皮蛋模拟胃肠道消化物对HepG2细胞的影响

皮蛋是中国传统食品,其水解物具有抗氧化、抗炎和抗癌等功效,具有良好的医学前景,但目前皮蛋发挥抗癌功效的途径及作用机制尚不清楚。探究了皮蛋模拟胃肠道消化物(preserved eggs simulated gastrointestinal digests,PESD)对人肝癌HepG2细胞增殖和细胞周期的影响。将皮蛋经体外模拟胃肠道消化处理后,进行细胞实验,用CCK-8法进行细胞增殖分析,研究PESD对HepG2细胞存活率的影响,采用碘化丙啶(propidium iodide, PI)染色标记的方法,通过流式细胞术测定PESD对HepG2细胞周期的影响,用western blot法测定细胞周期相关调控蛋白的表达。研究发现:PESD以剂量依赖性方式对HepG2细胞增殖进行抑制,IC₅₀为4.17mg/mL；PESD处理显著增加了S期细胞的占比(P<0.05),使HepG2细胞阻滞于S期；4mg/mL的PESD处理HepG2细胞24h后,细胞中cyclin A、cyclin E、ATM、chk2和CDC25A的蛋白表达水平上升(P<0.05),而CDK2蛋白表达水平下降(P<0.05)。研究认为,皮蛋模拟胃肠道消化物是以剂量依赖性的方式来抑制人肝癌HepG2细胞的增殖,主要是通过ATM-chk2-CDC25A信号通路,上调cyclin A和cyclin E蛋白的表达,下调CDK2蛋白的表达来实现人肝癌HepG2细胞阻滞于S期,影响人肝癌HepG2细胞周期进程,抑制癌细胞的增殖。研究结果旨在为皮蛋抗癌作用机制的阐明提供一定的理论基础。

Effect of Preserved Eggs Simulated Gastrointestinal Digests on HepG2 Cells

Preserved egg is a traditional Chinese food, and its hydrolysates possess anti-oxidant, anti-inflammatory and anti-cancer effects, which has promising medical prospects. However, the anti-cancer efficacy and mechanism of preserved egg are still unclear. This study investigated the influence of preserved egg simulated gastrointestinal digests (PESD) on cell proliferation and cell cycle of human hepatocellular carcinoma HepG2 cells. After in vitro digestion treatment of preserved eggs by simulated gastrointestinal tract, a cell experiment was conducted. The CCK-8 method was employed to determine the effect of PESD on cell proliferation. Propidium iodide (PI) staining was used to detect the effect of PESD on HepG2 cells cycle by flow cytometry, and the expression of cell cycle regulatory proteins was determined by western blot. The results showed that the HepG2 cells proliferation was inhibited by PESD in a dose-dependent manner, and the IC₅₀ was 4.17mg/mL. The PESD significantly increased the proportion of cells in S phase (P<0.05), and blocked the cell cycle in S phase. The protein expression levels of cyclin A, cyclin E, ATM, chk2 and CDC25A increased (P<0.05), while the protein expression of CDK2 decreased (P<0.05) after 24h treatment with 4mg/mL PESD. Therefore, it was concluded that PESD could significantly inhibit the proliferation of HepG2 cells in a dose-dependent manner. It could up-regulate the expression of cyclin A and cyclin E protein and down-regulate CDK2 protein expression through the ATM-chk2-CDC25A signaling pathway to block the HepG2 cells cycle in S phase, affect the HepG2 cells cycle progress, and inhibit the proliferation of cancer cells. The results of the study might provide a theoretical basis for the elucidation of the anti-cancer mechanism of preserved eggs.