Yokoe Hidetaka, Nomura Hitomi, Yamano Yukio, Fushimi Kazuaki, Sakamoto Yosuke, Ogawara Katsunori, Shiiba Masashi, Bukawa Hiroki, Uzawa Katsuhiro, Takiguchi Yuichi, Tanzawa Hideki
Division of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital;
Exp Ther Med. 2010 Jul;1(4):585-590. doi: 10.3892/etm_00000092. Epub 2010 Jul 1.
Oxidative stress results in damage to cellular structures and has been linked to numerous diseases, including cancer. Extracellular superoxide dismutase (EC-SOD) is a principal enzymatic antioxidant in extracellular space. The purpose of this study was to determine whether the expression of EC-SOD protein is altered in the carcinogenetic process of oral squamous-cell carcinoma (OSCC). Immunohistochemical analysis was carried out in matched normal and tumour specimens collected from 58 OSCCs and 20 oral premalignant lesions (OPLs). Correlations between the EC-SOD expression levels and clinicopathological features of OSCC patients were evaluated by Fisher's exact test. Although EC-SOD protein was consistently expressed on the plasma membrane of cells in normal tissues, plasma membranous EC-SOD expression was lost in almost all the OSCC specimens examined (98%). Instead, positive EC-SOD expression was detected in the cytoplasmic compartments of cancerous cells in both OPLs (65%) and OSCCs (52%), together with a high incidence of lymph node metastasis (p=0.0397). These results suggest that the dysregulation of EC-SOD protein expression is a frequently occuring and early event in oral carcinogenesis, and that cytoplasmic EC-SOD may contribute to the increased aggressiveness of OSCC.
氧化应激会导致细胞结构受损，并与包括癌症在内的多种疾病相关联。细胞外超氧化物歧化酶（EC-SOD）是细胞外空间中的一种主要酶促抗氧化剂。本研究的目的是确定在口腔鳞状细胞癌（OSCC）的致癌过程中EC-SOD蛋白的表达是否发生改变。对从58例OSCC和20例口腔癌前病变（OPL）中收集的配对正常和肿瘤标本进行了免疫组织化学分析。通过Fisher精确检验评估EC-SOD表达水平与OSCC患者临床病理特征之间的相关性。虽然EC-SOD蛋白在正常组织细胞的质膜上持续表达，但在几乎所有检测的OSCC标本（98%）中质膜EC-SOD表达缺失。相反，在OPL（65%）和OSCC（52%）的癌细胞胞质区室中均检测到EC-SOD阳性表达，同时伴有高淋巴结转移发生率（p=0.0397）。这些结果表明，EC-SOD蛋白表达失调是口腔癌发生中经常发生的早期事件，并且胞质EC-SOD可能导致OSCC侵袭性增加。
