Cellular penetration and nuclear importation properties of 111In-labeled and 123I-labeled HIV-1 tat peptide immunoconjugates in BT-474 human breast cancer cells
Cellular penetration and nuclear importation properties of 111In-labeled and 123I-labeled HIV-1 tat peptide immunoconjugates in BT-474 human breast cancer cells
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DOI：
10.1016/j.nucmedbio.2006.10.008
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发表时间：
2007-01-01
影响因子：
3.1
通讯作者：
Reilly, Raymond M.
中科院分区：
文献类型：
--
作者：
Cornelissen, Bart;Hu, Meiduo;Reilly, Raymond M.
目的：比较HIV-1反式转录激活蛋白(TAT)蛋白16聚体多肽(GRKKRRQRRRRRPPQGYG)和抗鼠免疫球蛋白(MIGG)组成的In-111标记和I-123标记的免疫结合物(ICs)在BT-474乳腺癌细胞中的穿透和核输入特性。在竞争试验中对MIGG的免疫反应性进行了评估。测定了[In-111]抗Migg-Tat IC和[I-123]抗Migg-Tat IC在BT-474细胞中蓄积和放射性从细胞、胞浆或细胞核中清除的动力学。结果：[In-111]抗Migg-Tat的放射化学纯度为97%，并与Migg表位具有良好的免疫反应性。[I-123]抗Migg-Tat比[In-111]抗Migg-Tat IC更快地渗透BT-474细胞，并实现了1.5倍至2倍的细胞和细胞核摄取。过量的TAT多肽和NH4Cl抑制了[In-111]抗Migg-Tat的细胞穿透和核摄取。与In-111标记的抗Migg-Tat IC相比，I-123标记的抗Migg-Tat IC对BT-474细胞和细胞核的放射性清除更快、更彻底。结论：HIV-1 Tat蛋白来源的TAT多肽促进了BT-474人BC细胞与In-111标记和I-123标记的抗Migg抗体的穿透和核摄取。In-111标记的TAT IC可用于将放射性核素插入癌细胞，具有靶向细胞内，特别是用于成像和/或放射治疗应用的核表位的潜力。(C)2007 Elsevier Inc.保留所有权利。
Introduction: Our objective was to compare the cell penetration and nuclear importation properties of In-111-labeled and I-123-labeled immunoconjugates (ICs) composed of 16-mer peptides (GRKKRRQRRRPPQGYG) derived from HIV-1 transactivator of transcription (tat) protein and anti-mouse IgG (mIgG) in BT-474 breast cancer (BC) cells.Methods: [In-111]tat ICs were constructed by site-specific conjugation of tat peptides to NaIO4--oxidized carbohydrates in the Fc domain of diethylenetriaininepentaacetic-acid-modified anti-mIgG antibodies. Immunoreactivity against mIgG was assessed in a competition assay. The kinetics of the accumulation of [In-111] anti-mIgG-tat IC and [I-123]anti-mIgG-tat ICs in BT-474 cells and the elimination of radioactivity from cells, cytoplasm or nuclei were determined. The effects of excess tat peptides or NH4Cl (an inhibitor of endosomal acidification) on cellular uptake and nuclear importation of [In-111] anti-mIgG-tat were measured.Results: [In-111]anti-mIgG-tat was > 97% radiochemically pure and exhibited preserved immunoreactivity with mIgG epitopes. [I-123]Anti-mIgG-tat penetrated BT-474 cells more rapidly than [In-111]anti-mIgG-tat ICs and achieved a 1.5-fold to a 2-fold higher uptake in cells and nuclei. Cell penetration and nuclear uptake of [In-111]anti-mIgG-tat were inhibited by excess tat peptides and NH4Cl. Elimination of radioactivity from BT-474 cells and nuclei was more rapid and complete for I-123-labeled than for In-111-labeled anti-mIgG-tat ICs.Conclusion: Tat peptides derived from HIV-1 tat protein promoted the penetration and nuclear uptake of radioactivity following the incubation of In-111-labeled and I-123-labeled anti-mIgG antibodies with BT-474 human BC cells. In-111-labeled tat ICs are feasible for inserting radionuclides into cancer cells with potential for targeting intracellular and, particularly, nuclear epitopes for imaging and/or radiotherapeutic applications. (c) 2007 Elsevier Inc. All rights reserved.