c-Jun-NH₂-kinase-1 inhibition leads to antitumor activity in ovarian cancer

Purpose: To show the functional, clinical, and biological significance of c-Jun-NH₂-kinase (JNK)-1 in ovarian carcinoma. Experimental Design: Analysis of the impact of JNK on 116 epithelial ovarian cancers was conducted. The role of JNK in vitro and in experimental models of ovarian cancer was assessed. We studied the role of N-5-[4-(4-methyl piperazine methyl)-benzoylamido]-2-methylphenyl-4-[3-(4-methyl)-pyridyl]-2-pyrimidine amine (WBZ-4), a novel JNK inhibitor redesigned from imatinib based on targeting wrapping defects, in cell lines and in experimental models of ovarian cancer. Results: We found a significant association of pJNK with progression-free survival in the 116 epithelial ovarian cancers obtained at primary debulking therapy. WBZ-4 led to cell growth inhibition and increased apoptosis in a dose-dependent fashion in four ovarian cancer cell lines. In vivo, whereas imatinib had no effect on tumor growth, WBZ-4 inhibited tumor growth in orthotopic murine models of ovarian cancer. The antitumor effect was further increased in combination with docetaxel. Silencing of JNK-1 with systemically administered siRNA led to significantly reduced tumor weights compared with nonsilencing siRNA controls, indicating that indeed the antitumor effects observed were due to JNK-1 inhibition. Conclusions: These studies identify JNK-1 as an attractive therapeutic target in ovarian carcinoma and that the redesigned WBZ-4 compound should be considered for further clinical development.