scholarly journals C-terminal–modified LY2510924: a versatile scaffold for targeting C-X-C chemokine receptor type 4

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kentaro Suzuki ◽  
Takashi Ui ◽  
Akio Nagano ◽  
Akihiro Hino ◽  
Yasushi Arano
Keyword(s):  
Chemokine Receptor ◽  
Tumor Imaging ◽  
Specific Binding ◽  
Receptor Type ◽  
Tetraacetic Acid ◽  
Cxcr4 Antagonist ◽  
High Accumulation ◽  
Biodistribution Studies ◽  
C Terminus ◽  
Promising Target

Abstract C-X-C chemokine receptor type 4 (CXCR4) constitutes a promising target for tumor diagnosis and therapy. Herein, we evaluate a new 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-conjugated CXCR4 antagonist derived from LY2510924, FRM001, and its metal complexes as CXCR4-targeting probes. FRM001 was synthesized by modifying the C-terminus of LY2510924 with maleimido-mono-amide-DOTA via a cysteine linker. FRM001 exhibited CXCR4-specific binding with an affinity similar to that of the parental LY2510924. The binding affinity of FRM001 remained unchanged after complexation with Ga, Lu, and Y. The internalization of 67Ga-FRM001 into the cells was hardly observed. In mice biodistribution studies, 67Ga-FRM001 exhibited high accumulation in the tumor and the liver with rapid elimination rates from the blood. The hepatic accumulation of 67Ga-FRM001 was preferentially and significantly reduced by co-injecting a CXCR4 antagonist, AMD3100. The C-terminal–modified LY2510924 would constitute a versatile scaffold to develop CXCR4-targeting probes or therapeutics for tumor imaging or therapy.

Structure–Activity Relationships and Biological Characterization of a Novel, Potent, and Serum Stable C-X-C Chemokine Receptor Type 4 (CXCR4) Antagonist

2017 ◽  
Vol 60 (23) ◽  
pp. 9641-9652 ◽  
Author(s):  
Salvatore Di Maro ◽  
Francesco Saverio Di Leva ◽  
Anna Maria Trotta ◽  
Diego Brancaccio ◽  
Luigi Portella ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Receptor Type ◽  
Biological Characterization ◽  
Cxcr4 Antagonist ◽  
Structure Activity Relationships ◽  
Structure Activity

Novel Peptide-Based PET Probe for Non-invasive Imaging of C-X-C Chemokine Receptor Type 4 (CXCR4) in Tumors

2021 ◽  
Vol 64 (6) ◽  
pp. 3449-3461
Author(s):  
Anna Maria Trotta ◽  
Michela Aurilio ◽  
Crescenzo D’Alterio ◽  
Caterina Ieranò ◽  
Daria Di Martino ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Receptor Type ◽  
Non Invasive

scholarly journals Determinants That Control the Specific Interactions between TAB1 and p38α

2006 ◽  
Vol 26 (10) ◽  
pp. 3824-3834 ◽  
Author(s):  
Huamin Zhou ◽  
Min Zheng ◽  
Jianming Chen ◽  
Changchuan Xie ◽  
Anand R. Kolatkar ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Conformational Changes ◽  
Transforming Growth Factor ◽  
Mutational Analysis ◽  
Specific Binding ◽  
Point Mutations ◽  
Transforming Growth Factor Β ◽  
Mitogen Activated Protein Kinase ◽  
Docking Site ◽  
C Terminus

ABSTRACT Previous studies have revealed that transforming growth factor-β-activated protein kinase 1 (TAB1) interacts with p38α and induces p38α autophosphorylation. Here, we examine the sequence requirements in TAB1 and p38α that drive their interaction. Deletion and point mutations in TAB1 reveal that a proline residue in the C terminus of TAB1 (Pro412) is necessary for its interaction with p38α. Furthermore, a cryptic D-domain-like docking site was identified adjacent to the N terminus of Pro412, putting Pro412 in the φB+3 position of the docking site. Through mutational analysis, we found that the previously identified hydrophobic docking groove in p38α is involved in this interaction, whereas the CD domain and ED domain are not. Furthermore, chimeric analysis with p38β (which does not bind to TAB1) revealed a previously unidentified locus of p38α comprising Thr218 and Ile275 that is essential for specific binding of p38α to TAB1. Converting either of these residues to the corresponding amino acid of p38β abolishes p38α interaction with TAB1. These p38α mutants still can be fully activated by p38α upstream activating kinase mitogen-activated protein kinase kinase 6, but their basal activity and activation in response to some extracellular stimuli are reduced. Adjacent to Thr218 and Ile275 is a site where large conformational changes occur in the presence of docking-site peptides derived from p38α substrates and activators. This suggests that TAB1-induced autophosphorylation of p38α results from conformational changes that are similar but unique to those seen in p38α interactions with its substrates and activating kinases.

