Masri Fares A, Comhair Suzy A A, Koeck Thomas, Xu Weiling, Janocha Allison, Ghosh Sudakshina, Dweik Raed A, Golish Joseph, Kinter Michael, Stuehr Dennis J, Erzurum Serpil C, Aulak Kulwant S
Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Am J Respir Crit Care Med. 2005 Sep 1;172(5):597-605. doi: 10.1164/rccm.200411-1523OC. Epub 2005 Jun 9.
A cellular prooxidant state promotes cells to neoplastic growth, in part because of modification of proteins and their functions. Reactive nitrogen species formed from nitric oxide (NO) or its metabolites, can lead to protein tyrosine nitration, which is elevated in lung cancer.
To determine the alteration in these NO derivatives and the role they may play in contributing to lung carcinogenesis.
We analyzed levels of NO, nitrite (NO2-), nitrate (NO3-), and the location of the protein nitration and identified the proteins that are modified.
Although exhaled NO and NO2- were increased, endothelial NO synthase or inducible NO synthase expression was similar in the tumor and tumor-free regions. However, immunohistochemistry showed that nitrotyrosine was increased in the tumor relative to non-tumor-bearing sections. We used proteomics to identify the modified proteins (two-dimensional polyacrylamide gel electrophoresis; mass spectrometry). Both the degree of nitration and the protein nitration profile were altered. We identified more than 25 nitrated proteins, including metabolic enzymes, structural proteins, and proteins involved in prevention of oxidative damage. Alterations of the biology of NO metabolites and nitration of proteins may contribute to the mutagenic processes and promote carcinogenesis.
This study provides evidence in favor of a role for reactive nitrogen and oxygen species in lung cancer.
细胞内的促氧化状态会促使细胞发生肿瘤性生长，部分原因是蛋白质及其功能发生了改变。由一氧化氮（NO）或其代谢产物形成的活性氮物质可导致蛋白质酪氨酸硝化，而这种硝化作用在肺癌中有所增强。
确定这些NO衍生物的变化及其在肺癌发生过程中可能发挥的作用。
我们分析了NO、亚硝酸盐（NO2-）、硝酸盐（NO3-）的水平，以及蛋白质硝化的位置，并鉴定了被修饰的蛋白质。
尽管呼出的NO和NO2-有所增加，但肿瘤区域和无肿瘤区域的内皮型NO合酶或诱导型NO合酶表达相似。然而，免疫组织化学显示，相对于无肿瘤切片，肿瘤中的硝基酪氨酸有所增加。我们使用蛋白质组学来鉴定被修饰的蛋白质（二维聚丙烯酰胺凝胶电泳；质谱分析）。硝化程度和蛋白质硝化图谱均发生了改变。我们鉴定出了25种以上的硝化蛋白质，包括代谢酶、结构蛋白以及参与预防氧化损伤的蛋白质。NO代谢产物的生物学改变和蛋白质硝化可能有助于诱变过程并促进癌症发生。
本研究为活性氮和氧物质在肺癌中的作用提供了证据。
