Guangdong Institute of Gastroenterology and the Sixth Affiliated Hospital, Sun Yat-Sen University, 26 Yuancun Er Heng Road, Guangzhou, 510655, China.
Department of Gastrointestinal Endoscopy, the Sixth Affiliated Hospital of Sun Yat-sen University, 26 Yuancun Er Heng Road, Guangzhou, 510655, China.
Cell Biol Int. 2018 Apr;42(4):495-503. doi: 10.1002/cbin.10926. Epub 2018 Jan 22.
RNA activation mediated by small double-stranded RNAs targeting promoter sequence named small activating RNAs (saRNAs) is one of the mechanisms for gene activation. Artificial regulation of gene expression through RNA activation does not affect the alteration of the genomic DNA sequences or exogenous plasmid DNA, therefore it is a relative manageable approach for gene perturbation. KLF4 is a member of zinc-finger transcription factors and its functions in colorectal cells are still controversial. In order to elucidate the functions of KLF4, we synthesized saRNAs that target the promoter regions of KLF4 and transfected into varied colorectal epithelial cell lines. We found the KLF4 gene expression is specifically increased in the human normal epithelial cell NCM460 and colorectal epithelial cancer cell Caco-2 and HCT116, but not in other human colorectal epithelial cell lines. In addition, we observed that saRNAs induced overexpression of KLF4 could promote cell migration/invasion in NCM460 and HCT116 cell lines. This effect is mediated partly by inducing EMT and facilitating nuclear translocation of β-catenin.
小双链 RNA 通过靶向启动子序列的方式介导 RNA 激活，这种小激活 RNA（saRNA）是基因激活的机制之一。通过 RNA 激活对基因表达进行人工调控不会影响基因组 DNA 序列或外源性质粒 DNA 的改变，因此，这是一种相对可控的基因干扰方法。KLF4 是锌指转录因子家族的成员，其在结直肠细胞中的功能仍存在争议。为了阐明 KLF4 的功能，我们合成了靶向 KLF4 启动子区域的 saRNA，并转染到不同的结直肠上皮细胞系中。我们发现 KLF4 基因表达在人正常上皮细胞系 NCM460 和结直肠癌细胞系 Caco-2 和 HCT116 中特异性增加，但在其他结直肠上皮细胞系中没有增加。此外，我们观察到 saRNA 诱导的 KLF4 过表达可促进 NCM460 和 HCT116 细胞系的细胞迁移/侵袭。这种作用部分是通过诱导 EMT 和促进β-catenin 的核转位来介导的。
