Study Of Novel Aziridine-Based Brutonís Tyrosine Kinase Inhibitor In Mantle Cell Lymphoma

Nadezhda ROMANCHIKOVA, , Latvia

1 Latvian Institute of Organic Synthesis, Aizkraukles str 21, Riga, LV-1006, Latvia
2 Latvian Biomedical Research and Study Centre, Ratsupites str 1,k-1, Riga, LV-1067, Latvia

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin’s lymphoma showing hyperactive, autonomously growing neoplastic B cells with extended tumor cell survival. Bruton’s tyrosine kinase (BTK), a crucial kinase enzyme in the B-cell antigen receptor (BCR) signaling pathway was emerged as a novel target of MCL therapy. A novel BTK- targeting inhibitor JuSt-23F, which belongs to the class of aziridine-based compound, was prepared. JuSt-23F possessed BTK catalytic activity in vitro with the IC50 value 37,3 µM. As a model for inhibitor testing we have used two mantle cell lymphoma cell lines Mino and Maver-1. WST-8 cytotoxicity assay was explored to determine cytotoxicity and IC50 values were calculated as 32 µM and 37 µM for Mino and Maver-1, respectively. Annexin V-FITC method revealed JuSt-23F - mediated apoptosis selectively in B-lymphoma, but not T lymphoma cells. We detected phosphorylation of p65/RelA on Serine 536 (pNF-kB) in whole Jurkat (T lymphoma), Mino and Maver-1 cells treated with JuSt-23F or untreated after stimulation with tumor necrosis factor alpha (TNF-a). As a result, downregulation of pNF-kB was determined in a dose- depending manner (P <0.001) in TNF-α-induced Mino and Maver-1 cells: 1,6 folds inhibition of pNF-kB in Mino cells and 2,3 folds in Maver-1 cells. We also demonstrated JuSt-23F for mediated inhibition of phosphorylation of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in mantle lymphoma stimulated by phorbol-12-myristate-13-acetate (PMA). Thus, JuSt-23F exerts its activity through targeting of the downstream BTK signaling cascade via NF-kB and ERK1/2 pathways downregulation. Our findings propose a novel aziridine-based BTK inhibitor JuSt-23F as an attractive potential agent for mantle cell lymphoma treatment. We are planning to develop new derivatives with more efficient inhibition of BTK catalytic activity and downstream signaling pathways.