Destabilization of ROR1 enhances activity of Ibrutinib against chronic lymphocytic leukemia in vivo. (January 2020)

• Record Type: Journal Article
• Authors: Liu, Zhuojun; Liu, Jia; Zhang, Tianming; Shi, Mingxia; Chen, Xiaofang; Chen, Yun; Yu, Jian
• Is Part Of: Pharmacological research. Volume 151(2020)
• Publication Date: 2020-01
• Subjects: ROR1 Receptor tyrosine kinase-like orphan receptor 1 -- HSP90 Heat Shock Protein 90 -- CLL Chronic Lymphocytic Leukemia -- MCL Mantle Cell Lymphoma -- I.P. Immune Precipitates -- Co-IP Co-immunoprecipitation -- BCR B-cell Receptor -- BTK Bruton's Tyrosine Kinase -- HSP90i HSP90 Inhibitor -- 17-DMAG 17-dimethylamino-geldanamycin -- BLK B-lymphoid Tyrosine Kinase -- LCK Lymphocyte-specific Protein Tyrosine Kinase -- LYN LCK/YES-Related Novel Protein Tyrosine Kinase -- WB Western Blotting -- MFI Mean Fluorescence Intensity -- WT Wild Type -- MU Mutant -- iTARQ Isobaric Tags for Relative and Absolute Quantitation -- GO Gene Ontology -- KEGG Kyoto Encyclopedia of Genes and Genomes; Ibrutinib (PubChem CID: 24821094) -- Acalabrutinib (PubChem CID: 71226662) -- 17-DMAG (PubChem CID: 5288674) -- AUY922 (PubChem CID: 135539077) -- PU-H71 (PubChem CID: 9549213); ROR1 -- HSP90 -- Ibrutinib -- Bruton's tyrosine kinase -- Chronic lymphocytic leukemia; Pharmacology -- Periodicals; Pharmacology -- Periodicals; Research -- Periodicals; Médicaments -- Recherche -- Périodiques; Pharmacologie -- Périodiques; 615.105
• DOI: 10.1016/j.phrs.2019.104512
• Languages: English
• ISSNs: 1043-6618

Abstract

Graphical abstract: Abstract: Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an onco-embryonic antigen presented on chronic lymphocytic leukemia (CLL), but not on normal adult tissues, which promotes CLL-cell survival. Here, ROR1 was identified as a new client of Heat Shock Protein 90 (HSP90) via a mass spectrometry-based screen for ROR1-associated partners followed by co-immunoprecipitation (co-IP) analysis. A binding motif (ELHHPNIV) on ROR1 for HSP90 was revealed, which forms a αC-β4 loop and is necessary for HSP90-facilitated ROR1 stabilization. We also found that targeting HSP90 leads to ROR1 degradation in a ubiquitin-proteasome dependent pathway, by which pro-survival ROR1 signaling was attenuated in CLL. Based on our previous finding that a humanized monoclonal antibody against ROR1 increases the activity of Ibrutinib against CLL, which is currently undergoing evaluation in clinical trials for the treatment of B-cell lymphoid malignancies, we then provided evidence that treatment with HSP90 inhibitor (17-DMAG) enhances anti-CLL activity of Ibrutinib in vitro and in vivo, by down-modulating ROR1. iTRAQ-based quantitative proteomic analysis of other HSP90 oncogenic clients in addition to ROR1, followed by GO/KEGG enrichment analysis, showed that Bruton's Tyrosine Kinase (BTK), B-lymphoid Tyrosine Kinase (BLK), Lymphocyte-specific Protein Tyrosine Kinase (LCK), or LCK/YES-Related Novel Protein Tyrosine Kinase (LYN), as HSP90 clients, were significantly involved in 11 biological processes and 6 signaling pathways. However, immunoblotting validation confirmed that Ibrutinib treatment dramatically deprived HSP90 inhibitors, 17-DMAG, AUY922 or PU-H71, of inducing the degradation of BTK, BLK, LCK or LYN, but not ROR1. Collectively, our data suggested that depletion of ROR1 induced by targeting HSP90 might facilitate the enhancement of Ibrutinib activity against CLL.