PI3K/AKT/mTOR/p70S6K通路在人舌鳞癌细胞耐药中的作用

目的:通过抑制舌鳞癌细胞中PI3K/AKT/mTOR/p70S6K信号通路的表达,检测细胞凋亡与自噬的变化,探讨舌鳞癌耐药的机制。方法:以舌鳞癌细胞Cal27与舌鳞癌耐顺铂细胞Cal27/CDDP为研究对象。分别用PI3K/AKT抑制剂LY294002、mTOR抑制剂Rapamycin、p70S6K抑制剂LY2584702作用该通路各个环节。Western blot检测通路抑制剂作用后相关蛋白的变化。Cyto-ID荧光染色检测自噬体的形成。流式细胞术检测细胞凋亡水平。结果:Western blot结果显示加入抑制剂后舌鳞癌细胞Beclin1表达分别高于对照组,LC3II与LC3I以及Bax与Bcl-2的比值均升高,该通路的p-AKT、p-mTOR、p-p70S6K等蛋白均有下降(P<0.05)。流式结果显示加入抑制剂后的舌鳞癌细胞凋亡率分别较对照组升高(P<0.05)。Cyto-ID荧光染色后结果显示加入抑制剂后的舌鳞癌细胞自噬小体的数目明显高于对照组(P<0.05)。对比两组细胞显示加入抑制剂后的Cal27细胞发生凋亡与自噬的水平高于Cal27/CDDP(P<0.05)。结论:抑制PI3K/AKT/mTOR/p70S6K信号通路可诱导舌鳞癌细胞Cal27与舌鳞癌耐顺铂细胞Cal27/CDDP发生凋亡与自噬,激活的PI3K/AKT/mTOR/p70S6K通路抑制细胞凋亡与自噬是Cal27/CDDP细胞产生顺铂耐药的原因之一。

Role of PI3K/AKT/mTOR/p70S6K Pathway in Drug Resistance of Tongue Squamous Cells

Objective: To investigate the role of PI3K/AKT/mTOR/p70S6K signaling pathway in drug resistance of tongue squamous cells. Methods: Tongue squamous cell carcinoma line Cal27 and tongue squamous cell carcinoma cell line Cal27/CDDP with cisplatin resistance were repeatedly treated with the specific inhibitor, LY294002 (PI3K/AKT inhibitor) , Rapamycin (mTOR inhibitor), and LY2584702 (p70S6K inhibitor). Related proteins in PI3K/AKT/mTOR/p70S6K pathway were detected by Western blot. The level of autophagy was detected with Cyto-ID fluorescence staining. Cellular apoptosis was detected by flow cytometry. Results: After applying the pathway inhibitors, the expression level of Beclin1 of the tongue squamous cells were enhanced compared with the control group. Moreover, the ratio of the LC3II to LC3I and the ratio of the Bax to Bcl-2 were increased. The expression of p-AKT, p-mTOR, and p-p70S6K were decreased (P<0.05). The apoptosis and autophagy level were increased in tongue squamous cells, compared with control group. Conclusion: Inhibiting the PI3K/AKT/mTOR/p70S6K signaling pathway shows a significant effect on apoptosis and autophagy in Cal27 and Cal27/CDDP.