柴油机废气颗粒潜在致癌作用机制及其细胞毒性观察

摘要

Objective To investigate the potential mechanism of carcinogenesis and cytotoxicity of diesel exhaust par -ticles (DEP) by observing the changes of epidermal growth factor receptor (EGFR), PI3K and AKT when we added DEP into the normal human bronchial epithelial ( HBE) cells.Methods DEP of 0, 50, 100, 200 and 400 μg/ml was added respectively into the studied HBE cells , and the expression change of EGFR was detected by Western blotting and then we chose the most obvious stimulating concentration as the research object .The expression changes of EGFR , PI3K, AKT and p-AKT were detected by Western blotting .The toxicity changes of HBE cells were observed , the cell invasion ability was detected by Transwell , and the cell cycle and apoptosis by flow cytometry .Results The expression of EGFR in HBE cells when treated with 100 μg/ml DEP was significantly higher than that in other concentrations (P<0.05).Western blotting showed that the expression of PI3K, AKT and p-AKT in HBE cells of the treatment group was higher as compared with that of the control group .The cytotoxicity results also showed that , after treating with DEP , the cell cycle of HBE cells was ar-rested in G0/G1 phase, the apoptosis rate was increased and the invasive ability was decreased .Conclusion DEP have specific cytotoxicity , and the increased expression of EGFR may play an important role in the process of lung carcinogenesis coursed by DEP, whose potential mechanism may be related to activation of PI 3K/AKT pathway.%目的：通过柴油机废气颗粒（DEP）作用于正常支气管上皮细胞（HBE），从表皮生长耐受体（EGFR）、磷酸肌醇-3激酶（PI3K）、蛋白激酶B（AKT）的变化探讨柴油机颗粒潜在致癌机制及对细胞毒性影响。方法将DEP以0、50、100、200、400μg/mL加入待测HBE细胞中，用Western blot检测EGFR表达量的变化，从中选择对HBE细胞影响最大的浓度作为研究对象实验组。 Western blot 检测DEP处理后实验组及空白对照组HBE细胞内EGFR、PI3K、AKT及p-AKT的变化。 DEP对细胞毒性的检测，通过Transwell 实验检测细胞侵袭能力，流式细胞术检测细胞周期和凋亡变化。结果加入浓度为100μg/mL的DEP处理后，HBE细胞中EGFR表达量明显高于其他浓度组（P均＜0．05）；Western blot表明，实验组HBE细胞PI3K、AKT及p-AKT的表达量较空白对照组显著上升（P均＜0．05），细胞毒性结果显示，与空白对照组比较，实验组HBE细胞周期阻滞于G0/G1期（P＜0．01），凋亡率增加（P＜0．01），侵袭能力下降。结论 DEP存在确切的细胞毒性，EGFR表达增加可能在DEP导致肺癌变的过程中起到重要作用，其作用机制可能与激活下游PI3 K/AKT通路有关。