Noninvasive visualization and quantification of tumor αVß3 integrin expression using a novel positron emission tomography probe, 64Cu-cyclam-RAFT-c(-RGDfK-)4.
Nucl Med Biol
; 38(4): 529-40, 2011 May.
Article
em En
| MEDLINE
| ID: mdl-21531290
ABSTRACT
INTRODUCTION:
The α(V)ß(3) integrin is a well-known transmembrane receptor involved in tumor invasion, angiogenesis and metastasis. Our aim was to evaluate a novel positron emission tomography (PET) probe, (64)Cu-cyclam-RAFT-c(-RGDfK-)(4), for noninvasive visualization and quantification of α(V)ß(3) integrin expression.METHODS:
RAFT-c(-RGDfK-)(4), a tetrameric cyclic Arg-Gly-Asp (RGD)-based peptide, was conjugated with a bifunctional chelator, 1,4,8,11-tetraazacyclotetradecane (cyclam), radiolabeled with the positron emitter (64)Cu and evaluated in vitro by cell binding and competitive inhibition assays and in vivo by biodistribution and receptor blocking studies, and PET imaging. The following cell lines, human embryonic kidney HEK293(ß(1)) [α(V)ß(3)-negative] and HEK293(ß(3)) [α(V)ß(3)-overexpressing] and human glioblastoma U87MG [naturally expressing α(V)ß(3)], together with their subcutaneous xenografts in athymic nude mice, were used for the present study. The expression levels of α(V)ß(3) on these cell lines and tumor xenografts were analyzed by flow cytometry and sodium dodecyl sulfate-polyacrylamide gel electrophoresis/autoradiography, respectively.RESULTS:
(64)Cu-cyclam-RAFT-c(-RGDfK-)(4) demonstrated the in vitro and in vivo specificity for the α(V)ß(3) integrin and displayed rapid blood clearance, predominantly renal excretion and low uptake in nontumor tissues. Tumor uptake of (64)Cu-cyclam-RAFT-c(-RGDfK-)(4) (3 h postinjection) in HEK293(ß(3)) (high levels of α(V)ß(3)), U87MG (moderate levels of α(V)ß(3)) and HEK293(ß(1)) (undetectable levels of α(V)ß(3)) tumors was 9.35%±1.19%, 3.46%±0.45% and 1.18%±0.30% injected dose per gram, respectively, with a strong and positive correlation with the tumor α(V)ß(3) expression levels (correlation coefficient=0.967; P<.0001). Positron emission tomographic images showed that α(V)ß(3)-positive tumors were clearly visualized with high tumor-to-background contrast, and agreed well with the biodistribution results.CONCLUSION:
(64)Cu-cyclam-RAFT-c(-RGDfK-)(4) exhibits potential for noninvasively quantifying α(V)ß(3) expression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligopeptídeos
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Peptídeos Cíclicos
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Regulação Neoplásica da Expressão Gênica
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Integrina alfaVbeta3
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Tomografia por Emissão de Pósitrons
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Complexos de Coordenação
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Imagem Molecular
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Neoplasias
Limite:
Animals
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Female
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Humans
Idioma:
En
Revista:
Nucl Med Biol
Assunto da revista:
BIOLOGIA
/
MEDICINA NUCLEAR
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Japão