Identification of hypoxia-induced genes in a malignant glioma cell line (U-251) by cDNA microarray analysis
Identification of hypoxia-induced genes in a malignant glioma cell line (U-251) by cDNA microarray analysis
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DOI：
10.1007/s10143-007-0070-z
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发表时间：
2007-07-01
影响因子：
2.8
通讯作者：
Jensen, Randy L.
中科院分区：
文献类型：
--
作者：
Ragel, Brian T.;Couldwell, William T.;Jensen, Randy L.
克服缺氧的代谢限制可能会使低级别肿瘤进展为多形性胶质母细胞瘤。我们在高级别胶质瘤中上调HIF-1α及其下游靶向血管内皮生长因子、GLUT-1和CAIX的发现支持这一假说。我们比较了U-251恶性胶质瘤细胞系在常氧和低氧条件下的基因表达谱，以寻找下一步的研究目标。将U-251细胞培养至75%融合状态，在常氧或低氧条件下培养24小时，提取RNA，扩增后与含有8800个通用细胞基因的基因芯片杂交。以mRNA表达增加三倍作为差异表达的阈值。已识别的基因分为细胞周期控制基因、应激反应基因和“新连接”基因。杂交发现11个低氧诱导基因：1个参与细胞周期调控(CCNG2)，6个参与应激反应(IGFBP3、SLC2A3、GSTT2、FOS、DDIT3、AKR1C3)，以及2个新连接的基因(Depp、AKAP4)。一个与压力相关的基因(AKR1C3)编码一种合成孕酮的酶。在新连接的基因中，孕酮(Depp)诱导的基因蜕膜蛋白的表达最高(4.2倍)。未来可能针对“低氧”胶质瘤细胞的靶点包括AP-1转录因子复合体(FOS)的靶点，以及用非类固醇抗炎药阻断AKR1C3酶。高表达基因Depp的可能功能包括肿瘤血管形成。未来的研究将集中在这样的假设上，即在低氧条件下，AKR1C3酶以自分泌方式上调Depp在U-251胶质瘤细胞中的表达。
Overcoming the metabolic restrictions of hypoxia may allow the progression of lower-grade tumors to glioblastoma multiforme. Our findings of up-regulation of HIF-1 alpha and its downstream targets VEGF, GLUT-1, and CAIX in higher-grade gliomas support this hypothesis. We compared the gene expression profiles of the U-251 malignant glioma cell line under normoxic and hypoxic conditions to discover future research targets. U-251 cells were grown to 75% confluence and exposed to either normoxic or hypoxic conditions for 24 h. RNA was extracted, amplified, and hybridized to a cDNA microarray chip containing similar to 8,800 universal cellular genes. A threefold increase in mRNA expression was used as a threshold value for differential expression. Identified genes were divided into cell cycle control, stress response, and "newly connected" genes. Hybridization identified 11 hypoxia-induced genes: 1 involved with cell cycle control (CCNG2), 6 in stress response (IGFBP3, SLC2A3, GSTT2, FOS, DDIT3, AKR1C3), and 2 newly connected genes (Depp, AKAP4). One stress-related gene (AKR1C3) encodes for an enzyme that synthesizes progesterone. Of newly connected genes, the gene decidual protein induced by progesterone (Depp) showed the highest expression (4.2-fold increase). Possible future targeting for "hypoxic" glioma cells includes the targets for the AP-1 transcription factor complex (FOS), as well as blockade of the enzyme AKR1C3 with nonsteroidal anti-inflammatory drugs. Possible functions of the highly expressed gene Depp include tumor vascularization. Future studies will focus on the hypothesis that Depp is up-regulated in an autocrine fashion by the AKR1C3 enzyme in U-251 glioma cells under hypoxic conditions.