Chemically stable inhibitors of 14-3-3 protein–protein interactions derived from BV02

Leire Iralde-Lorente,Ylenia Cau,Letizia Clementi,Lorenzo Franci,Giusy Tassone,Daniela Valensin,Mattia Mori,Adriano Angelucci,Mario Chiariello,Maurizio Botta

doi:10.1080/14756366.2019.1574779

Abstract

14-3-3 are regulatory proteins that through protein–protein interactions (PPI) with numerous binding partners could be involved in several human diseases, including cancer, neurodegenerative disorders, and pathogens infections. Following our research interest in the development of 14-3-3 PPI inhibitors, here we exploited the privileged 4-aminoantipyrine scaffold in the design and synthesis of some derivatives endowed with antiproliferative activity against K-562 cells, and capable of binding to recombinant 14-3-3σ as evidenced by NMR spectroscopy. The binding mode was further explored by molecular modelling, while coupling confocal microscopy with intensitometric analysis showed that compound 1 was able to promote the nuclear translocation of c-Abl at low micromolar concentrations. Overall, 1 is chemically stable compared to parent 14-3-3 PPI inhibitors, and thus emerged as a confirmed hit for further development.

Highlights

14-3-3 is a family of eukaryotic regulatory proteins that interact with a multitude of different targets by means of protein–protein interactions (PPI)
We have previously shown that the BV02 inhibitor of 14-3-3/c-Abl interaction is able to promote c-Abl translocation into the nucleus and to provide antiproliferative effects in chronic myeloid leukaemia (CML) cells expressing the Imatinib-resistant T315I Bcr-Abl construct[8]
Modulation of 14-3-3 proteins is a valuable tool to probe the regulatory functions of eukaryotic cells, and to develop effective therapeutic strategies against a number of human diseases

Summary

Introduction

14-3-3 is a family of eukaryotic regulatory proteins that interact with a multitude of different targets by means of protein–protein interactions (PPI). More than 500 partners of 14-3-3 have been identified through biochemical and bioinformatics studies, most of which are disease-relevant phosphorylated proteins sharing the optimal binding sequence R(X)XpS/TXP1. Expression levels of specific 14-3-3 isoforms might vary in different tissues, organs, or in particular disease conditions, these isoforms share a significantly high degree of sequence and structural conservation[7]. The characterisation of the mechanism of action of BV02 has required a combination of chemical, computational, and spectroscopic studies, which have led to the identification of the phthalimide 9 as the bioactive form of BV02 in physiological conditions, the persistency of 9 was found to be strictly dependent on the pH as well as the incubation time[12]. Interaction with 14-3-3r was monitored by NMR spectroscopy and molecular modelling, while the mechanism of action and anticancer potential were assayed in in vitro cancer cell models

Methods

Results

Conclusion