中文摘要：

背景与目的nm23-H1是公认的肿瘤转移抑制基因。我们的前期研究结果发现nm23-H1基因可明显抑制人高转移大细胞肺癌细胞株L9981中细胞外信号调节激酶ERK1／2的活性。本研究旨在探讨肿瘤转移抑制基因nm23-H1及外源性ERK1／2通路抑制剂U0126对人高转移大细胞肺癌细胞株L9981中ERK1／2及其细胞恶性生物学行为的影响，为阐明nm23-H1基因调控肺癌转移相关信号传导通路的分子机制提供实验依据。方法将稳定转染nm23-H1基因的人高转移大细胞肺癌细胞株L9981-nm23-H1、原代细胞株L9981（nm23-H1基因杂合性缺失）和转染空载体细胞株L9981-PLXSN培养传代，应用蛋白印迹法（Western blot）和免疫沉淀法，检测应用U0126（40μmol／L，处理细胞20min）处理后三个肺癌细胞株中总ERK1／2和双磷酸化ERK1／2表达水平的变化；应用MTT法及改良Boyden小室法分别检测三个肺癌细胞株应用U0126处理后细胞体外增殖活性及侵袭能力的变化。结果L9981-nm23-H1细胞株磷酸化ERK1／2表达水平、ERK1／2相对活性经U0126处理后均显著低于L9981和L9981-PLXSN细胞株（P〈0．01），而L9981和L9981-PLXSN细胞株间磷酸化ERK1／2表达水平、ERK1／2相对活性比较均无显著性差异（P〉0．05）；三个肺癌细胞株总ERK1／2水平处理后比较均无明显变化，差异均无显著性（P〉0．05）；L9981-nm23-H1细胞株体外增殖能力及侵袭力均显著低于L9981细胞株和L9981-PLXSN细胞株（P％0．01）；U0126能显著下调L9981细胞株体外增殖活性及侵袭能力（P〈0．01）。结论阻断L9981细胞株中ERK1／2的激活后可发生与转染nm23-H1基因相似的细胞生物学行为的变化，即细胞的体外增殖能力及侵袭力均显著降低，提示nm23-H1基因转染逆转人高转移大细胞肺癌恶性表型的分子机制可能与其下调ERK1／2信号转导通路中关键激酶ERK1／2的活性有关。

英文摘要：

Background and objective nm23-H1 gene is a well-known tumor metastasis suppression gene. Our previous study has found that transfection of wild type nm23-H1 gene can significantly downregulate the ERK1/2 activity of human high-metastatic large cell lung cancer cell line L9981. The aim of this study is to investigate the influence of nm23-H1 and exogenous ERK1/2 pathway inhibitor U0126 on the extracellular signal-regulated kinase （ERK1/2） of human high-metastatic large cell lung cancer cell line L9981 and its malignant biological behaviors. Methods The expressive levels of total-ERK1/2, dually phosphorylated ERK1/2 and ERK1/2 relative activity of the human high-metastatic large cell lung cancer cell lines, L9981 （parent cell line with nm23-H1 gene hetero-deletion）, L9981-nm23-H1 （transfected with nm23-H1 gene ） and L9981-PLXSN （transfected with vector） were detected by Western blot and immunoprecipitation technique after treating with U0126 （40/lmol/L for 20 minutes）. The in vitro proliferative and invasive abilities among the above three lung cancer cell lines were determined by MTT and improved Boyden chamber methods. Results The phosphorylated ERK1/2 expression level and relative activity in L9981-nm23-H1 lung cancer cell line were remarkably lower than those in 1.9981 and L9981-PLXSN lung cancer cell lines after being treated with U0126 （P〈0.01）, but there was no significant difference between 1.9981 and L9981-PLXSN lung cancer cell lines. No significant difference of total ERK1/2 expression level was observed among the three lung cancer cell lines （P〉0.05） after being treated with U0126. The in vitro proliferation and invasion of L9981-nm-23H1 lung cancer cell line were remarkably lower than those of 1.9981 and L9981-PLXSN lung cancer cell lines （P〈0.01）, but no significant difference was found between L9981 and L9981-PLXSN lung cancer cell lines （P〉 0.05）; U0126 could significantly down-regulate the in vitro proliferation and invasion of 1.9981 lung cancer cell lin