Fusion protein tTF-EG3287 induces occlusion of tumor vessels and impairs tumor growth in human colon caner

Guo-Qin Qiu, X Xie, Bin Zhao, Li-Zhen Xu,  Yu-Qiang Chen

Abstract:

The problems including narrow indications, low drug loading, and difficulty in intervention severely affect the clinical efficacy of anti-tumor embolization. Here, we designed a novel tTF-EG3287 protein consisting of the truncated tissue factor (tTF) fused with the bicyclic polypeptide which was encoded by exons 7 and 8 for accurate localization in the tumor vascular endothelial cells (EG3287). This study aims to explore its anti-cancer effect. Gene sequencing was used to verify the fusion gene and SDS-PAGE gel to confirm the optimal induction time and concentration of tTF-EG3287. Nickel affinity chromatography column was used to purify the fusion protein. Confocal microscopy was used to assess the target activity of tTF-EG3287 on colon cancer cells in vitro. Thrombelastography assay was used to identify the pro-coagulant activity of tTF-EG3287. In in vivo experiments, the specific localization of tTF-EG3287 in tumor tissues and the effect of tTF-EG3287 on tumor thrombosis were further detected by in vivo imaging and HE staining, respectively. The tTF-EG3287 fusion protein was efficiently purified by nickel-affinity chromatography column. Moreover, tTF-EG3287 fusion protein showed strong coagulation a ctivity and specific binding ability to the cell surface of colon cancer. In vivo, tTF-EG3287 stably and persistently accumulated in tumor tissues, and specifically induced mixed thrombus formation in tumor vessels, and then impaired tumor growth (tumor inhibition rate=79.2%, p<0.01). Our data prove that the fusion protein tTF-EG3287 could be used as a novel and promising anti-cancer strategy and has great potential value for clinical applications.