青龙衣多糖对结肠癌HCT-116细胞增殖、凋亡及PI3K/Akt信号通路的影响

目的:从磷脂酰肌醇3激酶/蛋白激酶B(PI3K/Akt)信号通路方面探讨青龙衣多糖对结肠癌HCT-116细胞增殖、凋亡的影响。方法:青龙衣多糖(10,20,50,100 mg·L-1)处理处于对数生长期的HCT-116细胞,另设空白组,MTS法检测24,48,72,96 h后的细胞增殖抑制率,PI单染法,Annexin-FITC/PI双染法分别检测48 h后细胞周期及细胞凋亡情况,蛋白质免疫印迹(Western blot)法检测48 h后Akt及p-Akt蛋白表达水平。结果:青龙衣多糖对HCT-116细胞的增殖具有明显的抑制作用,呈剂量依赖和时间依赖效应;与空白组比较,各处理组G0/G1期细胞比例增加,S期和G2/M期细胞比例下降,且各质量浓度间的差异具有统计学意义(P0.05);与空白组比较,除10 mg·L-1组外,其余组早期凋亡率均有显著性增加,而各剂量组的晚期凋亡率及总凋亡率均明显升高,且各质量浓度间的凋亡率均具有统计学意义(P0.05);与空白组比较,各给药组p-Akt/Akt明显降低,且各质量浓度间p-Akt/Akt差异具有统计学意义(P0.05)。结论:青龙衣多糖在体外可直接抑制或杀伤人结肠癌HCT-116细胞,具有较强的增殖抑制及诱导凋亡能力,其抗肿瘤机制可能与PI3K/Akt信号通路相关。

Effects of Juglandis Immaturum ExocarpiumPolysaccharide on Proliferation, Apoptosis and PI3K/Akt Signaling Pathway of Human Colon Carcinoma Cell Line HCT-116

Objective: To explore the effects of Juglandis Immaturum Exocarpium polysaccharide(JIP) on the proliferation, apoptosis and phosphatidylinositol 3''-OH kinase/protein kinase B(PI3K/Akt) signaling pathway of human colon carcinoma cell line HCT-116. Method: The HCT-116 cells in logarithmic growth phase were treated with JIP(10, 20, 50, 100 mg·L^-1), and another blank group was set up. The inhibition rates of proliferation at 24, 48, 72, 96 h post-treatment were measured by MTS assay. The cell cycle and apoptosis rate at 48 h post-treatment were detected by PI single staining and Annexin-FITC/PI double staining methods, and the protein levels of Akt and p-Akt at 48 h post-treatment were detected by Western blot assay. Result: JIP presented significant inhibitory effect on HCT-116 cell proliferation in a dose-and time-dependent manner. As compared with the blank group, the cells ratio in G₀/G₁ phase was increased and cells ratio in S phase and G₂/M phase was declined with significant differences in various groups(P<0.05). As compared with the blank group, the early apoptosis rate of JIP in all the groups except 10 mg·L^-1 group was significantly increased, and the apoptosis rate of late phase and total apoptosis rate in various groups were significantly increased with statistical significance(P<0.05). As compared with the blank group, the ratio of p-Akt/Akt was decreased in various treatment groups, and there was statistically significant difference in ratio of p-Akt/Akt between various concentrations(P<0.05). Conclusion: JIP can directly inhibit or kill human colon cells HCT-116 cellsin vitro, and present ability to inhibit proliferation and induce apoptosis. The mechanism might associated with PI3K/Akt signaling pathway.