β-catenin在食管鳞癌中的异常表达及临床意义

摘要

目的 探讨β-catenin基因在食管鳞状细胞癌(Esophageal squamous cell carcinoma,ESCC)中的表达及其意义.方法 免疫组化法检测65例ESCC及20例因ESCC手术切除的远切端正常食管黏膜组织中β-catenin的表达及定位,分析其与临床病理学参数的关系;RT-PCR检测31例新鲜ESCC及相应的远切断正常食管黏膜组织中β-catenin mRNA的表达.结果 免疫组化结果显示:在20例因ESCC手术切除的远切端正常食管黏膜组织中,β-catenin主要位于胞膜;在65例ESCC组织中,β-catenin的胞质积累阳性率为63.1%,胞核积累阳性率为30.8%;β-catenin的胞质/核积累与淋巴结转移相关(P=0.005),但与患者的年龄、性别、肿瘤的分化程度及浸润深度等无关.RT-PCR结果显示:在31例ESCC及相应的远切端正常食管黏膜组织中,均检测到β-catenin mRNA的表达,与相应的远切端正常食管黏膜组织比较,癌组织中β-catenin基因mRNA的表达水平明显升高(P=0.037),其中表达升高的21例,占67.7%,表达无明显差异的8例,占25.8%,表达降低的2例,占6.5%.结论 在ESCC中存在β-catenin mRNA表达水平的升高以及β-catenin蛋白的异常胞质/胞核积累,并与淋巴结转移有关.%Objective To explore the expression and significance of β-catenin in esophageal squamous cell carcinoma (ESCC). Methods Immunohistochemiscal staining was used to examine the expression of β-catenin protein in 65 cases of formalin-fixed, paraffin-embeded ESCC tissue (n=65) and their corresponding nonneoplastic epithelial tissues (n=20). RT-PCR was used to determine the expression of β-catenin in 31 cases of fresh ESCC tissue (n=31) and their corresponding nonneoplastic epithelial tissues (n=31).Results In the 20 samples of normal esophageal mucosa, immunohistochemistry showed that β-catenin was mainly located in the membrane, while 41 in 65 (63. 1％) tumor samples had cytoplasmic accumulation of β-catenin and 20 (30. 8％ ) had nuclear staining. The cytoplasmicuclear β-catenin was significantly associated with lymph node metastasis (P=0. 005) , but not with the patient's age, gender, tumor grade or differentiation grade. In 31 fresh ESCC tissues studied, all tumor samples and paired normal samples expressed β-catenin mRNA. Twenty-one of 31 (66. 7％) tumors expressed β-catenin mRNA at a higher level than their corresponding nonneoplastic tissues, 8 of 31 (25. 8％) were almost the same, and 2 of 31 (6.5％) showed lower expression. Altogether, tumor tissues expressed a significantly higher level of β-catenin mRNA than the corresponding nonneoplastic tissues (P = 0. 037). Conclusion ESCC shows an increased expression of β-catenin mRNA, and the abnormal cytoplasmicuclear accumulation of β-catenin is significantly associated with lymph node metastasis.