Identification of Novel Class of Triazolo-Thiadiazoles as Potent Inhibitors of Human Heparanase and their Anticancer Activity

C P Baburajeev,Basappa Basappa,Daniel J Mason,Chakrabhavi Dhananjaya Mohan,Andreas Bender,Julian E Fuchs,Shobith Rangappa,Israel Vlodavsky,Uri Barash,Kanchugarakoppal S Rangappa

doi:10.1186/s12885-017-3214-8

Abstract

BackgroundExpression and activity of heparanase, an endoglycosidase that cleaves heparan sulfate (HS) side chains of proteoglycans, is associated with progression and poor prognosis of many cancers which makes it an attractive drug target in cancer therapeutics.MethodsIn the present work, we report the in vitro screening of a library of 150 small molecules with the scaffold bearing quinolones, oxazines, benzoxazines, isoxazoli(di)nes, pyrimidinones, quinolines, benzoxazines, and 4-thiazolidinones, thiadiazolo[3,2-a]pyrimidin-5-one, 1,2,4-triazolo-1,3,4-thiadiazoles, and azaspiranes against the enzymatic activity of human heparanase. The identified lead compounds were evaluated for their heparanase-inhibiting activity using sulfate [35S] labeled extracellular matrix (ECM) deposited by cultured endothelial cells. Further, anti-invasive efficacy of lead compound was evaluated against hepatocellular carcinoma (HepG2) and Lewis lung carcinoma (LLC) cells.ResultsAmong the 150 compounds screened, we identified 1,2,4-triazolo-1,3,4-thiadiazoles bearing compounds to possess human heparanase inhibitory activity. Further analysis revealed 2,4-Diiodo-6-(3-phenyl-[1, 2, 4]triazolo[3,4-b][1, 3, 4]thiadiazol-6yl)phenol (DTP) as the most potent inhibitor of heparanase enzymatic activity among the tested compounds. The inhibitory efficacy was demonstrated by a colorimetric assay and further validated by measuring the release of radioactive heparan sulfate degradation fragments from [35S] labeled extracellular matrix. Additionally, lead compound significantly suppressed migration and invasion of LLC and HepG2 cells with IC50 value of ~5 μM. Furthermore, molecular docking analysis revealed a favourable interaction of triazolo-thiadiazole backbone with Asn-224 and Asp-62 of the enzyme.ConclusionsOverall, we identified biologically active heparanase inhibitor which could serve as a lead structure in developing compounds that target heparanase in cancer.

Highlights

Expression and activity of heparanase, an endoglycosidase that cleaves heparan sulfate (HS) side chains of proteoglycans, is associated with progression and poor prognosis of many cancers which makes it an attractive drug target in cancer therapeutics
The powdered X-ray diffraction (PXRD), Burner- Ememett-Teller (BET) and Scanning Electron microscope patterns of sulphated ceria (SCe) matched with the standard material
In order to synthesize the novel 1,2,4-triazolo-1,3,4-thiadiazoles, we focused on the efficiency of SCe in cyclisation reaction

Summary

Introduction

Expression and activity of heparanase, an endoglycosidase that cleaves heparan sulfate (HS) side chains of proteoglycans, is associated with progression and poor prognosis of many cancers which makes it an attractive drug target in cancer therapeutics. Fibronectin, laminin and several growth factors and cytokines interact with heparan sulfate proteolglycans (HSPGs) in the ECM and cell surface to maintain cellular framework and function [2, 3]. Elevated levels of heparanase are positively correlated with triggered expression of MMP-9, hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) that are entangled with cancer progression [11,12,13]. Together, these and other results critically support the intimate involvement of heparanase in tumor progression and encourage the development of heparanase inhibitors as anti-cancer therapeutics [14,15,16]

Methods

Results

Discussion

Conclusion