Gene expression in normal human bronchial epithelial (NHBE) cells following in vitro exposure to cigarette smoke condensate
Gene expression in normal human bronchial epithelial (NHBE) cells following in vitro exposure to cigarette smoke condensate
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DOI：
10.1093/toxsci/kfi179
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发表时间：
2005-07-01
影响因子：
3.8
通讯作者：
Doolittle, DJ
中科院分区：
文献类型：
--
作者：
Fields, WR;Leonard, RM;Doolittle, DJ
燃烧烟草的香烟产生复杂的化学物质混合物，包括诱变剂和致癌物。主要加热烟草的香烟产生的烟雾中诱变剂和致癌物的量显著减少，并在一系列毒理学试验中显示出降低的诱变性和致癌性。化学诱导的氧化应激、DNA损伤和炎症可能改变细胞周期调控，是致癌过程中重要的生物学事件。本研究的目的是表征和比较来自燃烧烟草的香烟和主要加热烟草的香烟的烟雾冷凝物对NHBE细胞中基因表达的影响。为了进行比较，我们使用了定量RT/PCR，并使用流式细胞术进一步评估了对细胞周期的影响。使用FTC机器抽吸条件，由肯塔基州1 R4 F香烟（设计成代表美国市场中的平均全香味、低“焦油”香烟的烟草燃烧产品）和Eclipse（主要加热烟草的香烟）制备香烟烟雾冷凝物（CSC）。与来自Eclipse香烟的CSC相比，来自1 R4 F香烟的CSC诱导响应于DNA损伤（GADD 45）和参与细胞周期调节（p21; WAF 1/CIP 1）的基因的mRNA水平的统计学显著增加。此外，分别与氧化应激和炎症相关的环氧合酶-2（考克斯-2）和白细胞介素8（IL-8）的编码基因在1 R4 F的CSC中的增加在统计学上显著高于Eclipse。此外，IL-8蛋白分泌到细胞培养基中的剂量依赖性增加受到1 R4 F暴露的刺激，而Eclipse处理后分泌的IL-8蛋白最少。基因表达差异效应的生物学相关性反映在差异细胞周期调节中，因为暴露于1 R4 F CSC的细胞比暴露于Eclipse CSC的细胞表现出更显著的S期和G2期蓄积。这些数据表明，与代表性的烟草燃烧香烟相比，烟草加热Eclipse香烟的简化烟雾化学在正常人支气管上皮细胞中参与DNA损伤、氧化应激、炎症反应和细胞周期调节的关键基因的表达方面产生统计学显著的降低。
Cigarettes that burn tobacco produce a complex mixture of chemicals, including mutagens and carcinogens. Cigarettes that primarily heat tobacco produce smoke with marked reductions in the amount of mutagens and carcinogens and demonstrate reduced mutagenicity and carcinogenicity in a battery of toxicological assays. Chemically induced oxidative stress, DNA damage, and inflammation may alter cell cycle regulation and are important biological events in the carcinogenic process. The objective of this study was to characterize and compare the effects of smoke condensates from cigarettes that burn tobacco and those that primarily heat tobacco on gene expression in NHBE cells. For this comparison, we used quantitative RT/PCR and further evaluated the effects on cell cycling using flow cytometry. Cigarette smoke condensates (CSCs) were prepared from Kentucky 1R4F cigarettes (a tobacco-burning product designed to represent the average full-flavor, low "tar" cigarette in the US market) and Eclipse (a cigarette that primarily heats tobacco) using FTC machine smoking conditions. The CSC from 1R4F cigarettes induced statistically significant increases in the mRNA levels of genes responsive to DNA damage (GADD45) and involved in cell cycle regulation (p21;WAF1/CIP1), compared to the CSC from Eclipse cigarettes. In addition, genes coding for cyclooxygenase-2 (COX-2) and interleukin 8 (IL-8), which are associated with oxidative stress and inflammation, respectively, were increased statistically significantly more by CSC from 1R4F than by that from Eclipse. Furthermore, a dose-dependent increase in IL-8 protein secretion into cell culture media was stimulated by 1R4F exposure, whereas minimal IL-8 protein was secreted after Eclipse treatment. The biological relevance of the differential effect on gene expression was reflected in differential cell cycle regulation, as cells exposed to 1R4F CSC exhibited more significant S phase and G2 phase accumulation than cells exposed to Eclipse CSC. These data indicate that the simplified smoke chemistry of the tobacco-heating Eclipse cigarette yields statistically significant reductions in the expression of key genes involved in DNA damage, oxidative stress, inflammatory response, and cell cycle regulation in normal human bronchial epithelial cells compared to a representative tobacco-burning cigarette.