EA 4552, Université de Toulouse 3 , Toulouse, France.
ACS Nano. 2014 Feb 25;8(2):1350-63. doi: 10.1021/nn404954s. Epub 2014 Jan 14.
Nanotherapy using targeted magnetic nanoparticles grafted with peptidic ligands of receptors overexpressed in cancers is a promising therapeutic strategy. However, nanoconjugation of peptides can dramatically affect their properties with respect to receptor recognition, mechanism of internalization, intracellular trafficking, and fate. Furthermore, investigations are needed to better understand the mechanism whereby application of an alternating magnetic field to cells containing targeted nanoparticles induces cell death. Here, we designed a nanoplatform (termed MG-IONP-DY647) composed of an iron oxide nanocrystal decorated with a ligand of a G-protein coupled receptor, the cholecystokinin-2 receptor (CCK2R) that is overexpressed in several malignant cancers. MG-IONP-DY647 did not stimulate inflammasome of Raw 264.7 macrophages. They recognized cells expressing CCK2R with a high specificity, subsequently internalized via a mechanism involving recruitment of β-arrestins, clathrin-coated pits, and dynamin and were directed to lysosomes. Binding and internalization of MG-IONP-DY647 were dependent on the density of the ligand at the nanoparticle surface and were slowed down relative to free ligand. Trafficking of CCK2R internalized with the nanoparticles was slightly modified relative to CCK2R internalized in response to free ligand. Application of an alternating magnetic field to cells containing MG-IONP-DY647 induced apoptosis and cell death through a lysosomal death pathway, demonstrating that cell death is triggered even though nanoparticles of low thermal power are internalized in minute amounts by the cells. Together with pioneer findings using iron oxide nanoparticles targeting tumoral cells expressing epidermal growth factor receptor, these data represent a solid basis for future studies aiming at establishing the proof-of-concept of nanotherapy of cancers using ligand-grafted magnetic nanoparticles specifically internalized via cell surface receptors.
使用靶向磁性纳米粒子与在癌症中过表达的受体的肽配体进行纳米治疗是一种很有前途的治疗策略。然而，肽的纳米缀合会极大地影响其与受体识别、内化机制、细胞内运输和命运相关的特性。此外，还需要进行研究以更好地理解将交变磁场应用于含有靶向纳米粒子的细胞会诱导细胞死亡的机制。在这里，我们设计了一种由氧化铁纳米晶体修饰的配体组成的纳米平台（称为 MG-IONP-DY647），该配体是一种 G 蛋白偶联受体，即胆囊收缩素-2 受体（CCK2R），该受体在几种恶性肿瘤中过表达。MG-IONP-DY647 不会刺激 Raw 264.7 巨噬细胞中的炎症小体。它们以高特异性识别表达 CCK2R 的细胞，随后通过涉及招募β-arrestin、网格蛋白包被凹陷和动力蛋白的机制内化，并被导向溶酶体。MG-IONP-DY647 的结合和内化依赖于纳米粒子表面配体的密度，并且相对于游离配体的内化速度较慢。与响应游离配体内化的 CCK2R 相比，与纳米粒子内化的 CCK2R 的转运略有改变。将交变磁场应用于含有 MG-IONP-DY647 的细胞会通过溶酶体死亡途径诱导细胞凋亡和死亡，这表明即使细胞以少量的低热能纳米粒子内化，也会引发细胞死亡。结合使用针对表达表皮生长因子受体的肿瘤细胞的氧化铁纳米粒子的先驱性发现，这些数据为未来的研究提供了坚实的基础，这些研究旨在使用通过细胞表面受体特异性内化的配体接枝磁性纳米粒子建立癌症的纳米治疗概念验证。
