| 1. |
- Bastard, Paul, et al.
(författare)
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Preexisting autoantibodies to type I IFNs underlie critical COVID-19 pneumonia in patients with APS-1.
- 2021
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Ingår i: The Journal of experimental medicine. - 1540-9538. ; 218:7
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Tidskriftsartikel (refereegranskat)abstract
- Patients with biallelic loss-of-function variants of AIRE suffer from autoimmune polyendocrine syndrome type-1 (APS-1) and produce a broad range of autoantibodies (auto-Abs), including circulating auto-Abs neutralizing most type I interferons (IFNs). These auto-Abs were recently reported to account for at least 10% of cases of life-threatening COVID-19 pneumonia in the general population. We report 22 APS-1 patients from 21 kindreds in seven countries, aged between 8 and 48 yr and infected with SARS-CoV-2 since February 2020. The 21 patients tested had auto-Abs neutralizing IFN-α subtypes and/or IFN-ω; one had anti-IFN-β and another anti-IFN-ε, but none had anti-IFN-κ. Strikingly, 19 patients (86%) were hospitalized for COVID-19 pneumonia, including 15 (68%) admitted to an intensive care unit, 11 (50%) who required mechanical ventilation, and four (18%) who died. Ambulatory disease in three patients (14%) was possibly accounted for by prior or early specific interventions. Preexisting auto-Abs neutralizing type I IFNs in APS-1 patients confer a very high risk of life-threatening COVID-19 pneumonia at any age.
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| 2. |
- Ahlgren, Sara, et al.
(författare)
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Evaluation of maleimide derivative of DOTA for site-specific labeling of recombinant affibody molecules
- 2008
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Ingår i: Bioconjugate chemistry. - : American Chemical Society (ACS). - 1043-1802 .- 1520-4812. ; 19:1, s. 235-243
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules are a new class of small (7 kDa) scaffold affinity proteins, which demonstrate promising properties as agents for in vivo radionuclide targeting. The Affibody scaffold is cysteine-free and therefore independent of disulfide bonds. Thus, a single thiol group can be engineered into the protein by introduction of one cysteine. Coupling of thiol-reactive bifunctional chelators can enable site-specific labeling of recombinantly produced Affibody molecules. In this study, the use of 1,4,7,10-tetraazacyclododecane-1,4,7-tris-acetic acid-10-maleimidoethylacetamide (MMA-DOTA) for 111 In-labeling of anti-HER2 Affibody molecules His 6-Z HER2:342-Cys and Z HER2:2395-Cys has been evaluated. The introduction of a cysteine residue did not affect the affinity of the proteins, which was 29 pM for His 6-Z HER2:342-Cys and 27 pM for Z HER2:2395-Cys, comparable with 22 pM for the parental Z HER2:342. MMA-DOTA was conjugated to DTT-reduced Affibody molecules with a coupling efficiency of 93% using a 1:1 molar ratio of chelator to protein. The conjugates were labeled with 111 In to a specific radioactivity of up to 7 GBq/mmol, with preserved binding for the target HER2. In vivo, the non-His-tagged variant 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys demonstrated appreciably lower liver uptake than its His-tag-containing counterpart. In mice bearing HER2-expressing LS174T xenografts, 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys showed specific and rapid tumor localization, and rapid clearance from blood and nonspecific compartments, leading to a tumor-to-blood-ratio of 18 +/- 8 already 1 h p.i. Four hours p.i., the tumor-to-blood ratio was 138 +/- 8. Xenografts were clearly visualized already 1 h p.i.
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| 3. |
- Almqvist, Ylva, et al.
(författare)
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In vitro characterization of 211 At-labeled antibody A33 : a potential therapeutic agent against metastatic colorectal carcinoma
- 2005
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Ingår i: Cancer Biotherapy and Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1084-9785 .- 1557-8852. ; 20:5, s. 514-523
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Tidskriftsartikel (refereegranskat)abstract
- The humanized antibody A33 binds to the A33 antigen, expressed in 95% of primary and metastatic colorectal carcinomas. The restricted pattern of expression in normal tissue makes this antigen a possible target for radioimmunotherapy of colorectal micrometastases. In this study, the A33 antibody was labeled with the therapeutic nuclide 211At using N-succinimidyl para-(tri-methylstannyl)benzoate (SPMB). The in vitro characteristics of the 211At-benzoate-A33 conjugate (211At-A33) were investigated and found to be similar to those of 125I-benzoate-A33 (125I-A33) in different assays. Both conjugates bound with high affinity to SW1222 cells (Kd = 1.7 ± 0.2 nM, and 1.8 ± 0.1 nM for 211At-A33 and 125I-A33, respectively), and both showed good intracellular retention (70% of the radioactivity was still cell associated after 20 hours). The cytotoxic effect of 211At-A33 was also confirmed. After incubation with 211At-A33, SW1222 cells had a survival of approximately 0.3% when exposed to some 150 decays per cell (DPC). The cytotoxic effect was found to be dose-dependent, as cells exposed to only 56 DPC had a survival of approximately 5%. The 211At-A33 conjugate shows promise as a potential radioimmunotherapy agent for treatment of micrometastases originating from colorectal carcinoma.
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| 4. |
- Altai, Mohamed, et al.
