He Lian, Yang Huijun, Tang Jianli, Liu Zhudong, Chen Yiyan, Lu Binghua, He Haocheng, Tang Sijia, Sun Yunjun, Liu Fei, Ding Xuezhi, Zhang Youming, Hu Shengbiao, Xia Liqiu
1Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081 People's Republic of China.
2School of Basic Medical Science, Changsha Medical University, Changsha, 410298 People's Republic of China.
J Biol Eng. 2019 Jun 28;13:58. doi: 10.1186/s13036-019-0189-9. eCollection 2019.
Traditional cancer therapies, such as surgery treatment, radiotherapy, and chemotherapy, often fail to completely eliminate tumor cells in an anaerobic microenvironment of tumor regions. In contrast to these traditional cancer therapies, the use of targeted delivery vectors to deliver anticancer genes or antitumor drugs to hypoxic areas in tumors is the most clinically promising cancer treatment with rapid development in recent years. In this study, Nissle 1917 (EcN), an intestinal probiotic, was utilized as a targeted transport vector to deliver p53 and Tum-5 protein to tumor hypoxic regions. The tumor-targeting characteristics of EcN were investigated using luciferase CDABE operon, and the results demonstrated that EcN could specifically accumulate in the solid tumor areas of SMMC-7721 tumor-bearing BALB/c nude mice. The Tum 5-p53 bifunctional proteins were initially constructed and then delivered to solid tumor regions by using the targeted transporter EcN for cancer therapy. The antitumor effect and safety of three engineered bacteria, namely, EcN (Tum-5), EcN (p53), and EcN (Tum 5-p53), were also examined. The calculated tumor volume and tumor weight indicated that these three engineered bacteria could inhibit the growth of human hepatoma SMMC-7721 cells, and the antitumor effect of EcN (Tum 5-p53) expressing the Tum 5-p53 fusion protein was significantly better than those of EcN (Tum-5) and EcN (p53) alone. Immunofluorescence demonstrated that the expression of Ki-67, a nuclear proliferation-related protein, was inhibited in the tumor areas of the groups treated with the engineered bacteria, whereas the expression of caspase-3 was upregulated. The expression trends of Ki-67 and caspase-3 were consistent with the different antitumor efficacies of these three engineered bacteria. EcN did not elicit obvious side effects on mice. This research not only provids a foundation for tumor-targeted therapy but also contributes greatly to the development of antitumor agents and anticancer proteins.
传统的癌症治疗方法，如手术治疗、放射治疗和化学治疗，往往无法在肿瘤区域的厌氧微环境中完全清除肿瘤细胞。与这些传统癌症治疗方法不同，使用靶向递送载体将抗癌基因或抗肿瘤药物递送至肿瘤缺氧区域是近年来发展迅速且临床上最具前景的癌症治疗方法。在本研究中，肠道益生菌Nissle 1917（EcN）被用作靶向运输载体，将p53和Tum-5蛋白递送至肿瘤缺氧区域。利用荧光素酶CDABE操纵子研究了EcN的肿瘤靶向特性，结果表明EcN可特异性积聚在荷SMMC-7721肿瘤的BALB/c裸鼠的实体瘤区域。首先构建了Tum 5-p53双功能蛋白，然后利用靶向转运体EcN将其递送至实体瘤区域进行癌症治疗。还检测了三种工程菌，即EcN（Tum-5）、EcN（p53）和EcN（Tum 5-p53）的抗肿瘤效果和安全性。计算得出的肿瘤体积和肿瘤重量表明，这三种工程菌均可抑制人肝癌SMMC-7721细胞的生长，表达Tum 5-p53融合蛋白的EcN（Tum 5-p53）的抗肿瘤效果明显优于单独的EcN（Tum-5）和EcN（p53）。免疫荧光显示，在工程菌治疗组的肿瘤区域，核增殖相关蛋白Ki-67的表达受到抑制，而caspase-3的表达上调。Ki-67和caspase-3的表达趋势与这三种工程菌不同的抗肿瘤疗效一致。EcN对小鼠未引起明显副作用。本研究不仅为肿瘤靶向治疗提供了基础，也为抗肿瘤药物和抗癌蛋白的开发做出了巨大贡献。
