Hepatoma-derived growth factor/nucleolin axis as a novel oncogenic pathway in liver carcinogenesis

// San-Cher Chen 1, * , Tsung-Hui Hu 2, * , Chao-Cheng Huang 3 , Mei-Lang Kung 4 , Tian-Huei Chu 5 , Li-Na Yi 2 , Shih-Tsung Huang 6 , Hoi-Hung Chan 7 , Jiin-Haur Chuang 8 , Li-Feng Liu 9 , Han-Chung Wu 6, 10 , Deng-Chyang Wu 11 , Min-Chi Chang 12 , Ming-Hong Tai 1, 5, 6 1 Center for Neuroscience, National Sun Yat-Sen University, Kaohsiung 804, Taiwan 2 Division of Hepato-Gastroenterology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung 833, Taiwan 3 Department of Pathology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung 833, Taiwan 4 Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 804, Taiwan 5 Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan 6 Graduate Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan 7 Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan 8 Department of Pediatric Surgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung 833, Taiwan 9 Department of Biological Science & Technology, I-Shou University, Kaohsiung 840, Taiwan 10 Institute of Cellular and Organismic Biology and Genomics Research Center, Academia Sinica, Taipei 115, Taiwan 11 Center for Stem Cell Research and Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan 12 Division of Colorectal Surgery, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan * These authors have contributed equally to this work Correspondence to: Min-Chi Chang, e-mail: smartzhang0205@gmail.com Ming-Hong Tai, e-mail: minghongtai@gmail.com Keywords: hepatoma-derived growth factor, nucleolin, hepatocellular carcinoma, tumour progression Received: September 15, 2014      Accepted: April 07, 2015      Published: April 17, 2015 ABSTRACT Hepatoma-derived growth factor (HDGF) overexpression is involved in liver fibrosis and carcinogenesis. However, the receptor(s) and signaling for HDGF remain unclear. By using affinity chromatography and proteomic techniques, nucleolin (NCL) was identified and validated as a HDGF-interacting membrane protein in hepatoma cells. Exogenous HDGF elicited the membrane NCL accumulation within 0.5 hour by protein stabilization and transcriptional NCL upregulation within 24 hours. Blockade of surface NCL by antibodies neutralization potently suppressed HDGF uptake and HDGF-stimulated phosphatidylinositol 3-kinase (PI3K)/Akt signaling in hepatoma cells. By using rescectd hepatocellular carcinoma (HCC) tissues, immunohistochemical analysis revealed NCL overexpression was correlated with tumour grades, vascular invasion, serum alpha-fetoprotein levels and the poor survival in HCC patients. Multivariate analysis showed NCL was an independent prognostic factor for survival outcome of HCC patients after surgery. To delineate the role of NCL in liver carcinogenesis, ectopic NCL overexpression promoted the oncogenic behaviours and induced PI3K/Akt activation in hepatoma cells. Conversely, NCL knockdown by RNA interference attenuated the oncogenic behaviours and PI3K/Akt signaling, which could be partially rescued by exogenous HDGF supply. In summary, this study provides the first evidence that surface NCL transmits the oncogenic signaling of HDGF and facilitates a novel diagnostic and therapeutic target for HCC.