An anticancer C-Kit kinase inhibitor is reengineered to make it more active and less cardiotoxic
Ariel Fernández, … , Anil K. Sood, Gabriel Lopez-Berestein
Ariel Fernández, … , Anil K. Sood, Gabriel Lopez-Berestein
Published December 3, 2007
Citation Information: J Clin Invest. 2007;117(12):4044-4054. https://doi.org/10.1172/JCI32373.
View: Text | PDF | Corrigendum
Technical Advance

An anticancer C-Kit kinase inhibitor is reengineered to make it more active and less cardiotoxic

Abstract

Targeting kinases is central to drug-based cancer therapy but remains challenging because the drugs often lack specificity, which may cause toxic side effects. Modulating side effects is difficult because kinases are evolutionarily and hence structurally related. The lack of specificity of the anticancer drug imatinib enables it to be used to treat chronic myeloid leukemia, where its target is the Bcr-Abl kinase, as well as a proportion of gastrointestinal stromal tumors (GISTs), where its target is the C-Kit kinase. However, imatinib also has cardiotoxic effects traceable to its impact on the C-Abl kinase. Motivated by this finding, we made a modification to imatinib that hampers Bcr-Abl inhibition; refocuses the impact on the C-Kit kinase; and promotes inhibition of an additional target, JNK, a change that is required to reinforce prevention of cardiotoxicity. We established the molecular blueprint for target discrimination in vitro using spectrophotometric and colorimetric assays and through a phage-displayed kinase screening library. We demonstrated controlled inhibitory impact on C-Kit kinase in human cell lines and established the therapeutic impact of the engineered compound in a novel GIST mouse model, revealing a marked reduction of cardiotoxicity. These findings identify the reengineered imatinib as an agent to treat GISTs with curbed side effects and reveal a bottom-up approach to control drug specificity.

Authors

Ariel Fernández, Angela Sanguino, Zhenghong Peng, Eylem Ozturk, Jianping Chen, Alejandro Crespo, Sarah Wulf, Aleksander Shavrin, Chaoping Qin, Jianpeng Ma, Jonathan Trent, Yvonne Lin, Hee-Dong Han, Lingegowda S. Mangala, James A. Bankson, Juri Gelovani, Allen Samarel, William Bornmann, Anil K. Sood, Gabriel Lopez-Berestein

×

Figure 1

Comparison of de-wetting propensities of major imatinib targets and drug redesign dictated by de-wetting differences.

Options: View larger image (or click on image) Download as PowerPoint
Comparison of de-wetting propensities of major imatinib targets and drug...
(A) De-wetting propensities of C-Kit residues in contact with imatinib (PDB.1T46; green bars) and of aligned residues in Bcr-Abl kinase (PDB.1FPU; red bars) and Lck (PDB.3LCK; black bars). Residue i is in contact with the ligand if an atom of the latter lies within its domain, D(i) (see Methods). The de-wetting propensity is quantified by the mean residence time of solvating water molecules. Error bars denote Gaussian dispersion over 5 molecular dynamics runs. (B) Pattern of de-wetting hot spots that arise as backbone hydrogen-bonded residues in C-Kit kinase (ribbon backbone representation in light blue; de-wetting hot spots in green), aligned with Bcr-Abl kinase (magenta backbone; de-wetting hot spots in red). The imatinib methylation site leading to the expulsion of water from C-Kit C673-G676 de-wetting hot spot is highlighted (yellow rectangle). Imatinib is thus modified to favorably expel interfacial water molecules from the C-Kit microenvironment, a feature not conserved in Bcr-Abl. Hydrogen bonds are represented as segments joining α-carbons of the paired residues, and those lacking the propensity for dehydration are shown as light gray segments. Residues from the C-Kit chain are labeled in green, and those from Bcr-Abl are labeled in white. (C) Differences in de-wetting hot spots upon alignment of C-Kit (light blue backbone; hot spots in green) and Lck kinase (gold backbone; hot spots in black). Labels for Lck residues are shown in white. (D) Prototype molecule WBZ_4 (N-{5-[4-(4-methyl piperazine methyl)-benzoylamido]-2-methylphenyl}-4-[3-(4-methyl)-pyridyl]-2-pyrimidine amine). The added methyl group is indicated in red.