Oncogenic function of the homeobox A13-long noncoding RNA HOTTIP-insulin growth factor-binding protein 3 axis in human gastric cancer

Abstract

// Sophie S.W. Wang 1, 2 , Kenly Wuputra 3 , Chung-Jung Liu 1, 2 , Yin-Chu Lin 4 , Yi-Ting Chen 5 , Chee-Yin Chai 5 , Chen-Lung Steve Lin 3, 6 , Kung-Kai Kuo 6 , Ming-Ho Tsai 3 , Shin-Wei Wang 1, 2 , Ker-Kong Chen 4 , Hiroyuki Miyoshi 7 , Yukio Nakamura 8 , Shigeo Saito 9, 10 , Tadashi Hanafusa 11 , Deng-Chyang Wu 1, 2, 12, 13, 14 , Chang-Shen Lin 3, 15 , Kazunari K. Yokoyama 2, 3, 16, 17, 18 1 Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan 2 Center for Stem Cell Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan 3 Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan 4 School of Dentistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan 5 Department of Pathology, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan 6 Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan 7 Department of Physiology, Keio University School of Medicine, Shinanomachi, Tokyo 160-8582, Japan 8 Cell Engineering Division, BioResource Center, RIKEN, Tsukuba, Ibaraki 305-0074, Japan 9 School of Science and Engineering, Teikyo University, Utsunomia, Tochigi 329-2192, Japan 10 Saito Laboratory of Cell Technology, Yaita, Tochigi 329-2192, Japan 11 Advanced Science Research Center, Okayama University, Okayama, Okayama 700-8558, Japan 12 Department of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan 13 Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 807, Taiwan 14 Center of Infectious Disease and Cancer Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan 15 Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan 16 Center of Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan 17 Faculty of Science and Engineering, Tokushima Bunri University, Sanuki 763-2193, Japan 18 Department of Molecular Preventive Medicine, Graduate School of medicine, The University of Tokyo, Tokyo 113-0033, Japan Correspondence to: Chang-Shen Lin, email: changshen.lin@gmail.com Kazunari K Yokoyama, email: kazu@kmu.edu.tw Keywords: gastric cancer cells, HOTTIP, HoxA13, IGFBP-3, p53-E2F signaling Received: January 30, 2016      Accepted: April 11, 2016      Published: April 29, 2016 ABSTRACT To study the mechanisms of gastric tumorigenesis, we have established CSN cell line from human normal gastric mucosa, and CS12, a tumorigenic and invasive gastric cancer cell line from CSN passages. Many stem cell markers were expressed in both CSN and CS12 cells, but LGR5 and NANOG were expressed only in CS12 cells. Increased expression of homeobox A13 (HoxA13) and its downstream cascades was significant for the tumorigenic activity of CS12 cells, and was associated with recruitment of E2F-1 to HoxA13 promoter accompanied with increased trimethylation of histone H3 lysine 4 (H3K4me3) at the hypomethylated E2F motifs. Knockdown of HoxA13 caused the downregulation of long non-coding RNA HOTTIP and insulin growth factor-binding protein 3 (IGFBP-3) genes, indicating that both were targets of HoxA13. Concurrent regulation of HoxA13-HOTTIP was mediated by the mixed lineage leukemia-WD repeat domain 5 complex, which caused the trimethylation of H3K4 and then stimulated cell proliferation. HoxA13 transactivated the IGFBP-3 promoter through the HOX-binding site. Activation of IGFBP-3 stimulated the oncogenic potential and invasion activity. Increased expression of HoxA13 (63.2%) and IGFBP-3 (28.6%) was detected in human gastric cancer tissues and was found in the gastric cancer data of The Cancer Genome Atlas. Taken together, the HoxA13–HOTTIP–IGFBP-3 cascade is critical for the carcinogenic characteristics of CS12 cells.