缺氧条件下全反式维甲酸对U87胶质瘤细胞血管内皮生长因子表达的影响

摘要

目的 研究模拟缺氧条件下全反式维甲酸(ATRA)对U87胶质瘤细胞血管内皮生长因子(VEGF)表达的影响及其可能的机制.方法 U87胶质瘤细胞分为空白对照组、缺氧对照组、低浓度干预组、高浓度干预组.CoCl2模拟缺氧,U87胶质瘤细胞经不同浓度ATRA(5、10 μmol/L)干预后,实时定量PCR法及Western blot法分别检测细胞中VEGF mRNA、缺氧诱导因子1α(HIF-1α)mRNA及VEGF蛋白的表达.结果 与缺氧对照组相比,低、高浓度干预组VEGF mRNA表达分别为缺氧对照组的(2.08±0.23)倍及(3.13±0.14)倍,两组与缺氧对照组的差异均具有统计学意义(均P＜0.01)；低、高浓度干预组HIF1α mRNA表达分别为缺氧对照组的(1.62±0.07)倍及(1.83±0.09)倍,两组与缺氧对照组的差异均具有统计学意义(均P＜0.01).而VEGF蛋白相对表达量在缺氧对照组为(2.15±0.12),低浓度干预组为(2.32±0.20),高浓度干预组为(3.09±0.08),各组间差异均具有统计学意义(均P ＜0.05).结论 在模拟缺氧条件下,ATRA可在转录及翻译水平增加U87细胞中VEGF的表达,而这种表达上调可能部分通过上调HIF-1α表达实现.%Objective To investigate the effects and probable mechanism of all-trans retinoid acid (ATRA) on expression of vascular endothelial growth factor (VEGF) in U87 glioma cells under hypoxia. Methods U87 glioma cells were divided into blank control group, hypoxia control group, low-concentration intervention group and high-concentration intervention group. CoCI2 was used to simulate hypoxia condition, and U87 glioma cell was treated by ATRA at different concentrations (S, 10 μmol/L) under hypoxia condition. Then the expression of VEGF mRNA and hypoxia-inducible factor-la (HIF-lα) mRNA were detected by real-time PCR, and the expression of VEGF protein by Western blot. Results Compared with the hypoxia control group, the expression of VEGF mRNA was 2.08 ± 0.23 fold and 3.13 ± 0.14 fold of that in hypoxia control group respectively in low- and high-concentration intervention groups. The differences between above two groups and hypoxia control group were obvious (both P< 0.01). The expression of HIF-lα mRNA was 1.62 ± 0.07 fold and 1.83 ± 0.09 fold of that in hypoxia control group respectively in low- and high-concentration intervention groups. The differences between above two groups and hypoxia control group were obvious (both P< 0.01). The relative expression of VEGF protein was 2.15 ± 0.12, 2.32 ± 0.20 and 3.09 ± 0.08 respectively in hypoxia control group, low- and high-concentration intervention group and the difference between any two groups was significant (all P < O.OS). Conclusions ATRA can increase the expression of VEGF in U87 cells at transcription level and translational level under hypoxia condition, and this up-regulation may partly depend on the up-regulation of HIF-la expression.