环境多环芳烃调控GSK-3β对胶质瘤发生发展的影响及机制

In recent years, environmental polycyclic aromatic hydrocarbons (PAHs) pollution is going worse. Our preliminary work showed that detectable levels of PAHs in adult Chinese is far more than that in the American population. Therefore the health risks can not be ignored. PAHs are a kind of recognized carcinogens. However, its effects on glioma are rarely reported. We, for the first time, found significant higher PAH-DNA adduct levels in glioma tissue than in normal brain, which provided direct evidences of PAHs on glioma pathogenesis. After exposure to BaP, on of the PAHs, GSK-3β was found to be signicantly highly expressed in the brain tissue of mice using gene microarray. While the relationship between PAHs, GSK-3β, and glioma remains unclear. In this project, firstly, we will explore the correlation between PAHs exposure levels, GSK-3β expression and the development of glioma based on population study. Secondly, we will clarify the regulation of PAHs on GSK-3β in mice exposed to BaP with/without its inhibitor. Thirdly, the biological function of GSK-3β in the development of glioma will be explored. By interpretating the above data comprehensively, the regulatory effects of environmental PAHs on GSK-3β to induce glioma will be illuminated. This study can provide evidences in glioma etiology.

近年环境多环芳烃（PAHs）污染日趋严重，前期工作发现我国成年人体内PAHs检出水平远超美国，故其健康危害不容忽视。PAHs是一类公认致癌物，但其与胶质瘤的发病鲜有报道。我们首次报道了，PAH-DNA加合物含量在正常脑和各级胶质瘤组织存在显著差异，提供了PAHs与胶质瘤发病的直接证据。小鼠BaP染毒后脑基因芯片筛检出差异表达基因GSK-3β。究竟PAHs、GSK-3β、胶质瘤三者之间关系如何，仍不清楚。本研究拟用人群研究分析PAHs内暴露水平，GSK-3β表达，胶质瘤发生发展之间的关联；以小鼠BaP染毒结合抑制剂使用，明确PAHs对GSK-3β表达调控；细胞水平阐明GSK-3β在胶质瘤发生中的生物学功能；综合"人群-动物-细胞"数据，多角度探讨"环境多环芳烃调控GSK-3β对胶质瘤发生发展的影响及其机制"，本研究可为阐明胶质瘤的病因学机制提供理论线索，为胶质瘤的有效防治提供科学依据。

研究对象：探讨糖原合成酶激酶-3（GSK-3β）在人脑胶质瘤自噬的过程中的作用。.方法:利用免疫印迹法检测GSK-3β、p-GSK-3β、LC3、AMPK和m-TOR的蛋白质水平。采用免疫印迹法、免疫荧光和电镜测定自噬水平。过表达Y216A-GSK-3β的神经胶质瘤细胞被用来在体外和体内水平验证功能。.结果:过高的GSK-3β水平能够诱导胶质瘤细胞自噬流增加。过表达的GSK-3β增加了p-GSK-3β(Ser9)和p-GSK-3β(Tyr216)的磷酸化。GSK-3β诱导自噬是由于p-GSK-3β(Ser9)的增加而不是p-GSK-3β(Tyr216)。在此过程中AMPK-ULK1信号通路扮演着重要角色。异位表达p-GSK-3β(Ser9)并不影响细胞凋亡、细胞周期和细胞增殖,但增加了对TMZ的耐药性。通过3-MA抑制自噬之后,TMZ抵抗在 Y216A-GSK-3β过表达胶质瘤细胞中得到逆转。.结论:这些结果表明,p-GSK-3β(Ser9)通过增强AMPK / ULK1依赖性的自噬调节TMZ抵抗，这可能有助于发展基于GSK-3β治疗神经胶质瘤的新方法。