Phase II Clinical Trial of Gefitinib for the Treatment of Chemonaïve Patients with Advanced Non-small Cell Lung Cancer with Poor Performance Status

[Clinical Evaluation of A New Pathological Classification for Non-small Cell Lung Cancer Based on Histogenesis of Bronchial Tree]

背景与目的

近年来对肺癌研究的巨大发展，肺癌的病理学分类不断推陈出新。本研究旨在研究和验证非小细胞肺癌（non-small cell lung cancer, NSCLC）组织起源分子病理分类的临床价值和意义。

方法

通过免疫组织化学双染法对105例肺癌标本及正常肺组织进行P63/NapsinA、TTF-1/CK7标记，结合肿瘤免疫特征、组织学特点及正常肺组织的免疫特征，提出了NSCLC组织起源分子病理分类体系，将NSCLC分为支气管上皮癌、细支气管肺泡癌、肺泡细胞癌及分泌腺癌，并分析本分类与表皮生长因子受体（epidermal growth factor receptor, EGFR）突变及临床预后的关系。

结果

本分类体系下不同亚型NSCLC中EGFR突变及其类型具有相对特异性；生存分析表明该分类有助于NSCLC患者预后情况的判断。

结论

本研究提出的基于组织起源的NSCLC分类体系具有较好的临床实用价值。

Gefitinib induces lung cancer cell autophagy and apoptosis via blockade of the PI3K/AKT/mTOR pathway

Gefitinib is a selective inhibitor of the tyrosine kinase epidermal growth factor receptor, which inhibits tumor pathogenesis, metastasis and angiogenesis, as well as promoting apoptosis. Therefore, gefitinib presents an effective drug for the targeted therapy of lung cancer. However, the underlying mechanisms by which gefitinib induces lung cancer cell death remain unclear. To investigate the effects of gefitinib on lung cancer cells and the mechanism of such, the present study analyzed the effect of gefitinib on the autophagy, apoptosis and proliferation of the A549 and A549-gefitinib-resistant (GR) cell lines GR. The regulation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway was also investigated. Acridine orange staining revealed that gefitinib induced autophagy of A549 cells but not A549-GR cells. In addition, gefitinib promoted apoptosis and inhibited proliferation of A549 cells but not A549-GR cells. Furthermore, western blot analysis demonstrated that gefitinib treatment led to the downregulation of PI3K, AKT, pAKT, mTOR and phosphorylated-mTOR protein expression in A549 cells but not A549-GR cells. LY294002 blocked the PI3K/AKT/mTOR pathway and induced autophagy and apoptosis of A549 cells, however, no synergistic effect was observed following combined treatment with gefitinib and LY294002. In conclusion, the results of the present study indicate that gefitinib promotes autophagy and apoptosis of lung cancer cells via blockade of the PI3K/AKT/mTOR pathway, which leads to lung cancer cell death.