Regorafenib is approved for patients with unresectable hepatocellular carcinoma (HCC) following sorafenib. However, the effect of regorafenib on HCC metastasis and its mechanism are poorly understood. Here, our data showed that regorafenib significantly restrained the migration, invasion and vasculogenic mimicry (VM) of HCC cells, and downregulated the expression of epithelial‐to‐mesenchymal transition (EMT)/VM‐related molecules. Using RNA‐seq and cellular thermal shift assays, we found that inhibitor of differentiation 1 (ID1) was a key target of regorafenib. In HCC tissues, the protein expression of ID1 was positively correlated with EMT and VM formation (CD34⁻/PAS⁺). Functionally, ID1 knockdown inhibited HCC cell migration, invasion, metastasis, and VM formation in vitro and in vivo, with upregulation of E‐cadherin and downregulation of Snail and VE‐cadherin. Moreover, Snail overexpression promoted the migration, invasion, and VM formation of ID1 knockdown cells. Snail knockdown reduced the migration, invasion, and VM formation of ID1 overexpression cells. Finally, regorafenib suppressed VM formation and decreased the expression of ID1, VE‐cadherin and Snail in HCC PDX model. In conclusion, we manifested that regorafenib distinctly inhibited EMT in HCC cells via targeting ID1, leading to the suppression of cell migration, invasion and VM formation. These findings suggest that regorafenib may be developed as a suitable therapeutic agent for HCC metastasis.

中文翻译：

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Regorafenib通过靶向ID1介导的EMT抑制肝细胞癌的迁移，侵袭和血管生成模拟

瑞戈非尼被批准用于索拉非尼后不可切除的肝细胞癌（HCC）患者。然而，对瑞格非尼对肝癌转移的作用及其机制了解甚少。在这里，我们的数据表明瑞戈非尼显着抑制了HCC细胞的迁移，侵袭和血管生成模拟（VM），并下调了上皮-间质转化（EMT）/ VM相关分子的表达。使用RNA-seq和细胞热位移分析，我们发现分化抑制剂1（ID1）是雷戈非尼的主要靶标。HCC组织中，ID1的蛋白表达与EMT和VM形成（CD34相关^- / PAS ⁺）。从功能上讲，ID1抑制可在体外和体内抑制HCC细胞迁移，侵袭，转移和VM形成，同时上调E-钙黏着蛋白并下调Snail和VE-钙黏着蛋白。此外，蜗牛的过表达促进了ID1敲低细胞的迁移，侵袭和VM形成。蜗牛敲低减少了ID1过表达细胞的迁移，侵袭和VM形成。最后，regorafenib在HCC PDX模型中抑制了VM的形成并降低了ID1，VE-cadherin和Snail的表达。总之，我们证明瑞格非尼通过靶向ID1明显抑制HCC细胞中的EMT，从而抑制了细胞迁移，侵袭和VM形成。这些发现表明，regorafenib可能被开发为HCC转移的合适治疗剂。