title: 5-Hydroxytryptamine promotes hepatocellular carcinoma proliferation by influencing β-catenin.
abstract: 5-Hydroxytryptamine (5-HT), a neurotransmitter and vasoactive factor, has been reported to promote proliferation of serum-deprived hepatocellular carcinoma (HCC) cells but the detailed intracellular mechanism is unknown. As Wnt/β-catenin signalling is highly dysregulated in a majority of HCC, this study explored the regulation of Wnt/β-catenin signalling by 5-HT. The expression of various 5-HT receptors was studied by quantitative real-time polymerase chain reaction (qPCR) in HCC cell lines as well as in 33 pairs of HCC tumours and corresponding adjacent non-tumour tissues. Receptors 5-HT1D (21/33, 63.6%), 5-HT2B (12/33, 36.4%) and 5-HT7 (15/33, 45.4%) were overexpressed whereas receptors 5-HT2A (17/33, 51.5%) and 5-HT5 (30/33, 90.1%) were reduced in HCC tumour tissues. In vitro data suggests 5-HT increased total β-catenin, active β-catenin and decreased phosphorylated β-catenin protein levels in serum deprived HuH-7 and HepG2 cells compared to control cells under serum free medium without 5-HT. Activation of Wnt/β-catenin signalling was evidenced by increased expression of β-catenin downstream target genes, Axin2, cyclin D1, dickoppf-1 (DKK1) and glutamine synthetase (GS) by qPCR in serum-deprived HCC cell lines treated with 5-HT. Additionally, biochemical analysis revealed 5-HT disrupted Axin1/β-catenin interaction, a critical step in β-catenin phosphorylation. Increased Wnt/β-catenin activity was attenuated by antagonist of receptor 5-HT7 (SB-258719) in HCC cell lines and patient-derived primary tumour tissues in the presence of 5-HT. SB-258719 also reduced tumour growth in vivo. This study provides evidence of Wnt/β-catenin signalling activation by 5-HT and may represent a potential therapeutic target for hepatocarcinogenesis.
authors.affiliation: Lab of Brain and Gut Research, Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Sarwat
authors.initials: S
authors.lastname: Fatima
authors.affiliation: Lab of Brain and Gut Research, Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Shi
authors.affiliation: Lab of Brain and Gut Research, Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; School of Fundamental Medical Science, University of Chinese Medicine, Guangzhou, China.
authors.forename: Zesi
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Lab of Brain and Gut Research, Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; Chongqing Academy of Chinese Materia Medica, Chongqing, 400065, China.
authors.forename: Guo-qing
authors.initials: GQ
authors.lastname: Chen
authors.affiliation: Shen Zhen People's Hospital, Shenzhen, 518020, China.
authors.forename: Xiao-hua
authors.initials: XH
authors.lastname: Pan
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
authors.forename: Justin Che-Yuen
authors.initials: JC
authors.lastname: Wu
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region.
authors.forename: John W
authors.initials: JW
authors.lastname: Ho
authors.affiliation: Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
authors.forename: Nikki P
authors.initials: NP
authors.lastname: Lee
authors.affiliation: Institute of Digestive Disease, Department of Gastroenterology, Tongji Hospital, Tongji University, Shanghai, 200065, China; Shanghai Engineering Center for Molecular Medicine, National Engineering Center for Biochip at Shanghai, Shanghai, 201203, China.
authors.forename: Hengjun
authors.initials: H
authors.lastname: Gao
authors.affiliation: Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Ge
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, 100700, China; School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Aiping
authors.initials: A
authors.lastname: Lu
authors.affiliation: Lab of Brain and Gut Research, Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region. Electronic address: bzxiang@hkbu.edu.hk.
authors.forename: Zhao Xiang
authors.initials: ZX
authors.lastname: Bian
mesh_terms: D000818:Animals; D060466:Axin Protein / Q000378:metabolism; D063646:Carcinogenesis / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D005260:Female; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D010766:Phosphorylation; D010880:Piperidines / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000737:chemistry / Q000378:metabolism*; D000096926:Benzenesulfonamides
chemical_list: D060466:Axin Protein; D019938:Cyclin D1; D005974:Glutamate-Ammonia Ligase; D036341:Intercellular Signaling Peptides and Proteins; D010880:Piperidines; D011985:Receptors, Serotonin; D012701:Serotonin; D012702:Serotonin Antagonists; D013449:Sulfonamides; D051176:beta Catenin; C111309:3,N-dimethyl-N-(1-methyl-3-(4-methylpiperidin-1-yl)propyl)benzenesulfonamide; D000096926:Benzenesulfonamides; C491761:AXIN2 protein, human; C530104:CCND1 protein, human; C495270:CTNNB1 protein, human; C501126:DKK1 protein, human
keywords: 5-HT; SB-258719; Wnt/β-catenin signalling