Heparanase modulation by Wingless/INT (Wnt)

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Heparanase is a key enzyme cleaving heparan sulfate/heparin, influencing cell proliferation, migration, inflammation, and carcinogenesis.
• Heparanase regulation is not fully understood, despite its known inactive 65 kDa precursor and active 50 kDa form.

Purpose of the Study:

• To investigate if heparanase is regulated by its substrate, heparin.
• To elucidate the signaling pathway involved in heparin-mediated heparanase regulation.

Main Methods:

• Chinese hamster ovary (CHO-K1) cells treated with varying doses of heparin.
• Analysis of heparanase expression via Real-time PCR and flow cytometry.
• Measurement of heparanase activity using a biotinylated heparan sulfate-coated plate assay.
• Assessment of Wnt/beta-catenin pathway activation using TCF-driven luciferase activity.
• Validation using lithium chloride to activate the Wnt/beta-catenin pathway in zebrafish embryos and CHO-K1 cells.

Main Results:

• Exogenous heparin treatment significantly increased heparanase mRNA and protein levels in CHO-K1 cells.
• The Wnt/beta-catenin pathway was identified as a key mediator in enhancing heparanase expression upon heparin treatment.
• Lithium chloride treatment confirmed the involvement of the Wnt/beta-catenin pathway in regulating heparanase in vitro and in vivo.

Conclusions:

• Heparin modulates heparanase expression through the Wnt/beta-catenin signaling pathway.
• This study uncovers a novel feedback mechanism where the substrate influences the expression of the enzyme heparanase.
• Understanding this regulation offers potential therapeutic targets for diseases involving heparanase activity.