Yu Qian-Qian, Wu Hao, Huang Xiang, Shen Hua, Shu Yong-Qian, Zhang Bin, Xiang Cheng-Cheng, Yu Shao-Min, Guo Ren-Hua, Chen Liang
Department of Oncology, First Affiliated Hospital of Nanjing Medical University, 300, Guangzhou Road, Nanjing, Jiangsu 210029, China.
Department of Cardiothoracic Surgery, First Affiliated Hospital of Nanjing Medical University, 300, Guangzhou Road, Nanjing, Jiangsu 210029, China.
Biomed Pharmacother. 2014 Mar;68(2):155-61. doi: 10.1016/j.biopha.2014.01.005. Epub 2014 Jan 15.
MicroRNAs are small endogenous RNAs that play important roles in the pathogenesis of human diseases, including malignancy. MicroRNA-1 (miR-1) is downregulated in non-small cell lung cancer (NSCLC); however, the underlying mechanisms by which it suppresses tumorigenesis in NSCLC are largely unknown. We investigated whether phosphoinositide-3-kinase catalytic subunit alpha (PIK3CA) was a novel target of miR-1 in the NSCLC cell line A549, and the mechanism of miR-1 inhibition of the tumorigenic properties of A549 cells is discussed. The influence of miR-1 on A549 cells was studied by transfection with miR-1 mimics or inhibitor. MiR-1 overexpression led to downregulation of PIK3CA protein, but not mRNA by western blot and quantitative real-time PCR, respectively. The dual-luciferase reporter assay confirmed that miR-1 targeted PIK3CA directly. PIK3CA downregulation by miR-1 mimics led to a significant reduction of phosphorylated Akt and survivin protein, the downstream targets of the PI3K/Akt pathway. Cell proliferation was studied using a cell counting kit. Migration and invasion were evaluated by Transwell and Matrigel assays, respectively. Cell cycle and apoptosis were detected by flow cytometry. The results were that miR-1 upregulation inhibited A549 cell proliferation, migration, and invasion. These findings indicate that miR-1 may play an important role in the pathogenesis of NSCLC by regulating PIK3CA through the PI3K/Akt pathway. Increasing miR-1 expression may provide a novel approach for NSCLC treatment.
微小RNA是一类小的内源性RNA，在包括恶性肿瘤在内的人类疾病发病机制中发挥重要作用。微小RNA-1（miR-1）在非小细胞肺癌（NSCLC）中表达下调；然而，其在NSCLC中抑制肿瘤发生的潜在机制尚不清楚。我们研究了磷酸肌醇-3-激酶催化亚基α（PIK3CA）是否是NSCLC细胞系A549中miR-1的新靶点，并探讨了miR-1抑制A549细胞致瘤特性的机制。通过转染miR-1模拟物或抑制剂研究miR-1对A549细胞的影响。miR-1过表达分别通过蛋白质印迹法和定量实时PCR导致PIK3CA蛋白表达下调，但mRNA表达未下调。双荧光素酶报告基因检测证实miR-1直接靶向PIK3CA。miR-1模拟物下调PIK3CA导致PI3K/Akt途径的下游靶点磷酸化Akt和生存素蛋白显著减少。使用细胞计数试剂盒研究细胞增殖。分别通过Transwell和基质胶实验评估迁移和侵袭能力。通过流式细胞术检测细胞周期和凋亡。结果显示，miR-1上调抑制A549细胞增殖、迁移和侵袭。这些发现表明，miR-1可能通过PI3K/Akt途径调节PIK3CA在NSCLC发病机制中发挥重要作用。增加miR-1表达可能为NSCLC治疗提供一种新方法。
