College of Pharmacy and Research Institute of Life and Pharmaceutical Sciences, Sunchon National University, Sunchon, Republic of Korea.
College of Pharmacy and Research Institute of Life and Pharmaceutical Sciences, Sunchon National University, Sunchon, Republic of Korea.
Toxicol In Vitro. 2019 Sep;59:300-311. doi: 10.1016/j.tiv.2019.05.022. Epub 2019 May 30.
Exposure to environmental pollutants is a major public health concern. This study investigated the inflammatory and tumorigenic effects of environmental pollutants (benzene, benzo[a]pyrene, cadmium, and diisononyl phthalate) on transformed A549 and H292 lung alveolar epithelial cells and non-transformed BEAS-2B lung bronchial epithelial cells. The cytotoxic effects of the pollutants were analyzed by the methyl thiazolyl tetrazolium assay. The anchorage-independent soft agar assay demonstrated that treatment with benzene, cadmium, and diisononyl phthalate for 4 weeks induced malignant transformation of BEAS-2B cells and tumorigenesis of A549 and H292 cells. mRNA expression of the inflammation-related genes tenascin-C, matrix metalloproteinase (MMP)-9, and MMP-2, as well as inhibitors of MMPs (TIMP-1 and TIMP-2), was analyzed by RT-PCR. The pollutants largely upregulated expression of MMP-9 and MMP-2, but suppressed expression of their inhibitors TIMP-1 and TIMP-2. Measurement of transepithelial electrical resistance revealed that cadmium and diisononyl phthalate significantly increased cell permeability. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a transcription factor of inflammatory genes, including MMP-9 and MMP-2, while signal transducer and activator of transcription (STAT) 3 is a key regulator of malignant transformation. All the pollutants activated the NF-κB promoter, while only cadmium induced activation of the STAT3 promoter in HEK293T cells. Moreover, all the pollutants increased the phospho-NF-κB level, but only cadmium and diisononyl phthalate increased the phospho-STAT3 level in A549 and BEAS-2B cells. These findings suggest that specific environmental pollutants enhance inflammation, cell permeability, and malignant transformation in lung epithelial cells by activating the oncogenic transcription factors STAT3 and NF-κB.
暴露于环境污染物是一个主要的公共卫生关注点。本研究调查了环境污染物（苯、苯并[a]芘、镉和邻苯二甲酸二异壬酯）对转化的 A549 和 H292 肺肺泡上皮细胞和非转化的 BEAS-2B 肺支气管上皮细胞的炎症和肿瘤形成作用。污染物的细胞毒性作用通过甲基噻唑基四唑测定法进行分析。锚定非依赖性软琼脂测定表明，苯、镉和邻苯二甲酸二异壬酯处理 4 周诱导 BEAS-2B 细胞恶性转化和 A549 和 H292 细胞肿瘤发生。通过 RT-PCR 分析与炎症相关基因腱蛋白-C、基质金属蛋白酶（MMP）-9 和 MMP-2 以及 MMP 抑制剂（TIMP-1 和 TIMP-2）的 mRNA 表达。污染物大量上调 MMP-9 和 MMP-2 的表达，但抑制其抑制剂 TIMP-1 和 TIMP-2 的表达。跨上皮电阻测量显示，镉和邻苯二甲酸二异壬酯显著增加细胞通透性。核因子 kappa-轻链增强子的 B 细胞（NF-κB）是炎症基因，包括 MMP-9 和 MMP-2 的转录因子，而信号转导和转录激活因子（STAT）3 是恶性转化的关键调节剂。所有污染物均激活 NF-κB 启动子，而只有镉在 HEK293T 细胞中诱导 STAT3 启动子激活。此外，所有污染物均增加了磷酸化 NF-κB 水平，但只有镉和邻苯二甲酸二异壬酯增加了 A549 和 BEAS-2B 细胞中磷酸化 STAT3 水平。这些发现表明，特定的环境污染物通过激活致癌转录因子 STAT3 和 NF-κB 来增强肺上皮细胞中的炎症、细胞通透性和恶性转化。
