Targeted Delivery of Immunotoxin by Antibody to Ganglioside GD3: A Novel Drug Delivery Route for Tumor Cells
Targeted Delivery of Immunotoxin by Antibody to Ganglioside GD3: A Novel Drug Delivery Route for Tumor Cells
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DOI：
10.1371/journal.pone.0055304
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发表时间：
2013-01-31
期刊：
影响因子：
3.7
通讯作者：
Daniotti, Jose L.
中科院分区：
文献类型：
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作者：
Demichelis, Vanina Torres;Vilcaes, Aldo A.;Daniotti, Jose L.
神经节苷是一种含唾液酸的糖脂，在几乎所有脊椎动物细胞的质膜上表达。神经节苷脂GD3在正常大脑发育中起重要作用，在成人中表达减少，但在神经外胚层和上皮源性癌症中表达上调。针对神经节苷脂GD3的R24抗体是一种经过验证的肿瘤靶点，它被特异性内吞并积累在核内体中。在这里，我们利用R24抗体的内化特性，选择性地将saporin（一种核糖体失活蛋白）递送到表达gd3的细胞[人（SK-Mel-28）和小鼠（B16）黑色素瘤细胞和中国仓鼠卵巢(CHO)-K1细胞]。这种免疫毒素对生长在二维单层上的肿瘤细胞具有特异性的细胞毒性，对gd3阴性细胞没有任何作用，这进一步证明了这一点。为了评估r24 -皂苷复合物的潜在抗肿瘤活性，我们还评估了免疫毒素对无附着条件下培养的SK-Mel-28和CHO-K1（GD3+）细胞克隆生长的影响。免疫毒素处理3天后，细胞菌落生长抑制明显（bbb80 -90%）。相反，在免疫毒素浓度相同的情况下，在不含R24抗体的情况下，或者在不含免疫毒素和R24的情况下，菌落仍能继续生长，这无疑说明了所观察到的效果的特异性。因此，神经节苷脂GD3作为一类新颖而有吸引力的细胞表面分子出现，用于靶向递送细胞毒性药物，因此为未来的癌症治疗干预提供了理论依据。
Gangliosides are sialic acid-containing glycolipids expressed on plasma membranes from nearly all vertebrate cells. The expression of ganglioside GD3, which plays essential roles in normal brain development, decreases in adults but is up regulated in neuroectodermal and epithelial derived cancers. R24 antibody, directed against ganglioside GD3, is a validated tumor target which is specifically endocytosed and accumulated in endosomes. Here, we exploit the internalization feature of the R24 antibody for the selective delivery of saporin, a ribosome-inactivating protein, to GD3-expressing cells [human (SK-Mel-28) and mouse (B16) melanoma cells and Chinese hamster ovary (CHO)-K1 cells]. This immunotoxin showed a specific cytotoxicity on tumor cells grew on 2D monolayers, which was further evident by the lack of any effect on GD3-negative cells. To estimate the potential antitumor activity of R24-saporin complex, we also evaluated the effect of the immunotoxin on the clonogenic growth of SK-Mel-28 and CHO-K1(GD3+) cells cultured in attachment-free conditions. A drastic growth inhibition (>80-90%) of the cell colonies was reached after 3 days of immunotoxin treatment. By the contrary, colonies continue to growth at the same concentration of the immuntoxin, but in the absence of R24 antibody, or in the absence of both immunotoxin and R24, undoubtedly indicating the specificity of the effect observed. Thus, the ganglioside GD3 emerge as a novel and attractive class of cell surface molecule for targeted delivery of cytotoxic agents and, therefore, provides a rationale for future therapeutic intervention in cancer.