多环芳烃诱癌过程中端粒酶激活的端粒位置效应机制与相关生物标志

The epidemiological and toxicological studies demonstrate that inhalation of polycyclic aromatic hydrocarbons (PAHs) from occupational and living environments leads to human lung cancer. Although damage of telomere and activation of telomerase signaling pathways are involved in the carcinogenic process induced by PAHs, it remains unclear whether changes in telomere length can activate the telomerase signaling pathways through telomere position effects (TPE) and subsequently initiate the carcinogenesis. This project is proposed to evaluate the conditions of malignant transformation of BEAS-2B cells and 16HBE cells induced by PAHs in vitro, and detect single telomere length induced by PAHs in different generations and draw the telomere damage profile (time, position and length) to screen target telomere; expression levels for hTERT and transcription factors will be detected in order to determine the target genes; through combining these experimental results, the role of TPE will be investigated. Furthermore, single telomere length and the expression of target genes will be detected in human bronchial epithelioid cells and peripheral blood leukocytes of exposure population and lung cancer patient in order to explore biomarkers of damage of target telomere and activation of telomerase in carcinogenesis induced by PAHs. The development of this project will provide new ideas and theoretical basis for the pathogenesis research and disease prevention and control of lung cancer.

流行病学和毒理学研究证明人吸入来自职业环境和生活环境的多环芳烃（PAHs）能够诱发肺癌。PAHs致癌过程中存在端粒损伤和端粒酶信号通路激活现象，其中是否存在端粒位置效应作用机制尚不清楚。该项目拟开展PAHs染毒BEAS-2B细胞和16HBE细胞体外恶性转化实验，检测PAHs染毒后不同代细胞各个端粒长度绘制PAHs诱导端粒损伤图谱（时间、位置、长度）以筛查PAHs的靶端粒；检测端粒酶逆转录酶(hTERT)及相关转录因子表达情况确定端粒酶通路的靶基因；结合上述结果探讨PAHs诱发的端粒酶激活的端粒位置效应作用机制。通过调查PAHs暴露人群和肺癌患者人群支气管上皮细胞和外周血白细胞端粒损伤情况和端粒酶及转录因子的表达水平，筛选PAHs致癌的靶端粒损伤和端粒酶激活生物标志。该项目的开展将为肺癌的发病机理研究和疾病预防控制提供新思路和理论依据。

流行病学和毒理学研究证明人吸入来自职业环境和生活环境的多环芳烃（PAHs）能够诱发肺癌。PAHs致癌过程中存在端粒损伤和端粒酶信号通路激活现象，其中是否存在端粒位置效应作用机制尚不清楚。该项目开展B(a)p急性染毒A549细胞系，转录组测序发现暴露组端粒相关基因TERB1表达量明显降低，同时对差异表达基因进行了KEGG和GO功能富集分析，以便后续实验筛选相关机制和通路。焦炉工人群研究发现PAHs暴露可引起氧化应激、端粒长度缩短以及线粒体DNA拷贝数（mtDNAcn）的降低，TEP1、STING/cGAS、TERT、TNKS、miR-612、miR-145、miR-30a和miR-197基因多态性参与到PAHs致端粒损伤的调节过程，为职业PAHs暴露中易感人群的筛查和保护提供理论依据。此外，基于氧化损伤、端粒损伤和mtDNAcn异常进行PAHs尿代谢物或焦炉逸散物（COEs）累计暴露剂量的剂量-反应关系与基准剂量研究，发现目前我国COEs职业接触限制可能引起端粒损伤，为职业卫生标准的修订提供依据。中介效应分析COEs暴露、总抗氧化能力、端粒长度和mtDNAcn之间的关系，为探索COEs暴露致氧化应激、端粒长度和线粒体损伤的机制提供依据。开发的人外周血中期Q-FISH检测端粒长度可以更精确地测量每个染色体末端的端粒长度，并进行定量分析，该方法对机制研究价值大，不仅可以绘制不同疾病的特征性端粒图谱，还可以用于特定染色体端粒损伤分子机制和通路的研究。筛选与肺癌相关的miRNAs及其易感基因型，为阐明肺癌的发生机制和早期预防提供理论依据，建立原发性肺癌诊断和预后模型，提高肺癌三级预防。