窖蛋白-1在肺癌中的表达及意义

Significance of caveolin-1 expression in primary lung cancer

目的探讨窖蛋白-1(caveolin-1)在不同类型肺癌组织中的表达及其与微血管密度(MVD)和临床病理因素之间的关系。方法对154例原发性肺癌、相应癌旁正常肺组织及36例淋巴结转移癌行caveolin-1免疫组织化学染色;对154例原发性肺癌行CD34免疫组织化学(SP法)染色并进行微血管密度计数;Western印迹法检测其中50例新鲜肺癌组织及其癌旁正常肺组织中caveolin-1的表达情况。结果caveolin-1为膜/质表达蛋白,在正常支气管上皮细胞和肺泡上皮细胞中的阳性率为100%。在肺癌组织中的阳性率为59.1%(91/154),低于癌旁正常肺组织,P<0.01;Western印迹结果进一步证实caveolin-1在肺鳞癌、肺腺癌组织中的表达均显著低于癌旁正常肺组织,P<0.01。caveolin-1在小细胞肺癌(SCLC)和非小细胞肺癌(NSCLC)中的阳性率分别为7.1%和64.3%,二者间差异有统计学意义,P<0.01。NSCLC中,有淋巴结转移组caveolin-1表达高于无淋巴结转移组(P=0.005);Ⅲ、Ⅳ期组caveolin-1表达显著高于Ⅰ、Ⅱ期组(P=0.042),caveolin-1表达与NSCLC的其他临床病理因素及MVD值无关(P>0.05)。结论caveolin-1其作为一种肿瘤抑制因子的同时,可能还具有促进NSCLC进展和转移的活性。

Objective To study the expression of caveolin-1 in primary lung cancer and its relationship with microvessel density and clinicopathologic parameters. Methods Immunohistochemical study for eaveolin-1 and CD34 was performed on paraffin sections of 154 cases of primary lung cancer and adjacent non-neoplastic lung parenchymal tissue, as well as 36 cases with nodal metastasis. Microvessel density was analyzed by CD34 immunostaining. Western blot assay was also employed in tumor and nonneoplastic lung tissues of the 50 cases （25 cases of pulmonary squamous cell carcinoma and 25 cases of pulmonary adenocarcinoma） with fresh specimens available. Results Immunohistochemical study showed that non-neoplastic bronchial and alveolar epithelium was positive for caveolin-1 （membranous and cytoplasmic）. The expression rate of caveolin-1 in lung cancer was 59. 1% , which was significantly lower than that in normal lung tissues （P 〈 0.01 ）. Western blot assay confirmed that the expression of caveolin-1 in pulmonary squamous cell carcinoma and adenocarcinoma was lower than in surrounding non-neoplastic lung tissues （P 〈 0.01 ）. Caveolln-1 expression in pulmonary small cell carcinoma （7. 1%） was significantly lower than that in non-small cell carcinoma （64. 3% ） （P 〈0. 01 ）. Within the group of non- small cell carcinoma, the expression of caveolin-1 was much higher in patients with lymph node metastasis （P=0.005）. The expression was also higher in stage Ⅲ and Ⅳ than in stage Ⅰ and Ⅱ disease （P = 0. 042）. Conclusions The expression of caveolin-1 is lower in lung cancer tissues than that in non-small cell carcinoma, it is also significantly correlated with tumor stage and lymph node metastasis. Caveolin-1 may play some role in the progression of pulmonary non-small cell carcinoma.