Journal Article

Improved Pharmacokinetic and Biodistribution Properties of the Selective Urokinase Inhibitor PAI-2 (SerpinB2) by Site-Specific PEGylation: Implications for Drug Delivery

Lobov, Sergei, Vine, Kara Lea, Ranson, Marie, Harris, Nathanial Lachlan Ewart, Chandran, Vineesh Indira

2015

Overview

Purpose Overexpression of the serine protease urokinase (uPA) is recognised as an important biomarker of metastatic disease and a druggable anticancer target. Plasminogen activator inhibitor type-2 (PAI-2/SerpinB2) is a specific uPA inhibitor with proven potential for use in targeted therapy. However, PAI-2 is rapidly cleared via the renal system which impairs tumor uptake and efficacy. Here we aimed to improve the pharmacological properties of PAI-2 by site-specific PEGylation. Methods Several cysteine to serine substitution mutants were generated for PEGylation with PEG-maleimide (size range 12–30 kDa) and the physico-chemical and biochemical properties of the PEG-PAI-2 conjugates characterised. Radiolabeled proteins were used for evaluation of blood clearance and tissue uptake profiles in an orthotopic breast tumor xenograft mouse model. Results PEGylation of the PAI-2 C161S mutant gave a predominant mono-PEGylated-PAI-2 product (~90%) with full uPA inhibitory activity, despite a significant increase in hydrodynamic radius. Compared to un-PEGylated protein the plasma half-life and AUC for PEG 20 -PAI-2 C161S were significantly increased. This translated to a 10-fold increase in tumor retention after 24 h compared to PAI-2 C161S , an effect not seen in non-target organs. Conclusions Our data underscores the potential for PEG 20 -PAI-2 C161S drug conjugates to be further developed as anti-uPA targeted therapeutics with enhanced tumor retention.

• Publisher: Springer US,Springer Nature B.V
• Subject: Animals / Antineoplastic Agents - administration & dosage / Antineoplastic Agents - blood / Antineoplastic Agents - chemistry / Antineoplastic Agents - pharmacokinetics / Biochemistry / Biomedical and Life Sciences / Biomedical Engineering and Bioengineering / Biomedicine / Breast cancer / Breast Neoplasms - metabolism / Cell Line, Tumor / Chemistry, Pharmaceutical / Drug Carriers / Drug Stability / Female / Humans / Injections, Intravenous / Medical Law / Metabolic Clearance Rate / Metastasis / Mice, Inbred BALB C / Mice, Nude / Models, Molecular / Mutation / Pharmaceutical sciences / Pharmacology/Toxicology / Pharmacy / Plasminogen Activator Inhibitor 2 - administration & dosage / Plasminogen Activator Inhibitor 2 - blood / Plasminogen Activator Inhibitor 2 - chemistry / Plasminogen Activator Inhibitor 2 - genetics / Plasminogen Activator Inhibitor 2 - pharmacokinetics / Polyethylene glycol / Polyethylene Glycols - chemistry / Protein Conformation / Research Paper / Serine Proteinase Inhibitors - administration & dosage / Serine Proteinase Inhibitors - blood / Serine Proteinase Inhibitors - chemistry / Serine Proteinase Inhibitors - pharmacokinetics / Technology, Pharmaceutical - methods / Tissue Distribution