目的:探讨米非司酮抑制前列腺癌PC-3细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白表达过程中糖皮质激素受体(glucocorticoid receptor,GR)信号通路的作用。方法:采用免疫细胞化学法检测前列腺癌PC-3细胞中GR的表达情况,然后采用RT-PCR法检测不同浓度米非司酮作用48h后PC-3细胞中GR mRNA的表达变化,并用ELISA法检测不同浓度米非司酮作用不同时间以及不同激素作用后PC-3细胞中VEGF蛋白表达的变化。结果:免疫细胞化学检测证实了前列腺癌PC-3细胞中存在GR的表达。进一步用RT-PCR法检测发现,5、10和50μmol/L米非司酮作用PC-3细胞48h后GR mRNA的表达呈逐渐降低趋势,其中5μmol/L米非司酮组与未处理对照组差异无统计学意义(P〉0.05),而10和50μmol/L米非司酮组与对照组比较,差异有统计学意义(P〈0.01)。不同浓度的米非司酮作用PC-3细胞48h后,其VEGF的分泌量随着米非司酮浓度的增加而逐渐减少,其中≥10μmol/L的米非司酮组VEGF分泌量比对照组下降≥48.29%;而10μmol/L米非司酮作用PC-3细胞24~96h后,其VEGF的分泌量随着作用时间延长而呈递减趋势,其中48h后的VEGF分泌量比对照组下降超过48.23%,差异有统计学意义(P〈0.01)。不同激素作用PC-3细胞后,除米非司酮可减少VEGF的表达(P〈0.01)外,孕激素可使VEGF蛋白的表达水平略有升高,而其他激素对VEGF蛋白的表达无影响;同时,地塞米松可以部分阻断米非司酮对PC-3细胞中VEGF蛋白的抑制作用。结论:米非司酮抑制前列腺癌细胞分泌VEGF蛋白,可能是通过GR信号通路发挥作用的。
Objective: To investigate the role of glucocorticoid receptor (GR) signalling pathway in the expression of vascular endothelial growth factor (VEGF) inhibited by mifepristone in prostate cancer cell line PC-3. Methods: The expression of GR in prostate cancer cell line PC-3 was determined by immunocytochemical technique. After treatment with different concentrations of mifepristone for 48 h, the expression change of GR mRNA was evaluated by using RT-PCR. The expression level of VEGF protein in PC-3 cells was detected by using ELISA after treatment with different concentrations of mifepristone for different time or different hormones. Results: Immunocytochemical analysis revealed the expression of GR in PC-3 cells. The expression level of GR mRNA in PC-3 cells treated with 5, 10 or 50 μmol/L mifepristone exhibited a descending trend. The expression of GR mRNA in PC-3 cells treated with 5 μmol/L mifepristone for 48 h was similar to that of the untreated PC-3 cells (P0.05), but the expression of GR mRNA in PC-3 cells treated with 10 or 50 μmol/L of mifepristone for 48 h was significantly different from that of the untreated PC-3 cells (P0.01). The secretion level of VEGF was gradually down-regulated in PC-3 cells treated with 1 μmol/L to 100 μmol/L of mifepristone for 48 h. Mifepristone at 10 μmol/L down-regulated the level of VEGF secretion by 48.29%, as compared with that of the untreated PC-3 cells. The level of VEGF secretion was gradually Mifepristone inhibits the expression of vascular endothelial growth factor through glucocorticoid receptor signalling pathway in prostate cancer cell line PC-3 ZHANG Hui1, Wang Yu-qiu1, ZHANG Jie2, MA Chun-yan2, Lü Jia-ju1 1. Department of Urology, 2. Central Laboratory, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China Abstract Objective: To investigate the role of glucocorticoid receptor (GR) signalling pathway in the expression of vascular endothelial growth factor (VEGF) inhibited by mifepristone in prostate ca