Zhang Lu, Li Jun, Hu Jing, Li Dandan, Wang Xiaohui, Zhang Rui, Zhang Hui, Shi Meng, Chen Hong
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Department of Respiratory Medicine, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China.
Lung Cancer. 2017 Jul;109:109-116. doi: 10.1016/j.lungcan.2017.05.011. Epub 2017 May 13.
Epithelial growth factor receptor (EGFR) somatic-mutated non-small cell lung cancer (NSCLC) patients with smoking history always show a poor response to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of the study is to explore the molecular mechanism of EGFR-TKI resistance induced by cigarette smoke extract and investigate the novel anti-resistance strategies.
The effect of cigarette smoke extract (CSE) on gefitinib sensitivity, EGFR signaling, apoptosis and reactive oxygen species (ROS) levels were detected in vitro by MTT assays, western blot, flow cytometry and laser scanning confocal microscope, respectively.
MTT assays presented that CSE claimed antagonistic effect on gefitinib sensitivity via the up-regulated half maximal inhibitory concentration (IC50) values, western blot showed that CSE instigated EGFR, AKT phosphorylation, while N-Acetyl-l-Cysteine (NAC) could alleviate gefitinib resistance and abort the aberrant phosphorylation in both PC-9 and A549 cells. Confocal microscope and flow cytometry displayed that ROS generation increased after CSE exposure in NSCLC cells and this change could be inhibited by NAC.
Cigarette smoke extract induces EGFR-TKI resistance via promoting EGFR signaling and ROS generation in NSCLC cell lines which could be suppressed by NAC. Alternatively, combined NAC with EGFR-TKIs to treat EGFR mutated NSCLC patients with smoking history may be a potential choice in clinical setting.
有吸烟史的表皮生长因子受体（EGFR）体细胞突变的非小细胞肺癌（NSCLC）患者对EGFR酪氨酸激酶抑制剂（EGFR-TKIs）的反应往往较差。本研究旨在探讨香烟烟雾提取物诱导EGFR-TKI耐药的分子机制，并研究新的抗耐药策略。
分别通过MTT法、蛋白质印迹法、流式细胞术和激光扫描共聚焦显微镜在体外检测香烟烟雾提取物（CSE）对吉非替尼敏感性、EGFR信号传导、细胞凋亡和活性氧（ROS）水平的影响。
MTT法显示，CSE通过上调半数最大抑制浓度（IC50）值对吉非替尼敏感性产生拮抗作用；蛋白质印迹法表明，CSE促使EGFR、AKT磷酸化，而N-乙酰半胱氨酸（NAC）可减轻PC-9和A549细胞中的吉非替尼耐药性并消除异常磷酸化。共聚焦显微镜和流式细胞术显示，NSCLC细胞暴露于CSE后ROS生成增加，而这种变化可被NAC抑制。
香烟烟雾提取物通过促进NSCLC细胞系中的EGFR信号传导和ROS生成来诱导EGFR-TKI耐药，而NAC可抑制这种作用。另外，将NAC与EGFR-TKIs联合用于治疗有吸烟史的EGFR突变NSCLC患者可能是临床中的一种潜在选择。
