Novel indazole-based small compounds enhance TRAIL-induced apoptosis by inhibiting the MKK7-TIPRL interaction in hepatocellular carcinoma

// Ji-Yong Yoon 1, * , Jeong-Ju Lee 1, * , Sujin Gu 2 , Myoung Eun Jung 2 , Hyun-Soo Cho 1, 4 , Jung Hwa Lim 3, 4 , Soo Young Jun 1, 4 , Jun-Ho Ahn 1 , Ju-Sik Min 1 , Min-Hyuk Choi 1, 4 , Su-Jin Jeon 1, 4 , Yong-Jae Lee 1 , Areum Go 2, 5 , Yun-Jeong Heo 2 , Cho-Rok Jung 3, 4 , Gildon Choi 2, 5 , Kwangho Lee 2, 5 , Moon-Kook Jeon 2 and Nam-Soon Kim 1, 4 1 Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-333, Republic of Korea 2 Bio and Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea 3 Gene Therapy Research Unit, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-333, Republic of Korea 4 Department of Functional Genomics, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea 5 Medicinal Chemistry and Pharmacology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea * Co-first authors Correspondence to: Nam-Soon Kim, email: nskim37@kribb.re.kr Moon-Kook Jeon, email: moteta@krict.re.kr Keywords: TIPRL, apoptosis, HCC, TRAIL sensitizer Received: January 25, 2017      Accepted: September 29, 2017      Published: November 03, 2017 ABSTRACT Hepatocellular carcinoma (HCC) is one of the most malignant tumors. Although various treatments, such as surgery and chemotherapy, have been developed, a novel alternative therapeutic approach for HCC therapy is urgently needed. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a promising anti-cancer agent, but many cancer cells are resistant to TRAIL-induced apoptosis. To help overcome TRAIL resistance in HCC cancer cells, we have identified novel chemical compounds that act as TRAIL sensitizers. We first identified the hit compound, TRT-0002, from a chemical library of 6,000 compounds using a previously developed high-throughput enzyme-linked immunosorbent assay (ELISA) screening system, which was based on the interaction of mitogen-activated protein kinase kinase 7 (MKK7) and TOR signaling pathway regulator-like (TIPRL) proteins and a cell viability assay. To increase the efficacy of this TRAIL sensitizer, we synthesized 280 analogs of TRT-0002 and finally identified two lead compounds (TRT-0029 and TRT-0173). Co-treating cultured Huh7 cells with either TRT-0029 or TRT-0173 and TRAIL resulted in TRAIL-induced apoptosis due to the inhibition of the MKK7-TIPRL interaction and subsequent phosphorylation of MKK7 and c-Jun N-terminal kinase (JNK). In vivo , injection of these compounds and TRAIL into HCC xenograft tumors resulted in tumor regression. Taken together, our results suggest that the identified lead compounds serve as TRAIL sensitizers and represent a novel strategy to overcome TRAIL resistance in HCC.