Role of miR-143 targeting KRAS in colorectal tumorigenesis
Role of miR-143 targeting KRAS in colorectal tumorigenesis
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DOI：
10.1038/onc.2008.474
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发表时间：
2009-03-01
期刊：
影响因子：
8
通讯作者：
Zhang, C-Y
中科院分区：
文献类型：
--
作者：
Chen, X.;Guo, X.;Zhang, C-Y
microRNAs （miRNAs）的表达失调与多种疾病有关，包括结直肠癌。通过qRT-PCR和微阵列分析，我们比较了13对匹配的结直肠癌和正常邻近组织样本中的200多个miRNA，发现在结直肠癌发生过程中miRNA的表达普遍中断。特别是，在由计算机分析产生的一组可能与这些异常表达的mirna相互作用的假定靶标中，KRAS癌基因已被进一步实验验证为miR-143的靶标。首先，在体内发现KRAS蛋白与miR-143呈负相关。其次，miR-143模拟物处理显著消除了Lovo细胞中的KRAS表达，而miR-143抑制剂则增加了KRAS蛋白水平。第三，荧光素酶报告基因检测证实miR-143直接识别KRAS转录本的30个未翻译区域。第四，用miR-143抑制剂处理的Lovo细胞显示出受刺激的细胞增殖，而miR-143过表达具有相反的效果。最后，miR-143抑制KRAS表达可抑制ERK1/2的组成性磷酸化。综上所述，本研究首次提供了miR-143通过抑制KRAS翻译抑制结直肠癌细胞生长的证据。
Dysregulated expression of microRNAs ( miRNAs) is associated with a variety of diseases, including colorectal cancer. Bycomparing more than 200 miRNAs in 13 pairs of matched colorectal cancer and normal adjacent tissue samples through qRT-PCR and microarray analysis, we found a widespread disruption of miRNA expression during colorectal tumorigenesis. In particular, among a panel of presumed targets generated by in silico analysis that may interact with these aberrantly expressed miRNAs, KRAS oncogene has been further experimentally validated as the target of miR-143. First, an inverse correlation between KRAS protein and miR-143 in vivo was found. Second, KRAS expression in Lovo cells was significantly abolished by treatment with miR-143 mimic, whereas miR-143 inhibitor increased KRAS protein level. Third, luciferase reporter assay confirmed that miR-143 directly recognize the 30-untranslated region of KRAS transcripts. Four, Lovo cells treated with miR-143 inhibitor showed a stimulated cell proliferation, whereas miR-143 overexpression had an opposite effect. Finally, inhibition of KRAS expression by miR-143 inhibits constitutive phosphorylation of ERK1/2. Taken together, the present study provides the first evidences that miR-143 is significant in suppressing colorectal cancer cell growth through inhibition of KRAS translation.