FoxM1/ASPM轴上调在脑胶质瘤替莫唑胺化疗抵抗中的作用及机制研究

Temozolomide (TMZ) is the standard chemotherapy treatment for malignant gliomas. The TMZ chemoresistance is a key determinant of the prognosis of malignant glioma. By using public database and laboratory study, we observed that ASPM mRNA expression was increased in gliomas, and higher ASPM expression was associated with poor prognosis; We observed that down-regulation of ASPM expression by siRNA could decrease cell growth of U251, a gliomas cell line, induce phase G2/M arrest, and increase the cytotoxicity of TMZ. What’s more, a positive correlation between FoxM1 and ASPM1 mRNA was observed in gliomas. Based on these findings, this study is designed to make clear influence of ASPM1 and FoxM1 expression on TMZ sensitivity prognogis of gliomas in clinic, and confirm direct regulation of FoxM1 on ASPM1 expression by reporter gene assay and ChiP analysis. Finally, microprotein immunofluorescence assay, tumor subclone formation assays, and flow cytometry analysis will be applied to clarify the role of FoxM1-ASPM axis in regulation of TMZ chemosensitivity via interfering with mitotic catastrophe and promoting functions of gliomas stem cells. This study will provide new insight for individualized therapy for gliomas and provide potentially new targets for the treatment of gliomas based on the FoxM1-ASPM axis.

恶性胶质瘤临床预后差，替莫唑胺（TMZ）是其一线化疗药物，TMZ化疗抵抗是胶质瘤复发和死亡的主要原因。本项目前期研究发现胶质瘤组织中ASPM表达显著升高且影响预后，干预ASPM表达可抑制胶质瘤细胞增殖、引起G2/M期阻滞，增加TMZ的细胞毒性，且胶质瘤组织中ASPM表达与转录因子FoxM1正相关的基础上，拟通过临床研究结合细胞实验，查明FoxM1和ASPM表达对胶质瘤患者TMZ敏感性和预后的影响；并应用报告基因实验和染色质免疫共沉淀技术确证FoxM1可在转录水平直接调节ASPM表达；最后应用微蛋白免疫荧光技术、肿瘤单克隆形成和亚球形成实验等技术，通过干预FoxM1和ASPM表达，在细胞水平查明FoxM1-ASPM轴是否通过影响有丝分裂灾难形成、促进肿瘤干细胞的功能而介导胶质瘤细胞TMZ抵抗。项目旨在为寻找胶质瘤治疗新靶点和基于FoxM1-ASPM轴表达的胶质瘤个体化治疗奠定理论基础。

恶性胶质瘤是中枢神经系统常见恶性肿瘤，其临床预后极差，寻找有效治疗靶点对其具有重要临床意义。本项目发现胶质瘤组织中ASPM表达显著升高且影响预后，干预ASPM表达可抑制胶质瘤细胞增殖、引起细胞周期阻滞和增加TMZ的细胞毒性；且在胶质瘤组织中ASPM表达与转录因子FoxM1正相关的基础上，通过染色质免疫共沉淀技术和报告基因实验发现FoxM1通过结合ASPM启动子区域介导了胶质瘤组织中ASPM异常高表达并促进胶质瘤细胞的增殖和迁移；并通过RNA-seq分析查明FoxM1/ASPM轴可能通过影响P53信号通路、肿瘤的碳代谢和肿瘤的转录调控等基因的表达而影响胶质瘤的发生发展。本项目为寻找胶质瘤治疗靶点和胶质瘤个体化治疗提供了实验和理论基础。