Ki-67 as a Molecular Target for Therapy in an In vitro Three-Dimensional Model for Ovarian Cancer
Ki-67 as a Molecular Target for Therapy in an In vitro Three-Dimensional Model for Ovarian Cancer
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DOI：
10.1158/0008-5472.can-10-1190
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发表时间：
2010-11-15
期刊：
影响因子：
11.2
通讯作者：
Hasan, Tayyaba
中科院分区：
文献类型：
--
作者：
Rahmanzadeh, Ramtin;Rai, Prakash;Hasan, Tayyaba
针对癌细胞生长的分子标记和通路是开发有效疗法的一条有前途的途径。尽管 Ki-67 蛋白 (pKi-67) 是与癌细胞增殖和不良预后相关的关键标志物，但其作为治疗靶点的全部潜力此前从未成功展现。在这方面，由于需要细胞内和核内递送靶向和治疗部分，其核定位提出了主要障碍。使用脂质体封装的构建体，我们首次在人卵巢癌细胞系 OVCAR-5 中展示了 Ki-67 定向抗体的特异性递送以及随后的光触发死亡。光免疫缀合物封装脂质体 (PICEL) 由与荧光素 5(6)-异硫氰酸酯缀合的抗 pKi-67 抗体构建，作为光活化剂，然后封装在非阳离子脂质体中。通过共聚焦成像证实了 PICEL 的核仁定位。 PICEL 的光动力激活可特异性杀死单层和 OVCAR-5 细胞三维 (3D) 培养物中的 pKi-67 阳性癌细胞，抗体 TuBB-9 靶向 pKi-67 的生理活性形式，但不针对 MIB-1，针对不同的表位。这是首次演示 (a) 利用 Ki-67 作为治疗的分子靶标，以及 (b) 在单层癌细胞和体外 3D 模型系统中将抗体特异性递送至核仁。鉴于 pKi-67 在癌症增殖细胞中的普遍存在以及 3D 多细胞腺泡中靶向的特异性，这些发现是有希望的，并且该方法值得进一步研究。癌症研究； 70(22)； 9234-42。 (C) 2010 AACR。
Targeting molecular markers and pathways implicated in cancer cell growth is a promising avenue for developing effective therapies. Although the Ki-67 protein (pKi-67) is a key marker associated with aggressively proliferating cancer cells and poor prognosis, its full potential as a therapeutic target has never before been successfully shown. In this regard, its nuclear localization presents a major hurdle because of the need for intracellular and intranuclear delivery of targeting and therapeutic moieties. Using a liposomally encapsulated construct, we show for the first time the specific delivery of a Ki-67-directed antibody and subsequent light-triggered death in the human ovarian cancer cell line OVCAR-5. Photoimmunoconjugate-encapsulating liposomes (PICEL) were constructed from anti-pKi-67 antibodies conjugated to fluorescein 5(6)-isothiocyanate, as a photoactivatable agent, followed by encapsulation in noncationic liposomes. Nucleolar localization of the PICELs was confirmed by confocal imaging. Photodynamic activation with PICELs specifically killed pKi-67-positive cancer cells both in monolayer and in three-dimensional (3D) cultures of OVCAR-5 cells, with the antibody TuBB-9 targeting a physiologically active form of pKi-67 but not with MIB-1, directed to a different epitope. This is the first demonstration of (a) the exploitation of Ki-67 as a molecular target for therapy and (b) specific delivery of an antibody to the nucleolus in monolayer cancer cells and in an in vitro 3D model system. In view of the ubiquity of pKi-67 in proliferating cells in cancer and the specificity of targeting in 3D multicellular acini, these findings are promising and the approach merits further investigation. Cancer Res; 70(22); 9234-42. (C) 2010 AACR.