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Zhang X, Lin Z, Feng Y, Kang F, Wang J, Lan X. Melanin-Targeting Radiotracers and Their Preclinical, Translational, and Clinical Status: From Past to Future. J Nucl Med 2024; 65:19S-28S. [PMID: 38719238 DOI: 10.2967/jnumed.123.266945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/31/2024] [Indexed: 07/16/2024] Open
Abstract
Melanin is one of the representative biomarkers of malignant melanoma and a potential target for diagnosis and therapy. With advancements in chemistry and radiolabeling technologies, promising strides have been made to synthesize radiolabeled melanin-binding molecules for various applications. We present an overview of melanin-targeted radiolabeled molecules and compare their features reported in preclinical studies. Clinical practice and trials are also discussed to elaborate on the safety and validity of the probes, and expanded applications beyond melanoma are reviewed. Melanin-targeted imaging holds potential value in the diagnosis, staging, and prognostic assessment of melanoma and other applications. Melanin-targeted radionuclide therapy possesses immense potential but requires more clinical validation. Furthermore, an intriguing avenue for future research involves expanding the application scope of melanin-targeted probes and exploring their value.
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Affiliation(s)
- Xiao Zhang
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, China
- Key Laboratory of Biological Targeted Therapy, Ministry of Education, Wuhan, China; and
| | - Zhaoguo Lin
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, China
- Key Laboratory of Biological Targeted Therapy, Ministry of Education, Wuhan, China; and
| | - Yuan Feng
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, China
- Key Laboratory of Biological Targeted Therapy, Ministry of Education, Wuhan, China; and
| | - Fei Kang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jing Wang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiaoli Lan
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China;
- Hubei Key Laboratory of Molecular Imaging, Wuhan, China
- Key Laboratory of Biological Targeted Therapy, Ministry of Education, Wuhan, China; and
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Rouanet J, Quintana M, Auzeloux P, Cachin F, Degoul F. Benzamide derivative radiotracers targeting melanin for melanoma imaging and therapy: Preclinical/clinical development and combination with other treatments. Pharmacol Ther 2021; 224:107829. [PMID: 33662452 DOI: 10.1016/j.pharmthera.2021.107829] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2021] [Indexed: 12/16/2022]
Abstract
Cutaneous melanoma arises from proliferating melanocytes, cells specialized in the production of melanin. This property means melanin can be considered as a target for monitoring melanoma patients using nuclear imaging or targeted radionuclide therapy (TRT). Since the 1970s, many researchers have shown that specific molecules can interfere with melanin. This paper reviews some such molecules: benzamide structures improved to increase their pharmacokinetics for imaging or TRT. We first describe the characteristics and biosynthesis of melanin, and the main features of melanin tracers. The second part summarizes the preclinical and corresponding clinical studies on imaging. The last section presents TRT results from ongoing protocols and discusses combinations with other therapies as an opportunity for melanoma non-responders or patients resistant to treatments.
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Affiliation(s)
- Jacques Rouanet
- Université Clermont Auvergne, INSERM, Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, 58 Rue Montalembert, 63005 Clermont-Ferrand, Cedex, France; Department of Dermatology and Oncodermatology, CHU Estaing, 1 place Lucie et Raymond Aubrac, 63000 Clermont-Ferrand, France; Centre Jean Perrin, Clermont-Ferrand F-63011, France.
| | - Mercedes Quintana
- Université Clermont Auvergne, INSERM, Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, 58 Rue Montalembert, 63005 Clermont-Ferrand, Cedex, France.
| | - Philippe Auzeloux
- Université Clermont Auvergne, INSERM, Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, 58 Rue Montalembert, 63005 Clermont-Ferrand, Cedex, France.
| | - Florent Cachin
- Université Clermont Auvergne, INSERM, Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, 58 Rue Montalembert, 63005 Clermont-Ferrand, Cedex, France; Centre Jean Perrin, Clermont-Ferrand F-63011, France.
| | - Françoise Degoul
- Université Clermont Auvergne, INSERM, Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, 58 Rue Montalembert, 63005 Clermont-Ferrand, Cedex, France.
