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.
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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

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Figure 7

Comparison of inhibitory impact of imatinib and WBZ_4 on cell proliferation.

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Comparison of inhibitory impact of imatinib and WBZ_4 on cell proliferat...
(A) Cell proliferation assay for GIST882 cells. WBZ_4 inhibits cell proliferation of C-Kit–positive ST882 cells. GIST cancer cells ST882 (GIST882) were seeded in 96-well plates at a density of 8 × 103 cells per well. The cells were treated with various concentrations of WBZ_4 (red) and imatinib (light blue) for an additional 48 hours. Cell proliferation was determined by Alamar blue assay (see Methods). Cell proliferation is expressed as the percentage of proliferating cells relative to untreated cells. The WBZ_4 compound was incorporated into liposomes (see Methods) to facilitate cellular delivery. (B) Cell proliferation assay for K562 cells. WBZ_4 does not significantly inhibit cell proliferation of Bcr-Abl–expressing K562 cells. K562 cells were seeded in 96-well plates at a density of 1 × 104 cells per well in 50 μl of medium. Two hours later, 50 μl medium containing different concentrations (0.01, 0.1, 1 μM) of liposome-encapsulated WBZ_4 (red) or soluble imatinib (light blue) were added to the wells to reach a final volume of 100 μl per well. Following 48 hours of exposure, the Alamar blue assay was performed (see Methods). Plates were read at dual wavelength (570 and 595 nm) in an ELISA plate reader.