Ouyang Jun, Pan Xiaohui, Hu Zecheng
Department of Gastrointestinal Surgery, The First Affiliated Hospital of University of South China, Hengyang, Hunan 421001, P.R. China.
Department of Urology, The First Affiliated Hospital of University of South China, Hengyang, Hunan 421001, P.R. China.
Exp Ther Med. 2017 Nov;14(5):5193-5199. doi: 10.3892/etm.2017.5122. Epub 2017 Sep 18.
Aplysia ras homolog I (ARHI) acts as a tumor suppressor in certain cancer cells. However, the role of ARHI in colon cancer development has not previously been reported. The present study aimed to investigate the functional role of ARHI in colon cancer focusing on the aspect of metastasis. Furthermore, the molecular mechanism underlying its function was explored. The present study detected the expression of ARHI in a human colon epithelial cell line and colon cancer cell lines using reverse transcription-quantitative polymerase chain reaction and western blotting analysis. It was demonstrated that ARHI expression was significantly downregulated in colon cancer cell lines compared with the normal colon epithelial cell line (P<0.05). An ARHI-pcDNA3.1 plasmid was transfected into HCT116 cells to overexpress ARHI. The number of invaded cells and the adhesive ability were significantly decreased in the ARHI overexpression group compared with the control group, as determined by cell invasion and adhesion assays (P<0.05). Furthermore, ARHI overexpression led to increased mRNA and protein expression levels of E-cadherin, and decreased mRNA and protein expression levels of N-cadherin and vimentin. Wnt/β-catenin signaling was suppressed in HCT116 cells overexpressing ARHI. Lithium chloride, a wnt/β-catenin signaling activator, was able to attenuate the effect of ARHI on HCT116 cell invasion and adhesion. In addition, the effect of ARHI on epithelial-mesenchymal transition (EMT) in HCT116 cells was reversed by the activation of wnt/β-catenin signaling. In conclusion, the present study provided novel evidence that ARHI could inhibit colon cancer cell invasion and adhesion through suppressing EMT, and these effects were achieved, at least partially, via the suppression of the wnt/β-catenin signaling pathway. The present findings may help in developing novel therapeutic approaches for colon cancer.
海兔Ras同源物I（ARHI）在某些癌细胞中起肿瘤抑制作用。然而，ARHI在结肠癌发生发展中的作用此前尚未见报道。本研究旨在探讨ARHI在结肠癌转移方面的功能作用。此外，还探究了其功能背后的分子机制。本研究采用逆转录-定量聚合酶链反应和蛋白质免疫印迹分析检测了人结肠上皮细胞系和结肠癌细胞系中ARHI的表达。结果表明，与正常结肠上皮细胞系相比，结肠癌细胞系中ARHI的表达明显下调（P<0.05）。将ARHI-pcDNA3.1质粒转染至HCT116细胞中以过表达ARHI。通过细胞侵袭和黏附实验测定，与对照组相比，ARHI过表达组中侵袭细胞数量和黏附能力均显著降低（P<0.05）。此外，ARHI过表达导致E-钙黏蛋白的mRNA和蛋白表达水平升高，N-钙黏蛋白和波形蛋白的mRNA和蛋白表达水平降低。过表达ARHI的HCT116细胞中Wnt/β-连环蛋白信号通路受到抑制。氯化锂是一种Wnt/β-连环蛋白信号激活剂，能够减弱ARHI对HCT116细胞侵袭和黏附的影响。此外，Wnt/β-连环蛋白信号的激活逆转了ARHI对HCT116细胞上皮-间质转化（EMT）的影响。总之，本研究提供了新的证据，表明ARHI可通过抑制EMT来抑制结肠癌细胞的侵袭和黏附，且这些作用至少部分是通过抑制Wnt/β-连环蛋白信号通路实现的。本研究结果可能有助于开发结肠癌的新型治疗方法。
