Cyclin G2 suppresses Wnt/β-catenin signaling and inhibits gastric cancer cell growth and migration through Dapper1
Cyclin G2 suppresses Wnt/β-catenin signaling and inhibits gastric cancer cell growth and migration through Dapper1
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Cyclin G2 通过 Dapper1 抑制 Wnt/β-catenin 信号传导并抑制胃癌细胞生长和迁移
DOI：
10.1186/s13046-018-0973-2
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发表时间：
2018-12-14
影响因子：
11.3
通讯作者：
Luo, Yang
中科院分区：
文献类型：
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作者：
Gao, Jinlan;Zhao, Chenyang;Luo, Yang
背景胃癌是最常见的恶性肿瘤之一。细胞周期蛋白G2已被证明与多种类型的肿瘤的发展，但其在胃肿瘤中的潜在机制还不清楚。本研究旨在探讨cyclin G2在胃癌中Wnt/β-catenin信号通路中的作用及其机制。TCGA数据集用于评估细胞周期蛋白G2表达与胃癌预后状况之间的关联。采用MTS法、集落形成法、细胞周期法、创伤愈合法和transwell法检测外源性和内源性cyclin G2对胃癌细胞增殖和迁移的影响。此外，在裸鼠移植瘤模型和转移模型中，用于确定细胞周期蛋白G2对体内胃肿瘤生长和迁移的影响。采用TOPFlash荧光素酶报告基因检测技术，研究cyclin G2表达对Wnt/β-catenin信号通路的影响，并采用免疫印迹、酵母双杂交、免疫沉淀和Duolink原位PLA等方法研究cyclin G2对Wnt/β-catenin信号通路的影响机制。结果胃癌组织中cyclin G2表达水平降低，且与肿瘤大小、迁移能力及低分化状态有关。此外，细胞周期蛋白G2的过表达在体外和体内均减弱肿瘤的生长和转移。Dpr 1是一种与细胞周期蛋白G2相互作用的蛋白质，在细胞周期蛋白G2介导的β-catenin表达抑制中起重要作用。在机制上，细胞周期蛋白G2影响CKI磷酸化Dpr 1的活性，Dpr 1已被证明是一种蛋白质，当未磷酸化时，其充当Wnt/β-连环蛋白信号转导的抑制剂。GSK-3β抑制剂可阻断cyclin G2对胃癌细胞增殖和迁移的抑制作用。结论cyclin G2通过Dapper 1抑制Wnt/β-catenin信号通路，抑制胃癌细胞的增殖和迁移。
BackgroundGastric cancer is one of the most common malignant tumors. Cyclin G2 has been shown to be associated with the development of multiple types of tumors, but its underlying mechanisms in gastric tumors is not well-understood. The aim of this study is to investigate the role and the underlying mechanisms of cyclin G2 on Wnt/β-catenin signaling in gastric cancer.MethodsReal-time PCR, immunohistochemistry and in silico assay were used to determine the expression of cyclin G2 in gastric cancer. TCGA datasets were used to evaluate the association between cyclin G2 expression and the prognostic landscape of gastric cancers. The effects of ectopic and endogenous cyclin G2 on the proliferation and migration of gastric cancer cells were assessed using the MTS assay, colony formation assay, cell cycle assay, wound healing assay and transwell assay. Moreover, a xenograft model and a metastasis model of nude mice was used to determine the influence of cyclin G2 on gastric tumor growth and migration in vivo. The effects of cyclin G2 expression on Wnt/β-catenin signaling were explored using a TOPFlash luciferase reporter assay, and the molecular mechanisms involved were investigated using immunoblots assay, yeast two-hybrid screening, immunoprecipitation and Duolink in situ PLA.Ccng2−/−mice were generated to further confirm the inhibitory effect of cyclin G2 on Wnt/β-catenin signaling in vivo. Furthermore, GSK-3β inhibitors were utilized to explore the role of Wnt/β-catenin signaling in the suppression effect of cyclin G2 on gastric cancer cell proliferation and migration.ResultsWe found that cyclin G2 levels were decreased in gastric cancer tissues and were associated with tumor size, migration and poor differentiation status. Moreover, overexpression of cyclin G2 attenuated tumor growth and metastasis both in vitro and in vivo. Dpr1 was identified as a cyclin G2-interacting protein which was required for the cyclin G2-mediated inhibition of β-catenin expression. Mechanically, cyclin G2 impacted the activity of CKI to phosphorylate Dpr1, which has been proved to be a protein that acts as a suppressor of Wnt/β-catenin signaling when unphosphorylated. Furthermore, GSK-3β inhibitors abolished the cyclin G2-induced suppression of cell proliferation and migration.ConclusionsThis study demonstrates that cyclin G2 suppresses Wnt/β-catenin signaling and inhibits gastric cancer cell growth and migration through Dapper1.