(författare)
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Feasibility of Affibody-Based Bioorthogonal Chemistry Mediated Radionuclide Pretargeting
- 2016
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Ingår i: Journal of Nuclear Medicine. - : SOC NUCLEAR MEDICINE. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 57:3, s. 431-436
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules constitute a new class of probes for radionuclide tumor targeting. The small size of Affibody molecules is favorable for rapid localization in tumors and clearance from circulation. However, high renal reabsorption of Affibody molecules prevents the use of residualizing radiometals, including several promising low-energy (beta- and alpha-emitters, for radionuclide therapy. We tested a hypothesis that Affibody-based pretargeting mediated by a bioorthogonal interaction between trans-cyclooctene (TCO) and tetrazine would provide higher accumulation of radiometals in tumor xenografts than in the kidneys. Methods: TCO was conjugated to the anti-human epidermal growth factor receptor 2 (HER2) Affibody molecule Z(2395). DOTA-tetrazine was labeled with In-111 and Lu-177. In vitro pretargeting was studied in HER2-expressing SKOV-3 and BT474 cell lines. In vivo studies were performed on BALB/C nu/nu mice bearing SKOV-3 xenografts. Results: I-125-Z(2395)-TCO bound specifically to HER2-expressing cells in vitro with an affinity of 45 +/- 16 pM. In-111-tetrazine bound specifically and selectively to Z(2325)-TCO pretreated cells. In vivo studies demonstrated HER2-specific I-125-Z(2395)-TCO accumulation in xenografts. TCO-mediated In-111-tetrazine localization was shown in tumors, when the radiolabeled tracer was injected 4 h after an injection of Z(2395)-TCO. At 1 h after injection, the tumor uptake of In-111-tetrazine and Lu-177-tetrazine was approximately 2-fold higher than the renal uptake. Pretargeting provided more than a 56-fold reduction of renal uptake of In-111 in comparison with direct targeting. Conclusion: The feasibility of Affibody-based bioorthogonal chemistry-mediated pretargeting was demonstrated. The use of pre-targeting provides a substantial reduction of radiometal accumulation in kidneys, creating preconditions for palliative radionuclide therapy.
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| 5. |
- Altai, Mohamed, et al.
(författare)
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Preclinical evaluation of anti-HER2 Affibody molecules site-specifically labeled with In-111 using a maleimido derivative of NODAGA
- 2012
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 39:4, s. 518-529
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Affibody molecules have demonstrated potential for radionuclide molecular imaging. The aim of this study was to synthesize and evaluate a maleimido derivative of the 1,4,7-triazacyclononane-l-glutaric acid-4,7-diacetic acid (NODAGA) for site-specific labeling of anti-HER2 Affibody molecule. Methods: The maleimidoethylmonoamide NODAGA (MMA-NODAGA) was synthesized and conjugated to Z(HER2:2395) Affibody molecule having a C-terminal cysteine. Labeling efficiency, binding specificity to and cell internalization by HER2-expressing cells of [In-111-MMA-NODAGA-Cys(61)]-Z(HER2:2395) were studied. Biodistribution of [In-111-MMA-NODAGA-Cys(61)]-Z(HER2:2395) and [In-111-MMA-DOTA-Cys(61)]-Z(HER2:2395) was compared in mice. Results: The affinity of [MMA-NODAGA-Cys(61)]-Z(HER2:2395) binding to HER2 was 67 pM. The In-1111-labeling yield was 99.6%+/- 0.5% after 30 min at 60 degrees C. [In-111-MMA-NODAGA-Cys(61)]-Z(HER2:2395) bound specifically to HER2-expressing cells in vitro and in vivo. Tumor uptake of [In-111-MMA-NODAGA-Cys(61)]-ZHER(2:2395) in mice bearing DU-145 xenografts (4.7%+/- 0.8% ID/g) was lower than uptake of [In-111-MMA-DOTA-Cys(61)]-Z(HER2:2395) (7.5%+/- 1.6% ID/g). However, tumor-to-organ ratios were higher for [In-111-MMA-NODAGA-Cys(61)]-Z(HER2:2395) due to higher clearance rate from normal tissues. Conclusions: MMA-NODAGA is a promising chelator for site-specific labeling of targeting proteins containing unpaired cysteine. Appreciable influence of chelators on targeting properties of Affibody molecules was demonstrated.
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| 6. |
- Bragina, Olga, et al.
(författare)
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Phase I study of 99mTc-ADAPT6, a scaffold protein-based probe for visualization of HER2 expression in breast cancer
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Radionuclide molecular imaging of human epidermal growth factor (HER2) expression may be helpful to stratify breast and gastroesophageal cancer patients for HER2-targeting therapies. ADAPTs (albumin-binding domain derived affinity proteins) are a new type of small (46-59 amino acids) proteins useful as probes for molecular imaging. The aim of this first in-human study was to evaluate biodistribution, dosimetry, and safety of HER2-specific 99mTc-ADAPT6.METHODS. Twenty-two patients with HER2-positive (n=11) or HER2-negative (n=11) primary breast cancer were intravenously injected with 385125 MBq. The injected amount of protein was either 500 μg (n=11) or 1000 μg (n=11). Planar scintigraphy followed by SPECT imaging was performed after 2, 4, 6 and 24 h. An additional cohort received a dose of 250 μg, and the planar scintigraphy followed by SPECT imaging was performed after 2 h only.RESULTS. Injection of 99mTc-ADAPT6 was well tolerated for all doses evaluated in the study, and was not associated with any adverse effects. 99mTc-ADAPT6 cleared rapidly from the blood and the majority of tissues. The normal organs with the highest accumulation were kidney, liver and lung. The effective doses were determined to 0.0090.002 and 0.0100.003 mSv/MBq when injecting protein amounts of 500 and 1000 μg, respectively. Injection of 500 μg resulted in excellent discrimination between HER2-positive and HER2-negative tumors already 2 h after injection (tumor-to-contralateral breast ratio was 3719 vs 52, p < 0.01). The tumor-to-contralateral breast ratios for HER2-positive tumors were significantly (p < 0.5) higher for the injected mass of 500 μg than for both 250 and 1000 μg. In one patient, the imaging using 99mTc-ADAPT6 revealed three bone metastases, which were not found at the time of diagnosis by CT or 99mTcpyrophosphate bone scan. MRI imaging confirmed this finding.CONCLUSION. Injections of 99mTc-ADAPT6 are safe and associated with low absorbed and effective doses. A protein dose of 500 μg is preferable for discrimination between tumors with high and low expression of HER2. 99mTc-ADAPT6 is a promising imaging probe for the stratification of patients for HER2-targeting therapy.
