Development of a 1,2,4-Triazole-Based Lead Tankyrase Inhibitor: Part II.

Ruben G G Leenders,Sven T Sowa,Lari Lehtiö,Enya Amundsen-Isaksen,Sjoerd Aertssen,Anita Wegert,Johannes N Smits,Albert Galera-Prat,Shoshy Alam Brinch,Marc Nazaré,Piotr Nieczypor,Jo Waaler,Sudarshan Murthy,Eddy Damen,Stefan Krauss

doi:10.1021/acs.jmedchem.1c01264

Abstract

Tankyrase 1 and 2 (TNKS1/2) catalyze post-translational modification by poly-ADP-ribosylation of a plethora of target proteins. In this function, TNKS1/2 also impact the WNT/β-catenin and Hippo signaling pathways that are involved in numerous human disease conditions including cancer. Targeting TNKS1/2 with small-molecule inhibitors shows promising potential to modulate the involved pathways, thereby potentiating disease intervention. Based on our 1,2,4-triazole-based lead compound 1 (OM-1700), further structure–activity relationship analyses of East-, South- and West-single-point alterations and hybrids identified compound 24 (OM-153). Compound 24 showed picomolar IC50 inhibition in a cellular (HEK293) WNT/β-catenin signaling reporter assay, no off-target liabilities, overall favorable absorption, distribution, metabolism, and excretion (ADME) properties, and an improved pharmacokinetic profile in mice. Moreover, treatment with compound 24 induced dose-dependent biomarker engagement and reduced cell growth in the colon cancer cell line COLO 320DM.

Highlights

Tankyrase 1 and tankyrase 2 (TNKS1/2) are members of the poly(ADP-ribose) polymerase (PARP) family of enzymes that regulate the turnover of specific target proteins through covalently linking the cellular redox metabolite NAD+ to target proteins in a process called poly-ADP-ribosylation (PARylation)
The PAR chain produced in this post-translational modification is subsequently recognized by the E3 ubiquitin ligase ring finger protein 146 (RNF146) leading to polyubiquitination of the PARylated target proteins followed by proteasomal degradation.[1−4] Independent of their catalytic activity, Tankyrase 1 and 2 (TNKS1/2) provides scaffolding functions that are important in the formation of protein complexes.[5−8] TNKS1/2
These compounds block the catalytic domain of TNKS1/2, either by binding with high selectivity to the adenosine binding pocket or by binding to the more conserved nicotinamide pocket

Summary

■ INTRODUCTION

Tankyrase 1 and tankyrase 2 (TNKS1/2) are members of the poly(ADP-ribose) polymerase (PARP) family of enzymes that regulate the turnover of specific target proteins through covalently linking the cellular redox metabolite NAD+ to target proteins in a process called poly-ADP-ribosylation (PARylation). The best compound of this set was selected and further evaluated with respect to early ADME properties, off-target effects, binding affinity in the catalytic pocket of the TNKS2 protein, as well as inhibition of WNT/β-catenin signaling and proliferation in the colon cancer cell line COLO 320DM The results from these experiments culminated in the identification of a new 1,2,4-triazole based lead tankyrase inhibitor. East Quinoxaline Variationsa pubs.acs.org/jmc aThe IC50 values of the compounds of this work were determined with both the TNKS2 biochemical assay (quadruplicates used for each concentration tested, 95% confidence intervals are given in parentheses) and the cellular (HEK293) WNT/β-catenin signaling reporter assay (triplicates used for each concentration tested, T/F-tests were performed for the IC50 curve fitting; all p > 0.95). TPSA aSee Figure 1, Supporting Information. bSee Table 1, Supporting Information. cHighest concentration, 100 μM. dCalculated by DataWarrior v5.5.0

■ CONCLUSIONS

■ ACKNOWLEDGMENTS

■ REFERENCES