  Valine-based biphenylsulphonamide matrix metalloproteinase inhibitors as tumor imaging agents; ; et al in Applied Radiation & Isotopes (2006), 64(6), 677-685 Among matrix metalloproteinases (MMPs), the subfamily of gelatinases (MMP-2, MMP-9) is of particular interest due to their ability to degrade type IV collagen and other non-fibrillar collagen domains and ... [more ▼] Among matrix metalloproteinases (MMPs), the subfamily of gelatinases (MMP-2, MMP-9) is of particular interest due to their ability to degrade type IV collagen and other non-fibrillar collagen domains and proteins such as fibronectin and laminin. Whilst malignant cells often over-express various MMPs, the gelatinases have been most consistently detected in malignant tissues and associated with tumor growth, metastatic potential and angiogenesis. Radiosynthesis of carboxylic (1') and hydroxamic (2') MMPIs resulted in radiochemical yields of 70 +/- 5% (n = 6) and 60 5% (n = 4), respectively. Evaluation in A549-inoculated athymic mice showed a tumor uptake of 2.0 +/- 0.7%ID/g (3 h p.i.), a tumor/blood ratio of 0.5 and a tumor/muscle ratio of 4.6 at 48 h p.i. for 1'. For compound 2' a tumor uptake of 0.7 +/- 0.2%ID/g (3 h p.i.), a tumor/blood ratio of 1.2 and a tumor/muscle ratio of 1.8 at 24 h p.i. were observed. HPLC analysis of the blood (plasma) showed no dehalogenation or other metabolites of 1' 2 h p.i. For compound 2', 65.4% of intact compound was found in the blood (plasma) and one polar metabolite (31%) was detected whereas in the tumor 91.8% of the accumulated activity was caused by intact compound and only 8.1% by the metabolite. Planar imaging, using a Toshiba GCA-9300A/hg SPECT camera, showed that tumor tissue could be visualized and that image quality improved by decreasing specific activity resulting in lower liver uptake, indicating some degree of saturable binding in the liver. In vivo evaluation of these radioiodinated carboxylic and hydroxamic MMP inhibitor tracers revealed that MMP inhibitors could have potential as tumor imaging agents, but that further research is necessary. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲] Detailed reference viewed: 24 (0 ULg) Tryptophane-based biphenylsulfonamide matrix metalloproteinase inhibitors as tumor imaging agents; ; Labied, Soraya  et alin Cancer Biotherapy & Radiopharmaceuticals (2005), 20(6), 639-47 Aim: As a part of our efforts to use small organic matrix metalloproteinase (MMP) inhibitors with improved characteristics for the diagnosis and treatment of different kinds of tumor tissues ... [more ▼] Aim: As a part of our efforts to use small organic matrix metalloproteinase (MMP) inhibitors with improved characteristics for the diagnosis and treatment of different kinds of tumor tissues, biphenylsulfonamide analogues were synthesized. This study reports on the in vivo biodistribution of iodine-123-labeled biphenylsulfonide and analogues in A549 lung carcinoma inoculated into athymic mice and the evaluation of their suitability as imaging agents using a single photon emission computed tomography (SPECT) camera. Methods: The radioiodinated carboxylic and hydroxamic MMP inhibitors 2-(4′- [123I]iodobiphenyl-4-sulfonylamino)-3-(1H-indol-3-yl)-propionic acid (1′) and 2-(4′-[123I]iodobiphenyl-4- sulfonylamino)-3-(1H-indol-3-yl)-propionamide (2′) were synthesized by electrophilic aromatic substitution of the tributylstannyl derivatives. Planar gamma camera imaging was performed in nu/nu athymic mice bearing an A549 tumor using a Toshiba GCA-9300A/hg SPECT camera in planar mode equipped with a high-resolution, parallel-hole collimator. Results: Radiosynthesis of (1′) and (2′) resulted in radiochemical yields of 60 ± 5% (n ± 3) and 70 ± 5% (n = 6), respectively. Evaluation of tumors induced in athymic mice by the inoculation of non-small cell lung A549 carcinoma cells, showed a tumor uptake of 0.27–0.01 percent injected dose per gram (%ID/g) (3 hours–48 hours p.i.), a tumor-blood ratio of 0.7, a tumor-muscle ratio of 1.6, and a tumor-fat ratio of 0.5 at 24 hours (p.i.) for compound 1′. For compound 2′ a tumor uptake of 0.7–0.04 %ID/g (3 hours–48 hours p.i.), a postinjection tumor-blood ratio of 1.2, a tumor-muscle ratio of 3.2, and a tumor-fat ratio of 2.4 at 48 hours p.i. was observed. SPECT evaluation confirmed the results obtained from biodistribution. Conclusion: In vivo evaluation of these radioiodinated carboxylic and hydroxamic MMP inhibitor tracers revealed that they do not appear suitable as tumor-imaging agents. [less ▲] Detailed reference viewed: 12 (1 ULg) |
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