Hsp27对可溶性环氧化物水解酶抑制剂t-AUCB诱导胶质瘤细胞凋亡的影响及机制

As an efficient and specific soluble epoxide hydrolase inhibitor, t-AUCB was reported to significantly inhibit glioma cell growth. Blocking activation of Hsp27 was considered to highly improve t-AUCB-induced apoptosis. To explore the mechanism, we also found that activating of Hsp27 regulate the expression of Oct4 which was reported to be involved in chemoresistance of some tumors including glioma. This indicated that activating of Hsp27 may affect t-AUCB-induced apoptosis by regulating Oct4 expression. No reports ever mentioned this. In following research, the methods of gene overexpression and gene knock-down will be used to confirm the effects and mechanisms of Hsp27 on t-AUCB induced glioma cell apoptosis. This research would suggest new targets for improving t-AUCB-induced glioma apoptosis and make a preparation for studying t-AUCB on glioma treatment. Moreover, this research may open perspectives for studying chemoresistance of tumors.

t-AUCB是一种高效特异的可溶性环氧化物水解酶抑制剂。既往研究证实，t-AUCB能有效抑制胶质瘤细胞的生长；阻碍细胞内Hsp27的活化能显著增强t-AUCB对胶质瘤细胞的促凋亡作用。为进一步探讨其机制，我们初步证实，Hsp27的活化伴随着细胞内Oct4表达的变化，而文献报道Oct4参与包括胶质瘤在内的多种肿瘤细胞的耐药，提示Hsp27活化后可能通过调节Oct4机制影响t-AUCB的促凋亡作用。迄今国内外尚无相关研究报道。拟进一步用基因过表达与敲低策略，明确Hsp27在影响t-AUCB促胶质瘤细胞凋亡中的作用，并以Oct4为研究线索，分析Hsp27如何影响t-AUCB诱导凋亡，为增强t-AUCB的促凋亡能力提供新的靶标，为研究t-AUCB治疗胶质瘤奠定基础，同时也为研究胶质瘤耐药机制提供新的思路。

该项目我们从多个靶点入手，详细研究了Hsp27对t-AUCB抗胶质瘤作用的影响及其机制。首先，我们研究了γ-分泌酶抑制剂DAPT对t-AUCB抗胶质瘤的影响，结果显示，DAPT能通过调控p38 MAPK/MAPKAPK2/Hsp27通路逆转胶质瘤细胞对t-AUCB的抵抗作用，说明γ-分泌酶抑制剂能通过调控Hsp27增强t-AUCB的抗胶质瘤作用；其次，我们研究了处于p38 MAPK/MAPKAPK2/Hsp27通路下游的AKT对t-AUCB抗胶质瘤的影响。结果显示，Hsp27诱导的AKT磷酸化也是导致胶质瘤细胞抵抗t-AUCB的因素之一，抑制AKT能增强t-AUCB的抗胶质瘤作用；接着，我们发现t-AUCB能通过Hsp27增加COX-2的表达水平，Hsp27的活化和COX-2的高表达均是导致胶质瘤细胞抵抗t-AUCB的因素，槲皮素（Quercetin）通过同时抑制Hsp27和COX-2增强t-AUCB的抗胶质瘤作用；然后，为了进一步探索t-AUCB抗胶质瘤的潜在靶点以及t-AUCB抑制胶质瘤的机制，我们利用基因芯片技术检测了t-AUCB处理后胶质瘤细胞中mRNA和长链非编码RNA（lncRNA）表达谱的变化，结果显示：t-AUCB导致了605个lncRNA和689个mRNA表达的显著变化（表达变化Fold Change≥2.0, P<0.05），其中375个lncRNA和338个mRNA表达上调，230个lncRNA和351个mRNA表达下调。综上所述，本项目深入研究了t-AUCB在抗胶质瘤方面的作用以及Hsp27对t-AUCB抗胶质瘤的影响，并找到了多个抗胶质瘤的潜在靶点，为进一步深入研究和临床转化提供了基础。