Department of Biochemistry and Molecular Biology and Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
PLoS One. 2010 Jun 3;5(6):e10929. doi: 10.1371/journal.pone.0010929.
Similar to other integrin-targeting strategies, disintegrins have previously shown good efficacy in animal cancer models with favorable pharmacological attributes and translational potential. Nonetheless, these polypeptides are notoriously difficult to produce recombinantly due to their particular structure requiring the correct pairing of multiple disulfide bonds for biological activity. Here, we show that a sequence-engineered disintegrin (called vicrostatin or VCN) can be reliably produced in large scale amounts directly in the oxidative cytoplasm of Origami B E. coli. Through multiple integrin ligation (i.e., alphavbeta3, alphavbeta5, and alpha5beta1), VCN targets both endothelial and cancer cells significantly inhibiting their motility through a reconstituted basement membrane. Interestingly, in a manner distinct from other integrin ligands but reminiscent of some ECM-derived endogenous anti-angiogenic fragments previously described in the literature, VCN profoundly disrupts the actin cytoskeleton of endothelial cells (EC) inducing a rapid disassembly of stress fibers and actin reorganization, ultimately interfering with EC's ability to invade and form tubes (tubulogenesis). Moreover, here we show for the first time that the addition of a disintegrin to tubulogenic EC sandwiched in vitro between two Matrigel layers negatively impacts their survival despite the presence of abundant haptotactic cues. A liposomal formulation of VCN (LVCN) was further evaluated in vivo in two animal cancer models with different growth characteristics. Our data demonstrate that LVCN is well tolerated while exerting a significant delay in tumor growth and an increase in the survival of treated animals. These results can be partially explained by potent tumor anti-angiogenic and pro-apoptotic effects induced by LVCN.
类似于其他整合素靶向策略，解整合素在具有良好药理特性和转化潜力的动物癌症模型中表现出良好的疗效。尽管如此，由于这些多肽的特殊结构需要多个正确配对的二硫键才能具有生物活性，因此它们的重组生产非常困难。在这里，我们展示了一种经过序列工程改造的解整合素（称为 vicrostatin 或 VCN）可以在 Origami B E. coli 的氧化细胞质中可靠地大量生产。通过多种整合素结合（即 alphavbeta3、alphavbeta5 和 alpha5beta1），VCN 靶向内皮细胞和癌细胞，通过重建的基底膜显著抑制它们的迁移。有趣的是，与其他整合素配体不同，但与文献中先前描述的一些源自 ECM 的内源性抗血管生成片段相似，VCN 深刻地破坏了内皮细胞 (EC) 的肌动蛋白细胞骨架，诱导应激纤维的快速解聚和肌动蛋白的重组，最终干扰 EC 的侵袭和形成管状结构的能力（管状形成）。此外，我们首次表明，在体外 Matrigel 层之间夹心的管状形成的 EC 中添加解整合素，尽管存在丰富的趋化因子，但会对其存活产生负面影响。进一步在具有不同生长特征的两种动物癌症模型中体内评估了 VCN 的脂质体制剂 (LVCN)。我们的数据表明，LVCN 具有良好的耐受性，同时显著延迟肿瘤生长并增加治疗动物的存活率。LVCN 诱导的肿瘤抗血管生成和促凋亡作用可以部分解释这些结果。
