Han Peng, Li Jing-Wen, Zhang Bo-Miao, Lv Jia-Chen, Li Yong-Min, Gu Xin-Yue, Yu Zhi-Wei, Jia Yun-He, Bai Xue-Feng, Li Li, Liu Yan-Long, Cui Bin-Bin
Department of Colorectal Surgery, The Affiliated Tumor Hospital of Harbin Medical University, 150 Haping Road, Harbin, 150040, People's Republic of China.
Mol Cancer. 2017 Jan 13;16(1):9. doi: 10.1186/s12943-017-0583-1.
With more than 600,000 mortalities each year, colorectal cancer (CRC) is the third most commonly diagnosed type of cancer worldwide. Recently, mechanisms involving noncoding RNAs have been implicated in the development of CRC.
We examined expression levels of lncRNA CRNDE and miR-181a-5p in 64 cases of CRC tissues and cell lines by qRT-PCR. Gain-of-function and loss-of-function assays were performed to examine the effect of CRNDE and miR-181a-5p on proliferation and chemoresistance of CRC cells. Using fluorescence reporter and western blot assays, we also explored the possible mechanisms of CRNDE in CRC cells.
In this study, we found that the expression levels of the CRNDE were upregulated in CRC clinical tissue samples. We identified microRNA miR-181a-5p as an inhibitory target of CRNDE. Both CRNDE knockdown and miR-181a-5p overexpression in CRC cell lines led to inhibited cell proliferation and reduced chemoresistance. We also determined that β-catenin and TCF4 were inhibitory targets of miR-181a-5p, and that Wnt/β-catenin signaling was inhibited by both CRNDE knockdown and miR-181a-5p overexpression. Significantly, we found that the repression of cell proliferation, the reduction of chemoresistance, and the inhibition of Wnt/β-catenin signaling induced by CRNDE knockdown would require the increased expression of miR-181a-5p.
Our study demonstrated that the lncRNA CRNDE could regulate the progression and chemoresistance of CRC via modulating the expression levels of miR-181a-5p and the activity of Wnt/β-catenin signaling.
结直肠癌（CRC）每年导致超过60万人死亡，是全球第三大常见诊断癌症类型。最近，涉及非编码RNA的机制与CRC的发生发展有关。
我们通过qRT-PCR检测了64例CRC组织和细胞系中lncRNA CRNDE和miR-181a-5p的表达水平。进行了功能获得和功能丧失实验，以研究CRNDE和miR-181a-5p对CRC细胞增殖和化疗耐药性的影响。我们还通过荧光报告基因和蛋白质印迹实验，探讨了CRNDE在CRC细胞中的可能机制。
在本研究中，我们发现CRC临床组织样本中CRNDE的表达水平上调。我们鉴定出microRNA miR-181a-5p是CRNDE的抑制靶点。CRC细胞系中CRNDE敲低和miR-181a-5p过表达均导致细胞增殖受抑制和化疗耐药性降低。我们还确定β-连环蛋白和TCF4是miR-181a-5p的抑制靶点，并且CRNDE敲低和miR-181a-5p过表达均抑制Wnt/β-连环蛋白信号通路。重要的是，我们发现CRNDE敲低诱导的细胞增殖抑制、化疗耐药性降低以及Wnt/β-连环蛋白信号通路抑制需要miR-181a-5p表达增加。
我们的研究表明，lncRNA CRNDE可通过调节miR-181a-5p的表达水平和Wnt/β-连环蛋白信号通路的活性来调控CRC的进展和化疗耐药性。