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| 7. |
- Bragina, Olga, et al.
(författare)
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Phase I study of 99mTc-ADAPT6, a scaffold protein-based probe for visualization of HER2 expression in breast cancer
- 2021
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 62:4, s. 493-499
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Tidskriftsartikel (refereegranskat)abstract
- Radionuclide molecular imaging of human epidermal growth factor (HER2) expression may be helpful to stratify breast and gastroesophageal cancer patients for HER2-targeting therapies. ADAPTs (albumin-binding domain derived affinity proteins) are a new type of small (46-59 amino acids) proteins useful as probes for molecular imaging. The aim of this first-in-human study was to evaluate biodistribution, dosimetry, and safety of the HER2-specific 99mTc-ADAPT6.METHODS: Twenty-nine patients with primary breast cancerwere included. In 22 patients with HER2-positive (n = 11) or HER2-negative (n = 11) histopathology an intravenous injection with 385±125 MBq 99mTc-ADAPT6 was performed, randomized to an injected protein mass of either 500 µg (n = 11) or 1000 µg (n = 11). Planar scintigraphy followed by SPECT imaging was performed after 2, 4, 6 and 24 h. An additional cohort (n = 7) was injected with 165±29 MBq (injected protein mass 250 µg) and imaging was performed after 2 h only.RESULTS: Injections of 99mTc-ADAPT6 at all injected mass levels were well tolerated and not associated with adverse effects. 99mTc-ADAPT6 cleared rapidly from blood and most other tissues. The normal organs with the highest accumulation were kidney, liver and lung. Effective doses were 0.009±0.002 and 0.010±0.003 mSv/MBq for injected protein masses of 500 and 1000 µg, respectively. Injection of 500 µg resulted in excellent discrimination between HER2-positive and HER2-negative tumors already 2 h after injection (tumor-to-contralateral breast ratio was 37±19 vs 5±2, p<0.01). The tumor-to-contralateral breast ratios for HER2-positive tumors were significantly (p<0.05) higher for injected mass of 500 µg than for both 250 and 1000 µg.CONCLUSION: Injections of 99mTc-ADAPT6 are safe and associated with low absorbed and effective doses. Protein dose of 500 µg is preferable for discrimination between tumors with high and low expression of HER2. Further studies are justified to evaluate if 99mTc-ADAPT6 can be used as an imaging probe for stratification of patients for HER2-targeting therapy in the areas where PET imaging is not readily available.
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| 8. |
- Bragina, Olga, et al.
(författare)
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Phase I Trial of 99mTc-(HE)3-G3, a DARPin-Based Probe for Imaging of HER2 Expression in Breast Cancer
- 2022
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 63:4, s. 528-535
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Tidskriftsartikel (refereegranskat)abstract
- Radionuclide molecular imaging of human epidermal growth factor receptor type 2 (HER2) expression may enable a noninvasive discrimination between HER2-positive and HER2-negative breast cancers for stratification of patients for HER2-targeted treatments. DARPin (designed ankyrin repeat proteins) G3 is a small (molecular weight, 14 kDa) scaffold protein with picomolar affinity to HER2. The aim of this first-in-humans study was to evaluate the safety, biodistribution, and dosimetry of 99mTc-(HE)3-G3.Methods: Three cohorts of patients with primary breast cancer (each including at least 4 patients with HER2-negative and 5 patients with HER2-positive tumors) were injected with 1,000, 2,000, or 3,000 μg of 99mTc-(HE)3-G3 (287 ± 170 MBq). Whole-body planar imaging followed by SPECT was performed at 2, 4, 6, and 24 h after injection. Vital signs and possible side effects were monitored during imaging and up to 7 d after injection.Results: All injections were well tolerated. No side effects were observed. The results of blood and urine analyses did not differ before and after studies. 99mTc-(HE)3-G3 cleared rapidly from the blood. The highest uptake was detected in the kidneys and liver followed by the lungs, breasts, and small intestinal content. The hepatic uptake after injection of 2,000 or 3,000 μg was significantly (P < 0.05) lower than the uptake after injection of 1,000 μg. Effective doses did not differ significantly between cohorts (average, 0.011 ± 0.004 mSv/MBq). Tumor–to–contralateral site ratios for HER-positive tumors were significantly (P < 0.05) higher than for HER2-negative at 2 and 4 h after injection.Conclusion: Imaging of HER2 expression using 99mTc-(HE)3-G3 is safe and well tolerated and provides a low absorbed dose burden on patients. This imaging enables discernment of HER2-positive and HER2-negative breast cancer. Phase I study data justify further clinical development of 99mTc-(HE)3-G3.
