Institute of Toxicology, College of Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing 400038, PR China.
Institute of Toxicology, College of Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing 400038, PR China; College of Public Health and Management, Ningxia Medical University, Yinchuan 750004, PR China.
Sci Total Environ. 2021 Jun 1;771:144839. doi: 10.1016/j.scitotenv.2020.144839. Epub 2021 Jan 23.
3-methylcholanthrene (3-MCA) is a typical representative PAH. It has strong toxicity and is a typical chemical carcinogen. However, the epigenetic mechanisms underlying 3-MCA-induced tumourigenesis are largely unknown. In this study, a model of the 3-MCA-induced malignant transformation of human bronchial epithelial (HBE) cells was established successfully. The profiles of gene expression and DNA methylation and hydroxymethylation were obtained and analysed with an Illumina HiSeq 4000. A total of 707 genes were found to be significantly up-regulated, and 686 genes were found to be significantly down-regulated. Compared to control cells, 8545 mRNA-associated differentially methylated regions and 15,121 mRNA-associated differentially hydroxymethylated regions in promoters were found to be significantly altered in transformed cells. By using mRNA expression and DNA methylation and hydroxymethylation interaction analysis, 99 differentially expressed genes were identified. Among them, CA9 and EGLN3 were verified to be significantly down-regulated, and CARD6 and LCP1 were shown to be significantly up-regulated, and these genes mainly participated in cell growth, migration and invasion, indicating that these genes were key genes involved in the 3-MCA-induced malignant transformation of HBE cells. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that a large number of differentially expressed genes (DEGs) were involved mainly in RNA polymerase II transcription factor activity, chemical carcinogenesis, base-excision repair (BER), cytokine-cytokine receptor interactions, glycerolipid metabolism, steroid hormone biosynthesis, cAMP signalling pathways and other signalling pathways. Our study suggested that characteristic gene alterations associated with DNA methylation and hydroxymethylation could play important roles in environmental 3-MCA-induced lung carcinogenesis.
3-甲基胆蒽（3-MCA）是一种典型的多环芳烃（PAH），具有较强的毒性，是一种典型的化学致癌物。然而，3-MCA 诱导肿瘤发生的表观遗传机制在很大程度上尚不清楚。在本研究中，成功建立了 3-MCA 诱导人支气管上皮（HBE）细胞恶性转化的模型。利用 Illumina HiSeq 4000 获得并分析了基因表达和 DNA 甲基化及羟甲基化的图谱。结果发现，707 个基因显著上调，686 个基因显著下调。与对照细胞相比，转化细胞中启动子的 8545 个 mRNA 相关差异甲基化区域和 15121 个 mRNA 相关差异羟甲基化区域发生了显著改变。通过使用 mRNA 表达和 DNA 甲基化及羟甲基化相互作用分析，鉴定出 99 个差异表达基因。其中，CA9 和 EGLN3 被证实显著下调，CARD6 和 LCP1 显著上调，这些基因主要参与细胞生长、迁移和侵袭，表明这些基因是 3-MCA 诱导 HBE 细胞恶性转化的关键基因。基因本体（GO）分析和京都基因与基因组百科全书（KEGG）通路分析表明，大量差异表达基因（DEGs）主要参与 RNA 聚合酶 II 转录因子活性、化学致癌作用、碱基切除修复（BER）、细胞因子-细胞因子受体相互作用、甘油磷脂代谢、甾体激素生物合成、cAMP 信号通路等信号通路。本研究表明，与 DNA 甲基化和羟甲基化相关的特征基因改变可能在环境 3-MCA 诱导的肺癌发生中发挥重要作用。
