Design, synthesis, and biological evaluation of trizole-based heteroaromatic derivatives as Bcr-Abl kinase inhibitors

Bcr-Abl is a key driver in the pathophysiology of CML. Broadening the chemical diversity of Bcr-Abl kinase inhibitors to overcome drug resistance is a current medical demand for CML treatment. As a continuation to our research, a series of compounds with heteroaromatics-trizole scaffold as hinge binding moiety (HBM) were developed as Bcr-Abl inhibitors based on in silico modeling analysis. Biological results indicated that these compounds exhibited a significantly enhanced inhibition against Bcr-Abl^WT and Bcr-Abl^T315I in kinases assays, along with improved anti-proliferative activities in leukemia cell assays, compared with previous disclosed compounds. In particular, compounds 9f, 28c, 31, and 44c displayed comparable even better potency with that of Imatinib in enzymatic assay and cell assays including K562 cells and adriamycin-resistant K562/A cells. Moreover, compounds 9f, 28c, and 44c exhibited potent inhibition activities against K562R cells bearing T315I mutant with IC₅₀ of 13.35 μM, 40.14 μM, and 1.91 μM, respectively, outperforming that of Imatinib. Meanwhile, the inhibition of Bcr-Abl activity in Ba/F3 cells demonstrated that these compounds exerted effects mainly by acting on Bcr-Abl. Additionally, compounds 9f, 28c, and 44c effectively induced apoptosis, arrest the cell cycle at S or G₂/M phase, and inhibited phosphorylation of Bcr-Abl and STAT5 in a dose-dependent manner. Docking studies indicated that trizole indeed retained the hydrophobic interaction of aromatic heterocycles with hinge region, and ADME prediction suggested that tested compounds had a favorable safety profile. Therefore, aromatic heterocycles incorporated with trizole could serve as a promising HBM for Bcr-Abl inhibitors with proline as fexibile linker, and compounds 9f, 28c, especially 44c could be served as a starting point for further optimization.