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| 9. |
- Chernov, Vladimir, et al.
(författare)
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Phase I Trial of [Tc-99m]Tc-maSSS-PEG(2)-RM26, a Bombesin Analogue Antagonistic to Gastrin-Releasing Peptide Receptors (GRPRs), for SPECT Imaging of GRPR Expression in Malignant Tumors
- 2023
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 15:6
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Tidskriftsartikel (refereegranskat)abstract
- The gastrin-releasing peptide receptor (GRPR) is overexpressed in prostate cancer (PCa) and in hormone-driven breast cancer (BCa). The aim of this phase I clinical trial was to evaluate safety, biodistribution, and dosimetry after the administration of the recently developed GRPR-targeting antagonistic bombesin analogue [Tc-99m]Tc-maSSS-PEG(2)-RM26 in PCa and BCa patients. Planar and whole-body SPECT/CT imaging was performed in six PCa patients and seven BCa patients 2, 4, 6, and 24 h post the intravenous administration of 40 mu g of [Tc-99m]Tc-maSSS-PEG(2)-RM26 (600-700 MBq). No adverse events or pathological changes were observed. The rapid blood clearance of [Tc-99m]Tc-maSSS-PEG(2)-RM26 was observed with predominantly hepatobiliary excretion. The effective doses were 0.0053 +/- 0.0007 for male patients and 0.008 +/- 0.003 mSv/MBq for female patients. The accumulation of [Tc-99m]Tc-maSSS-PEG(2)-RM26 in tumors was observed in four out of six PCa and in seven out of seven BCa patients. In four BCa patients, a high uptake of the agent into the axillary lymph nodes was detected. Immunohistochemistry revealed positive GRPR expression in 60% of primary PCa, 71.4% of BCa tumors, and 50% of examined BCa lymph nodes. In conclusion, a single administration of [Tc-99m]Tc-maSSS-PEG(2)-RM26 was safe and well tolerated. [Tc-99m]Tc-maSSS-PEG(2)-RM26 SPECT may be useful for tumor detection in PCa and BCa patients, pending further studies.
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| 10. |
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| 11. |
- Honarvar, Hadis, et al.
(författare)
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Position for site-specific attachment of a DOTA chelator to synthetic affibody molecules has a different influence on the targeting properties of 68Ga-Compared to 111in-labeled conjugates
- 2014
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Ingår i: Molecular Imaging. - : SAGE Publications. - 1535-3508 .- 1536-0121. ; 13:10
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules, small (7 kDa) scaffold proteins, are a promising class of probes for radionuclide molecular imaging. Radiolabeling of Affibody molecules with the positron-emitting nuclide 68Ga would permit the use of positron emission tomography (PET), providing better resolution, sensitivity, and quantification accuracy than single-photon emission computed tomography (SPECT). The synthetic anti-HER2 ZHER2:S1 Affibody molecule was conjugated with DOTA at the N-terminus, in the middle of helix 3, or at the Cterminus. The biodistribution of 68Ga-and 111In-labeled Affibody molecules was directly compared in NMRI nu/nu mice bearing SKOV3 xenografts. The position of the chelator strongly influenced the biodistribution of the tracers, and the influence was more pronounced for 68Ga-labeled Affibody molecules than for the 111In-labeled counterparts. The best 68Ga-labeled variant was 68Ga-[DOTA-A1]-ZHER2:S1, which provided a tumor uptake of 13 ± 1 %ID/g and a tumor to blood ratio of 39 ± 12 at 2 hours after injection. 111In-[DOTA-A1]-ZHER2:S1 and 111In-[DOTA-K58]-ZHER2:S1 were equally good at this time point, providing a tumor uptake of 15 to 16 %ID/g and a tumor to blood ratio in the range of 60 to 80. In conclusion, the selection of the best position for a chelator in Affibody molecules can be used for optimization of their imaging properties. This may be important for the development of Affibody-based and other protein-based imaging probes.
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| 12. |
- Leitao, Charles Dahlsson, et al.
(författare)
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Conditionally activated affibody-based prodrug targeting EGFR demonstrates improved tumor selectivity
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Safety and efficacy of cancer-targeting treatments can be improved by conditional activation conferred by the distinct milieu of the tumour microenvironment. Proteases are intricately involved in tumorigenesis and commonly dysregulated with elevated expression and activity. Design of prodrug molecules with protease-dependent activation has the potential to increase tumor-selective targeting, while decreasing the exposure to healthy tissues, thus improving safety, allowing for administration of higher doses or use of more aggressive treatment options, leading to higher therapeutic efficacy. We have previously performed in vitro characterizations of an affibody-based prodrug approach for protease-mediated targeting of EGFR. In this study we demonstrate the potential for selective tumor-targeting and shielded uptake in healthy tissues in vivo using tumor-bearing mice for an EGFR-targeting affibody prodrug.
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| 13. |
- Leitao, Charles Dahlsson, 1992-, et al.
