Journal Article

Novel BET protein proteolysis-targeting chimera exerts superior lethal activity than bromodomain inhibitor (BETi) against post-myeloproliferative neoplasm secondary (s) AML cells

Verstovsek, S, DiNardo, C, Pemmaraju, N, Bhalla, K N, Sun, B, Qiu, P, Rajapakshe, K, Crew, A P, Saenz, D T, Coarfa, C, Crews, C M, Raina, K, Qian, Y, Fiskus, W, Shen, A, Kadia, T M, Nowak, A J, Kim, M-S, Coleman, K G, Manshouri, T, Mill, C P

2017

Overview

The PROTAC (proteolysis-targeting chimera) ARV-825 recruits bromodomain and extraterminal (BET) proteins to the E3 ubiquitin ligase cereblon, leading to degradation of BET proteins, including BRD4. Although the BET-protein inhibitor (BETi) OTX015 caused accumulation of BRD4, treatment with equimolar concentrations of ARV-825 caused sustained and profound depletion (>90%) of BRD4 and induced significantly more apoptosis in cultured and patient-derived (PD) CD34+ post-MPN sAML cells, while relatively sparing the CD34+ normal hematopoietic progenitor cells. RNA-Seq, Reverse Phase Protein Array and mass cytometry ‘CyTOF’ analyses demonstrated that ARV-825 caused greater perturbations in messenger RNA (mRNA) and protein expressions than OTX015 in sAML cells. Specifically, compared with OTX015, ARV-825 treatment caused more robust and sustained depletion of c-Myc, CDK4/6, JAK2, p-STAT3/5, PIM1 and Bcl-xL, while increasing the levels of p21 and p27. Compared with OTX015, PROTAC ARV-771 treatment caused greater reduction in leukemia burden and further improved survival of NSG mice engrafted with luciferase-expressing HEL92.1.7 cells. Co-treatment with ARV-825 and JAK inhibitor ruxolitinib was synergistically lethal against established and PD CD34+ sAML cells. Notably, ARV-825 induced high levels of apoptosis in the in vitro generated ruxolitinib-persister or ruxolitinib-resistant sAML cells. These findings strongly support the in vivo testing of the BRD4-PROTAC based combinations against post-MPN sAML.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 13 / 13/1 / 13/106 / 13/2 / 13/31 / 14 / 14/1 / 14/19 / 14/34 / 38 / 38/91 / 59/5 / 631/67/1059/602 / 631/80/82/23 / 64 / 64/60 / 82/79 / 96 / 96/2 / Acute myeloid leukemia / Animals / Antigens, CD34 / Apoptosis / Apoptosis - drug effects / Azepines - pharmacology / Azepines - therapeutic use / Bcl protein / Bcl-x protein / Bet protein / Biocompatibility / Biomedical materials / c-Myc protein / Cancer Research / CD34 antigen / Cell Cycle Proteins / Cell Line, Tumor / Cells (biology) / Critical Care Medicine / Cyclin-dependent kinase 4 / Cytometry / Degradation / Depletion / Hematology / Hematopoietic stem cells / Humans / In vitro methods and tests / In vivo methods and tests / Inhibitors / Intensive / Internal Medicine / Janus kinase 2 / Leukemia / Leukemia, Myeloid, Acute - drug therapy / Leukemia, Myeloid, Acute - pathology / Medicine / Medicine & Public Health / Mice / mRNA / Myc protein / Myeloproliferative Disorders - pathology / Nitriles / Nuclear Proteins - metabolism / Oncology / original-article / Perturbation / Progenitor cells / Protein arrays / Proteins / Proteolysis / Pyrazoles - pharmacology / Pyrimidines / Ribonucleic acid / RNA / Stat3 protein / Surgical implants / Thalidomide - analogs & derivatives / Thalidomide - pharmacology / Thalidomide - therapeutic use / Transcription Factors - metabolism / Tumor Burden - drug effects / Ubiquitin / Ubiquitin-protein ligase / Ubiquitin-Protein Ligases - metabolism