Akt特异性抑制剂鱼藤素对前列腺癌PC-3细胞生长的影响

Inhibitory effect of Akt inhibitor deguelin on the growth of PC-3 prostate cancer cells

目的:观察Akt抑制剂鱼藤素对前列腺癌PC-3细胞株的抑制作用并探讨其可能的作用机制。方法:用MTT法检测鱼藤素对PC-3细胞的增殖抑制率;流式细胞术(FCM)检测鱼藤素对细胞周期的影响;RT-PCR检测细胞中小鼠双微体2(MDM2)、糖元合成酶激酶3β(GSK3β)mRNA表达的变化;Western印迹法检测MDM2、GSK3β蛋白表达的变化。结果:MTT法显示,10、100、500、1 000 nmol/L的鱼藤素作用于前列腺癌PC-3细胞24、48、72 h后,对前列腺癌PC-3细胞增殖抑制率分别为(91.10±3.75)%、(86.39±1.16)%、(79.51±2.63)%;(82.46±3.65)%、(76.84±0.97)%、(69.69±2.30)%;(81.46±0.41)%、(75.56±1.12)%、(54.07±3.21)%;(66.77±2.82)%、(58.22±0.35)%、(39.34±2.40)%,均能显著抑制其增殖(P均<0.01);FCM检测显示各浓度的鱼藤素使前列腺癌PC-3细胞周期阻滞在G0/G1期比例增加[(53.4±2.3)%、(62.4±2.2)%、(63.6±1.1)%、(65.0±0.3)%、(66.5±1.9)%,P均<0.01],S期细胞比例减少[(26.9±1.7)%、(14.7±2.4)%、(11.1±5.2)%、(5.8±1.1)%、(7.0±0.6)%,P均<0.01];RT-PCR和Western印迹法结果显示鱼藤素上调了GSK3βmRNA和蛋白的表达水平,而下调了MDM2 mRNA和蛋白的表达水平。结论:Akt抑制剂鱼藤素能抑制前列腺癌PC-3细胞的增殖,其机制可能与影响Akt信号通路下游分子GSK3β、MDM2的表达相关。

Objective ： To study the inhibitory effect of Akt inhibitor deguelin on PC-3 human prostate cancer cell lines and its possible mechanism. Methods： PC-3 human prostate cancer cells were cultured in deguelin at the concentrations of 10, 100, 500 and 1 000 nmol/L for 24, 48 and 72 hours, respectively. Then the inhibitory effect of deguelin on the proliferation of the PC-3 cells was determined by MTT assay and that on the cell cycle was detected by flow cytometry. The expression levels of MDM2 and GSK3 mRNA were measured by RT-PCR and those of MDM2 and GSK3β proteins by Western blot. Results ： At 24, 48 and 72 hours, the inhibition rates of deguelin on the proliferation of the PC-3 prostate cancer cells were （91.10 ± 3.75 ）, （ 86.39 ± 1.16） and （79.51 ± 2.63） % at 10 nmol/L, （82.46 ±3.65）, （76.84 ±0.97） and （69.69 ±2.30） % at 100 nmol/L, （81.46 ±0.41）, （75.56 ± 1.12） and （54.07 ±3.21） % at 500 nmol/L, and （66.77 ±2.82）, （58.22 ±0.35） and （39.34 ±2.40） % at 1000 nmol/L, all with statistically significant differences from the control group （P 〈0.01 ）. Deguelin at 10, 100,500 and 1 000 nmolfL increased the cell cycles blocked in theG0/G1 phase （[62.4±2.2], [63.6±1.1], [65.0±0.3] and [66.5±1.9] %, P〈0.01） and re- duced the percentage of the S-phase cells （[14.7 ±2.4], [11.1±5.2], [5.8±1.1] and [7.0 ±0.6] %, P〈0.01）. RT-PCR and Western blot showed markedly up-regulated expressions of GSK3β and down-regulated expressions of MDM2 mRNA and proteins in the PC-3 cells treated with deguelin. Conclusion ： Akt inhibitor deguelin can inhibit the proliferation of PC-3 human prostate cancer cells by affecting the down-stream signal molecules GSK3β and MDM2 in the Akt pathway.