锰超氧化物歧化酶在食管鳞癌组织中的表达及其临床意义

Expression of MnSOD mRNA and protein in esophageal squamous cell carcinoma and its clinical significance

目的 探讨锰超氧化物歧化酶（MnSOD）在食管鳞癌组织中的表达及其与食管鳞癌临床病理特征及生物学行为的关系.方法 采用免疫组织化学SP法和逆转录聚合酶链反应（RT-PCR）,检测45例食管鳞癌组织及距肿瘤组织边缘＞5 cm的正常组织中MnSOD蛋白和mRNA的表达水平,并分析其与食管癌临床病理特征及生物学行为之间的关系.结果 MnSOD蛋白在45例食管鳞癌组织中的阳性表达率为31.1%,明显低于正常食管组织中的阳性表达率（86.7%,P＜0.05）.MnSOD mRNA在45例食管鳞癌组织的相对表达量为0.310±0.036,亦明显低于其在正常食管组织中的相对表达量（0.482±0.053,P＜0.05）.MnSOD蛋白和mRNA的表达与食管鳞癌的病变长度、浸润深度和组织学分级有关,即病变长度越长、浸润深度越深、组织学分级越高者,MnSOD表达水平越低（均P＜0.05）.MnSOD蛋白和mRNA的表达与食管鳞癌的淋巴结转移状况、病变部位和病变类型均无关（均P＞0.05）.结论 食管鳞癌组织中,MnSOD蛋白和mRNA的表达水平均明显降低,检测MnSOD的表达对食管癌的临床治疗和预后判断有一定的参考价值.

Objective To investigate the expression of manganese superoxide dismutase （MnSOD） and to determine the relationship between MnSOD expression and clinicopathological features, biological behaviors in esophageal carcinoma. Methods Immunohistochemistry （SP） and RT-PCR were respectively used to detect the expression of MnSOD in 45 specimens of esophageal carcinoma tissues and normal esophageal mucosa （5 cm distant from the margin of cancer）. Results The positive rate of MnSOD protein expression was 31.1% in esophageal carcinoma tissues, significantly lower than 86.7% in the normal tissues （P〈0.05）. The expressions of MnSOD mRNA and protein were significantly correlated with the lesion length, depths of invasion and histological grade （ P 〈 0.05 ）, but not with lymph node metastasis, lesion site and gross type of the tumor （ P 〉 0.05 ）. The relative content of MnSOD mRNA was （0.310 ± 0.036 ） and （0.482 ±0.053） in the cancer and normal tissues, respectively, with a significant difference between the two groups （P〈0.05）. The relative content of MnSOD mRNA was significantly related to lesion length,depths of invasion and histological grade （P 〈0.05） ,but not correlated with lymph node status, lesion site and gross type of the tumor （ P 〉 0.05 ）. Conclusion The expression of MnSOD protein and mRNA is decreased in esophageal carcinoma, suggesting that MnSOD gene may be closely associated with the carcinogenesis and the degree of malignancy. Detection of MnSOD expression may be useful in diagnosis,treatment and prognosis of esophageal carcinoma.