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Abstract
With the emergence of new therapeutic modalities, the diagnosis of melanoma at the earliest practicable stage has become more important for improving the survival of patients. We developed a positron emission tomography (PET) imaging probe, N-(2-(dimethylamino)ethyl)-5-[18F]fluoropicolinamide ([18F]DMPY2) and evaluated diagnostic performance in animal models. [18F]DMPY2 PET exhibited excellent performance in detecting primary and metastatic melanomas, demonstrating strong/prolonged tumoral uptake and rapid background clearance. This suggests that this radiotracer could be used as a novel PET imaging agent to obtain outstanding image quality in the diagnosis of melanoma. This is the pioneering report of pyridine-based benzamide derivative with reduced alkyl chains in the amine residue and ultrasensitive detection of melanoma lesions in living subjects compared to conventional PET imaging agents. Malignant melanoma has one of the highest mortality rates of any cancer because of its aggressive nature and high metastatic potential. Clinical staging of the disease at the time of diagnosis is very important for the prognosis and outcome of melanoma treatment. In this study, we designed and synthesized the 18F-labeled pyridine-based benzamide derivatives N-(2-(dimethylamino)ethyl)-5-[18F]fluoropicolinamide ([18F]DMPY2) and N-(2-(dimethylamino)ethyl)-6-[18F]fluoronicotinamide ([18F]DMPY3) to detect primary and metastatic melanoma at an early stage and evaluated their performance in this task. [18F]DMPY2 and [18F]DMPY3 were synthesized by direct radiofluorination of the bromo precursor, and radiochemical yields were ∼15–20%. Cell uptakes of [18F]DMPY2 and [18F]DMPY3 were >103-fold and 18-fold higher, respectively, in B16F10 (mouse melanoma) cells than in negative control cells. Biodistribution studies revealed strong tumor uptake and retention of [18F]DMPY2 (24.8% injected dose per gram of tissue [ID/g] at 60 min) and [18F]DMPY3 (11.7%ID/g at 60 min) in B16F10 xenografts. MicroPET imaging of both agents demonstrated strong tumoral uptake/retention and rapid washout, resulting in excellent tumor-to-background contrast in B16F10 xenografts. In particular, [18F]DMPY2 clearly visualized almost all metastatic lesions in lung and lymph nodes, with excellent image quality. [18F]DMPY2 demonstrated a significantly higher tumor-to-liver ratio than [18F]fluorodeoxyglucose ([18F]FDG) and the previously reported benzamide tracers N-[2-(diethylamino)-ethyl]-5-[18F]fluoropicolinamide ([18F]P3BZA) and N-[2-(diethylamino)-ethyl]-4-[18F]fluorobenzamide ([18F]FBZA) in B16F10-bearing or SK-MEL-3 (human melanoma)-bearing mice. In conclusion, [18F]DMPY2 might have strong potential for the diagnosis of early stage primary and metastatic melanoma using positron emission tomography (PET).
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Parat A, Kryza D, Degoul F, Taleb J, Viallard C, Janier M, Garofalo A, Bonazza P, Heinrich-Balard L, Cohen R, Miot-Noirault E, Chezal JM, Billotey C, Felder-Flesch D. Radiolabeled dendritic probes as tools for high in vivo tumor targeting: application to melanoma. J Mater Chem B 2015; 3:2560-2571. [DOI: 10.1039/c5tb00235d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A small-sized and bifunctional111In-radiolabeled dendron shows highin vivotargeting efficiency towards an intracellular target in a murine melanoma model.
