上皮钙黏蛋白在肺癌组织中的表达及其基因点突变

Expression of E-cadherin in lung cancer and its point mutationt

目的：探讨上皮钙黏蛋白在肺腺癌及腺鳞癌组织中的表达以及该基因发生点突变与肺癌发生的关系。方法：采用免疫组织化学检测31例肺癌临床标本及13例癌旁肺组织中上皮钙黏蛋白的表达；PCR法检测上皮钙黏蛋白基因7号和9号染色体点突变在25对肺癌组织及配对的癌旁肺组织中的表达。结果：上皮钙黏蛋白在肺腺癌和腺鳞癌组织中的阳性表达率低于癌旁组织26．56％，其表达在低分化肺癌组织中较高分化和中分化肺癌组织中下调约40％，在转移组中比未转移组中低18．5％；肺癌组织与配对的癌旁肺组织中上皮钙黏蛋白基因7号染色体点的突变率均为52％，9号染色体的点突变率分别为64％和60％，两者无差异。结论：上皮钙黏蛋白表达下调与肺癌发生相关，且其表达随着肺癌分化程度降低及发生转移而下调；肺癌组织中上皮钙黏蛋白基因发生了突变，但基因突变不是引起上皮钙黏蛋白在肺癌组织中下调的唯一因素。

Objective： To investigate the expressions of E-cadherin in pulmonary adenocarcmoma ana aaenosquamous carcinoma, and explore the relationship between its point mutation and genesis of lung cancer. Methods： The expressions of E-cadherin in 31 cases of lung cancer tissues and 13 cases of adjacent normal tissues were examined by inwaunohistochemistry. Point mutations of E-cadherin on chromosome 7 and 9 were detected in 25 pairs of lung cancer tissues and adiacent normal tissues with PCR method. Results： The positive rate of E-cadherin in lung cancer was significantly lower than that in adia- cent normal tissues （26.56%）. Compared with well-differentiated and medium-differentiated lung cancer, the expression of E-cadherin in low-differentiation type was decreased by 40%. Compared with the non-metastasis group, the expression of E-cadherin in the metastasis group was decreased by 18. 5%. The point mutations on chromosome 7 of E-cadherin were both 52% in lung cancer tissues and adiaeent normal tissues. The point mutations on chromosome 9 were 640% and 60% respectively. There was no difference between two groups. Conclusion： The expression of E-cadherin plays an important role in the genesis, development and metastasis of lung cancer. The mutation of E-cadherin does occur in lung cancer, but it is not the only factor in determining its down-regulation.