(författare)
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Conditionally activated affibody-based prodrug targeting EGFR demonstrates improved tumour selectivity
- 2023
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Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 357, s. 185-195
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Tidskriftsartikel (refereegranskat)abstract
- Safety and efficacy of cancer-targeting treatments can be improved by conditional activation enabled by the distinct milieu of the tumour microenvironment. Proteases are intricately involved in tumourigenesis and commonly dysregulated with elevated expression and activity. Design of prodrug molecules with protease -dependent activation has the potential to increase tumour-selective targeting while decreasing exposure to healthy tissues, thus improving the safety profile for patients. Higher selectivity could also allow for adminis-tration of higher doses or use of more aggressive treatment options, leading to higher therapeutic efficacy. We have previously developed an affibody-based prodrug with conditional targeting of EGFR conferred by an anti-idiotypic affibody masking domain (ZB05). We could show that binding to endogenous EGFR on cancer cells in vitro was restored following proteolytic removal of ZB05. In this study we evaluate a novel affibody-based pro -drug design, which incorporates a protease substrate sequence recognized by cancer-associated proteases and demonstrate the potential of this approach for selective tumour-targeting and shielded uptake in healthy tissues in vivo using tumour-bearing mice. This may widen the therapeutic index of cytotoxic EGFR-targeted thera-peutics by decreasing side effects, improving selectivity of drug delivery, and enabling the use of more potent cytotoxic drugs.
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| 14. |
- Liu, Yongsheng, et al.
(författare)
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Biologic Evaluation of a Heterodimeric HER2-Albumin Targeted Affibody Molecule Produced by Chemo-Enzymatic Peptide Synthesis
- 2022
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Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 14:11
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Tidskriftsartikel (refereegranskat)abstract
- Targeted molecular radiation therapy is a promising emerging treatment modality in oncology, and peptide synthesis may shorten the time to reach the clinical stage. In this study, we have explored Chemo-Enzymatic Peptide Synthesis, or CEPS, as a new means of producing a therapeutic HER2 targeted Affibody((R)) molecule, comprising a C-terminal albumin binding domain (ABD) for half-life extension and a total length of 108 amino acids. In addition, a DOTA moiety could be incorporated at N-terminus directly during the synthesis step and subsequently utilized for site-specific radiolabeling with the therapeutic radionuclide Lu-177. Retained thermodynamic stability as well as retained binding to both HER2 and albumin was verified. Furthermore, HER2 binding specificity of the radiolabeled Affibody molecule was confirmed by an in vitro saturation assay showing a significantly higher cell-bound activity of SKOV-3 (high HER2 expression) compared with BxPC3 (low HER2 expression), both in the presence and absence of HSA. In vivo evaluation in mice bearing HER2 expressing xenografts also showed specific tumor targeting as well as extended time in circulation and reduced kidney uptake compared with a HER2 targeted Affibody molecule without the ABD moiety. To conclude, we have demonstrated that CEPS can be used for production of Affibody-fusion molecules with retained in vitro and in vivo functionality.
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| 15. |
- Malmberg, Jennie, et al.
(författare)
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Comparative evaluation of synthetic anti-HER2 Affibody molecules site-specifically labelled with 111In using N-terminal DOTA, NOTA and NODAGA chelators in mice bearing prostate cancer xenografts.
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:3, s. 481-492
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: In disseminated prostate cancer, expression of human epidermal growth factor receptor type 2 (HER2) is one of the pathways to androgen independence. Radionuclide molecular imaging of HER2 expression in disseminated prostate cancer might identify patients for HER2-targeted therapy. Affibody molecules are small (7 kDa) targeting proteins with high potential as tracers for radionuclide imaging. The goal of this study was to develop an optimal Affibody-based tracer for visualization of HER2 expression in prostate cancer. METHODS: A synthetic variant of the anti-HER2 Z(HER2:342) Affibody molecule, Z(HER2:S1), was N-terminally conjugated with the chelators DOTA, NOTA and NODAGA. The conjugated proteins were biophysically characterized by electrospray ionization mass spectroscopy (ESI-MS), circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR)-based biosensor analysis. After labelling with (111)In, the biodistribution was assessed in normal mice and the two most promising conjugates were further evaluated for tumour targeting in mice bearing DU-145 prostate cancer xenografts. RESULTS: The HER2-binding equilibrium dissociation constants were 130, 140 and 90 pM for DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1), respectively. A comparative study of (111)In-labelled DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1) in normal mice demonstrated a substantial influence of the chelators on the biodistribution properties of the conjugates. (111)In-NODAGA-Z(HER2:S1) had the most rapid clearance from blood and healthy tissues. (111)In-NOTA-Z(HER2:S1) showed high hepatic uptake and was excluded from further evaluation. (111)In-DOTA-Z(HER2:S1) and (111)In-NODAGA-Z(HER2:S1) demonstrated specific uptake in DU-145 prostate cancer xenografts in nude mice. The tumour uptake of (111)In-NODAGA-Z(HER2:S1), 5.6 ± 0.4%ID/g, was significantly lower than the uptake of (111)In-DOTA-Z(HER2:S1), 7.4 ± 0.5%ID/g, presumably because of lower bioavailability due to more rapid clearance. (111)In-NODAGA-Z(HER2:S1) provided higher tumour-to-blood ratio, but somewhat lower tumour-to-liver, tumour-to-spleen and tumour-to-bone ratios. CONCLUSION: Since distant prostate cancer metastases are situated in bone or bone marrow, the higher tumour-to-bone ratio is the most important. This renders (111)In-DOTA-Z(HER2:S1) a preferable agent for imaging of HER2 expression in disseminated prostate cancer.
