Objective: To study the effects of myo-inositol and luteolin on human lung cancer A549 cells and explore the possible mechanisms.
Methods: A549 cells were treated with different concentrations of myo-inositol and luteolin, either alone or in combination, and the cell viability was examined using MTT assay. A549 cells and human bronchial epithelial Beas-2B cells were treated for 48 h with 10 mmol/L myo-inositol and 20 μmol/L luteolin, alone or in combination, and the cell proliferation was detected using MTT assay; the colony formation and migration of the cells were examined with colony formation assay and wound healing assay, respectively. The protein expression levels in A549 cells were detected using Western blotting.
Results: Both myo-inositol and luteolin could dose-dependently inhibit the viability of A549 cells. Treatments with 10 mmol/L myo-inositol, 20 μmol/L luteolin, and both for 48 h caused significant reduction in the cell viability (92%, 83% and 70% of the control level, respectively) and colony number (79%, 73% and 43%, respectively), and significantly lowered the wound closure rate (24.61%, 13.08% and 8.65%, respectively, as compared with 29.99% in the control group). Similar treatments with myoinositol and luteolin alone or in combination produced no significant inhibitory effect on the growth, colony formation or migration of Beas-2B cells. The expressions of p-PDK1 and p-Akt in myo-inositol-treated A549 cells and the expression of pPDK1 in luteolin-treated cells were significantly decreased (P < 0.05), and the decrements were more obvious in the combined treatment group (P < 0.05).
Conclusions: Luteolin combined with myo-inositol can selectively inhibit the proliferation and migration of A549 cells, and these effects are probably mediated, at least in part, by suppressing the activation of PDK1 and Akt.
目的: 研究肌醇（MI）和木樨草素（LUT）对人肺腺癌A549细胞的作用，并探讨其机制。
方法: 不同浓度的肌醇和木樨草素处理A549细胞24 h或48 h，MTT法检测细胞活性。10 mmol/L肌醇和20 μmol/L木樨草素单独或共同处理A549细胞和永生化肺支气管上皮细胞Beas-2B 48 h，MTT法、平板克隆形成实验和划痕愈合实验分别检测肌醇和木樨草素对两种细胞活性、细胞克隆形成和迁移的影响，Western blot法检测肌醇和木樨草素对A549细胞中相关蛋白质表达水平的影响。
结果: 肌醇和木樨草素均可抑制A549细胞的活性，且呈浓度依赖性。10 mmol/L肌醇和20 μmol/L木樨草素作用A549细胞48 h后，肌醇处理组、木樨草素处理组和联合处理组A549细胞的活性分别是对照组的92%、83%和70%，平板克隆形成数分别是对照组的79%、73%和43%，划痕愈合度分别为24.61%、13.08%和8.65%，对照组划痕愈合度为29.99%；同等剂量下的肌醇和木樨草素单独或共同处理对Beas-2B细胞的活性、克隆形成和迁移没有明显的抑制作用。与对照组相比，肌醇处理组细胞中p-PDK1和p-Akt以及木樨草素处理组细胞中p-PDK1的蛋白质表达明显减少（P < 0.05），联合处理组下调的幅度更为明显（P < 0.05）。
结论: 肌醇和木樨草素可选择性的抑制A549细胞的活性、克隆形成和迁移，合用时抑制作用更为明显，可能是通过下调p-PDK1和p-Akt的表达发挥的作用。
Keywords: A549 cells; chemoprevention; combined treatment; luteolin; myo-inositol.