Manganese superoxide dismutase overexpression changes plating efficiency bidirectionally according to change in redox for SaOS2 human osteosarcoma cell line.
Manganese superoxide dismutase overexpression changes plating efficiency bidirectionally according to change in redox for SaOS2 human osteosarcoma cell line.
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DOI：
10.3892/ijo.26.4.853
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发表时间：
2005-04
影响因子：
5.2
通讯作者：
M. Komatsu;M. Kuroda;Yadi Wang;D. S. St. Clair;M. Urano;S. Akaki;J. Asaumi;S. Kawasaki;Y. Hiraki;S. Kanazawa
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文献类型：
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作者：
M. Komatsu;M. Kuroda;Yadi Wang;D. S. St. Clair;M. Urano;S. Akaki;J. Asaumi;S. Kawasaki;Y. Hiraki;S. Kanazawa
锰超氧化物歧化酶（MnSOD）是一种线粒体酶，可将细胞毒性超氧化物自由基转化为过氧化氢。MnSOD活性在肿瘤细胞中较低，据报道MnSOD过表达可改善恶性表型。我们从人骨肉瘤细胞系SaOS 2中建立了稳定的MnSOD过表达细胞系，然后研究了MnSOD过表达对平板效率（PE）和活性氧（包括一氧化氮（NO））参与这些效应的影响。MnSOD中度过表达的SaOS 2FM（L）细胞的PE增加，而MnSOD高度过表达的SaOS 2FM（H）细胞的PE减少。虽然我们使用集落形成试验评估PE，但延时显微镜观察显示，贴附在烧瓶上的细胞既没有凋亡也没有坏死。此外，MnSOD过表达并不影响细胞倍增时间。因此，MnSOD过表达可能与细胞粘附对PE变化的影响直接相关。当施用L-丁硫氨酸-[S，R]-亚砜亚胺（BSO）以增加过氧化氢的细胞内浓度时，两种细胞系的PE降低，并且当通过施用丙酮酸钠消除过氧化氢时，仅SaOS 2FM（H）的PE增加。BSO和NO（NOR 4或5-单硝酸异山梨酯）给药的组合协同降低了两种细胞系中的PE。这些发现表明，细胞粘附特性的变化与过氧化氢水平增加和超氧自由基水平减少之间的平衡相关。这是第一份报告表明，PE和细胞粘附性能的变化是双向的，根据MnSOD过表达的水平：首先增加，然后减少MnSOD活性的增加。我们的研究结果表明，PE的变化可能是由两种细胞毒性化合物（降低超氧自由基水平和增加过氧化氢水平）之间的平衡决定的，并且NO负载和增加过氧化氢协同降低PE和细胞粘附。
Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that converts cytotoxic superoxide radicals into hydrogen peroxide. MnSOD activity is lower in tumor cells, and MnSOD overexpression reportedly ameliorates malignant phenotypes. We established stable MnSOD overexpressing cell lines from a human osteosarcoma cell line, SaOS2, and then investigated the effects of MnSOD overexpression on plating efficiency (PE) and the involvement of reactive oxygen species, including nitric oxide (NO) in those effects. The PE of SaOS2FM(L), a moderate MnSOD overexpression cell line, increased, while that of SaOS2FM(H), a high MnSOD overexpression cell line, decreased. Although we assessed PE using a colony-formation assay, time-lapse microscopic observation revealed that cells attached to the flasks had undergone neither apoptosis nor necrosis. Moreover, MnSOD overexpression did not affect cell doubling time. Therefore, MnSOD overexpression might correlate directly with cellular adhesion's effect on PE changes. When L-buthionine-[S,R]-sulfoximine (BSO) was administered to increase the intracellular concentration of hydrogen peroxide, the PEs of both cell lines decreased, and when hydrogen peroxide was eliminated by the administration of sodium pyruvate, only the PE of SaOS2FM(H) increased. The combination of BSO and NO (NOR4 or isosorbide 5-mononitrate) administration synergistically decreased PE in both cell lines. These findings suggest that changes in cellular adhesion properties correlate with the balance between increased hydrogen peroxide levels and decreased superoxide radical levels. This is the first report to indicate that PE and cellular adhesion properties change bidirectionally according to the levels of MnSOD overexpression: first increasing then decreasing as MnSOD activity increases. Our results indicate that PE changes might be decided by the balance between two cytotoxic compounds (decreased superoxide radical levels and increased hydrogen peroxide levels), and that NO loading and increased hydrogen peroxide synergistically reduce PE and cellular adhesion.