Internalization by multiple endocytic pathways and lysosomal processing impact maspin-based therapeutics.
Internalization by multiple endocytic pathways and lysosomal processing impact maspin-based therapeutics.
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DOI：
10.1158/1541-7786.mcr-14-0067
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发表时间：
2014-10
期刊：
影响因子：
--
通讯作者：
Hendrix MJ
中科院分区：
文献类型：
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作者：
Bodenstine TM;Seftor RE;Seftor EA;Khalkhali-Ellis Z;Samii NA;Monarrez JC;Chandler GS;Pemberton PA;Hendrix MJ
患有转移性疾病的患者面临高死亡率和缺乏治疗选择。基于蛋白质的疗法通过增加特异性、降低免疫应答和更直接的递送方式提供优于传统化疗的优势。然而，由于对外源性应用时细胞的蛋白水解加工的了解不足，开发常常受到阻碍。这项研究的重点是重组Maspin（rMaspin），一种丝氨酸蛋白酶抑制剂（SERPINB 5），当直接应用于癌细胞时，它会改变侵袭性。先前的证据表明，与内源性再表达相比，rMaspin治疗的效果存在差异，但对这些差异几乎没有解释。一个主要的假设是，与内源性表达相比，外源性应用的rMaspin在癌细胞中受到不同的调节和/或加工机制的影响。因此，需要更详细地了解rMaspin的内化和亚细胞运输机制，以指导未来的翻译开发。我们描述了rMaspin在内体/溶酶体途径的胞质囊泡中的分子运输，并通过多种内吞机制表征其摄取。延时激光扫描共聚焦显微镜显示了癌细胞中染料标记的rMaspin的实时摄取。这项研究表明，rMaspin的细胞加工在影响其生物学活性方面发挥着关键作用，并强调了在用于治疗癌症时，需要新的方法来增加rMaspin的可用性。
Patients with metastatic disease face high rates of mortality with a paucity of therapeutic options. Protein-based therapeutics provides advantages over traditional chemotherapy through increased specificity, decreased immune responses and more direct means of delivery. However, development is often hindered due to insufficient knowledge regarding proteolytic processing by cells when exogenously applied. This study focuses on recombinant Maspin (rMaspin), a serine protease inhibitor (SERPINB5), which alters invasive properties when directly applied to cancer cells. Previous evidence suggests differences in the effects of rMaspin treatment when compared to endogenous re-expression, with little explanation for these discrepancies. A leading hypothesis is that exogenously applied rMaspin is subject to different regulatory and/or processing mechanisms in cancer cells when compared to endogenous expression. Therefore, a more detailed understanding of the mechanisms of internalization and subcellular trafficking of rMaspin is needed to guide future translational development. We describe the molecular trafficking of rMaspin in cytoplasmic vesicles of the endosomal/lysosomal pathway and characterize its uptake by multiple endocytic mechanisms. Time-lapse laser scanning confocal microscopy shows the uptake, in real-time, of dye labeled rMaspin in cancer cells. This study indicates that cellular processing of rMaspin plays a key role affecting its biological activity and highlights the need for new approaches aimed at increasing the availability of rMaspin when used to treat cancer.