Ye Jun, Li Yuping, Hamasaki Takeki, Nakamichi Noboru, Komatsu Takaaki, Kashiwagi Taichi, Teruya Kiichiro, Nishikawa Ryuhei, Kawahara Takeshi, Osada Kazuhiro, Toh Kazuko, Abe Masumi, Tian Huaize, Kabayama Shigeru, Otsubo Kazumichi, Morisawa Shinkatsu, Katakura Yoshinori, Shirahata Sanetaka
Graduate School of Systems Life Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan.
Biol Pharm Bull. 2008 Jan;31(1):19-26. doi: 10.1248/bpb.31.19.
Vascular endothelial growth factor (VEGF) is a key mediator of tumor angiogenesis. Tumor cells are exposed to higher oxidative stress compared to normal cells. Numerous reports have demonstrated that the intracellular redox (oxidation/reduction) state is closely associated with the pattern of VEGF expression. Electrolyzed reduced water (ERW) produced near the cathode during the electrolysis of water scavenged intracellular H(2)O(2) and decreased the release of H(2)O(2) from a human lung adenocarcinoma cell line, A549, and down-regulated both VEGF transcription and protein secretion in a time-dependent manner. To investigate the signal transduction pathway involved in regulating VEGF expression, mitogen-activated kinase (MAPK) specific inhibitors, SB203580 (p38 MAPK inhibitor), PD98059 (ERK1/2 inhibitor) and JNKi (c-Jun N-terminal protein kinase inhibitor) were applied. The results showed that only PD98059 blocks VEGF expression, suggesting an important role for ERK1/2 in regulating VEGF expression in A549 cells. As well, ERW inhibited the activation of extracellular signal-regulated kinase (ERK) in a time-dependent manner. Co-culture experiments to analyze in vitro tubule formation assay revealed that A549 cell-derived conditioned medium significantly stimulated the formation of vascular tubules in all analyzed parameters; tubule total area, tubule junction, number of tubules, and total tubule length. ERW counteracted the effect of A549 cell-conditioned medium and decreased total tube length (p<0.01). The present study demonstrated that ERW down-regulated VEGF gene transcription and protein secretion through inactivation of ERK.
血管内皮生长因子（VEGF）是肿瘤血管生成的关键介质。与正常细胞相比，肿瘤细胞面临更高的氧化应激。大量报告表明，细胞内氧化还原（氧化/还原）状态与VEGF表达模式密切相关。在水电解过程中，阴极附近产生的电解还原水清除了细胞内的H(2)O(2)，并减少了人肺腺癌细胞系A549中H(2)O(2)的释放，同时以时间依赖性方式下调VEGF转录和蛋白质分泌。为了研究调节VEGF表达的信号转导途径，应用了丝裂原活化激酶（MAPK）特异性抑制剂，SB203580（p38 MAPK抑制剂）、PD98059（ERK1/2抑制剂）和JNKi（c-Jun N端蛋白激酶抑制剂）。结果表明，只有PD98059能阻断VEGF表达，提示ERK1/2在调节A549细胞中VEGF表达方面起重要作用。同样，电解还原水以时间依赖性方式抑制细胞外信号调节激酶（ERK）的激活。用于分析体外小管形成试验的共培养实验表明，A549细胞衍生的条件培养基在所有分析参数中均显著刺激血管小管的形成；小管总面积、小管连接点、小管数量和小管总长度。电解还原水抵消了A549细胞条件培养基的作用，并降低了总管长度（p<0.01）。本研究表明，电解还原水通过使ERK失活来下调VEGF基因转录和蛋白质分泌。
