TET1调控MGMT启动子甲基化状态参与胶质母细胞瘤对TMZ耐药机制的研究

The promoter methylation status of MGMT gene is the most important marker that is predicts the sensitivity of the glioblastoma (GBM) toward temozolomide (TMZ) in clinical practice. TMZ is the first line chemotherapy drug after operation. It is research focus which increases GBMs toward TMZ sensitivity by regulate the promoter methylation status of MGMT gene. In our research, we found that MGMT promoter methylation convert to unmethylation after TMZ treatment between paired primary and recurrent GBM samples by MSP. We have integrated GBM datasets to screen conversion related genes by bioinformatics; established TMZ resistant glioblastoma cell lines, MGMT promoter methylation converted unmethylation in tumor cell lines by TMZ induced, we also screened conversion related genes by microarray in WT and TMZ resistant cell line. We found the relationship between TET1 and the promoter methylation status of MGMT gene. TET protein plays an important role in DNA demethylation, the relatiohship between TET protein and MGMT promoter methylation that is unclear. Next step, we will use RNA interference to study the mechanism of TET1 through self-regulation and the upstream gene to regulate the promoter methylation status of MGMT gene in TMZ resistant cell lines and mouse subcutaneous xenografts. It will provide new strategies to reverse TMZ resistant that has important theoretical and practical significance.

O6-甲基鸟嘌呤-DNA-甲基转移酶（MGMT）启动子甲基化状态是评估胶质母细胞瘤（GBM）对一线化疗药物替莫唑胺（TMZ）敏感性的重要指标。调控启动子甲基化状态增加TMZ敏感性是研究热点。本课题组分析配对的初发和复发GBM标本发现经TMZ治疗MGMT启动子由甲基化转换为非甲基化的现象。通过整合分析GBM微阵列数据和经TMZ诱导发生启动子甲基化状态转换的耐药细胞株微阵列数据，筛选出调控甲基化状态转换的基因DNA羟化酶TET1。TET1调控MGMT启动子的机制尚不清楚。本研究拟在前期工作基础上，通过应用RNA干扰等技术，进行体外细胞培养和裸鼠体内成瘤实验，探讨TET1与MGMT启动子甲基化状态转换的相关性，分析TET1对肿瘤生物学特性和体内致瘤性的影响，揭示TET1通过自我调控和上游基因调控MGMT启动子甲基化状态的机制。为逆转TMZ耐药的治疗提供新策略，具有重要的理论和现实意义。

O6-甲基鸟嘌呤-DNA-甲基转移酶（MGMT）启动子甲基化状态是评估胶质母细胞瘤（GBM）对一线化疗药物替莫唑胺（TMZ）敏感性的重要指标。调控启动子甲基化状态增加TMZ敏感性是研究热点。本课题组通过分析初发和复发GBM标本发现经TMZ治疗MGMT启动子由甲基化转换为非甲基化。整合分析TCGA的GBM微阵列数据和经TMZ诱导发生启动子甲基化状态转换的耐药细胞株微阵列数据，筛选出调控甲基化状态转换的基因DNA羟化酶TET1。通过细胞培养实验，研究TET1与MGMT启动子甲基化状态转换的相关性，分析TET1对肿瘤生物学特性的影响。