Han Ye, Kuang Yuting, Xue Xiaofeng, Guo Xiaobo, Li Pu, Wang Xu, Guo Xingpo, Yuan Bin, Zhi Qiaoming, Zhao Hong
Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215006, China.
Department of Gastrointestinal Surgery, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.
Biomed Pharmacother. 2014 Jun;68(5):497-505. doi: 10.1016/j.biopha.2014.05.003. Epub 2014 Jun 9.
We previously reported that miR-199a-3p is a newly biomarker for diagnosis and novel prognostic indicator in colorectal cancer. However, the miR-199a-3p regulatory mechanism and its target genes are still unclear. In our present study, we demonstrated miR-199a-3p could directly target 3'-UTR of NLK gene by luciferase reporter assay and western blot analysis. We detected NLK expressions in 92 colorectal cancer cases to evaluate its clinicopathologic characteristics in colorectal cancer. Our results showed that NLK expression was significantly downregulated in cancer tissues than NATs, and NLK low-expression was associated with lymph node metastasis, venous invasion, liver metastasis and the TNM stage (P<0.05). Moreover, Kaplan-Meier analysis showed that low expression of NLK correlated with a shorter overall survival rates of patients with CRC (P<0.05). In vitro, we also found that NLK suppressed the biological behaviors of colorectal cancer cells, including the abilities of cell proliferation, clone formation, wound healing, migration and invasion (P<0.05), while overexpression of NLK increased the apoptotic rate of colorectal cancer cells. All these results suggested that NLK was an identified miR-199a-3p target gene and functioned as a tumor suppressor gene in colorectal cancer. NLK could be a novel direction for developing diagnostic and therapeutic approaches in colorectal cancer.
我们之前报道过，miR-199a-3p是结直肠癌诊断的新型生物标志物和新的预后指标。然而，miR-199a-3p的调控机制及其靶基因仍不清楚。在我们目前的研究中，通过荧光素酶报告基因检测和蛋白质印迹分析，我们证明了miR-199a-3p可以直接靶向NLK基因的3'-UTR。我们检测了92例结直肠癌病例中的NLK表达，以评估其在结直肠癌中的临床病理特征。我们的结果显示，与正常相邻组织相比，癌组织中NLK表达明显下调，且NLK低表达与淋巴结转移、静脉侵犯、肝转移及TNM分期相关（P<0.05）。此外，Kaplan-Meier分析表明，NLK低表达与CRC患者较短的总生存率相关（P<0.05）。在体外，我们还发现NLK抑制结直肠癌细胞的生物学行为，包括细胞增殖、克隆形成、伤口愈合、迁移和侵袭能力（P<0.05），而NLK的过表达增加了结直肠癌细胞的凋亡率。所有这些结果表明，NLK是一个已确定的miR-199a-3p靶基因，在结直肠癌中发挥肿瘤抑制基因的作用。NLK可能是开发结直肠癌诊断和治疗方法的一个新方向。
