Increasing discordant antioxidant protein levels and enzymatic activities contribute to increasing redox imbalance observed during human prostate cancer progression
Increasing discordant antioxidant protein levels and enzymatic activities contribute to increasing redox imbalance observed during human prostate cancer progression
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DOI：
10.1016/j.freeradbiomed.2013.11.006
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发表时间：
2014-02-01
影响因子：
7.4
通讯作者：
Oberley, Terry D.
中科院分区：
文献类型：
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作者：
Chaiswing, Luksana;Zhong, Weixiong;Oberley, Terry D.
一项代谢组学研究表明，随着Gleason评分增加，人前列腺癌（PCa）组织中谷胱甘肽水平降低，半胱氨酸（Cys）水平升高，表明PCa进展时氧化还原失衡。本研究通过分析前列腺癌组织和细胞系中蛋白质硫氧还蛋白1（Trx 1）的氧化还原状态和过氧化物氧还蛋白（Prxs）的亚磺酰化（SO 3）（PrxSO（3））来扩展这些结果。将具有不同侵袭性程度的成对人PCa组织和相邻良性（BN）组织的裂解物用于分析。Trx 1的氧化还原蛋白质印迹分析表明，与中级PCa（Gleason评分3+3至3+4）或BN组织相比，高级PCa（Gleason评分4+4至4+5）中还原Trx 1水平较低，氧化Trx 1水平较高（分别为功能性和非功能性）。PrxSO（3）在高分级PCa中升高。氧化的Trx 1和PrxSO（3）是氧化应激的指标。为了研究氧化还原失衡是否可能影响抗氧化蛋白（AP）的酶活性，我们通过Western blot分析确定了PCa组织中选定AP的水平，发现线粒体锰超氧化物歧化酶（MnSOD），Prx 3和Trx 1在高级别PCa组织中比BN组织增加。高级别PCa组织中MnSOD酶活性显著增加，但与MnSOD蛋白水平相比幅度较低（0.5倍vs 2倍增加）。Trx 1活性在高级别PCa组织中没有改变，尽管有很大的。Trx 1蛋白表达增加。进一步的研究表明，在翻译后修饰的酪氨酸和赖氨酸残基MnSOD蛋白和氧化Cys的活性位点（Cys 32和Cys 35）和调节位点（Cys 62和Cys 69）的Trx 1在高级别PCa BN组织相比，显着增加。蛋白质水平和酶活性之间的这些不协调变化与氧化还原失衡和/或翻译后修饰引起的蛋白质失活一致。与此相反，蛋白水平和细胞外超氧化物歧化酶的活性显着降低，在高级别PCa与相邻BN组织相比。细胞系的结果反映了PCa组织的结果。了解特定癌症中的氧化还原状态谱可能有助于预测每种癌症对化疗药物和放射的行为和反应。(C)2013 Elsevier Inc. All rights reserved.
A metabolomics study demonstrated a decrease in glutathione and an increase in cysteine (Cys) levels in human prostate cancer (PCa) tissues as Gleason scores increased, indicating redox imbalance with PCa progression. These results were extended in the present study by analyzing the redox state of the protein thioredoxin 1 (Trx1) and sulfinylation (SO3) of peroxiredoxins (Prxs) (PrxSO(3)) in PCa tissues and cell lines. Lysates of paired human PCa tissues with varying degrees of aggressiveness and adjacent benign (BN) tissues were used for analysis. Redox Western blot analysis of Trx1 demonstrated low levels of reduced and high levels of oxidized Trx1 (functional and nonfunctional, respectively) in high-grade PCa (Gleason scores 4+4 to 4+5) in comparison to intermediate-grade PCa (Gleason scores 3+3 to 3+4) or BN tissues. PrxSO(3) were increased in high-grade PCa. Oxidized Trx1 and PrxSO(3) are indicators of oxidative stress. To study whether redox imbalance may potentially affect enzyme activities of antioxidant proteins (APs), we determined the levels of selected APs in PCa tissues by Western blot analysis and found that mitochondrial manganese superoxide dismutase (MnSOD), Prx3, and Trx1 were increased in high-grade PCa tissues compared with BN tissues. Enzyme activities of MnSOD in high-grade PCa tissues were significantly increased but at a lower magnitude compared with the levels of MnSOD protein (0.5-fold vs 2-fold increase). Trx1 activity was not changed in high-grade PCa tissues despite a large. increase in Trx1 protein expression. Further studies demonstrated a significant increase in posttranslational modifications of tyrosine and lysine residues in MnSOD protein and oxidation of Cys at the active site (Cys32 and Cys35) and the regulatory site (Cys62 and Cys69) of Trx1 in high-grade PCa compared to BN tissues. These discordant changes between protein levels and enzyme activities are consistent with protein inactivation by redox imbalance and/or posttranslational modifications. In contrast, the protein level and activity of extracellular superoxide dismutase were significantly decreased in high-grade PCa compared with adjacent BN tissues. Results from cell lines mirror those from PCa tissues. Knowledge of redox-state profiles in specific cancers may help to predict the behavior and response of each cancer to chemotherapeutic drugs and radiation. (C) 2013 Elsevier Inc. All rights reserved.