多环芳烃通过AhR调控OPN触发EMT在脑胶质瘤侵袭、迁移中的作用机制研究

With the environment seriously polluted by polycyclic aromatic hydrocarbon (PAH), it can’t be ignored for health effects. We have already confirmed that there are statistically significant differences between normal brain and gliomas grades 1-4. PAHs can facilitate the invasion and migration of gliomas and promote EMT in gliomas. Our preliminary experiment verified the association between EMT and activated AhR, while OPN is downstream targeted gene of AhR at the same time. However, it is still unclear for the exact mechanisms. From our previously completed National Natural Science Foundation, we found that OPN closely related to invasion and migration of glioma. There is almost no literature about relationship among PAHs, OPN and EMT of glioma, so it is worth for us to do further study. This program analyzes the correlation between internal exposure level of PAHs and expression regulation of OPN and EMT of glioma based research analysis of population. To clarify the linkage of contribution of PAHs to the AhR and its downstream target gene OPN, we use BaP infected glioma cell combined with cell signaling pathway analysis. To explore the effects of variant OPN on glioma through the initiation of PAHs, we take measures of knock-out and recovering of gene OPN combined with BaP dealing ways. In the last, we can explore “the mechanisms of contribution of polycyclic aromatic hydrocarbon (PAH) to protein OPN trigger epithelial-mesenchymal transition (EMT) in the regulation of glioma invasion and migration via aryl hydrocarbon receptor (AhR)” through combining date based on the level of cell, animals and population. This study can provide theoretical clues for the etiology of glioma and offer scientific evidence for the effective prevention and treatment.

环境多环芳烃(PAHs)污染日趋严重，其健康危害不容忽视。我们已报道PAH-DNA加合物在正常脑和各级胶质瘤组织存在显著差异，且促进胶质瘤细胞侵袭迁移、促进胶质瘤上皮间质性转化(EMT)，预研数据提示与芳烃受体(AhR)激活有关，骨桥蛋白(OPN)是其下游靶分子。在已完成的国自然项目中，我们揭示OPN与胶质瘤侵袭迁移密切相关。PAHs、OPN、胶质瘤EMT之间关系有待研究。本项目拟分析人群PAHs内暴露-OPN表达调控-胶质瘤EMT间关联；并以BaP染毒胶质瘤细胞结合通路分析明确PAHs对AhR 及OPN调控机制；以OPN基因“敲除+回复”合并BaP处理，探讨PAHs调控OPN各变异体在胶质瘤中的作用；综合“人群-动物-细胞”数据，探讨“PAHs通过AhR调控OPN触发EMT在脑胶质瘤侵袭迁移中的作用机制研究”，本研究可为阐明胶质瘤的病因学机制提供理论线索，为胶质瘤的防治提供科学依据。

BaP 作为一种常见的PAHs，能够激活胶质瘤细胞内AHR 的表达。siAHR 干扰AHR 的表达，研究细胞侵袭、迁移的变化，证实AHR 沉默却能够抑制PAHs 对胶质瘤细胞增殖和迁移的促进作用。为了证明AHR-OPN-EMT 的科研假说，我们通过分别敲低AHR 和OPN 发现，AHR 正向调控OPN 的表达，通过调控下游OPN 对侵袭、迁移相关marker（E-cadherin, Vimentin，MMP9）表达产生影响，从而发挥促进迁移、侵袭的作用。而敲除 PAHs 核内受体 AhR 后，细胞侵袭、迁移能力降低。构建裸鼠颅内成瘤模型，在动物水平证实BaP 能够显著促进胶质瘤的恶性进展。颅内原位成瘤实验进一步证明了多环芳烃BaP 能够促进胶质瘤的进展，同时还能够促进肿瘤转移。免疫组化结果显示BaP 处理的裸鼠肿瘤组织中AhR 表达增高，同时OPN 的表达也随之升高，进一步揭示了BaP可以 通过 AhR OPN EMT信号轴促进胶质瘤侵袭、迁移的过程。 本项目的结果，对于明确环境污染物促进胶质瘤侵袭复发机制、寻找致 病及预后的生物学标志、及改善胶质瘤的治疗方案均具有 极 其重要的参考价值。