E-cadherin、β-catenin、γ-catenin基因在胃癌组织中表达与侵袭转移的相关性

Correlation of E-cadherin, β-catenin and γ-catenin gene expression with the invasion and metastasis of gastric cacinoma

目的探讨上皮型钙粘蛋白(E-cadherin)、连接素-β(β-catenin)及连接素-γ(γ-catenin)基因在胃癌组织中表达与侵袭转移的关系。方法采用免疫组织化学SP方法对60例胃癌、20例癌前病变(包括10例肠化生胃粘膜和10例异型增生胃粘膜)及20例正常组织进行E-cadherin、β-catenin、γ-catenin基因表达情况的检测。结果正常胃粘膜及肠化生胃粘膜组织中E-cadherin、β-catenin、γ-catenin的细胞膜均呈清晰的棕褐色染色;胃异型增生组织中,E-cadherin及β-catenin在同1例细胞膜表达基本丢失,γ-catenin表达未见异常,即在异型增生胃粘膜三者异常表达率为10%(1/10),在胃癌原发灶为80%(48/60),与胃癌Ming分型、TNM分期、淋巴结转移密切相关(P<0.05)。E-cadherin、β-catenin、γ-catenin基因异常表达率分别为61.67%、55.00%、58.33%。结论E-cadherin、β-catenin、γ-catenin基因异常表达导致细胞间粘附性下降,影响了细胞接触性生长抑制等信号的传导,从而参与细胞的恶性转化,与胃癌的生长类型、侵袭转移密切相关,是判断胃癌生物学行为的良好指标。

Objective To study the association of the expressions of E-cadherin, β- and γ-catenins in gastric carcinoma tissues with the invasion and metastasis of the tumor. Methods From 60 patients with gastric carcinoma, the paraffin-embedded specimens including 60 carcinoma tissues, 20 precancerous lesions (10 intestinal metaplasia and 10 dysplasia specimens) and 20 corresponding normal tissues adjacent to the carcinomas were obtained for detecting E-cadherin, β- and γ-catenin expressions by immunohistochemistry. Results Positive staining for E-cadherin, β- and γ-catenins was clearly observed on the cellular membrane throughout the epithelium in all the normal and metaplastic gastric mucosa. In 1 out of the 10 specimens of dysplastic mucosa, the staining for E-cadherin and β-catenin was absent but γ-catenin staining appeared normal. Up to 80% (48/60) of the gastric carcinoma specimens presented abnormal staining for at least one of the components of the cadherin- catenin complex, showing a close correlation to Ming's classification, TNM staging and lymph node metastasis (P<0.05). The rates of abnormal expression were 6.67% for E-cadherin, 55% for β-catenin and 58.33% for γ-catenin. Conclusions Abnormal expression of E-cadherin, β- and γ-catenins results in loss of epithelial cell-to-cell adhesion, whith leads to uncontrolled cell growth, and may therefore participate in malignant transformation of the cells, and closely associates with the invasive growth and metastasis of human gastric carcinoma.