of the chelator moiety. Although all radiotracers cleared rapidly from the blood, [68Ga]Ga-NOTA-PEG2-RM26 showed significantly lower uptake in lung, muscle and bone compared to the other analogs. The uptake in tumors (5.40 ± 1.04 %ID/g at 2 h p.i.) and the tumor-to-organ ratios (25 ± 3, 157 ± 23 and 39 ± 4 for blood, muscle and bone, respectively) were significantly higher for the NOTA-conjugate than the other analogs.ConclusionsChelators had a clear influence on the biodistribution and targeting properties of 68Ga-labeled antagonistic BN analogs. Positively charged [68Ga]Ga-NOTA-PEG2-RM26 provided a low kidney radioactivity uptake, high affinity, high tumor uptake and high image contrast.
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| 29. |
- Varasteh, Zohreh, et al.
(författare)
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The Effect of Mini-PEG-Based Spacer Length on Binding and Pharmacokinetic Properties of a Ga-68-Labeled NOTA-Conjugated Antagonistic Analog of Bombesin
- 2014
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 19:7, s. 10455-10472
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Tidskriftsartikel (refereegranskat)abstract
- The overexpression of gastrin-releasing peptide receptor (GRPR) in cancer can be used for peptide-receptor mediated radionuclide imaging and therapy. We have previously shown that an antagonist analog of bombesin RM26 conjugated to 1,4,7-triazacyclononane-N, N', N ''-triacetic acid (NOTA) via a diethyleneglycol (PEG(2)) spacer (NOTA-PEG(2)-RM26) and labeled with Ga-68 can be used for imaging of GRPR-expressing tumors. In this study, we evaluated if a variation of mini-PEG spacer length can be used for optimization of targeting properties of the NOTA-conjugated RM26. A series of analogs with different PEG-length (n = 2, 3, 4, 6) was synthesized, radiolabeled and evaluated in vitro and in vivo. The IC50 values of Ga-nat-NOTA-PEG(n)-RM26 (n = 2, 3, 4, 6) were 3.1 +/- 0.2, 3.9 +/- 0.3, 5.4 +/- 0.4 and 5.8 +/- 0.3 nM, respectively. In normal mice all conjugates demonstrated similar biodistribution pattern, however Ga-68-NOTA-PEG(3)-RM26 showed lower liver uptake. Biodistribution of Ga-68-NOTA-PEG(3)-RM26 was evaluated in nude mice bearing PC-3 (prostate cancer) and BT-474 (breast cancer) xenografts. High uptake in tumors (4.6 +/- 0.6% ID/g and 2.8 +/- 0.4% ID/g for PC-3 and BT-474 xenografts, respectively) and high tumor-to-background ratios (tumor/ blood of 44 +/- 12 and 42 +/- 5 for PC-3 and BT-474 xenografts, respectively) were found already at 2 h p.i. of Ga-68-NOTA-PEG(3)-RM26. Results of this study suggest that variation in the length of the PEG spacer can be used for optimization of targeting properties of peptide-chelator conjugates. However, the influence of the mini-PEG length on biodistribution is minor when di-, tri-, tetra- and hexaethylene glycol are compared.
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| 30. |
- Velikyan, Irina, 1966-, et al.
