NADPH Oxidase 4 Contributes to Transformation Phenotype of Melanoma Cells by Regulating G2-MCell Cycle Progression
NADPH Oxidase 4 Contributes to Transformation Phenotype of Melanoma Cells by Regulating G2-MCell Cycle Progression
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DOI：
10.1158/0008-5472.can-08-3745
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发表时间：
2009-03-15
期刊：
影响因子：
11.2
通讯作者：
Kamata, Tohru
中科院分区：
文献类型：
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作者：
Yamaura, Maki;Mitsushita, Junji;Kamata, Tohru
活性氧（ROS）的产生与黑色素瘤的致癌发展有关，但其潜在的分子机制尚未完全阐明。我们研究了超氧化物生成NADPH氧化酶（Nox）4在人黑色素瘤细胞中的表达和功能。Nox4在测试的20个黑色素瘤细胞系中有13个上调。通过小干扰rna沉默黑色素瘤MM-BP细胞中Nox4的表达，可以减少ROS的产生，从而抑制裸小鼠非锚定依赖性细胞的生长和致瘤性。一般的氮氧化物抑制剂，二苯基碘，抗氧化剂维生素E和吡咯烷二硫代氨基甲酸酯都能抑制MM-BP细胞的增殖。流式细胞分析表明，Nox4小干扰rna和二苯基碘诱导G(2)-M细胞周期阻滞，在另一种黑色素瘤细胞系928mel中也观察到这种阻滞。这伴随着tyr1 -15磷酸化的诱导，周期蛋白依赖性激酶1的失活形式（G(2)-M检查点的标志）和cdc25c的过度磷酸化，导致其与14-3-3蛋白的结合增加。过氧化氢酶是一种活性氧清除剂，其异位表达也导致细胞在G(2)-M期积聚。免疫组化结果显示，在13例黑色素瘤患者样本中有31.0%检测到Nox4的表达，提示Nox4的表达与黑色素瘤发展的某些步骤有关。研究结果表明，nox4产生的ROS是黑色素瘤细胞转化表型所必需的，并通过调节G2-M细胞周期进程促进黑色素瘤的生长。[癌症研究2009；69 (6): 2647 - 54)
Generation of reactive oxygen species (ROS) has been implicated in carcinogenic development of melanoma, but the underlying molecular mechanism has not been fully elucidated. We studied the expression and function of the superoxide-generating NADPH oxidase (Nox)4 in human melanoma cells. Nox4 was up-regulated in 13 of 20 melanoma cell lines tested. Silencing of Nox4 expression in melanoma MM-BP cells by small interfering RNAs decreased ROS production and thereby inhibited anchorage-independent cell growth and tumorigenecity in nude mice. Consistently, a general Nox inhibitor, diphenylene iodonium, and antioxidants vitamine E and pyrrolidine dithiocarbamate blocked cell proliferation of MM-BP cells. Flow cytometric analysis indicated that Nox4 small interfering RNAs and diphenylene iodonium induced G(2)-M Cell cycle arrest, which was also observed with another melanoma cell line, 928mel. This was accompanied by induction of the Tyr-15 phosphorylated, inactive form of cyclin-dependent kinase 1 (a hallmark of G(2)-M checkpoint) and hyperphosphorylation of cdc25c leading to its increased binding to 14-3-3 proteins. Ectopic expression of catalase, a scavenger of ROS, also caused accumulation of cells in G(2)-M phase. Immunohistochemistry revealed that expression of Nox4 was detected in 31.0% of 13 melanoma patients samples, suggesting the association of Nox4 expression with some steps of melanoma development. The findings suggest that Nox4-generated ROS are required for transformation phenotype of melanoma cells and contribute to melanoma growth through regulation of G2-M cell cycle progression. [Cancer Res 2009;69(6):2647-54]