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| 16. |
- Malmberg, Jennie, et al.
(författare)
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Comparative evaluation of synthetic anti-HER2 Affibody molecules site-specifically labelled with In-111 using N-terminal DOTA, NOTA and NODAGA chelators in mice bearing prostate cancer xenografts
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:3, s. 481-492
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Tidskriftsartikel (refereegranskat)abstract
- Purpose In disseminated prostate cancer, expression of human epidermal growth factor receptor type 2 (HER2) is one of the pathways to androgen independence. Radionuclide molecular imaging of HER2 expression in disseminated prostate cancer might identify patients for HER2-targeted therapy. Affibody molecules are small (7 kDa) targeting proteins with high potential as tracers for radionuclide imaging. The goal of this study was to develop an optimal Affibody-based tracer for visualization of HER2 expression in prostate cancer. Methods A synthetic variant of the anti-HER2 Z(HER2:342) Affibody molecule, Z(HER2:S1), was N-terminally conjugated with the chelators DOTA, NOTA and NODAGA. The conjugated proteins were biophysically characterized by electrospray ionization mass spectroscopy (ESI-MS), circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR)-based biosensor analysis. After labelling with In-111, the biodistribution was assessed in normal mice and the two most promising conjugates were further evaluated for tumour targeting in mice bearing DU-145 prostate cancer xenografts. Results The HER2-binding equilibrium dissociation constants were 130, 140 and 90 pM for DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1), respectively. A comparative study of In-111-labelled DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1) in normal mice demonstrated a substantial influence of the chelators on the biodistribution properties of the conjugates. In-111-NODAGA-Z(HER2:S1) had the most rapid clearance from blood and healthy tissues. In-111-NOTA-Z(HER2:S1) showed high hepatic uptake and was excluded from further evaluation. In-111-DOTA-Z(HER2:S1) and In-111-NODAGAZHER2: S1 demonstrated specific uptake in DU-145 prostate cancer xenografts in nude mice. The tumour uptake of In-111-NODAGA-Z(HER2:S1), 5.6 +/- 0.4% ID/g, was significantly lower than the uptake of In-111-DOTA-Z(HER2:S1), 7.4 +/- 0.5% ID/g, presumably because of lower bioavailability due to more rapid clearance. In-111-NODAGA-Z(HER2:S1) provided higher tumour-to-blood ratio, but somewhat lower tumour-to-liver, tumour-to-spleen and tumour-to-bone ratios. Conclusion Since distant prostate cancer metastases are situated in bone or bone marrow, the higher tumour-to-bone ratio is the most important. This renders In-111-DOTA-Z(HER2:S1) a preferable agent for imaging of HER2 expression in disseminated prostate cancer.
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| 17. |
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| 18. |
- Orlova, Anna, et al.
(författare)
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Cellular processing of (125)I- and (111)in-labeled epidermal growth factor(EGF) bound to cultured A431 tumor cells
- 2000
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Ingår i: Nuclear Medicine and Biology. - 0969-8051 .- 1872-9614. ; 27:8, s. 827-35
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Tidskriftsartikel (refereegranskat)abstract
- Low molecular weight of epidermal growth factor (EGF) enables better intratumoral penetration in comparison with larger targeting proteins, but the cellular retention of EGF-associated radioactivity is poor for directly iodinated EGF. An attempt was made to improve intracellular retention by the use of metal-diethylenetriaminepentaacetic acid or nonphenolic linker (N-succinimidyl-para-iodobenzoate) as labeling agents. The use of nonphenolic linker did not improve retention of the radioactivity in A431 carcinoma cell line. The use of the radiometal label provided an appreciable prolongation of radioactivity residence inside the cell.
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| 19. |
- Orlova, Anna, et al.
(författare)
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Cellular processing of 125I- and 111in-labeled epidermal growth factor (EGF) bound to cultured A431 tumor cells
- 2000
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Ingår i: Nuclear Medicine and Biology. - 0969-8051 .- 1872-9614. ; 27:8, s. 827-835
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Recension (övrigt vetenskapligt/konstnärligt)abstract
- Low molecular weight of epidermal growth factor (EGF) enables better intratumoral penetration in comparison with larger targeting proteins, but the cellular retention of EGF-associated radioactivity is poor for directly iodinated EGF. An attempt was made to improve intracellular retention by the use of metal-diethylenetriaminepentaacetic acid or nonphenolic linker (N-succinimidyl-para-iodobenzoate) as labeling agents. The use of nonphenolic linker did not improve retention of the radioactivity in A431 carcinoma cell line. The use of the radiometal label provided an appreciable prolongation of radioactivity residence inside the cell.
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| 20. |
- Orlova, Anna, et al.
(författare)
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Cellular processing of indirectly astatinated and iodinated mAb A33 in SW1222 cultured cells
- 2001
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Ingår i: Journal of labelled compounds & radiopharmaceuticals. - : Wiley. - 0362-4803 .- 1099-1344. ; 44:suppl 1, s. S715-S717
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Recension (övrigt vetenskapligt/konstnärligt)abstract
- In principle, alpha-emitting radionuclides, such as 211At, are more efficient than beta-emitters to inactive single disseminated cancer cells. However, cellular processing of astatinated proteins has not yet been studied in detail. In this study an anti-colorectal cancer monoclonal antibody (mAb) A33 was indirectly labeled with 211At and for comparison with 125I. Binding and retention of radioactivity was studied in the colorectal cancer cell-line SW1222. A similar pattern of binding and retention of the two radiohalogens was seen. The main difference found, that the retention time of astatinated mAb in SW1222 was almost two times longer, might be of advantage in radionuclide therapy.
