包含SNP rs16906252的 MGMT增强子通过染色质高级结构调控神经胶质瘤细胞抗药性的研究

Temozolomide (TMZ) chemoresistance is a severe limitation to glioma therapy. As the standard of care for glioma patients is postoperative temozolomide adjuvant to radiation, efforts to better understand the mechanisms of TMZ chemoresistance and develop new methods to overcome chemoresistance are important to improve the clinical treatment. Previous researches showed that MGMT is involved in temozolomide chemoresistance, but is not the only factor that leads to chemoresistance. In addition, methods target to MGMT did not work well in overcoming temozolomide chemoresistance presently. SNP rs16906252 is located in the enhancer of MGMT and associated with the survival of glioma patients who were treated with temozolomide based on clinical data. Researches on chromatin conformation show that enhancers could regulate the transcription of long-distance genes through high-order chromatin structure. Capture C is used in this study to investigate if MGMT enhancer containing SNP rs16906252 is involved in temozolomide chemoresistance through regulation of long-range genes besides MGMT. This study develops new strategies to study chemoresistance and might be beneficial for overcoming chemoresistance.

肿瘤细胞抗药性是神经胶质瘤临床治疗中的重要难题，神经胶质瘤对其一线治疗药物替莫唑胺的抗药性严重影响其临床治疗和预后。对替莫唑胺抗药性的研究和改进是提高神经胶质瘤临床治疗效果的重要方法之一。以往研究表明MGMT基因与替莫唑胺抗药性存在关联，但不是抗药性产生的唯一原因；而目前针对MGMT的抑制胶质瘤抗药性的手段未取得理想效果。临床数据显示位于MGMT基因增强子区SNP rs16906252的基因型与使用替莫唑胺药物的神经胶质瘤患者的存活时间相关。染色质高级结构的研究揭示增强子可对非邻近基因进行调控。本研究将利用染色质构象捕获技术（Capture C）研究SNP rs16906252所在MGMT增强子区是否通过染色质高级结构对MGMT之外的非邻近基因也产生调控作用，从而影响胶质瘤细胞的抗药性。本研究期望发展从染色质高级结构的角度研究神经胶质瘤抗药性的新思路，并为改善神经胶质瘤抗药性提供一定参考。

神经胶质瘤对其一线治疗药物替莫唑胺的抗药性严重影响其临床治疗和预后。对替莫唑胺抗药性的研究和改进是提高神经胶质瘤临床治疗效果的重要方法之一。本项目从染色质高级结构的角度出发研究SNP rs16906252所在的MGMT基因增强子对神经胶质瘤替莫唑胺敏感性的调控机制。利用Capture Hi-C、CRISPR-Cas9等技术手段，本研究发现SNP rs16906252所在的MGMT基因增强子可以通过染色质高级结构远程调控包括MKI67基因在内的多个靶基因，从而调控神经胶质瘤细胞的替莫唑胺抗药性。同时，利用本项目的实验体系和方法，我们也发现一个HOTAIR调控元件和lncRNA HOTAIRM1也可以通过染色质高级结构远程调控靶基因从而影响神经胶质瘤细胞的替莫唑胺抗药性和增殖。本项目从染色质高级结构的角度揭示了神经胶质瘤细胞抗药的新机制，可以为神经胶质瘤的临床治疗提供参考。