Tumor vessel-specific antibody ScFvH1: Targeting efficiency and anti-tumor ability / 中国肿瘤生物治疗杂志

ABSTRACT

Objective: To investigate the targeting and anti-tumor ability of the tumor vessel-specific antibody ScFvH1 selected from phage-ScFv library, and to discuss the application of the antibody in clinical diagnosis and therapy of cancer. Methods: The ScFvH1 gene was inserted into pET-28a(+)/EGFP vector containing green fluorescent protein(GFP) gene and pTIG-Trx vector containing thioredoxin gene; the products were then expressed in E.coli and purified by using Ni-NTA. Tumor-bearing mice model was established by subcutanuous injection of cervical cancer cell line HeLa. The mice were injected with purified ScFv-EGFP fusion protein through vena caudalis and the GFP signals were observed by fluorescent microscope to evaluate the targeting ability of the antibody. Meanwhile, the mice model also received intratumoral injection of purified ScFv-EGFP fusion protein to evaluate the anti-tumor effect of the antibody. Results: Soluble ScFvH1 gene and ScFvH1-EGFP protein were successfully expressed in E.coli; a single band was showed in SDS-PAGE after the purification by Ni-NTA. We found that ScFvH1-EGFP fusion protein was enriched to tumor tissues, but there was only weak fluorescent signal when EGFP protein was injected. No EGFP signal was observed in the lung of tumor-bearing mice. Tumor inhibition experiment showed that the tumor growth in the antibody treatment group was similar to that of the PBS control group. Conclusion: The tumor vessel-specific antibody ScFvH1 selected from phage-ScFv library can specifically target tumor vessels, but it has no obvious inhibitory effect on tumor growth. Our findings pave a way for antibody in cancer diagnosis and treatment.