Enhanced immunoPET of ALCAM-positive colorectal carcinoma using site-specific ⁶⁴Cu-DOTA conjugation.
Enhanced immunoPET of ALCAM-positive colorectal carcinoma using site-specific ⁶⁴Cu-DOTA conjugation.
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DOI：
10.1093/protein/gzu030
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发表时间：
2014-10
期刊：
影响因子：
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通讯作者：
R. Tavaré;Wei Wu;K. Zettlitz;F. Salazar;K. McCabe;J. Marks;A. Wu
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作者：
R. Tavaré;Wei Wu;K. Zettlitz;F. Salazar;K. McCabe;J. Marks;A. Wu
活化白细胞粘附分子（Activated leukocyte cell adhesion molecule， ALCAM）是一种免疫球蛋白超家族细胞粘附分子，在多种人类肿瘤中异常表达，包括黑色素瘤、前列腺癌、乳腺癌、结直肠癌、膀胱癌和胰腺腺癌。这种广谱的人类恶性肿瘤使ALCAM成为一个有前景的泛癌症免疫pet靶标，以帮助检测和诊断多种恶性肿瘤。在这项研究中，我们评估了（64）Cu-DOTA（1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸）免疫pet成像的位点特异性和非位点特异性偶联策略，该偶联体长度减少，保留了其二价结合能力。ALCAM的连接体长度分别为8个、5个和3个氨基酸，从而制备出真正的非共价位点特异性修饰的cdb。通过凝胶电泳、大小排斥层析、流式细胞术和质谱法对各种构建物进行了表征。为了证明靶向表达ALCAM的多种恶性肿瘤的效用增加，我们比较了位点特异性和非位点特异性偶联cbs对人类结直肠癌异种移植LS174T的靶向性。有趣的是，偶联策略不仅影响肿瘤靶向，还影响肝脏和肾脏的摄取/清除。
Activated leukocyte cell adhesion molecule (ALCAM) is an immunoglobulin superfamily cell adhesion molecule that is aberrantly expressed in a wide variety of human tumors, including melanoma, prostate cancer, breast cancer, colorectal carcinoma, bladder cancer and pancreatic adenocarcinoma. This wide spectrum of human malignancies makes ALCAM a prospective pan-cancer immunoPET target to aid in detection and diagnosis in multiple malignancies. In this study, we assess site-specific versus non-site-specific conjugation strategies for (64)Cu-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) immunoPET imaging of a fully human ALCAM cys-diabody (cDb) with a reduced linker length that retains its bivalent binding ability. ALCAM constructs with linker lengths of eight, five and three amino acids were produced to make true non-covalent site-specifically modified cDbs. Characterization by gel electrophoresis, size exclusion chromatography, flow cytometry and mass spectrometry of the various constructs was performed. To demonstrate the increased utility of targeting multiple malignancies expressing ALCAM, we compare the targeting of the site-specific versus non-site-specific conjugated cDbs to the human colorectal cancer xenograft LS174T. Interestingly, the conjugation strategy not only affects tumor targeting but also hepatic and renal uptake/clearance.