Reduced expression of manganese superoxide dismutase mRNA may correlate with invasiveness in esophageal carcinoma

Little is known about the expression and antioxidant function of manganese superoxide dismutase (Mn-SOD) in esophageal squamous cell carcinoma, To det ermine the significance of Mn-SOD in esophageal squamous cell carcinomas, M n-SOD mRNA expression was examined in 45 esophageal squamous cell carcinoma s and the corresponding normal mucosal tissues by reverse transcription-pol ymerase chain reaction, The tumor/normal (T/N) ratio of 45 patients with es ophageal carcinoma was calculated, and the data were clinicopathologically analyzed. The T/N ratio of Mn-SOD mRNA expression was less than 0.5 in 11 ( 32.4%) of 34 esophageal carcinoma cases without any preoperative treatments , while none of 11 cases who underwent preoperative chemotherapy showed a T /N ratio of < 0.5 (p < 0.05), There was an inverse correlation between the Mn-SOD expression level and the degree of venous invasion (p < 0.05) as wel l as lymphatic invasion (p < 0.05), Furthermore, poorly differentiated squa mous cell carcinoma showed significantly lower Mn-SOD mRNA expression level s than well differentiated carcinoma (p < 0.05), Our results suggest that M n-SOD mRNA was frequently reduced in esophageal carcinoma when compared to the normal mucosa and the reduced expression levels of Mn-SOD mRNA may lead to an accumulation of superoxide radicals in conjunction with the increase d invasiveness of esophageal carcinoma, Copyright (C) 2000 S. Karger AG. Ba sel.