非小细胞肺癌中窖蛋白1基因的蛋白表达和甲基化及其意义

目的 检测窖蛋白1(Car-1)在非小细胞肺癌(NSCLC)中的蛋白表达以及启动子的甲基化状况,探讨Cav-1基因在NSCLC中的作用及其临床意义.方法 应用免疫组织化学(sP法)和量子点Qd600染色检测123例NSCLC组织、17例良性病变肺组织中Cav一1蛋白表达和亚细胞定位.亚硫酸氢钠处理DNA,甲基化特异性PCR(MSP)检测Cav-1基因启动子区域的甲基化水平.结果 Cav-1蛋白在肺支气管黏膜上皮细胞、肺泡上皮细胞、毛细血管内皮细胞、成纤维细胞、平滑肌细胞的胞质和胞膜高表达.癌旁组织(对照)组和肺癌组中Cav-1蛋白的阳性率分别为17/17、43.1%(53/123),两组间差异有统计学意义(P=0.001);Cav-1蛋白在NSCLC不同的组织学类型(P=0.552)和分化程度(P=0.160)中差异均无统计学意义.Cav-1蛋白阳性率与NSCLC的TNM分期(P=0.001)以及淋巴结转移(P=0.001)均相关.在40例Cav-1蛋白表达为阴性的肺癌组织和12例癌旁肺组织,MSP法均未检测到Cav-1因启动子区域的甲基化.结论 Cav-1蛋白失表达的机制可能与启动子区是否甲基化无关.Cav-1蛋白高表达预示NSCLC恶化进展和高侵袭性.

Study on expression and methylation of caveolin 1 gene in non-small cell lung cancers

Objective To study the methylation of CpG islands in the promoter region, expression of caveolin 1(Cav-1)gene and their clinical significance in non. small cell lung cancers(NSCLC). Methods Immunohistochemistry and quanta Qd600 staining were used to detect the expression of Cav-1 in tissues from benign lung lesions(n=17)and NSCLC(n=123). DNA was treated with sodium bisulfite and the Cav-1 promoter region was screened using methylation. specmc polymerase chain reaction for the possible methylation sites. Results Cav. 1 protein was highly expressed in cytoplasm and cell membrane of normal bronchial epithelium, alveolar epithelium, endothelial cells. fibroblasts and smooth muscle cells. The expression rates of Cav-1 protein were 100%(17/17)in the control group and 43. 1%(53/123)in the NSCLC group(P=0. 001). Amongst the NSCLC group, there was no statistically significant difference in Cav-1 protein expression in different histologic types(P=0. 552)and tumor grades(P=0. 160). 0n the other hand, Car-1 protein immunoreactivity was remarkably higher in advanced tumor stage:72. 7%in stage ⅢA+ⅢB, compared with 9. 4% in stage IA+IB and 38. 3%in stageⅡA+ⅡB(P=0. 001). The expression rate of Cav-1 protein in the NSCLC cases with lymph node metastasis was 53. 6%. compared with 20. 5%in those without nodal involvement(P=0. 001). DNA from 40 NSCLC cases with negative Cav-1 protein expression and 12 cases of pefitumoral lung tissues were extracted. Methylation in the promoter region of Car-1 gene was not detected in lung cancer or peritumoral tissues. Conclusions High expression of Cav1 protein is respected of the aggressive clinical behavior and advanced tumor stage. Loss of Cav-1 protein expression seems not correlated to the methylation status in the promoter region of Cav-1 gene.