Alteration of extracellular superoxide dismutase expression is associated with an aggressive phenotype of oral squamous-cell carcinoma

作者：Yokoe Hidetaka; Nomura Hitomi; Yamano Yukio; Fushimi Kazuaki; Sakamoto Yosuke; Ogawara Katsunori; Shiiba Masashi; Bukawa Hiroki; Uzawa Katsuhiro; Takiguchi Yuichi; Tanzawa Hideki^*

来源：Experimental and Therapeutic Medicine, 2010, 1(4): 585-590.

DOI：10.3892/etm_00000092

• extracellular superoxide dismutase
• oral squamous-cell carcinoma
• immunohistochemistry
• lymph node metastasis
• aggressive phenotype

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.

• 出版日期2010-8