Characterization of intracellular superoxide dismutase alterations in premalignant and malignant lesions of the oral cavity: correlation with lymph node metastasis.
OBJECTIVE
The purpose of this study was to characterize changes in the expression of copper-zinc superoxide dismutase (Cu/Zn-SOD) and manganese SOD (Mn-SOD) in oral squamous-cell carcinoma (OSCC).


METHODS
Real-time quantitative reverse transcriptase-polymerase chain reaction analysis of Cu/Zn-SOD and Mn-SOD mRNA expression was carried out in 50 pairs of OSCC tissue specimens and corresponding normal tissues. Mn-SOD protein expression was evaluated further in 65 OSCC tissue samples and 33 oral premalignant lesions (OPLs) using immunohistochemistry.


RESULTS
Significant (P < 0.001) upregulation of Mn-SOD mRNA expression was observed in OSCC tissues compared with the normal tissue counterparts, whereas no significant difference was detected in Cu/Zn-SOD expression. Significant increases in Mn-SOD protein expression were seen in both OPLs (P < 0.001) and OSCC tissue (P < 0.001) together with a high incidence of lymph node metastasis (P = 0.04).


CONCLUSIONS
Our findings suggested that Mn-SOD overexpression is a frequent and early event during oral carcinogenesis and could contribute to aggressive OSCC.
Yokoe
Hidetaka
H
Division of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Nomura
Hitomi
H
Yamano
Yukio
Y
Fushimi
Kazuaki
K
Sakamoto
Yosuke
Y
Ogawara
Katsunori
K
Shiiba
Masashi
M
Bukawa
Hiroki
H
Uzawa
Katsuhiro
K
Takiguchi
Yuichi
Y
Tanzawa
Hideki
H
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000473:pathology; D011230:Precancerous Conditions / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D013482:Superoxide Dismutase / Q000032:analysis / Q000235:genetics / Q000502:physiology*
D012333:RNA, Messenger; D013482:Superoxide Dismutase