米非司酮抑制前列腺癌PC-3细胞血管内皮生长因子表达过程中糖皮质激素受体的作用

Mifepristone inhibits the expression of vascular endothelial growth factor through glucocorticoid receptor signalling pathway in prostate cancer cell line PC-3

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 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 decreased in PC-3 cells treated with 10 μmol/L mifepristone for 24 h to 96 h. Mifepristone treatment for 48 h decreased the level of VEGF secretion by 48.23%, which was significantly different from that of the untreated PC-3 cells （P0.01）. In PC-3 cells which were treated with different hormones, only mifepristone could reduce the level of VEGF secretion （P0.01）. However, progesterone could slightly elevate the level of VEGF secretion, but the other hormones showed no such effects. Dexamethasone could block the inhibition effect of mifepristone on the level of VEGF secretion in PC-3 cells. Conclusion： Mifepristone can inhibit the secreation of VEGF protein in prostate cancer PC-3 cells which may be through GR signalling pathway in vitro.