Improved pharmacokinetic and biodistribution properties of the selective urokinase inhibitor PAI-2 (SerpinB2) by site-specific PEGylation: implications for drug delivery.

Abstract

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 PEG20-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 PEG20-PAI-2(C161S) drug conjugates to be further developed as anti-uPA targeted therapeutics with enhanced tumor retention.

• Authors: Kara Lea Vine, Sergei Lobov, Vineesh Indira Chandran, Nathanial Lachlan Ewart Harris, Marie Ranson
• Journal: Pharmaceutical research (Pharm Res) Vol. 32 Issue 3 Pg. 1045-54 (Mar 2015) ISSN: 1573-904X [Electronic] United States
• PMID: 25231010 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Drug Carriers
• Plasminogen Activator Inhibitor 2
• Serine Proteinase Inhibitors
• Polyethylene Glycols

Topics

• Animals
• Antineoplastic Agents (administration & dosage, blood, chemistry, pharmacokinetics)
• Breast Neoplasms (metabolism)
• Cell Line, Tumor
• Chemistry, Pharmaceutical
• Drug Carriers
• Drug Stability
• Female
• Humans
• Injections, Intravenous
• Metabolic Clearance Rate
• Mice, Inbred BALB C
• Mice, Nude
• Models, Molecular
• Mutation
• Plasminogen Activator Inhibitor 2 (administration & dosage, blood, chemistry, genetics, pharmacokinetics)
• Polyethylene Glycols (chemistry)
• Protein Conformation
• Serine Proteinase Inhibitors (administration & dosage, blood, chemistry, pharmacokinetics)
• Technology, Pharmaceutical (methods)
• Tissue Distribution