Yang Chao, Xu Yonghua, Cheng Feng, Hu Yuanchang, Yang Shikun, Rao Jianhua, Wang Xuehao
Department of Liver Surgery/Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University; Key Laboratory on Living Donor Liver Transplantation of National Health and Family Planning Commission of China, Nanjing, China.
Department of General Surgery, Yancheng City No.1 People's Hospital/The Fourth Affiliated Hospital of Nantong University, Yancheng, China.
Cell Death Dis. 2017 Aug 17;8(8):e2999. doi: 10.1038/cddis.2017.356.
Metastasis is the major cause of the poor prognosis of hepatocellular carcinoma (HCC), and increasing evidence supports the contribution of miRNAs to cancer progression. However, the exact relationship between the level of miR-1301 expression and HCC cell migration, invasion, and angiogenesis remains largely unknown. Quantitative PCR was used to evaluate the level of miR-1301 expression in HCC tissues and cell lines. Transwell and tube-formation assays were used to measure the effects of miR-1301 on HCC cell migration and invasion, and angiogenesis, respectively. Luciferase reporter assays and western blotting were used to confirm the miR-1301 target genes. We found that miR-1301 was significantly downregulated in HCC tissues and cell lines. Low miR-1301 expression was associated with tumor vascular invasion and Edmondson grade. Gain- and loss-of-function assays demonstrated that miR-1301 inhibited the migration, invasion, epithelial-mesenchymal transition, and angiogenesis of HCC cells in vitro and in vivo. BCL9, upregulated in HCC tissues compared with matched adjacent normal tissues, was inversely correlated to miR-1301 levels in HCC tissues. Through reporter gene and western blot assays, BCL9 was shown to be a direct miR-1301 target. BCL9 overexpression could partially reverse the effects of miR-1301 on HCC cell migration and invasion. Most importantly, miR-1301 overexpression markedly suppressed the death of xenograft mouse models of cancer by reducing tumor load, metastasis, and host angiogenesis by downregulating BCL9, β-catenin, and vascular endothelial growth factor expression in tumor cells. Our observations suggested that miR-1301 inhibits HCC migration, invasion, and angiogenesis via decreasing Wnt/β-catenin signaling through targeting BCL9, and might be a therapeutic target for HCC.
转移是肝细胞癌(HCC)预后不良的主要原因,越来越多的证据支持微小RNA(miRNA)对癌症进展的作用。然而,miR-1301表达水平与HCC细胞迁移、侵袭及血管生成的确切关系仍不清楚。采用定量PCR评估HCC组织和细胞系中miR-1301的表达水平。分别采用Transwell实验和管腔形成实验检测miR-1301对HCC细胞迁移、侵袭及血管生成的影响。采用荧光素酶报告基因实验和蛋白质免疫印迹法验证miR-1301的靶基因。我们发现,HCC组织和细胞系中miR-1301显著下调。miR-1301低表达与肿瘤血管侵犯及Edmondson分级相关。功能获得和功能缺失实验表明,miR-1301在体内外均可抑制HCC细胞的迁移、侵袭、上皮-间质转化及血管生成。与配对的癌旁正常组织相比,HCC组织中BCL9上调,且与HCC组织中miR-1301水平呈负相关。通过报告基因实验和蛋白质免疫印迹法表明,BCL9是miR-1301的直接靶基因。BCL9过表达可部分逆转miR-1301对HCC细胞迁移和侵袭的影响。最重要的是,miR-1301过表达通过下调肿瘤细胞中BCL9、β-连环蛋白和血管内皮生长因子的表达,显著降低肿瘤负荷、转移及宿主血管生成,从而明显抑制异种移植小鼠模型肿瘤的生长。我们的观察结果提示,miR-1301通过靶向BCL9降低Wnt/β-连环蛋白信号通路活性,从而抑制HCC的迁移、侵袭及血管生成,可能是HCC的一个治疗靶点。