Department of Cell Biology, School of Medicine, Nankai University, 94 Weijin Road, Nankai District, Tianjin, 300071, People's Republic of China.
Department of Pathology, Third Central Hospital of Tianjin Medical University, 83 Jintang Road, Tianjin, 300170, China.
J Exp Clin Cancer Res. 2019 Nov 21;38(1):471. doi: 10.1186/s13046-019-1464-9.
Adhesion molecules distributed on the cell-surface depends upon their dynamic trafficking that plays an important role during cancer progression. ADP-ribosylation factor 6 (Arf6) is a master regulator of membrane trafficking. CD147, a tumor-related adhesive protein, can promote the invasion of liver cancer. However, the role of Arf6 in CD147 trafficking and its contribution to liver cancer progression remain unclear.
Stable liver cancer cell lines with Arf6 silencing and over-expression were established. Confocal imaging, flow cytometry, biotinylation and endomembrane isolation were used to detect CD147 uptake and recycling. GST-pull down, gelatin zymography, immunofluorescence, cell adhesion, aggregation and tight junction formation, Transwell migration, and invasion assays were used to examine the cellular phenotypes. GEPIA bioinformatics, patient's specimens and electronic records collection, and immunohistochemistry were performed to obtain the clinical relevance for Arf6-CD147 signaling.
We found that the endocytic recycling of CD147 in liver cancer cells was controlled by Arf6 through concurrent Rab5 and Rab22 activation. Disruption of Arf6-mediated CD147 trafficking reduced the cell-matrix and cell-cell adhesion, weakened cell aggregation and junction stability, attenuated MMPs secretion and cytoskeleton reorganization, impaired HGF-stimulated Rac1 activation, and markedly decreased the migration and invasion of liver cancer cells. Moreover, high-expression of the Arf6-CD147 signaling components in HCC (hepatocellular carcinoma) was closely correlated with poor clinical outcome of patients.
Our results revealed that Arf6-mediated CD147 endocytic recycling is required for the malignant phenotypes of liver cancer. The Arf6-driven signaling machinery provides excellent biomarkers or therapeutic targets for the prevention of liver cancer.
细胞表面分布的黏附分子依赖于其动态运输，这在癌症进展中起着重要作用。ADP-核糖基化因子 6（Arf6）是膜运输的主要调节因子。CD147 是一种与肿瘤相关的黏附蛋白，可促进肝癌的侵袭。然而，Arf6 在 CD147 运输中的作用及其对肝癌进展的贡献尚不清楚。
建立了 Arf6 沉默和过表达稳定的肝癌细胞系。共聚焦成像、流式细胞术、生物素化和内膜分离用于检测 CD147 的摄取和再循环。GST 下拉、明胶酶谱、免疫荧光、细胞黏附、聚集和紧密连接形成、Transwell 迁移和侵袭实验用于检测细胞表型。GEPIA 生物信息学、患者标本和电子记录收集以及免疫组织化学用于获得 Arf6-CD147 信号的临床相关性。
我们发现肝癌细胞中 CD147 的内吞再循环受 Arf6 通过并发 Rab5 和 Rab22 激活的控制。破坏 Arf6 介导的 CD147 运输减少了细胞-基质和细胞-细胞黏附，削弱了细胞聚集和连接稳定性，减弱了 MMPs 分泌和细胞骨架重组，损害了 HGF 刺激的 Rac1 激活，并显著减少了肝癌细胞的迁移和侵袭。此外，HCC（肝细胞癌）中 Arf6-CD147 信号成分的高表达与患者的不良临床结局密切相关。
我们的研究结果表明，Arf6 介导的 CD147 内吞再循环是肝癌恶性表型所必需的。Arf6 驱动的信号机制为预防肝癌提供了优秀的生物标志物或治疗靶点。
