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 determine the significance of Mn-SOD in esophageal squamous cell carcinomas, Mn-SOD mRNA expression was examined in 45 esophageal squamous cell carcinomas and the corresponding normal mucosal tissues by reverse transcription-polymerase chain reaction. The tumor/normal (T/N) ratio of 45 patients with esophageal 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 well as lymphatic invasion (p < 0.05). Furthermore, poorly differentiated squamous cell carcinoma showed significantly lower Mn-SOD mRNA expression levels than well differentiated carcinoma (p < 0.05). Our results suggest that Mn-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 increased invasiveness of esophageal carcinoma.
Toh
Y
Y
Department of Gastroenterologic Surgery, National Kyushu Cancer Center, Fukuoka, Japan. ytoh@nk-cc.go.jp
Kuninaka
S
S
Mori
M
M
Oshiro
T
T
Ikeda
Y
Y
Nakashima
H
H
Baba
H
H
Kohnoe
S
S
Okamura
T
T
Sugimachi
K
K
D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D004938:Esophageal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D009092:Mucous Membrane / Q000201:enzymology; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000235:genetics*
D012333:RNA, Messenger; D013482:Superoxide Dismutase