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Mier W, Kratochwil C, Hassel JC, Giesel FL, Beijer B, Babich JW, Friebe M, Eisenhut M, Enk A, Haberkorn U. Radiopharmaceutical therapy of patients with metastasized melanoma with the melanin-binding benzamide 131I-BA52. J Nucl Med 2013; 55:9-14. [PMID: 24277756 DOI: 10.2967/jnumed.112.112789] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The performance of cytotoxic drugs is defined by their selectivity of uptake and action in tumor tissue. Recent clinical responses achieved by treating metastatic malignant melanoma with therapeutic modalities based on gene expression profiling showed that malignant melanoma is amenable to systemic treatment. However, these responses are not persistent, and complementary targeted treatment strategies are required for malignant melanoma. METHODS Here we provide our experience with different labeling procedures for the radioiodination of benzamides and report on initial dosimetry data and the first therapeutic application of (131)I-BA52, a novel melanin-binding benzamide in patients with metastatic malignant melanoma. Twenty-six adults with histologically documented metastasized malignant melanoma received a single dose of 235 ± 62 MBq of (123)I-BA52 for planar and SPECT/CT imaging. Nine patients were selected for radionuclide therapy and received a median of 4 GBq (minimum, 0.51 GBq; maximum, 6.60 GBq) of the β-emitting radiopharmaceutical (131)I-BA52. RESULTS A trimethyltin precursor-based synthesis demonstrated high radiochemical yields in the large-scale production of radioiodinated benzamides required for clinical application. (123)I-BA52 showed specific uptake and long-term retention in tumor tissue with low transient uptake in the excretory organs. In tumor tissue, a maximum dose of 12.2 Gy per GBq of (131)I-BA52 was calculated. The highest estimated dose to a normal organ was found for the lung (mean, 3.1 Gy/GBq). No relevant acute or mid-term toxicity was observed with the doses administered until now. Even though dosimetric calculations reveal that the doses applied in this early phase of clinical application can be significantly increased, we observed antitumor effects with follow-up imaging, and single patients of the benzamide-positive cohort of patients (3/5 of the patients receiving a dose > 4.3 GBq) demonstrated a surprisingly long survival of more than 2 y. CONCLUSION These data indicate that systemic radionuclide therapy using (131)I-BA52 as a novel approach for the therapy of malignant melanoma is of considerable potential. Future trials should be done to enhance the precision of dosimetry, validate the maximum tolerable dose, and evaluate the effectiveness of the treatment in a prospective manner.
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Affiliation(s)
- Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
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Pan J, Mason NS, Debnath ML, Mathis CA, Klunk WE, Lin KS. Design, synthesis and structure-activity relationship of rhenium 2-arylbenzothiazoles as β-amyloid plaque binding agents. Bioorg Med Chem Lett 2013; 23:1720-6. [PMID: 23411076 PMCID: PMC3594088 DOI: 10.1016/j.bmcl.2013.01.068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Revised: 01/06/2013] [Accepted: 01/16/2013] [Indexed: 11/19/2022]
Abstract
To continue our efforts toward the development of (99m)Tc PiB analogs, we have synthesized 24 neutral and lipophilic Re (as a surrogate of (99m)Tc) 2-arylbenzothiazoles, and explored their structure-activity relationship for binding to Aβ1-40 fibrils. These Re complexes were designed and synthesized via the integrated approach, so their (99m)Tc analogs would have a greater chance of crossing the blood-brain barrier. While the lipophilicities (logPC18=1.59-3.53) of these Re 2-arylbenzothiazoles were all within suitable range, their binding affinities (Ki=30-617nM) to Aβ1-40 fibrils varied widely depending on the selection and integration of the tetradentate chelator into the 2-phenylbenzothiazole pharmacophore. For potential clinical applications, further refinement to obtain Re 2-arylbenzothiazoles with better binding affinities (<10nM) will likely be needed. The integrated approach reported here to generate compact, neutral and lipophilic Re 2-arylbenzothiazoles could be applied to other potent pharmacophores as well to convert other current Aβ PET tracers to their (99m)Tc analogs for more widespread application via the use of SPECT scanners.
