多沙唑嗪对前列腺癌DU-145细胞生长的影响及机理研究

Effects of doxazosin on DU-145 cell proliferation and apoptosis in prostate cancer

目的 观察多沙唑嗪对激素非依赖性前列腺癌DU- 145细胞增殖与凋亡的影响并探讨其作用机理。 方法 DU -145细胞培养液中加入多沙唑嗪,使其终浓度分别为0. 1、1、10、25、100μmol/L,不加多沙唑嗪者为对照组。24、48、72、96h后分别检测各组癌细胞的吸光度A值,并计算细胞生长抑制率,取与对照组比较有显著性差异的最低浓度为多沙唑嗪最佳浓度,取有显著性差异的最短时间为最佳作用时间。分析25μmol/L多沙唑嗪作用48h后的细胞周期分布及早期凋亡率,观察细胞形态,检测凋亡相关因子及蛋白的表达。 结果 0. 1、1、10μmol/L组的A值与对照组相比差异无统计学意义; 25、100μmol/L组的A值与对照组相比差异有统计学意义(P<0. 01); 25μmol/L多沙唑嗪作用48h时即出现统计学差异。25μmol/L多沙唑嗪作用48h后,细胞周期分布情况与对照组相比差异无统计学意义;早期凋亡率为14. 31%,与对照组(1. 07% )相比差异有统计学意义;电镜观察显示部分细胞呈现典型的凋亡形态学改变;细胞转化生长因子β1 (TGF- β1 )呈阳性表达,Fas表达增强,bcl -2表达与对照组比较差异无统计学意义。 结论 多沙唑嗪可能通过Fas系统或直接激活TGF -β1 信号通路介导凋亡的发生,从而抑制激素非依赖性前列腺癌细胞生长。

ObjectiveTo investigate the biological action of doxazosin against human androgen-independent prostate cancer DU-145 cells and to explore the molecular mechanism.MethodsPassage cultures of DU-145 cells were exposed to increasing concentrations (0.1, 1, 10, 25,100 μmol/L) of doxazosin for 1-4 days,and DU-145 cells not exposing to doxazosin served as control group.The A values of the cancer cells in each group were determined after 24, 48,72 and 96h,respectively;and the cell growth inhibition rates were assessed.Compared with the controls,the significantly lowest concentration of doxazosin was regarded as the best concentration and the significantly shortest time as the best action time.The cycles,early apoptosis rate and morphological changes of the cells treated with 25 μmol/L of doxazosin for 48 h were assessed.The expressions of apoptosis-related factors and proteins were determined.ResultsThe A values of the cells treated with 0.1,1,10 μmol/L of doxazosin were similar to that of controls, while those of the cells treated with 25,100 μmol/L of doxazosin were significantly different from that of controls ( P <0.01).The A value of the cells treated with 25 μmol/L of doxazosin for 48h was significantly different from that of controls.In the cells treated with 25 μmol/L of doxazosin for 48h,the percentage of distribution in each phase of the cell cycle was similar to that of controls; the early apoptosis rate was 14.31%,which was significantly different from that of controls (1.07%). Electron microscopy showed typical morphological changes of apoptosis. Immunohistochemical analysis revealed moderately increased expression of both Fas and TGF-β_1,whereas expression of bcl-2 was not significantly different from that of controls.ConclusionsDoxazosin can activate apoptosis in prostate cancer cells without interfering with cell cycle progression,which acts possibly via direct activation of the TGF-β_1 signaling pathway, therefore,inhibiting androgen-independent prostate cancer cell growth.These findings provide a rationale for advancing doxazosin as potential antitumor agents in the treatment of progressive prostate cancer.