scholarly journals Evaluation of Radiolabeled Girentuximab In Vitro and In Vivo

2018 ◽  
Vol 11 (4) ◽  
pp. 132 ◽  
Author(s):  
Tais Basaco ◽  
Stefanie Pektor ◽  
Josue Bermudez ◽  
Niurka Meneses ◽  
Manfred Heller ◽  
...  
Keyword(s):  
Specific Binding ◽  
Sodium Ascorbate ◽  
Tumor Uptake ◽  
Tetraacetic Acid ◽  
In Vivo Experiments ◽  
Caix Expression ◽  
Tetraazacyclododecane Tetraacetic Acid

Girentuximab (cG250) targets carbonic anhydrase IX (CAIX), a protein which is expressed on the surface of most renal cancer cells (RCCs). cG250 labeled with 177Lu has been used in clinical trials for radioimmunotherapy (RIT) of RCCs. In this work, an extensive characterization of the immunoconjugates allowed optimization of the labeling conditions with 177Lu while maintaining immunoreactivity of cG250, which was then investigated in in vitro and in vivo experiments. cG250 was conjugated with S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid (DOTA(SCN)) by using incubation times between 30 and 90 min and characterized by mass spectrometry. Immunoconjugates with five to ten DOTA(SCN) molecules per cG250 molecule were obtained. Conjugates with ratios less than six DOTA(SCN)/cG250 had higher in vitro antigen affinity, both pre- and postlabeling with 177Lu. Radiochemical stability increased, in the presence of sodium ascorbate, which prevents radiolysis. The immunoreactivity of the radiolabeled cG250 tested by specific binding to SK-RC-52 cells decreased when the DOTA content per conjugate increased. The in vivo tumor uptake was < 10% ID/g and independent of the total amount of protein in the range between 5 and 100 µg cG250 per animal. Low tumor uptake was found to be due to significant necrotic areas and heterogeneous CAIX expression. In addition, low vascularity indicated relatively poor accessibility of the CAIX target.

scholarly journals Influence of Molecular Design on the Targeting Properties of ABD-Fused Mono- and Bi-Valent Anti-HER3 Affibody Therapeutic Constructs

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 164 ◽  
Author(s):  
Mohamed Altai ◽  
Charles Leitao ◽  
Sara Rinne ◽  
Anzhelika Vorobyeva ◽  
Christina Atterby ◽  
...  
Keyword(s):  
Half Life ◽  
Molecular Design ◽  
Growth Factor Receptor ◽  
Fusion Construct ◽  
Affibody Molecules ◽  
Binding Domains ◽  
Biodistribution Studies ◽  
C Terminus ◽  
Type 3

Overexpression of human epidermal growth factor receptor type 3 (HER3) is associated with tumour cell resistance to HER-targeted therapies. Monoclonal antibodies (mAbs) targeting HER3 are currently being investigated for treatment of various types of cancers. Cumulative evidence suggests that affibody molecules may be appropriate alternatives to mAbs. We previously reported a fusion construct (3A3) containing two HER3-targeting affibody molecules flanking an engineered albumin-binding domain (ABD035) included for the extension of half-life in circulation. The 3A3 fusion protein (19.7 kDa) was shown to delay tumour growth in mice bearing HER3-expressing xenografts and was equipotent to the mAb seribantumab. Here, we have designed and explored a series of novel formats of anti-HER3 affibody molecules fused to the ABD in different orientations. All constructs inhibited heregulin-induced phosphorylation in HER3-expressing BxPC-3 and DU-145 cell lines. Biodistribution studies demonstrated extended the half-life of all ABD-fused constructs, although at different levels. The capacity of our ABD-fused proteins to accumulate in HER3-expressing tumours was demonstrated in nude mice bearing BxPC-3 xenografts. Formats where the ABD was located on the C-terminus of affibody binding domains (3A, 33A, and 3A3) provided the best tumour targeting properties in vivo. Further development of these promising candidates for treatment of HER3-overexpressing tumours is therefore justified.

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