中文摘要：

目的调查上皮-间质转化（epithelial-mesenchymal transition,EMT）在非小细胞肺癌（non-small cell lungcancer,NSCLC）患者接受吉非替尼（Gefitinib）治疗反应性中的作用及机制。方法突变富集PCR法检测NSCLC患者EGFR突变状况;免疫组化法检测癌组织中上皮钙粘蛋白（E-cadherin）和纤维连接蛋白（Fibronectin）的表达情况,探讨EMT与表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitors,EGFR-TKIs）治疗敏感性的关系。体外选取人肺腺癌细胞系PC9细胞,经TGF-β1反复处理4周,观察细胞形态学变化;MTT检测TGF-β1处理后细胞对Gefitinib敏感性的影响;Western blot验证EMT相关标记蛋白表达变化并检测EGFR信号通路下游蛋白的变化。结果 43例NSCLC标本中,EGFR 19、21外显子突变率为58.14%（25/43）。具有EGFR基因突变的肿瘤E-cadherin的表达水平显著高于EGFR野生型（70.00%vs 30.00%,P〈0.05）。接受Gefitinib总体有效率为46.51%（20/43）,具有E-cadherin阳性表达的患者治疗反应性明显好于Fibronectin阳性的患者（65.00%vs 30.43%,P〈0.05）。TGF-β1可诱导PC9细胞向间质型细胞形态转化,上调Fibronectin的表达;与亲本PC9细胞相比,TGF-β1处理的细胞对Gefitinib的敏感性下降（P〈0.05）;这种敏感性的下降伴随着AKT和STAT3的持续活化。结论 EMT在EGFR-TKI耐药中发挥着重要作用,TGF-β1诱导的EMT可影响PC9细胞对Gefitinib的敏感性,这种效应可能是通过持续活化AKT和STAT3而发挥作用。

英文摘要：

Objective To clarify the role and mechanism of epithelial-mesenchymal transition（EMT） in the sensitivity of non-small cell lung cancer（NSCLC） patients treated with gefitinib.Methods Epidermal growth factor receptor（EGFR） mutations were detected by mutant-enriched PCR assay,and the expression of E-cadherin and fibronectin were evaluated by immunohistochemistry（IHC）.Cultured PC9 cells were treated with TGF-β1 for 4 weeks,and the morphological changes were observed by phase-contrast microscopy.MTT assay was used to detect the sensitivity of cells to gefitinib.In addition,the expression of EMTrelated marker proteins（E-cadherin and fibronectin） and EGFR downstream signaling molecules（p-ERK,p-AKT and p-STAT3） were assessed by Western blotting.Results EGFR gene mutations were identified in 25 of 43 samples（46.51%）.The frequency of E-cadherin-positive samples was significantly higher in the samples with EGFR mutants than in those with wild-type EGFR（70.00% vs 30.00%,P 0.05）,and the overall response rate to gefitinib was 46.51%（20 /43）.The treatment responsiveness in the E-cadherinpositive patients was significantly higher than that in the fibronectin-positive patients（65.00% vs 30.43%,P 0.05）.TGF-β1 could induce an EMT morphological alteration and up-regulate the expression of fibronectin in PC9 cells.The sensitivity to gefitinib was decreased in the PC9 cells treated with TGF-β1,and the activationof AKT and STAT3 were observed in vitro.Conclusion EMT plays an important role in the resistance to EGFR-tyrosine kinase inhibitors（TKIs）.Induction of EMT by TGF-β1 may contribute to the decreased efficacy of gefitinib therapy through sustaining activation of AKT and STAT3.