Andri Wardiana1, Christopher Howard1,2, Martina Jones1,2, Stephen Mahler* 1, 2

 

1 Australian Institute for Bioengineering and Nanotechnology
Corner College and Cooper Rds (Bldg 75)
The University of Queensland
Brisbane, QLD 4072, Australia

2 ARC Training Centre for Biopharmaceutical Innovation
Corner College and Cooper Rds (Bldg 75)
The University of Queensland
Brisbane, QLD 4072, Australia

 

Prostate cancer continues to be a major health problem and represents the second leading cause of death in men in most developed countries. The detection and treatment of early stage prostate cancer has been well improved; however, there is no effective treatment available for metastatic, castration-resistant prostate cancer. Thus, there is an urgent need for new therapeutics, which can target and directly treat advanced disease. Several biomarkers are ideal targets for monoclonal antibody imaging and therapy such as prostate specific membrane antigen (PSMA) and membrane-bound hepatocellular receptor tyrosine kinase class A2, Ephrin type-A receptor 2 (EphA2). These receptors are overexpressed in several cancers including prostate cancer, which can predict the metastatic stage. In this research, we propose active targeting therapy for prostate cancer treatment utilizing anti-PSMA and anti-EphA2 antibodies. We have engineered two designs utilizing bioconjugation of the antibody fragment and nanomaterials, including bispecific antibody (BsAb) linkage that exhibits dual specificity for methoxy PEG (mPEG) epitopes and prostate cancer target PSMA or EphA2 receptor, and also bioconjugation of a single-chain fragment against anti-PSMA with mPEG through click chemistry reaction utilizing an unnatural amino acid (UAA). The BsAbs J591-mPEG and AGH001-mPEG were successfully expressed in Chinese hamster ovary (CHO) cells. Purification was achieved using HisTrap excel column followed by desalting to remove imidazole for further biological assay purposes. Flow cytometry and ELISA binding analyses showed that the BsAbs bind toward both receptor and polymer targets. In a different expression system, J591 scFv incorporating UAA, p-Azido-L-phenylalanine (pAzF) was expressed in Escherichia coli. Purified Soluble and refolded solubilized scFv were well characterized, including binding studies to prostate cancer cell lines by flow cytometry and detection of incorporation of UAA into scFv. Further studies will involve bioconjugation of antibody-nanomaterials followed by extensive in vitro and in vivo assays for theranostic application.

 

Biographic Details

Name : Andri Wardiana

Title: Mr

Affiliation, Country: Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Australia

Phone: +61 7 3346 3877 Fax: +61 7 3346 3973 E-mail: andri.wardiana@uq.net.au

Research interests: biotherapeutics, nanomedicine