LINC00152通过激活LDHA促进瓦氏效应和胶质瘤增殖的机制研究

Our previous data indicated that long intergenic non-coding RNA 00152 (LINC00152) promoted the progression of glioma. We used the TANRIC to query the TCGA low grade glioma and glioblastoma datasets and found that there was a significant negative correlation between the LINC00152 expression and patient survival; LINC00152 knockdown could inhibit cell proliferation in both GBM cell lines and xenograft systems; meanwhile, the expression of LDHA was down-regulated and its enzyme activity was reduced after LINC00152 knockdown. Cancer cell metabolism is modified when compared with that of normal cells and is known as the Warburg effect or aerobic glycolysis, first observed by Otto Warburg in the 1920s. Cancer cells use LDHA to elevate the rate of glycolysis, ATP and lactate production even when oxygen is available. As the key gene in Warburg effect, LDHA is vital to the survival and metabolism of cancer cells. This project is designed to study how LINC00152 promotes the Warburg effect and glioma progression via transactivation of LDHA expression.

我们的前期数据表明长非编码RNA LINC00152参与了胶质瘤的发生发展。我们用TANRIC分析了TCGA低级别胶质瘤和胶质母细胞瘤数据库，发现LINC00152的表达高低与病人预后成明显的负相关关系；在胶质母细胞系LN229和U87中干扰LINC00152的表达可以显著抑制其细胞增殖能力和体内成瘤能力；同时，我们发现干扰LINC00152可以下调乳酸脱氢酶LDHA的表达，抑制LDHA的酶活性。肿瘤细胞在氧气充足的环境中也主要采取糖酵解的方式供能，这种效应被称为瓦氏效应。LDHA作为瓦氏效应所必需的关键基因，对肿瘤细胞的代谢和存活至关重要。本课题主要围绕LINC00152是如何通过调控LDHA表达实现其促肿瘤效应来展开。

我们用TANRIC分析了TCGA低级别胶质瘤和胶质母细胞瘤数据库，发现LINC00152的表达高低与病人预后成明显的负相关关系；在胶质母细胞系LN229和U87中干扰LINC00152的表达可以显著抑制其细胞增殖能力、细胞周期和体内成瘤能力。肿瘤细胞在氧气充足的环境中也主要采取糖酵解的方式供能，这种效应被称为瓦氏效应。LDHA作为瓦氏效应所必需的关键基因，对肿瘤细胞的代谢和存活至关重要。小样本临床标本检测和TCGA 数据库分析表明LINC00152 与LDHA的表达密切相关，且在胶质母细胞系干扰LINC00152后乳酸脱氢酶LDHA的表达下调伴随酶活性降低。体内外恢复实验表明在干扰LINC00152的胶母细胞系中恢复LDHA的表达可以补偿LINC00152对该细胞瓦氏效应、细胞增殖和体内成瘤能力的影响。荧光素酶启动子报告基因实验证实LDHA的启动子区存在转录因子FoxM1的结合位点；染色质免疫共沉淀实验证实FoxM1抗体沉淀的DNA片段中含有LDHA的启动子区，且这种结合作用因LINC00152的导入而增强；RNA 免疫共沉淀实验表明，FoxM1抗体沉淀的RNA片段中确实含有LINC00152。因此，LINC00152可能是通过增强FoxM1与LDHA 启动子区的结合来上调LDHA的表达从而调控胶质母细胞的瓦氏效应和细胞增殖。我们的研究结果不仅是对LncRNA 与肿瘤代谢理论的重要补充，通过结合临床数据更有望成为胶质瘤患者衡量预后的分子标志物和治疗的新靶点，具有良好的临床应用前景和潜在的经济效益。