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Affiliation(s)
- Jinhe Pan
- Department of Molecular Oncology, BC Cancer Agency, Vancouver, BC V5Z1L3, Canada
| | - Neale S. Mason
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Manik L. Debnath
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Chester A. Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - William E. Klunk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer Agency, Vancouver, BC V5Z1L3, Canada
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Moura C, Gano L, Mendes F, Raposinho PD, Abrantes A, Botelho M, Santos I, Paulo A. 99mTc(I)/Re(I) tricarbonyl complexes for in vivo targeting of melanotic melanoma: Synthesis and biological evaluation. Eur J Med Chem 2012; 50:350-60. [DOI: 10.1016/j.ejmech.2012.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 12/01/2022]
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Moura C, Gano L, Santos IC, Santos I, Paulo A. 99mTcI/ReI Tricarbonyl Complexes with Tridentate Cysteamine Based Ligands: Synthesis, Characterization and in vitro/in vivo Evaluation. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100796] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Peindy N'Dongo HW, Raposinho PD, Fernandes C, Santos I, Can D, Schmutz P, Spingler B, Alberto R. Preparation and biological evaluation of cyclopentadienyl-based 99mTc-complexes [(Cp-R)99mTc(CO)3] mimicking benzamides for malignant melanoma targeting. Nucl Med Biol 2010; 37:255-64. [DOI: 10.1016/j.nucmedbio.2009.11.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 11/11/2009] [Accepted: 11/25/2009] [Indexed: 10/19/2022]
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10
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Bashir-Uddin Surfraz M, King R, Mather SJ, Biagini SC, Blower PJ. Trifluoroacetyl as a protecting group for HYNIC: stability in the presence of electrophiles and application in the synthesis of 99mTc-radiolabelled peptides. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.01.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Moura C, Esteves T, Gano L, Raposinho PD, Paulo A, Santos I. Synthesis, characterization and biological evaluation of tricarbonyl M(i) (M = Re, 99mTc) complexes functionalized with melanin-binding pharmacophores. NEW J CHEM 2010. [DOI: 10.1039/c0nj00256a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Ren G, Miao Z, Liu H, Jiang L, Limpa-Amara N, Mahmood A, Gambhir SS, Cheng Z. Melanin-targeted preclinical PET imaging of melanoma metastasis. J Nucl Med 2009; 50:1692-9. [PMID: 19759116 DOI: 10.2967/jnumed.109.066175] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Dialkylamino-alkyl-benzamides possess an affinity for melanin, suggesting that labeling of such benzamides with (18)F could potentially produce melanin-targeted PET probes able to identify melanotic melanoma metastases in vivo with high sensitivity and specificity. METHODS In this study, N-[2-(diethylamino)ethyl]-4-(18)F-fluorobenzamide ((18)F-FBZA) was synthesized via a 1-step conjugation reaction. The sigma-receptor binding affinity of (19)F-FBZA was determined along with the in vitro cellular uptake of radiofluorinated (18)F-FBZA in B16F10 cells. In vivo distribution and small-animal PET studies were conducted on mice bearing B16F10 melanoma, A375M amelanotic melanoma, and U87MG tumors, and comparative studies were performed with (18)F-FDG PET in the melanoma models. RESULTS In vitro, uptake of (18)F-FBZA was significantly higher in B16F10 cells treated with l-tyrosine (P < 0.001). In vivo, (18)F-FBZA displayed significant tumor uptake; at 2 h, 5.94 +/- 1.83 percentage injected dose (%ID) per gram was observed in B16F10 tumors and only 0.75 +/- 0.09 %ID/g and 0.56 +/- 0.13 %ID/g was observed in amelanotic A375M and U87MG tumors, respectively. Lung uptake was significantly higher in murine lungs bearing melanotic B16F10 pulmonary metastases than in normal murine lungs (P < 0.01). Small-animal PET clearly identified melanotic lesions in both primary and pulmonary metastasis B16F10 tumor models. Coregistered micro-CT with small-animal PET along with biopsies further confirmed the presence of tumor lesions in the mouse lungs. CONCLUSION (18)F-FBZA specifically targets primary and metastatic melanotic melanoma lesions with high tumor uptake and may have translational potential.
