窖蛋白-1在肺癌中的表达及意义

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。

Significance of caveolin-1 expression in primary lung cancer

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 caveolin-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 non-neoplastic 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). Caveolin-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.