5-Hydroxytryptamine promotes hepatocellular carcinoma proliferation by influencing β-catenin
5-Hydroxytryptamine promotes hepatocellular carcinoma proliferation by influencing β-catenin
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DOI：
10.1016/j.molonc.2015.09.008
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发表时间：
2016-02-01
影响因子：
6.6
通讯作者：
Bian, Zhao Xiang
中科院分区：
文献类型：
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作者：
Fatima, Sarwat;Shi, Xiaoke;Bian, Zhao Xiang
5-羟色胺（5-HT）是一种神经递质和血管活性因子，已被报道可促进血清剥夺型肝细胞癌（HCC）细胞的增殖，但其详细的细胞内机制尚不清楚。由于Wnt/ β -catenin信号在大多数HCC中高度失调，本研究探讨了5-HT对Wnt/ β -catenin信号的调节。采用实时定量聚合酶链反应（qPCR）技术，研究了肝癌细胞系以及33对肝癌肿瘤和相应的邻近非肿瘤组织中各种5-HT受体的表达。受体5-HT1D（21/33, 63.6%）、5-HT2B（12/33, 36.4%）和5-HT7（15/33, 45.4%）在HCC肿瘤组织中过表达，而受体5-HT2A（17/33, 51.5%）和5-HT5（30/33, 90.1%）在HCC肿瘤组织中过表达。体外数据显示，与对照组细胞相比，在无血清培养基中，5-HT使血清剥夺的HuH-7和HepG2细胞中总β -连环蛋白、活性β -连环蛋白水平升高，磷酸化β -连环蛋白水平降低。在5-HT处理的血清缺失HCC细胞系中，通过qPCR检测β -catenin下游靶基因Axin2、cydin D1、dickopf -1 （DKK1）和谷氨酰胺合成酶（GS）的表达增加，证实了Wnt/ β -catenin信号通路的激活。此外，生化分析显示5-HT破坏了Axin1/ β -catenin相互作用，这是β -catenin磷酸化的关键步骤。受体5-HT7拮抗剂（SB-258719）在HCC细胞系和患者源性原发肿瘤组织中存在5-HT，可减弱Wnt/ β -连环蛋白活性的增加。SB-258719在体内也能抑制肿瘤生长。这项研究提供了Wnt/ β -连环蛋白信号被5-HT激活的证据，可能代表了肝癌发生的潜在治疗靶点。(C) 2015年欧洲生化学会联合会。Elsevier B.V.版权所有。
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/beta-catenin signalling is highly dysregulated in a majority of HCC, this study explored the regulation of Wnt/beta-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 beta-catenin, active beta-catenin and decreased phosphorylated beta-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/beta-catenin signalling was evidenced by increased expression of beta-catenin downstream target genes, Axin2, cydin 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/beta-catenin interaction, a critical step in beta-catenin phosphorylation. Increased Wnt/beta-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/beta-catenin signalling activation by 5-HT and may represent a potential therapeutic target for hepatocarcinogenesis. (C) 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.