Recently, cell-based therapies have been explored as a strategy to enhance the specificity of anticancer therapeutic agents. In this perspective, human mesenchymal stromal cells (MSC) hold a promising future as cell delivery systems for anticancer proteins due to their unique biological features. In this study, we engineered human MSC to secrete a human codon-optimized version of azurin (hazu), a bacterial protein that has demonstrated anticancer activity toward different cancer models both in vitro and in vivo. To this end, microporation was used to deliver plasmid DNA encoding azurin into MSC derived from bone marrow (BM) and umbilical cord matrix (UCM), leading to expression and secretion of hazu to the conditioned medium (CM). Engineered hazu-MSC were shown to preserve tumor tropism toward breast (MCF-7) and lung (A549) cancer cell lines, comparable to non-modified MSC. Azurin was detected in the CM of transfected MSC and, upon treatment with hazu-MSC-CM, we observed a decrease in cancer cell proliferation, migration, and invasion, and an increase in cell death for both cancer cell lines. Moreover, expression of azurin caused no changes in MSC expression profile of cytokines relevant in the context of cancer progression, thus suggesting that the antitumoral effects induced by hazu-MSC secretome might be due to the presence of azurin independently. In conclusion, data shown herein indicate that MSC-produced azurin in a CM configuration elicits an anticancer effect.

近来，已经探索了基于细胞的疗法作为增强抗癌治疗剂特异性的策略。从这个角度来看，人间充质基质细胞（MSC）由于其独特的生物学特性，有望成为抗癌蛋白的细胞递送系统。在这项研究中，我们设计了人类MSC来分泌人类密码子优化版本的天青蛋白（hazu），这是一种细菌蛋白，已证明对不同癌症模型均具有抗癌活性体外 和 体内。为此，微穿孔被用于将编码天青蛋白的质粒DNA递送至源自骨髓（BM）和脐带基质（UCM）的MSC中，从而导致hazu的表达和分泌至条件培养基（CM）。研究表明，与未经修饰的MSC相比，工程化的hazu-MSC保留了针对乳腺癌（MCF-7）和肺癌（A549）癌细胞系的肿瘤嗜性。在转染的MSC的CM中检测到了天青素，用hazu-MSC-CM处理后，我们观察到两种癌细胞系的癌细胞增殖，迁移和侵袭均减少，细胞死亡增加。此外，天青蛋白的表达没有引起与癌症进展相关的细胞因子的MSC表达谱的改变，因此表明由hazu-MSC分泌组诱导的抗肿瘤作用可能是由于天青蛋白的独立存在。