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Affiliation(s)
- Gang Ren
- Department of Radiology and Bio-X Program, Stanford University, Stanford, California 94305, USA
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Kim JH, Heller DA, Jin H, Barone PW, Song C, Zhang J, Trudel LJ, Wogan GN, Tannenbaum SR, Strano MS. The rational design of nitric oxide selectivity in single-walled carbon nanotube near-infrared fluorescence sensors for biological detection. Nat Chem 2009; 1:473-81. [DOI: 10.1038/nchem.332] [Citation(s) in RCA: 217] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 07/14/2009] [Indexed: 12/29/2022]
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Surfraz MBU, Biagini SCG, Blower PJ. A technetium intermediate specifically promotes deprotection of trifluoroacetyl HYNIC during radiolabelling under mild conditions. Dalton Trans 2008:2920-2. [PMID: 18493625 DOI: 10.1039/b805110k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The trifluoroacetyl group protects the nucleophilic HYNIC from unwanted side reactions yet allows radiolabelling with technetium-99m under mild conditions, due to efficient and specific promotion of deprotection by a technetium complex intermediate.
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Affiliation(s)
- M Bashir-Uddin Surfraz
- Cancer Research Group, Department of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
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15
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Surfraz MBU, King R, Mather SJ, Biagini SCG, Blower PJ. Trifluoroacetyl-HYNIC peptides: synthesis and 99mTc radiolabeling. J Med Chem 2007; 50:1418-22. [PMID: 17315986 DOI: 10.1021/jm061274l] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fmoc-lys(HYNIC-Boc)-OH, a precursor for solid-phase synthesis of 99mTc-labeled peptides, was synthesized efficiently without HPLC purification. HPLC-ESMS showed that deprotection and decoupling of peptide from the resin with trifluoroacetic acid gave initially HYNIC-peptide, which was trifluoroacetylated upon prolonged incubation. The trifluoroacetyl-HYNIC group was hydrolyzed during 99mTc labeling, rendering deprotection unnecessary. Trifluoroacetyl-HYNIC peptide was 99mTc-labeled as efficiently, producing the same product, as HYNIC-peptide. These modifications enhance the versatility of HYNIC for 99mTc peptide labeling.
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Affiliation(s)
- M Bashir-Uddin Surfraz
- Cancer Research Group, Department of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
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Méndez-Rojas MA, Kharisov BI, Tsivadze AY. Recent advances on technetium complexes: coordination chemistry and medical applications¶. J COORD CHEM 2007. [DOI: 10.1080/00958970500324633] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Miguel A. Méndez-Rojas
- a Departamento de Química y Biología , Universidad de las Américas-Puebla , Ex-Hacienda de Sta. Catarina Martir, AP 100, Cholula 72820, Puebla, México
| | - Boris I. Kharisov
- b Facultad de Ciencias Químicas , Universidad Autónoma de Nuevo León , 66450 San Nicolas de los Garza 18-F, Nuevo León, México
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Wolf M, Hull WE, Mier W, Heiland S, Bauder-Wüst U, Kinscherf R, Haberkorn U, Eisenhut M. Polyamine-Substituted Gadolinium Chelates: A New Class of Intracellular Contrast Agents for Magnetic Resonance Imaging of Tumors. J Med Chem 2006; 50:139-48. [PMID: 17201417 DOI: 10.1021/jm061003a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new class of intracellular contrast agents (CA) for magnetic resonance imaging has been developed, based on Gd(DTPA) with two positively charged amide-linked substituents. Uptake of Gd(DTPA) into cultured tumor cell lines (B16 mouse melanoma, MH3924A Morris hepatoma) was below the detection limit while CA with the melanin-binding pharmacophore 2-(diethylamino)ethylamine reached intracellular concentrations of ca. 0.03 fmol/cell (ca. 20 microM) for melanoma and 0.02 fmol/cell for hepatoma (24 h at 10 microM CA). With the polyamine substituents bis(2-aminoethyl)amine or spermidine, CA uptake increased up to 3-fold for melanoma (0.083 fmol/cell) and 9-fold for hepatoma (0.18 fmol/cell). Uptake of polyamine-substituted CA was reduced by the polyamine transport inhibitor benzyl viologen. Molar relaxivities for three Gd-DTPA-polyamine complexes were in the range 5.6-6.9 for the free complex in solution and 7.7-23.5 s-1 mM-1 for Morris hepatoma cell pellets. T1-weighted magnetic resonance imaging at 2.35 T of rats with MH3924A tumors showed contrast enhancement in tumor at 1 and 24 h postinjection of polyamine-substituted CA.
