低氧诱导下舌鳞癌SCC-6细胞中HIF-1α、VEGF的表达及TSA对其表达的抑制

Inhibition Effect of Trichostatin A on the Expression of Hypoxia-Induced HIF-1α and VEGF in Tongue Cancer SCC-6 Cells

目的:观察低氧与人舌鳞状细胞癌SCC-6细胞中HIF-1α、VEGF表达的相关性,曲古抑菌素A(TSA)对其表达的抑制作用,初步探讨其作用机制。方法:体外培养的舌鳞状细胞癌SCC-6细胞,经不同作用时间去铁胺处理,模拟低氧条件培养后,RT-PCR检测HIF-1α、VEGF的mRNA表达,Western Blot检测其蛋白表达;模拟低氧条件下,不同浓度、时间梯度TSA处理SCC-6细胞后,分别检测HIF-1α、VEGF的mRNA及蛋白表达。结果:①低氧下SCC-6细胞HIF-1α蛋白表达增加,但其mRNA的表达不受影响;作为HIF-1α下游基因的VEGF的mRNA和蛋白表达,随HIF-1α蛋白表达增加而增加;②低氧下,TSA可抑制HIF-1α的蛋白表达及VEGF的mRNA和蛋白表达,并呈量效和时效关系,但HIF-1α的mRNA表达不受影响;③HIF-1α的调节在蛋白水平。结论:体外条件下,模拟低氧可诱导舌鳞状细胞癌SCC-6细胞中HIF-1α蛋白、其下游基因VEGF的mRNA和蛋白的表达增加。TSA可抑制HIF-1α的蛋白表达,进而抑制其下游基因VEGF的表达,从而发挥抗肿瘤血管生成的作用,并且呈量效和时效关系。

Objective： The current study was designed to explore whether the inhibitory effect of histone deacetylase inhibitor trichostatin A （TSA） are associated with the expressions of hypoxia-induced HIF-1α and VEGF of tongue squamous cell carcinoma SCC-6 cell line in vitro. Methods： SCC-6 cells were treated with desferrioxamine （DFX） and trichostatin A （TSA） in different concentrations at various time periods in vitro. Expressions of HIF-1α and VEGF were detected by real-time reverse transcription PCR and Western Blot on mRNA and protein levels respectively. The data were analyzed by Student＇s t test and one-way analysis of variance. Statistical analyses were performed by SPSS 14.0 software. Results： ①The expression of HIF-1α protein, VEGF mRNA and protein increased when treated with hypoxia simulacrum DFX. ②TSA significantly inhibited the expressions of HIF-1α proteins, VEGF mRNA and protein （P〈0.05） in vitro in a time- and dose-dependent manner. ③The transcription activity of HIF-1α occurred at the protein level. Conclusion： Hypoxia can induce the expression of HIF-1α and its target gene VEGF in vitro, which can be inhibited by histone deacetylase inhibitor TSA in a dose- and time-dependent manner.