Wang Wen-Xia, Kong Bei-Hua, Li Peng, Song Kun, Qu Xun, Cui Bao-Xia, Jiang Jie, Zhang You-Zhong, Yang Xing-Sheng
Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Jinan 250012, China.
Zhonghua Fu Chan Ke Za Zhi. 2008 Sep;43(9):690-4.
To investigate whether the proteasomes inhibitor MG262 exerts its anti-cancer function by inducing apoptosis in human ovarian cancer cells, and whether the extracellular signal regulated kinase (ERK) signaling pathway is involved in the regulation of apoptosis induction.
Human ovarian cancer cell line SKOV3 was incubated with different concentrations of MG262 for 24 and 48 hours. Cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay at different time points of culturing. Flow cytometry was used to detect cell apoptosis rate. The expression of vascular endothelial growth factor (VEGF) was evaluated with western blot and enzyme-linked immunosorbent assay (ELISA). Western blot was used to detect the expression of phosphorylated ERK (p-ERK).
The viability of SKOV3 cells was decreased by MG262 in a concentration-dependent fashion (P < 0.05). After 24 h incubation with MG262 at 1, 10, 20, 40, 60 and 80 nmol/L, the viability rates of SKOV3 were (94.6 +/- 3.1)%, (92.7 +/- 3.7)%, (89.5 +/- 7.7)%, (84.2 +/- 5.1)%, (82.0 +/- 7.4)% and (76.8 +/- 11.0)% respectively, and after 48 h incubation, those figures were further decreased to (91.3 +/- 10.1)%, (86.8 +/- 4.5)%, (74.6 +/- 4.2)%, (56.8 +/- 2.1)%, (49.3 +/- 4.5)% and (37.4 +/- 5.4)%, respectively (P < 0.05). Apoptosis rate of SKOV3 cells induced by MG262, PD98059 or their combination was (30.7 +/- 4.3)%, (26.8 +/- 8.6)% and (50.3 +/- 10.6)%, respectively, which were significantly different compared with controls (P < 0.05). In contrast to SKOV3 cells, apoptosis rate of 293T cells induced by MG262, PD98059 or their combination was (14.5 +/- 5.3)%, (16.2 +/- 7.5)% and (10.8 +/- 7.3)%, respectively, which were not significantly different compared with controls (P > 0.05). p-ERK expression decreased gradually in a time-dependent manner. And wild-type p53 expression was not significantly different. There was no significant difference between experimental and control 293T cells (P < 0.05). In addition, MG262 down-regulated VEGF secretion and expression in SKOV3 cells (P < 0.05).
Proteasome inhibitors can induce apoptosis and inhibit cell proliferation and angiogenesis through ERK signal pathway in SKOV3 cells.
探讨蛋白酶体抑制剂MG262是否通过诱导人卵巢癌细胞凋亡发挥抗癌作用，以及细胞外信号调节激酶（ERK）信号通路是否参与凋亡诱导的调控。
将人卵巢癌细胞系SKOV3与不同浓度的MG262孵育24小时和48小时。在培养的不同时间点，用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法评估细胞活力。用流式细胞术检测细胞凋亡率。用蛋白质印迹法和酶联免疫吸附测定（ELISA）评估血管内皮生长因子（VEGF）的表达。用蛋白质印迹法检测磷酸化ERK（p-ERK）的表达。
MG262以浓度依赖性方式降低SKOV3细胞的活力（P<0.05）。在1、10、20、40、60和80 nmol/L的MG262孵育24小时后，SKOV3的活力率分别为(94.6±3.1)%、(92.7±3.7)%、(89.5±7.7)%、(84.2±5.1)%、(82.0±7.4)%和(76.8±11.0)%，孵育48小时后，这些数字分别进一步降至(91.3±10.1)%、(86.8±4.5)%、(74.6±4.2)%、(56.8±2.1)%、(49.3±4.5)%和(37.4±5.4)%（P<0.05）。MG262、PD98059或它们的组合诱导的SKOV3细胞凋亡率分别为(30.7±4.3)%、(26.8±8.6)%和(50.3±10.6)%，与对照组相比有显著差异（P<0.05）。与SKOV3细胞相反，MG262、PD98059或它们的组合诱导的293T细胞凋亡率分别为(14.5±5.3)%、(16.2±7.5)%和(10.8±7.3)%，与对照组相比无显著差异（P>0.05）。p-ERK表达呈时间依赖性逐渐降低。野生型p53表达无显著差异。实验细胞与对照293T细胞之间无显著差异（P<0.05）。此外，MG262下调SKOV3细胞中VEGF的分泌和表达（P<0.05）。
蛋白酶体抑制剂可通过ERK信号通路诱导SKOV3细胞凋亡，抑制细胞增殖和血管生成。