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| 21. |
- Orlova, Anna, et al.
(författare)
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Targeting against epidermal growth factor receptors : Cellular processing of astatinated EGF after binding to cultured carcinoma cells
- 2004
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 24:6, s. 4035-4042
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:The alpha-emitting nuclide 211At is of great interest for radionuclide therapy when coupled to a tumor-targeting biomolecule, e.g. epidermal growth factor (EGF) the receptors of which are overexpressed in many malignancies. However, almost no information concerning the cellular processing of astatinated targeting agents is available.MATERIALS AND METHODS:We indirectly astatinated EGF ([211At]-benzoate-EGF) and studied its cellular processing in A-431 carcinoma cells in comparison with data concerning [125I]-benzoate-EGF.RESULTS: The biological half-life of astatine (3.5 h) was longer than the half-life of the iodine label (1.5 h). The increase of the half-life was due to longer retention of the internalised astatine radioactivity. The maximum accumulation for the astatine label occurred later (4-6h) than that for the iodine label (2-4h), indicating a slower excretion of astatine that was confirmed in experiment with 211At/1251-benzoate-EGF.CONCLUSION:The long retention of astatine might be advantageous for radionuclide therapy.
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| 22. |
- Perols, Anna, et al.
(författare)
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Influence of DOTA Chelator Position on Biodistribution and Targeting Properties of In-111-Labeled Synthetic Anti-HER2 Affibody Molecules
- 2012
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Ingår i: Bioconjugate chemistry. - : American Chemical Society (ACS). - 1043-1802 .- 1520-4812. ; 23:8, s. 1661-1670
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules are a class of affinity proteins. Their small size (7 kDa) in combination with the high (subnanomolar) affinity for a number of cancer-associated molecular targets makes them suitable for molecular imaging. Earlier studies demonstrated that the selection of radionuclide and chelator may substantially influence the tumor-targeting properties of affibody molecules. Moreover, the placement of chelators for labeling of affibody molecules with Tc-99m at different positions in affibody molecules influenced both blood clearance rate and uptake in healthy tissues. This introduces an opportunity to improve the contrast of affibody-mediated imaging. In this comparative study, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was conjugated to the synthetic affibody molecule Z(HER2:S1) at three different positions: DOTA-A1-Z(HER2:S1) (N-terminus), DOTA-K58-Z(HER2:S1) (C-terminus), and DOTA-K50-Z(HER2:S1) (middle of helix 3). The affinity for HER2 differed slightly among the variants and the K-D values were determined to be 133 pM, 107 pM and 94 pM for DOTA-A1-Z(HER2:S1), DOTA-K50-Z(HER2:S1), and DOTA-K58-Z(HER2:S1), respectively. Z(HER2:S1) K50-DOTA showed a slightly lower melting point (57 degrees C) compared to DOTA-A1-Z(HER2:S1) (64 degrees C) and DOTA-K5S-Z(HER2:S1) (62 degrees C), but all variants showed good refolding properties after heat treatment All conjugates were successfully labeled with In-III resulting in a radiochemical yield of 99% with preserved binding capacity. In vitro specificity studies using SKOV-3 and LS174T cell lines showed that the binding of the radiolabeled compounds was HER2 receptor mediated, which also was verified in vivo using BALB/C nu/nu mice with LS174T and Ramos lymphoma xenografts. The three conjugates all showed specific uptake in L5174T xenografts in nude mice, where DOTA-A1-Z(HER2:S1) and DOTA-K58-Z(HER2:S1) showed the highest uptake. Overall, DOTA-K58-Z(HER2:S1) provided the highest tumor-to-blood ratio, which is important for a high contrast imaging. In conclusion, the positioning of the DOTA chelator influences the cellular processing and the biodistribution pattern of radiolabeled affibody molecules, creating preconditions for imaging optimization.
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| 23. |
- Rinne, Sara S., et al.
(författare)
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Targeting Tumor Cells Overexpressing the Human Epidermal Growth Factor Receptor 3 with Potent Drug Conjugates Based on Affibody Molecules
- 2022
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Ingår i: Biomedicines. - : MDPI AG. - 2227-9059. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Increasing evidence suggests that therapy targeting the human epidermal growth factor receptor 3 (HER3) could be a viable route for targeted cancer therapy. Here, we studied a novel drug conjugate, ZHER3-ABD-mcDM1, consisting of a HER3-targeting affibody molecule, coupled to the cytotoxic tubulin polymerization inhibitor DM1, and an albumin-binding domain for in vivo half-life extension. ZHER3-ABD-mcDM1 showed a strong affinity to the extracellular domain of HER3 (K-D 6 nM), and an even stronger affinity (KD 0.2 nM) to the HER3-overexpressing pancreatic carcinoma cell line, BxPC-3. The drug conjugate showed a potent cytotoxic effect on BxPC-3 cells with an IC50 value of 7 nM. Evaluation of a radiolabeled version, [99mTc]Tc-ZHER3-ABD-mcDM1, showed a relatively high rate of internalization, with a 27% internalized fraction after 8 h. Further in vivo evaluation showed that it could target BxPC-3 (pancreatic carcinoma) and DU145 (prostate carcinoma) xenografts in mice, with an uptake peaking at 6.3 +/- 0.4% IA/g at 6 h post-injection for the BxPC-3 xenografts. The general biodistribution showed uptake in the liver, lung, salivary gland, stomach, and small intestine, organs known to express murine ErbB3 naturally. The results from the study show that ZHER3-ABD-mcDM1 is a highly potent and selective drug conjugate with the ability to specifically target HER3 overexpressing cells. Further pre-clinical and clinical development is discussed.