(författare)
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Improved Radiolytic Stability of a 68Ga-labelled Collagelin Analogue for the Imaging of Fibrosis
- 2021
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Ingår i: Pharmaceuticals. - : MDPI. - 1424-8247. ; 14:10
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Tidskriftsartikel (refereegranskat)abstract
- There is an unmet medical need for non-invasive, sensitive, and quantitative methods for the assessment of fibrosis. Herein, an improved collagelin analogue labelled with gallium-68 for use with positron emission tomography (PET) is presented. A cyclic peptide, c[CPGRVNleHGLHLGDDEGPC], was synthesized by solid-phase peptide synthesis, conjugated to 2-(4,7-bis(2-(tert-butoxy)-2-oxoethyl)-1,4,7-triazonan-1-yl)acetic acid, and labelled with gallium-68. High performance liquid chromatography (HPLC) was used for the quality and stability assessment of the collagelin analogue. Non-specific organ distribution, blood clearance, and excretion rates were investigated in healthy mice and rats using ex vivo organ distribution analysis and dynamic in vivo PET/CT. Mice with carbon tetrachloride (CCl4) induced liver fibrosis were used for the investigation of specific binding via in vitro frozen section autoradiography, ex vivo organ distribution, and in vivo PET/CT. A non-decay corrected radiochemical yield (48 ± 6%) of [68Ga]Ga-NOTA-PEG2-c[CPGRVNleHGLHLGDDEGPC] ([68Ga]Ga-NO2A-[Nle13]-Col) with a radiochemical purity of 98 ± 2% was achieved without radical scavengers. The 68Ga-labelling was regioselective and stable at ambient temperature for at least 3 h. The autoradiography of the cryosections of fibrotic mouse liver tissue demonstrated a distinct heterogeneous radioactivity uptake that correlated with the fibrosis scores estimated after Sirius Red staining. The blood clearance and tissue washout from the [68Ga]Ga-NO2A-[Nle13]-Col was fast in both normal and diseased mice. Dosimetry investigation in rats indicated the possibility for 4–5 PET/CT examinations per year. Radiolytic stability of the collagelin analogue was achieved by the substitution of methionine with norleucine amino acid residue without a deterioration of its binding capability. [68Ga]Ga-NO2A-[Nle13]-Col demonstrated a safe dosimetry profile suitable for repeated scanning.
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| 31. |
- Wegrzyniak, Olivia, et al.
(författare)
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Imaging of fibrogenesis in the liver by [18F]TZ-Z0959 : an Affibody molecule targeting platelet derived growth factor receptor β
- 2023
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Ingår i: EJNMMI Radiopharmacy and Chemistry. - : Springer Nature. - 2365-421X. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Platelet-derived growth factor receptor beta (PDGFRβ) is a receptor overexpressed on activated hepatic stellate cells (aHSCs). Positron emission tomography (PET) imaging of PDGFRβ could potentially allow the quantification of fibrogenesis in fibrotic livers. This study aims to evaluate a fluorine-18 radiolabeled Affibody molecule ([18F]TZ-Z09591) as a PET tracer for imaging liver fibrogenesis. Results: In vitro specificity studies demonstrated that the trans-Cyclooctenes (TCO) conjugated Z09591 Affibody molecule had a picomolar affinity for human PDGFRβ. Biodistribution performed on healthy rats showed rapid clearance of [18F]TZ-Z09591 through the kidneys and low liver background uptake. Autoradiography (ARG) studies on fibrotic livers from mice or humans correlated with histopathology results. Ex vivo biodistribution and ARG revealed that [18F]TZ-Z09591 binding in the liver was increased in fibrotic livers (p = 0.02) and corresponded to binding in fibrotic scars. Conclusions: Our study highlights [18F]TZ-Z09591 as a specific tracer for fibrogenic cells in the fibrotic liver, thus offering the potential to assess fibrogenesis clearly. Graphical abstract: [Figure not available: see fulltext.]
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| 32. |
- Wegrzyniak, Olivia, et al.
(författare)
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Recent Progress in the Molecular Imaging of Nonalcoholic Fatty Liver Disease
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:14
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Forskningsöversikt (refereegranskat)abstract
- Pathological fibrosis of the liver is a landmark feature in chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Diagnosis and assessment of progress or treatment efficacy today requires biopsy of the liver, which is a challenge in, e.g., longitudinal interventional studies. Molecular imaging techniques such as positron emission tomography (PET) have the potential to enable minimally invasive assessment of liver fibrosis. This review will summarize and discuss the current status of the development of innovative imaging markers for processes relevant for fibrogenesis in liver, e.g., certain immune cells, activated fibroblasts, and collagen depositions.
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