Objective: To investigate the effect of myrislignan (MYR) on the apoptosis of gastric cancer cell line and its relationship with phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway.
Methods: The gastric cells (SGC-7901) were treated with MYR at different concentrations, i.e., 0, 25, 50, 100, and 200 μmol/L, for 48 h and 72 h and the effect of MYR on the proliferation of SGC-7901 cells was measured by CCK-8 assay. Then, SGC-7901 cells were treated with different concentrations of MYR at 50, 100, and 200 μmol/L for 48 h. Meanwhile, a normal control group and a dimethyl sulfoxide (DMSO) solvent control group (0.1% DMSO) were established. Flow cytometry was used to determine the apoptosis rate of SGC-7901 cells. The protein expression levels of PI3K, AKT, Bcl-2-associated X protein (BAX), cysteine-dependent aspartate-specifc protease-3 (Caspase-3), and Caspase-9 were determined by Western blot. Then, PI3K activator (20 μmol/mL) was used to treat SGC-7901 cells for 48 h in 4 groups, the control group, 0.1% DMSO group, MYR group, and MYR+PI3K activator group, and the effect on MYR's induction of apoptosis and regulation of the protein expression levels of PI3K, AKT, BAX, Caspase-3, and Caspase-9 in SGC-7901 cells.
Results: Compared with the control group, MYR at 50, 100 and 200 μmol/L inhibited the proliferation of gastric cancer cells, increased the apoptosis rate, down-regulated the protein expression levels of PI3K and AKT, and up-regulated the protein expression levels of BAX, Caspase-3, and Caspase-9 in a dose-dependent manner ( P<0.05). However, PI3K activator attenuated MYR-induced apoptosis in gastric cancer cells and MYR's regulation of PI3K, AKT, BAX, Caspase-3, and Caspase-9 protein expression ( P<0.05).
Conclusion: MYR induces the expression of BAX, Caspase-3, and Caspase-9 proteins by inhibiting the PI3K/AKT signaling pathway, thereby promoting the apoptosis of gastric cancer cells.
目的: 探讨肉豆蔻木脂素（myrislignan, MYR）对胃癌细胞凋亡的影响及与磷脂酰肌醇-3-激酶（phosphatidylinositol 3 kinase, PI3K）/蛋白激酶B（protein kinase B, AKT）信号通路的关系。
方法: 采用不同浓度的MYR（即0、25、50、100和200 μmol/L）作用胃癌细胞（SGC-7901）48 h和72 h，CCK8法检测细胞活性。选择MYR（50、100和200 μmol/L）作用胃癌细胞（SGC-7901）48 h，同时设置正常对照（Control）组和溶剂对照（0.1%DMSO）组，采用流式细胞仪检测凋亡率，蛋白质印迹法检测PI3K、AKT、Bcl2关联X蛋白（Bcl-2 associated X protein, BAX）、半胱天冬酶（cysteine-dependent aspartate-specifc protease, Caspase）-3和Caspase-9蛋白的表达水平。特异性PI3K激活剂（20 μmol/mL）作用胃癌细胞（SGC-7901）48 h（分组为：Control组、0.1%DMSO组、MYR组和MYR+PI3K激活剂组），观察其对MYR诱导胃癌细胞凋亡和调控PI3K、AKT、BAX、Caspase-3和Caspase-9蛋白表达的影响。
结果: 与对照组比较，MYR在50、100和200 μmol/L时以剂量依赖关系抑制胃癌细胞增殖，诱导胃癌细胞凋亡，下调PI3K和AKT蛋白表达水平，上调BAX、Caspase-3和Caspase-9蛋白表达水平（P<0.05）。PI3K激活剂减弱了MYR诱导胃癌细胞凋亡和对PI3K、AKT、BAX、Caspase-3和Caspase-9蛋白表达的调控作用（P<0.05）。
结论: 肉豆蔻木脂素通过抑制PI3K/AKT信号通路诱导BAX、Caspase-3和Caspase-9蛋白表达，促进胃癌细胞凋亡。
Keywords: Apoptosis; Myrislignan; PI3K/AKT signaling pathway; Stomach neoplasms.
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