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| 24. |
- Rinne, Sara, et al.
(författare)
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Targeting tumor cells overexpressing the human epidermal growth factor receptor 3 with potent drug conjugates based on affibody molecules
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Increasing evidence suggests that therapy targeting the human epidermal growth factor receptor 3 (HER3) could be a viable route for targeted cancer therapy. Here, we have studied a novel drug conjugate, ZHER3-ABD-mcDM1, consisting of a HER3-targeting affibody molecule, coupled to the cytotoxic tubulin polymerization inhibitor DM1, and an albumin- binding domain for in vivo half-life extension. ZHER3-ABD-mcDM1 showed strong affinity to the extracellular domain of HER3 (KD 6 nM), and an even stronger affinity (KD 0.2 nM) to the HER3-overexpressing pancreatic cancer cell line, BxPC3. The drug conjugate showed a potent cytotoxic effect on BxPC3 cells with an IC50 value of 7 nM. Further in vitro evaluation of a radiolabeled version [99mTc]Tc-ZHER3-ABD-mcDM1, showed that it had a relatively high rate of internalization into HER3-expressing BxPC-3 as well as DU145 (prostate cancer) cells, with a 27% internalized fraction after 8 h. Further in vivo evaluation showed that it could specifically target BxPC-3 and DU145-derived xenografts in mice, with an uptake peaking at 6.3 ± 0.4 %ID/g at 6 h post-injection for the BxPC-3-derived xenografts. The general biodistribution showed uptake in liver, lung, salivary gland, stomach, and small intestine, organs known to express HER3 naturally. The results from the study show that ZHER3-ABD- mcDM1 is a highly potent and specific drug conjugate, that may be further developed towards HER3-targeted cancer therapy.
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| 25. |
- Strand, Joanna, et al.
(författare)
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Influence of Macrocyclic Chelators on the Targeting Properties of Ga-68-Labeled Synthetic Affibody Molecules : Comparison with In-111-Labeled Counterparts
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8, s. e70028-
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules are a class of small (7 kDa) non-immunoglobulin scaffold-based affinity proteins, which have demonstrated substantial potential as probes for radionuclide molecular imaging. The use of positron emission tomography (PET) would further increase the resolution and quantification accuracy of Affibody-based imaging. The rapid in vivo kinetics of Affibody molecules permit the use of the generator-produced radionuclide Ga-68 (T-1/2 = 67.6 min). Earlier studies have demonstrated that the chemical nature of chelators has a substantial influence on the biodistribution properties of Affibody molecules. To determine an optimal labeling approach, the macrocyclic chelators 1,4,7,10-tetraazacylododecane-1,4,7,10-tetraacetic acid (DOTA), 1,4,7-triazacyclononane-N,N,N-triacetic acid (NOTA) and 1-(1,3-carboxypropyl)-1,4,7- triazacyclononane-4,7-diacetic acid (NODAGA) were conjugated to the N-terminus of the synthetic Affibody molecule Z(HER2:S1) targeting HER2. Affibody molecules were labeled with Ga-68, and their binding specificity and cellular processing were evaluated. The biodistribution of Ga-68-DOTA-Z(HER2:S1), Ga-68-NOTA-Z(HER2:S1) and Ga-68-NODAGA-Z(HER2:S1), as well as that of their In-111-labeled counterparts, was evaluated in BALB/C nu/nu mice bearing HER2-expressing SKOV3 xenografts. The tumor uptake for Ga-68-DOTA-Z(HER2:S1) (17.9 +/- 0.7%IA/g) was significantly higher than for both Ga-68-NODAGA-Z(HER2:S1) (16.13 +/- 0.67%IA/g) and Ga-68-NOTA-Z(HER2:S1) (13 +/- 3%IA/g) at 2 h after injection. Ga-68-NODAGA-Z(HER2:S1) had the highest tumor-to-blood ratio (60 +/- 10) in comparison with both Ga-68-DOTA-Z(HER2:S1) (28 +/- 4) and Ga-68-NOTA-Z(HER2:S1) (42 +/- 11). The tumor-to-liver ratio was also higher for Ga-68-NODAGA-Z(HER2:S1) (7 +/- 2) than the DOTA and NOTA conjugates (5.5 +/- 0.6 vs. 3.3 +/- 0.6). The influence of chelator on the biodistribution and targeting properties was less pronounced for Ga-68 than for In-111. The results of this study demonstrate that macrocyclic chelators conjugated to the N-terminus have a substantial influence on the biodistribution of HER2-targeting Affibody molecules labeled with Ga-68. This can be utilized to enhance the imaging contrast of PET imaging using Affibody molecules and improve the sensitivity of molecular imaging. The study demonstrated an appreciable difference of chelator influence for Ga-68 and In-111.
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