定位于染色体1p的长链非编码RNA在胶质瘤发生发展及化疗耐药中的分子机制研究

1p LOH(loss of heterozygosity), as the most common molecular biological characteristics of oligodendroglioma, may be contributed to the chemosensitivity and prognosis of tumors. However, underlying mechanisms are still unclear. Now available evidence indicate that a large number of lncRNA associated with tumor transforming exist in chromosome 1p. So we suppose that some lncRNA or genes required by oligodendrogliomas’ malignant transformation must hide in chromosome 1p and these specifically expressive lncRNA can be used as potential prediction and/or treatment targets of glioma. In this study, through analyzing the lncRNA expression profile of oligodendroglioma associated with temozolomide(TMZ) chemoresistance, we will screen out the lncRNA located in chromosome 1p, which are associated with TMZ chemoresistance; determine that high expression of lncRNA whether primary or secondary response; explore the molecular mechanisms and clinical significance of that lncRNA in the malignant progression of glioma. For the first time, we comprehensively study the transcript information of chromosome 1p in gliomas; seek lncRNA associated with chemoresistance; furtherly understand the molecular mechanisms of tumor progression and chemoresistance of glioma, through combining results of chemosensitivity in vitro and 1p status of oligodendrogliomas.

1p杂合性缺失是少枝胶质瘤最常见的分子生物学特征，并与肿瘤的化疗敏感性和预后有关，但其相关机制仍然不清；现有证据表明1p染色体上存在着大量与肿瘤转化相关的长链非编码RNA（lncRNA）。因此，我们推测1p染色体上可能隐藏有某些lncRNA或基因是少枝胶质瘤恶性转化所必须的，这些特异性表达的lncRNA可以作为胶质瘤潜在的预测和/或治疗靶点。本研究通过对少枝胶质瘤中替莫唑胺（TMZ）耐药性lncRNA表达谱的分析，筛选定位于1p染色体的与TMZ耐药相关的lncRNA；确定该lncRNA在TMZ药物处理后是原发性还是继发响应性的高表达；分析研究该lncRNA在胶质瘤恶性进展中的分子机制及其临床意义。本课题结合胶质瘤体外药敏和肿瘤1p缺失结果，首次全面性分析胶质瘤中1p上的转录本信息，寻找化疗耐药相关lncRNA，有望进一步了解胶质瘤发生发展和化疗耐药的分子机制。

MC1R可能与胶质瘤细胞的TMZ耐药有关，MC1R及其配体ACTH的结合可以进一步放大这一效应。本课题先通过建立人脑胶质瘤异位移植PDX模型筛选出对TMZ治疗敏感和耐药的标本各两例，然后通过RNAseq和生物信息学分析，并结合文献查阅，筛选出PGC1A、AMPKG、SIRT1、UBE2T、SLX1A、MYBBPA1、ZSWINM7、RAD51和MC1R 9个基因,使用siRNA验证，进一步挑选出MC1R进行细胞验证，发现MC1R表达能改变胶质瘤细胞对TMZ的敏感性，而MC1R的配体ACTH和TMZ的联合处理对MC1R高表达的胶质瘤细胞效果更明显。MC1R在临床胶质瘤组织中的表达率较高，但与胶质瘤的级别关系不大。此外，我们还建立了MC1R高表达的TMZ耐药胶质瘤细胞株U87的原位裸鼠移植模型可用于进一步研究。综上所述，本研究探讨了MC1R对胶质瘤细胞TMZ耐药的作用和可能机制，对临床TMZ耐药胶质瘤的机制和进一步治疗进行了重要的启示性探索。项目资助已发表SCI论文1篇，待发表论文两篇,拟申请专利一项。项目培养博士生2名，都已顺利毕业。项目投入经费55万元，已支出27.19万元，结余经费27.81万元，拟用于本项目的后续研究。