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Affiliation(s)
- Markus Wolf
- Department of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
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Donovan A, Forbes J, Dorff P, Schaffer P, Babich J, Valliant JF. A New Strategy for Preparing Molecular Imaging and Therapy Agents Using Fluorine-Rich (Fluorous) Soluble Supports. J Am Chem Soc 2006; 128:3536-7. [PMID: 16536524 DOI: 10.1021/ja0600375] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A convenient new strategy for producing radiolabeled compounds in high effective specific activity was developed using soluble fluorous supports. The reported methodology involves a fluorous linker group that is released from the substrate of interest upon reaction with radioiodine. The desired product can then be selectively separated from unreacted starting material and reaction byproducts using a simple fluorous solid-phase extraction procedure. The utility of this approach was demonstrated by labeling a series of benzoic acid derivatives which are commonly used to prepare molecular imaging agents. All compounds were produced in high radiochemical yields, purities, and effective specific activities. The strategy was further elaborated in that it was used to prepare a small collection of radiolabeled benzamides as a way of demonstrating the potential utility of this method for creating libraries of molecular imaging agents.
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Affiliation(s)
- Amanda Donovan
- Department of Chemistry, McMaster University, Hamilton, ON, Canada L8S 4M1
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19
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Wolf M, Bauder-Wüst U, Mohammed A, Schönsiegel F, Mier W, Haberkorn U, Eisenhut M. Alkylating benzamides with melanoma cytotoxicity. Melanoma Res 2004; 14:353-60. [PMID: 15457090 DOI: 10.1097/00008390-200410000-00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Radioiodinated N-(2-(diethylamino)ethyl)benzamides have recently been discovered as selective agents for melanotic melanoma and are used for scintigraphic imaging in nuclear medicine. Owing to the high binding capacity, benzamide derivatives conjugated with alkylating cytostatics were synthesized and tested for their potential for targeted drug delivery. Conjugates of chlorambucil with procainamide (1), diethylaminoethylamine (2) and 2-pyrrolidin-1-yl-ethylamine (3), as well as 4-(bis(2-chloroethyl)amino)- (6,7) and 4-(N,N-diethyltriazeno)-substituted (8-10) benzamides, were synthesized. Cell uptake studies with B16 melanoma cells revealed high uptake of radioiodinated 1 and 2, while radiolabelled chlorambucil was found to lack this characteristic. These results were confirmed by biodistribution studies in a mouse melanoma model. Viability measurements revealed that all chlorambucil-benzamide derivatives showed higher toxicity against B16 melanoma and SK-MEL-28 cells than did the parent chlorambucil itself, and that the triazene derivatives were more potent than dacarbazine, which is currently used as a standard cytostatic drug in melanoma therapy. Of all the compounds tested in this series, the triazenes 9 and 10 showed the most promising targeting effect. The toxicity of these compounds against hepatoma cells (MH3924A) and, to a lesser extent, against mouse fibroblast (NIH 3T3) and cervix carcinoma (HeLa) cells was also enhanced, but they were not as toxic as dacarbazine (HeLa). These findings support the concept of a selective, benzamide-mediated in vivo delivery of cytostatics in melanoma cells, leading to enhanced efficacy.
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Affiliation(s)
- Markus Wolf
- Department of Radiopharmaceutical Chemistry, German Cancer Research Centre Heidelberg and Department of Nuclear Medicine, University of Heidelberg, Heidelberg, Germany
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