Zhang Changcun, Mo Ren, Yin Binde, Zhou Libin, Liu Yongchao, Fan Jie
Department of Urology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, P.R. China.
Oncol Lett. 2014 May;7(5):1689-1694. doi: 10.3892/ol.2014.1931. Epub 2014 Mar 4.
MicroRNA-34a (miR-34a) is a tumor suppressive microRNA, which induces G1 arrest, apoptosis and senescence by repressing the expression of multiple oncogenes. This study aimed to investigate the biological function and molecular mechanisms of miR-34a in human renal cell carcinoma (RCC) cells. Quantitative polymerase chain reaction (qPCR) revealed that miR-34a expression was significantly downregulated in eight of the 10 (80%) RCC tissues compared with adjacent normal tissues. In RCC cell lines, several other target genes of miR-34a were dysregulated at the mRNA level when the expression of miR-34a was elevated. In addition, western blot analysis and qPCR revealed that forced expression of miR-34a downregulated the expression of Notch1 at the protein and mRNA level. The Cell Counting Kit-8 identified that transient forced expression of miR-34a inhibited cell growth and resulted in cell cycle arrest, which was evaluated by flow cytometry. Our data demonstrated that miR-34a inhibits cell proliferation by downregulating Notch1 in RCC cell lines.
微小RNA-34a（miR-34a）是一种具有肿瘤抑制作用的微小RNA，它通过抑制多种癌基因的表达来诱导G1期阻滞、细胞凋亡和衰老。本研究旨在探讨miR-34a在人肾细胞癌（RCC）细胞中的生物学功能和分子机制。定量聚合酶链反应（qPCR）显示，与相邻正常组织相比，10例RCC组织中有8例（80%）的miR-34a表达显著下调。在RCC细胞系中，当miR-34a表达升高时，其其他几个靶基因在mRNA水平上失调。此外，蛋白质印迹分析和qPCR显示，miR-34a的强制表达在蛋白质和mRNA水平上下调了Notch1的表达。细胞计数试剂盒-8检测发现，miR-34a的瞬时强制表达抑制细胞生长并导致细胞周期阻滞，这通过流式细胞术进行评估。我们的数据表明，miR-34a通过下调RCC细胞系中的Notch1来抑制细胞增殖。
