Abstract A148: Developing a baculovirus expression system to evaluate the role of B2-glycoprotein I in anti-tumor cell growth

Abstract

Abstract β2-glycoprotein I (β2-GPI) is a human plasma protein which has been reported to elicit an anti-cell migration effect on human aortic endothelial cells in our previous study. Migration of endothelial cells has been found to be involved in tumorigenesis, however, whether β2-GPI regulates tumor cell growth is unknown. In this study, we investigated the biological effect of β2-GPI on anti-cell migration and proliferation in tumor cells using a baculovirus expression system. Based on Bac-to-Bac Baculovirus Expression system, the cDNA encoding B2-GPI gene has been constructed and cloned into the pFastBac vector with additionally designed sequences, including a Honeybee Melittin Secretion Signal, a dual Flag/StrepII affinity tag and a Tabacco Etch Virus cleavage site at N terminal end and a C-terminal IgG1 Fc fusion protein sequences. This recombinant bacmid DNA containing a complete B2-GPI gene was transfected into insect Sf9 cells to generate recombinant baculovirus. Expression of these chimeric proteins in insect cells resulted in efficient assembly and release of hybrid recombinant B2-GPI protein into cultured media. The fusion proteins containing IgG1-Fc sequences can be purified by the protein A affinity column. Finally, we collected the recombinant B2-GPI in high purity and expression yield. Direct administration of recombinant B2-GPI protein resulted in an effective inhibition of the melanoma cell migration and tumor growth. Development of this baculoviral-based system provides an option for investigation in the anti-tumor cell growth function of B2-GPI in vitro and in vivo. Our study provides a baculoviral-based approach which opens a new perspective for developing B2-GPI as an agent in anti-cancer therapy. Citation Format: Yu-Shan Lin, Shr-Jeng Leu, An-Na Chiang. Developing a baculovirus expression system to evaluate the role of B2-glycoprotein I in anti-tumor cell growth. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A148.