上皮型钙黏素β-链接素在鼻咽原发癌和淋巴结转移癌组织中的表达差异

The different expression pattern of E-cadherin and β-catenin in primary and metastatic tumors of nasopharyngeal carcinoma

目的 研究鼻咽原发癌和淋巴结转移癌组织中上皮型钙黏素 (E- cadherin)和β-链接素 (β- catenin)蛋白水平和 m RNA水平表达的差异性 ,探讨鼻咽癌癌细胞侵袭转移的机制。方法 采用蛋白印迹法、免疫组化法和反转录聚合酶链反应 (RT- PCR)法检测 2 1例鼻咽原发癌和 2 1例淋巴结转移癌组织中上皮型钙黏素和β-链接素蛋白和m RNA的表达水平。结果 (1) 2 1例淋巴结转移癌组织中 ,癌细胞的上皮型钙黏素蛋白表达率 (5 0 % )和蛋白印迹相对强度 (6 5 .0± 15 .9)均明显低于 2 1例原发癌组织中的表达水平 (80 %和 2 0 6 .7± 32 .7) ,且淋巴结转移癌组织中的上皮型钙黏素 m RNA表达水平也低于原发癌组织 ,差异有显著性 (P<0 .0 5 ) ;(2 )β-链接素在鼻咽原发癌和淋巴结转移癌组织中均有较高的蛋白表达量 ,其 m RNA表达水平在不同组织中的表达也相似 ,均未显示有差异性 (P>0 .0 5 ) ;(3)鼻咽原发癌和淋巴结转移癌组织中癌细胞表达上皮型钙黏素和β-链接素未显示相关性 (P>0 .0 5 )。结论 (1)在鼻咽癌组织中 ,导致癌细胞侵袭转移的一个重要因素可能是上皮型钙黏素的表达下调。 (2 )

Objective To detect the expression level of protein and mRNA of E-cadherin and β-catenin in primary tumor and metastatic lymph node of nasopharyngeal carcinoma (NPC), and to investigate the mechanism of invasion and metastasis of neoplastic cell in NPC. Methods Biopsy specimens taken from primary tumor and metastatic lymph nodes of 42 NPC patients. Western blotting, immunohistochemical staining and reverse transcriptase-polymeraes chain reaction (RT-PCR) were adopted to detect the expression of protein and mRNA of E-cadherin and β-catenin in all 42 samples. Results (1) There was lower expression level of protein and mRNA of E-cadherin in metastatic lymph nodes than that in primary tumor of NPC ( P <0 05). (2) Both primary NPC and lymphoid metastatic NPC were found to have high β-catenin expression on the cell membrane, but there was no difference between two groups of specimens ( P >0 05). (3) There was no correlation between β-catenin expression and that of E-cadherin neither in primary tumor or in metastatic lymph nodes. Conclusion (1) Down regulated expression of E-cadherin may play a role in neoplastic cell invasion and metastasis in NPC. (2) Accumulation of β-catenin in NPC might be a promoting factor to induce tumor cell invasion and metastasis in NPC.