Li J, Zhang Z, Lv L, Qiao H, Chen X, Zou C. A bispecific antibody (ScBsAbAgn-2/TSPO) target for Ang-2 and TSPO resulted in therapeutic effects against glioblastomas.
Biochem Biophys Res Commun 2016;
472:384-91. [PMID:
26898800 DOI:
10.1016/j.bbrc.2016.02.035]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/10/2016] [Indexed: 01/19/2023]
Abstract
Antibody-based targeted therapy of cancers requires the antibody targeting of specific molecules inducing tumor cells apoptosis or death. Angiopoietin-2 (Agn-2) and translocator protein (TSPO) are identified as potential target molecules for glioblastoma therapy. The single chain anti-Agn-2 antibody (Anag-2) and anti-TSPO antibody (ATSPO) were obtained by monoclonal antibody screening. In the present study, for specific targeting and killing, we generated a recombinant bispecific antibody comprising a single-chain Fragment variable (ScFv) of anti-human Agn-2 and anti-human TSPO (ScBsAbAgn-2/TSPO), which is the mediator for mitochondrial apoptosis and tumor angiogenesis. In vitro, ScBsAbAgn-2/TSPO simultaneously bounded to both targets with a high antigen-binding affinity to Anag-2 and TSPO compared to the individual antibody. The higher expression of Ang-2 and TSPO was observed in bevacizumab-treated glioblastoma compared to normal rat brain endothelium. We also observed apoptosis-mediated cytotoxicity was improved, which resulted in the elimination of up to 90% of the target cells within 72 h. ScBsAbAgn-2/TSPO inhibited tumor growth, decreased vascular permeability, led to extended survival, improved pericyte coverage, depletion of tumor-associated macrophages, and increased numbers of intratumoral T lymphocytes infiltration in a murine bevacizumab-treated glioblastoma model. These findings were also confirmed ex vivo using glioblastoma cells from bevacizumab-treated rats with glioblastoma. We conclude that ScBsAbAgn-2/TSPO targeting of glioblastoma cell lines can be achieved in vitro and in vivo that the efficient elimination of glioblastoma cells supports the potential of ScBsAbAgn-2/TSPO as a potent, novel immunotherapeutic agent.
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