Dataset Information

Reduction of the Renal Radioactivity of ¹¹¹In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

ABSTRACT: The interposition of a cleavable linkage by enzymes on the renal brush border membrane constitutes a promising approach for reducing the renal radioactivity levels of radiolabeled low-molecular-weight antibody fragments and constructs (LMW Abs). Herein, we applied the molecular design to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-based reagents for radiotheranostic applications with trivalent radiometals. DOTA or a derivative thereof was conjugated to a Fab through an FGK linkage ([¹¹¹In]In-DO3AiBu-Bn-FGK-Fab or [¹¹¹In]In-DOTA-Bn-FGK-Fab). When injected into mice, both generated radiometabolites, [¹¹¹In]In-DO3AiBu-Bn-F and [¹¹¹In]In-DOTA-Bn-F, by the angiotensin-converting enzyme at similar rates. Both exhibited significantly lower renal radioactivity levels than a ¹¹¹In-labeled Fab prepared by the conventional procedure ([¹¹¹In]In-DOTA-Bn-SCN-Fab). The different elimination rates of each radiometabolite from the kidney significantly affected the renal radioactivity levels. [¹¹¹In]In-DO3AiBu-Bn-FGK-Fab preferentially reduced the renal localization without impairing tumor accumulation. These findings would pave the way for developing a DOTA-based radiotheranostic platform for LMW Abs bearing cleavable linkers for renal brush border enzymes.

SUBMITTER: Suzuki H

PROVIDER: S-EPMC10350918 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature

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Reduction of the Renal Radioactivity of <sup>111</sup>In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

Suzuki Hiroyuki H Araki Mari M Tatsugi Kouki K Ichinohe Kento K Uehara Tomoya T Arano Yasushi Y

Journal of medicinal chemistry 20230615 13

The interposition of a cleavable linkage by enzymes on the renal brush border membrane constitutes a promising approach for reducing the renal radioactivity levels of radiolabeled low-molecular-weight antibody fragments and constructs (LMW Abs). Herein, we applied the molecular design to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-based reagents for radiotheranostic applications with trivalent radiometals. DOTA or a derivative thereof was conjugated to a Fab through an FGK li ...[more]

PMID: 37322876

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Project description:Single domain antibody fragments (sdAbs) labeled with 18F have shown promise for assessing the status of oncological targets such as the human epidermal growth factor receptor 2 (HER2) by positron emission tomography (PET). Earlier, we evaluated two residualizing prosthetic agents for 18F-labeling of anti-HER2 sdAbs; however, these methods resulted in poor labeling yields and high uptake of 18F activity in the kidneys. To potentially mitigate these limitations, we have now developed an 18F labeling method that utilizes the trans-cyclooctene (TCO)-tetrazine (Tz)-based inverse-electron demand Diels-Alder reaction (IEDDAR) in tandem with a renal brush border enzyme-cleavable glycine-lysine (GK) linker in the prosthetic moiety. The HER2-targeted sdAb 2Rs15d was derivatized with TCO-GK-PEG4-NHS or TCO-PEG4-NHS, which lacks the cleavable linker. As an additional control, the non HER2-specific sdAb R3B23 was derivatized with TCO-GK-PEG4-NHS. The resultant sdAb conjugates were labeled with 18F by IEDDAR using [18F]AlF-NOTA-PEG4-methyltetrazine. As a positive control, the 2Rs15d sdAb was radioiodinated using the well-characterized residualizing prosthetic agent, N-succinimidyl 4-guanidinomethyl-3-[125I]iodobenzoate ([125I]SGMIB). Synthesis of [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d was achieved with an overall radiochemical yield (RCY) of 17.8 ± 1.5% ( n = 5) in 90 min, a significant improvement over prior methods (3-4% in 2-3 h). In vitro assays indicated that [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d bound with high affinity and immunoreactivity to HER2. In normal mice, when normalized to coinjected [125I]SGMIB-2Rs15d, the kidney uptake of [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d was 15- and 28-fold lower ( P < 0.001) than that seen for the noncleavable control ([18F]AlF-NOTA-Tz-TCO-2Rs15d) at 1 and 3 h, respectively. Uptake of [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d in HER2-expressing SKOV-3 ovarian carcinoma xenografts implanted in athymic mice was about 80% of that seen for coinjected [125I]SGMIB-2Rs15d. On the other hand, kidney uptake was 5-6-fold lower, and as a result, tumor-to-kidney ratios were 4-fold higher for [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d than those for [125I]SGMIB-2Rs15d. SKOV-3 xenografts were clearly delineated even at 1 h after administration of [18F]AlF-NOTA-Tz-TCO-GK-2Rs15d by Micro-PET/CT imaging with even higher contrast observed thereafter. In conclusion, this strategy warrants further evaluation for labeling small proteins such as sdAbs because it offers the benefits of good radiochemical yields and enhanced tumor-to-normal tissue ratios, particularly in the kidney.

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Dataset Information

Reduction of the Renal Radioactivity of ¹¹¹In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

Publications

Reduction of the Renal Radioactivity of <sup>111</sup>In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

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Dataset Information

Reduction of the Renal Radioactivity of 111In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

Publications

Reduction of the Renal Radioactivity of <sup>111</sup>In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Reduction of the Renal Radioactivity of ¹¹¹In-DOTA-Labeled Antibody Fragments with a Linkage Cleaved by the Renal Brush Border Membrane Enzymes.