Polysaccharide from Phellinus linteus induces S-phase arrest in HepG2 cells by decreasing calreticulin expression and activating the P27kip1-cyclin A/D1/E-CDK2 pathway
Polysaccharide from Phellinus linteus induces S-phase arrest in HepG2 cells by decreasing calreticulin expression and activating the P27kip1-cyclin A/D1/E-CDK2 pathway
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DOI：
10.1016/j.jep.2013.08.028
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发表时间：
2013-10-28
影响因子：
5.4
通讯作者：
Chen, Hua-Ping
中科院分区：
文献类型：
--
作者：
Li, You-Gui;Ji, Dong-Feng;Chen, Hua-Ping
民族药理学相关性：我们之前的研究表明，桑黄 (Mesima) 中的蛋白多糖 P1 对人肝癌细胞 (HepG2) 表现出显着的抗肿瘤活性；然而，其分子机制仍不清楚。本研究旨在深入了解P1针对HepG2细胞的抗肿瘤活性机制。方法：我们在体外和体内研究了P1对HepG2细胞增殖的影响。采用流式细胞术分析细胞周期分布和凋亡情况。通过蛋白质组学分析、实时（RT）-PCR和Western blot来观察HepG2细胞中几种细胞周期控制蛋白的表达。结果：与对照组相比，P1治疗小鼠（200 mg/kg）实体瘤的体积和重量均显着减少。 P1处理的肿瘤中的HepG2细胞显着减少、形状不规则且变小。 P1使荷瘤小鼠的体重略有增加，这表明P1在200mg/kg时对哺乳动物无毒。 P1 还引起 S 期停滞的显着剂量依赖性增加，但在 HepG2 细胞中未观察到细胞凋亡。蛋白质组学分析、RT-PCR和Western blot分析结果显示，P1处理的HepG2细胞（200 μg/ml）中calreticulin、cyclin D1、cyclin E和CDK2的表达显着下调，P27kip1和cyclin A的表达上调。结论：这些结果表明calreticulin表达与P27kip1-cydin的关系密切。 A/D1/E-CDK2 通路参与 P1 诱导的 HepG2 细胞 S 期细胞周期停滞。 (C) 2013 Elsevier Ireland Ltd. 保留所有权利。
Ethnopharmacology relevance: Our previous study showed that the proteoglycan P1 from Phellinus linteus (Mesima) exhibits significant anti-tumor activity against human hepatocellular carcinoma cells (HepG2); however, its molecular mechanism remains unknown. This study aims to provide insights into the mechanism of the anti-tumor activity of P1 against HepG2 cells.Methods: We examined the effects of P1 on HepG2 cell proliferation in vitro and in vivo. Flow cytometry was used to analyze the cell cycle distribution and apoptosis. Proteomic analysis, real-time (RT)-PCR, and Western blot were carried out to observe the expression of several cell cycle control proteins in HepG2 cells.Results: Both the volume and the weight of solid tumors were significantly decreased in P1-treated mice (200 mg/kg) compared with the control. The HepG2 cells in the P1-treated tumors were significantly decreased, irregularly shaped, and smaller. P1 slightly increased the body weight of the tumor-bearing mice, which indicates that P1 is nontoxic to mammals at 200 mg/kg. P1 also caused a significant dose-dependent increase in S phase arrest, but no apoptosis was observed in HepG2 cells. The results of the proteomic analysis, RT-PCR, and Western blot analysis showed that significantly downregulated expression of calreticulin, cyclin D1, cyclin E, and CDK2 and upregulated expression of P27kip1 and cyclin A in the P1-treated HepG2 cells (200 mu g/ml).Conclusion: These results suggest that calreticulin expression and the P27kip1-cydin A/D1/E-CDK2 pathway were involved in P1-induced S-phase cell cycle arrest in HepG2 cells. (C) 2013 Elsevier Ireland Ltd. All rights reserved.