miR-21调控非小细胞肺癌细胞增殖和凋亡的机制研究  

Overexpression of miR-21 promotes proliferation and reduces apoptosis in non-small cell lung cancer

作　　者：兰海[1] 林丛尧[1] 袁宏银[1] 熊斌[1] 

机构地区：[1]武汉大学中南医院肿瘤科,430071

出　　处：《中华肿瘤杂志》2011年第10期742-746,共5页Chinese Journal of Oncology

摘　　要：目的研究非小细胞肺癌（NSCLC）中高表达的miR-21对细胞增殖和凋亡的影响及其调控机制。方法采用荧光定量聚合酶链反应检测miR-21在人NSCLC组织、癌旁组织和A549细胞系中的表达。通过序列分析预测被miR-21调控的抑癌基因，通过荧光素酶活性检测和Western blot检测验证miR-21对靶基因表达调控的影响。采用RNA干扰技术抑制miR-21和程序性细胞死亡因子4（PDCD4），以台盼蓝染色和流式细胞术检测A549细胞增殖和凋亡的变化。结果NSCLC组织和A549细胞中miR-21的表达水平分别为癌旁组织的2．24倍和3．06倍。序列预测和基因表达调控研究表明，miR-21可以在NSCLC中反向调控PDCD4的表达（P〈0．01）。荧光素酶活性检测结果显示，共同转入Wt3’UTR和miR-21会显著抑制A549细胞中的荧光素酶表达（P〈0．001）。Western blot检测结果显示，导人反义寡核苷酸抑制miR-21的功能后，PDCD4的表达水平明显上升。抑制miR-21的作用可以显著抑制A549细胞的增殖，并使细胞凋亡率由2．6％上升到10．9％，而抑制PDCD4的表达可以在很大程度上消除miR-21介导的细胞增殖障碍，抑制细胞凋亡。结论在NSCLC中，抑制抑癌基因PDCD4的表达可能是miR-21介导肿瘤细胞增殖、抵抗凋亡的重要途径之一。Objective To elucidate the regulatory mechanism underlying proliferation and antiapoptosis in NSCLC by overexpression of miR-21. Methods Real-time PCR was used to measure miR-21 abundance in non-small cell lung cancer （ NSCLC ） tumor samples and adjacent normal tissues, as well as NSCLC cell lines. Tumor suppressor genes as potential targets of miR-21 were predicted by sequence analysis. Luciferase assay and Western blot were used to assess the regulatory effect. The effect on A549 cell viability and apoptosis by miR-21-induced gene repression was tested by trypan-blue exclusion and flow cytometry. Results miR-21 expression was 2.24-fold higher in the NSCLC tumor samples and 3.06-fold higher in the A549 cells than that in the adjacent normal tissues. Sequence prediction and gene expression regulation assays showed that miR-21 could reversely regulate the expression of PDCIM （ P 〈 0. 01 ）. Suppression of miR-21 expression is associated with an elevation of Pdcd4, resulting in a significant reduction of proliferation and the apoptosis rate （2.6%） was increased to 10.9%. Moreover, the anti- proliferation and pro-apoptotic effect by miR-21 suppression could be reversed by PDCIM knock down. Conclusion Suppression of the tumor suppressor PDCD4 expression may be one of the important regulatory pathways of the miR-21-mediated cell proliferation and decrease of apoptosis in non-small cell lung cancer.

关 键 词：癌 非小细胞肺 MIR-21 程序性细胞死亡因子4 细胞增殖 细胞凋亡 

分 类 号：R734.2[医药卫生—肿瘤]