Design, Synthesis, and Biological Evaluation of Pyrazolo[3,4-d]pyrimidines Active in Vivo on the Bcr-Abl T315I Mutant

Abstract

Starting from our in-house library of pyrazolo[3,4-d]pyrimidines, a cross-docking simulation was conducted on Bcr-Abl T315I mutant. Among the selected compounds (2a-e), the 4-bromo derivative 2b showed the best activity against the Bcr-Abl T315I mutant. Deeper computational studies highlighted the importance of the bromine atom in the para position of the N1 side chain phenyl ring for the interaction with the T315I mutant. A series of 4-bromo derivatives was thus synthesized and biologically evaluated. Compound 2j showed a good balance of different ADME properties, high activity in cell-free assays, and a submicromolar potency against T315I Bcr-Abl expressing cells. In addition, it was converted into a water-soluble formulation by liposome encapsulation, preserving a good activity on leukemic T315I cells and avoiding the use of DMSO as solubilizing agent. In vivo studies on mice inoculated with 32D-T315I cells and treated with 2j showed a more than 50% reduction in tumor volumes.

Expanding the structural diversity of Bcr-Abl inhibitors: Dibenzoylpiperazin incorporated with 1H-indazol-3-amine

“…The antiproliferative potency was identified in vitro against Bcr-Abl positive K562 cells by using MTT method with imatinib as positive control. 16 In vitro kinase inhibition and antiproliferative potency of all the title compounds were depicted in Table 1.…”

“…Much effort has been devoted to the discovery of ATPcompetitive inhibitors with potency for Bcr-Abl WT and Bcr-Abl T315I [16]. Our strategy for developing Bcr-Abl inhibitors is to incorporate novel HBF and flexible linker with the aim to enhance affinity with hinge region and reduce steric hindrance with side chain of isoleucine.…”

2-Aminothiazolones as Anti-HIV Agents That Act as gp120-CD4 Inhibitors

“…A series of chemical modifications will be performed to introduce polar groups in the part of the molecule exposed to the solvent as well as to increase the binding affinity toward the receptor in agreement with molecular modeling predictions. Furthermore, other strategies to overcome the solubility issue can be pursued, such as the development of prodrugs or liposome encapsulation (44). …”

A cascade screening approach for the identification of Bcr-Abl myristate pocket binders active against wild type and T315I mutant

“…As a continuation of our efforts in the discovery of novel compounds active against the T315I mutant, [11][12][13][14] we became interested in the identification of compounds that could bind the allosteric site of Abl: such compounds could mimic the synergistic effect of GNF-derivatives and ATP-competitive inhibitors but could also switch from the catalytic pocket to the MP depending on the nature of the gatekeeper residue (T315 or I315). To identify compounds with the above behavior, we planned to submit our internal collection of ATP mimetics 11,[15][16] to the following cascade screening approach: 1) high-throughput fluorescence polarization (FP) screening on Abl WT (kinase domain and full-length); 2) docking and molecular dynamics (MD) studies on the MP pocket; 3) kinetic-enzymatic studies on Abl WT and T315I; 4) assays on WT and T315I expressing cells.…”

“…To identify compounds with the above behavior, we planned to submit our internal collection of ATP mimetics 11,[15][16] to the following cascade screening approach: 1) high-throughput fluorescence polarization (FP) screening on Abl WT (kinase domain and full-length); 2) docking and molecular dynamics (MD) studies on the MP pocket; 3) kinetic-enzymatic studies on Abl WT and T315I; 4) assays on WT and T315I expressing cells. Around 200 compounds were initially analyzed for their ability to displace a GNF-2 based tracer (cmpd 1, Figure 2) from the MP using GNF-2 as positive control and C4 N-methyl GNF-2 as negative control 17 via FP assay (experimental details are reported in the Supporting Information).…”