Wang Yadong, Zhai Wenlong, Wang Haiyu, Xia Xiangqun, Zhang Congke
Department of Toxicology, Henan Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China,
Arch Toxicol. 2015 Mar;89(3):451-8. doi: 10.1007/s00204-014-1269-8. Epub 2014 May 22.
Benzo(a)pyrene (BaP) is one of the strongest carcinogens in cigarette smoke, which is an established human carcinogen. Twist, a transcription factor of the basic helix-loop-helix class, is reported to regulate lung cancer metastasis. Evidence has shown that BaP could induce Twist mRNA expression in non-small cell lung cancer (NSCLC) cell line A549 and promote lung adenocarcinoma cell invasion. However, it is unclear whether BaP promotes the migration and invasion of NSCLC cells by Twist modulation. A549 cell was exposed to BaP for different time. MTT assay was applied to assess cell proliferation. Silencing of Twist was done by small interfering RNA. Wound-healing assay was used to evaluate the capability of cell migration. Transwell assay was used to detect the capability of cell invasion. Western blotting and quantitative polymerase chain reaction were used to detect Twist expression. The levels of Twist protein expression and mRNA expression were increased with the treatment of BaP, compared with solvent control. The capability of wound healing of A549 cells was increased in BaP-treated group, compared with solvent control. BaP enhanced the capability of invasion of A549 cells. Twist knockdown could block the migration and invasion of A549 cells induced by BaP treatment. The mRNA levels of Twist were higher in metastatic NSCLC tissue samples than in primary NSCLC tissue samples, and higher levels of Twist mRNA were observed in metastatic NSCLC tissue samples with smoking history than in those with nonsmoking history. BaP treatment could promote the migration and invasion of NSCLC cells by up-regulating Twist expression.
苯并(a)芘（BaP）是香烟烟雾中最强的致癌物之一，它是一种已确定的人类致癌物。Twist是一种碱性螺旋-环-螺旋类转录因子，据报道可调节肺癌转移。有证据表明，BaP可诱导非小细胞肺癌（NSCLC）细胞系A549中Twist mRNA的表达，并促进肺腺癌细胞的侵袭。然而，尚不清楚BaP是否通过调节Twist来促进NSCLC细胞的迁移和侵袭。将A549细胞暴露于BaP不同时间。采用MTT法评估细胞增殖。通过小干扰RNA使Twist沉默。采用伤口愈合试验评估细胞迁移能力。采用Transwell试验检测细胞侵袭能力。采用蛋白质免疫印迹法和定量聚合酶链反应检测Twist表达。与溶剂对照组相比，BaP处理后Twist蛋白表达水平和mRNA表达水平均升高。与溶剂对照组相比，BaP处理组A549细胞的伤口愈合能力增强。BaP增强了A549细胞的侵袭能力。敲低Twist可阻断BaP处理诱导的A549细胞的迁移和侵袭。转移性NSCLC组织样本中Twist的mRNA水平高于原发性NSCLC组织样本，且有吸烟史的转移性NSCLC组织样本中Twist mRNA水平高于无吸烟史的样本。BaP处理可通过上调Twist表达促进NSCLC细胞的迁移和侵袭。
