Izutani R, Asano S, Imano M, Kuroda D, Kato M, Ohyanagi H
Second Department of Surgery, Kinki University, School of Medicine, Osaka-Sayama, Osaka, Japan.
J Gastroenterol. 1998 Dec;33(6):816-22. doi: 10.1007/s005350050181.
The tumor-killing activity of radiotherapy and chemotherapy for cancer is closely associated with the production of active oxygen, and the relation between therapeutic resistance and active oxygen scavengers produced by the tumor itself is gaining more attention. It is considered that manganese superoxide dismutase (MnSOD) protects host cells from oxidative stress, in synergy with other antioxidant enzymes. In this study, we used a quantitative polymerase chain reaction assay to measure MnSOD mRNA in resected specimens from patients with esophageal and gastric cancers. In both esophageal and gastric cancers, the level of MnSOD mRNA was significantly elevated in cancer tissue compared to non-cancer tissue (P < 0.01). In gastric cancer tissue, the MnSOD mRNA level was significantly higher than in esophageal cancer tissue (P < 0.01). The significance of MnSOD in cancer tissue was investigated further by measuring MnSOD content in resected specimens using an enzyme-linked immunosorbent assay, and by examining its location by an immunohistochemical method. Upregulation of MnSOD in cancer tissue most likely serves as a protective mechanism against anti-cancer therapies known to produce superoxide radicals as a key component of their tumor-killing activity.
放射疗法和化学疗法对癌症的肿瘤杀伤活性与活性氧的产生密切相关，并且肿瘤自身产生的治疗抗性与活性氧清除剂之间的关系正受到越来越多的关注。人们认为锰超氧化物歧化酶（MnSOD）与其他抗氧化酶协同作用，保护宿主细胞免受氧化应激。在本研究中，我们使用定量聚合酶链反应测定法来测量食管癌和胃癌患者切除标本中的MnSOD mRNA。在食管癌和胃癌中，与非癌组织相比，癌组织中MnSOD mRNA水平均显著升高（P < 0.01）。在胃癌组织中，MnSOD mRNA水平显著高于食管癌组织（P < 0.01）。通过使用酶联免疫吸附测定法测量切除标本中的MnSOD含量，并通过免疫组织化学方法检查其定位，进一步研究了癌组织中MnSOD的意义。癌组织中MnSOD的上调很可能作为一种保护机制，抵御已知在其肿瘤杀伤活性中产生超氧自由基作为关键成分的抗癌疗法。
