目的：探讨miRNA-101(miR-101)在肺癌组织和细胞中的表达及其对人肺癌细胞增殖、克隆形成和成瘤能力的影响。方法： 采用Western blotting和实时荧光定量RT-PCR技术分别检测10例患者肺癌组织及相应癌旁组织、人肺癌细胞A549和NCI-H26及正常人胚肺成纤维细胞MRC-5中环氧合酶2（cyclooxygenase-2,COX-2）及miR-101的表达。A549和NCI-H26细胞分别转染miR-NC和miR-101构建过表达miR-101的细胞系及其对照，Western blotting、CCK-8和克隆形成实验分别检测过表达miR-101对A549、NCI-H26细胞中COX-2的表达、细胞增殖和克隆形成能力的影响。用A549、A549/NC、A549/101细胞在BALB/c裸鼠皮下构建移植瘤模型，观察过表达miR-101对A549细胞小鼠移植瘤生长的影响。结果： 在肺癌组织和A549、NCI-H26细胞中，COX-2的表达明显高于癌旁组织（t=20.03，P=0.001）和MRC-5细胞（t=14.59，P=0.012），而miR-101的表达则相反（组织：t=18.33，P=0.002 ；细胞：t=28.95，P=0.000）。成功构建过表达miR-101的A549/101、NCI-H26/101细胞系，与A549、NCI-H26细胞相比，A549/101（t=26.03，P=0.000）、NCI-H26/101（t=23.29，P<0.01）细胞内COX-2表达量显著降低，A549/101和NCI-H26/101细胞的活力和克隆形成能力也显著降低（均P<0.05）。A549/101细胞小鼠皮下肿瘤的生长速度较A549细胞和A549/NC细胞显著减慢（F=14.81，P=0.003）。结论： 肺癌组织和A549、NCI-H26细胞中miR-101低表达、COX-2高表达，过表达miR-101可以抑制A549、NCI-H26细胞的增殖，其机制可能与下调了COX-2表达有关。

Objective:To investigate the expression of miRNA-101(miR-101) in lung cancer specimens and lung cancer cell lines as well as its impact on the proliferative, colony-forming and tumorigenic capacities of human lung cancer cells. Methods: Cyclooxygenase-2 (COX-2) and miR-101 mRNA and protein levels were assessed, respectively, by RT-PCR and Western blotting in clinical specimens (lung cancer tissue and the surrounding normal tissue) collected from 10 patients, human lung cancer cell lines A549 and NCI-H226, and human diploid MRC-5 fibroblasts. A549 and NCI-H226 cells were transfected with miR-NC and miR-101 respectively. The transfectants were assessed for COX-2 protein content by Western blotting, proliferative activity by CCK-8, colony-forming capacity by colony formation experiments, and tumorigenic capacity in vivo by xenograft experiments in nude BAL B/C mice. Results: COX-2 protein content was significantly higher in cancer tissue specimens than in both para-cancer tissue specimens (t=20.03, P=0.001) and human diploid MRC-5 fibroblasts (t=14.59, P=0.012). In contrast, the expression of miR-101 was down-regulated in lung cancer tissue specimens and cell lines as compared with para-cancer tissue specimens (t=18.33, P=0.002) and human diploid MRC-5 fibroblasts (t=28.95, P=0.000). Overexpression of miR101 resulted in a significant decreases in COX-2 expression (t=26.03, P=0.000) and proliferative (F=5.783, P=0.017) and colony-forming (Dunnett t test I-J=－0.28, P=0.035) capacities of A549 and NCI-H226 lung cancer cells in vitro. A549 cells overexpressing miR101 had a remarkably reduced tumorigenic capacity in nude BALB/c mice in vivo (F=14.8, P=0.003). Conclusion:MicroR-101 is downregulated whereas COX-2 is up-regulated in lung cancer. Over-expression of miR-101 results in significant inhibition of proliferation, colony formation and tumorigenesis of lung cancer cells through down-regulation of COX-2 and thus may offer a potential therapeutic option for lung cancer.

河南省卫生厅课题资助项目（No. 1203068）