Department of Gynecology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Arch Gynecol Obstet. 2012 Feb;285(2):459-67. doi: 10.1007/s00404-011-1942-6. Epub 2011 Jun 23.
Abnormal expression of aquaporin 5 (AQP5) is associated with ovarian cancer infiltration, metastasis and angiogenesis. AQP 5 expression and apoptosis have been shown to be closely related to nuclear transcription factor NF-κB. In this study, we investigated the inhibition of cell proliferation and the induction of apoptosis by Epigallocatechin gallate (EGCG), a potential anti-cancer drug, in the ovarian cancer cell line SKOV3 as well as the effect of EGCG on AQP5 expression and its possible mechanisms.
SKOV3 cells were treated with different concentrations of EGCG and the NF-κB-specific inhibitor pyrrolidine dithiocarbamate (PDTC) for different times. Cell proliferation was determined using the MTT assay, cell apoptosis was evaluated using the DNA ladder assay, the expression of AQP5, NF-κB p65 and IκBα was detected by immunohistochemistry, western blot analysis and RT-PCR, and the correlation of these protein expression was analyzed.
With increasing concentrations of EGCG and prolonged treatment times, the growth inhibition rate of SKOV3 cells gradually increased in a dose- and time-dependent manner. The expression of AQP5 and nuclear p65 and IκBα was significantly decreased (P < 0.01). The cytoplasmic expression of IκBα gradually increased (P < 0.05), and the apoptosis of SKOV3 cells was induced as evidenced by typical fragmentation pattern in a DNA ladder assay. With increasing concentrations of PDTC and prolonged treatment times, the protein and mRNA levels of AQP5 in SKOV3 cells decreased (P < 0.01). In addition, the growth inhibition rate of SKOV3 cells significantly increased in a dose- and time-dependent manner.
EGCG inhibited the proliferation and induced the apoptosis of ovarian cancer SKOV3 cells. EGCG also down-regulated expression of AQP5, which may inhibit tumor growth and be associated with nuclear transcription factor NF-κB.
水通道蛋白 5（AQP5）的异常表达与卵巢癌浸润、转移和血管生成有关。AQP5 的表达和凋亡与核转录因子 NF-κB 密切相关。本研究探讨了表没食子儿茶素没食子酸酯（EGCG）作为一种潜在的抗癌药物对卵巢癌细胞系 SKOV3 的细胞增殖抑制和凋亡诱导作用，以及 EGCG 对 AQP5 表达的影响及其可能的机制。
用不同浓度的 EGCG 和 NF-κB 特异性抑制剂吡咯烷二硫代氨基甲酸盐（PDTC）处理 SKOV3 细胞不同时间。用 MTT 法测定细胞增殖，用 DNA 梯状电泳法评估细胞凋亡，用免疫组织化学、Western blot 分析和 RT-PCR 检测 AQP5、NF-κB p65 和 IκBα的表达，并分析这些蛋白表达的相关性。
随着 EGCG 浓度的增加和处理时间的延长，SKOV3 细胞的生长抑制率呈剂量和时间依赖性逐渐增加。AQP5 和核 p65、IκBα的表达明显降低（P<0.01）。细胞质中 IκBα的表达逐渐增加（P<0.05），SKOV3 细胞出现典型的 DNA 梯状电泳法凋亡片段。随着 PDTC 浓度的增加和处理时间的延长，SKOV3 细胞中 AQP5 的蛋白和 mRNA 水平降低（P<0.01）。此外，SKOV3 细胞的生长抑制率呈剂量和时间依赖性显著增加。
EGCG 抑制卵巢癌 SKOV3 细胞的增殖并诱导其凋亡。EGCG 还下调 AQP5 的表达，这可能抑制肿瘤生长，并与核转录因子 NF-κB 有关。
