Hydrogen peroxide inducible clone-5 mediates reactive oxygen species signaling for hepatocellular carcinoma progression.

// Jia-Ru Wu 1 , Chi-Tan Hu 3 , Ren-In You 2 , Siou-Mei Pan 3 , Chuan-Chu Cheng 2 , Ming-Che Lee 4 , Chao-Chuan Wu 5 , Yao-Jen Chang 5 , Shu-Chuan Lin 3 , Chang-Shan Chen 2 , Teng-Yi Lin 6 , Wen-Sheng Wu 2 1 Institute of Medical Sciences, College of Medicine, Tzu Chi University, Hualien, Taiwan 2 Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan 3 Research Centre for Hepatology, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan 4 Department of Surgery, Buddhist Tzu Chi General Hospital, School of Medicine, Tzu Chi University, Hualien, Taiwan 5 Department of Surgery, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, School of Medicine, Tzu Chi University, Hualien, Taiwan 6 Department of Laboratory Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan Correspondence to: Wen-Sheng Wu, e-mail: wuwstcu1234@yahoo.com.tw Keywords: HGF, paxillin, metastasis, JNK, migration Received: April 18, 2015      Accepted: September 11, 2015      Published: September 22, 2015 ABSTRACT One of the signaling components involved in hepatocellular carcinoma (HCC) progression is the focal adhesion adaptor paxillin. Hydrogen peroxide inducible clone-5 (Hic-5), one of the paralogs of paxillin, exhibits many biological functions distinct from paxillin, but may cooperate with paxillin to trigger tumor progression. Screening of Hic-5 in 145 surgical HCCs demonstrated overexpression of Hic-5 correlated well with intra- and extra-hepatic metastasis. Hic-5 highly expressed in the patient derived HCCs with high motility such as HCC329 and HCC353 but not in the HCCs with low motility such as HCC340. Blockade of Hic-5 expression prevented constitutive migration of HCC329 and HCC353 and HGF-induced cell migration of HCC340. HCC329Hic-5(-), HCC353Hic-5(-), HCC372Hic-5(-), the HCCs stably depleted of Hic-5, exhibited reduced motility compared with each HCC expressing Scramble shRNA. Moreover, intra/extrahepatic metastasis of HCC329Hic-5(-) in SCID mice greatly decreased compared with HCC329Scramble. On the other hand, ectopic Hic-5 expression in HCC340 promoted its progression. Constitutive and HGF-induced Hic-5 expression in HCCs were suppressed by the reactive oxygen species (ROS) scavengers catalase and dithiotheritol and c-Jun N-terminal kinase (JNK) inhibitor SP600125. On the contrary, depletion of Hic-5 blocked constitutive and HGF-induced ROS generation and JNK phosphorylation in HCCs. Also, ectopic expression of Hic-5 enhanced ROS generation and JNK phosphorylation. These highlighted that Hic-5 plays a central role in the positive feedback ROS-JNK signal cascade. Finally, the Chinese herbal derived anti-HCC peptide LZ-8 suppressed constitutive Hic-5 expression and JNK phosphorylation. In conclusion, Hic-5 mediates ROS-JNK signaling and may serve as a therapeutic target for prevention of HCC progression.