Iron dyshomeostasis is associated with hepatocellular carcinoma (HCC) development. However, the role of iron in HCC metastasis is unknown. This study aimed to elucidate the underlying mechanisms of iron’s enhancement activity on HCC metastasis. In addition to the HCC cell lines and clinical samples in vitro, iron-deficient (ID) mouse models were generated using iron-free diet and transferrin receptor protein knockout, followed by administration of HCC tumors through either orthotopic or ectopic route. Clinical metastatic HCC samples showed significant ID status, accompanied by overexpression of sphingosine-1-phosphate transporter spinster homolog 2 (SPNS2). Mechanistically, ID increased SPNS2 expression, leading to HCC metastasis in both cell cultures and mouse models. ID not only altered the anti-tumor immunity, which was indicated by phenotypes of lymphatic subsets in the liver and lung of tumor-bearing mice, but also promoted HCC metastasis in a cancer cell autonomous manner through the SPNS2. Since germline knockout of globe SPNS2 showed significantly reduced HCC metastasis, we further developed hepatic-targeting recombinant adeno-associated virus vectors to knockdown SPNS2 expression and to inhibit iron-regulated HCC metastasis. Our observation indicates the role of iron in HCC pulmonary metastasis and suggests SPNS2 as a potential therapeutic target for the prevention of HCC pulmonary metastasis.

铁稳态失调与肝细胞癌 (HCC) 的发展有关。然而，铁在 HCC 转移中的作用尚不清楚。本研究旨在阐明铁增强 HCC 转移活性的潜在机制。除了 HCC 细胞系和体外临床样本，使用无铁饮食和转铁蛋白受体蛋白敲除生成缺铁 (ID) 小鼠模型，然后通过原位或异位途径给予 HCC 肿瘤。临床转移性 HCC 样本显示出显着的 ID 状态，并伴有鞘氨醇-1-磷酸转运体自旋同系物 2 (SPNS2) 的过表达。从机制上讲，ID 增加了 SPNS2 表达，导致细胞培养物和小鼠模型中的 HCC 转移。ID 不仅改变了抗肿瘤免疫力，这由荷瘤小鼠肝脏和肺部淋巴亚群的表型表明，而且还通过 SPNS2 以癌细胞自主方式促进 HCC 转移。由于全球 SPNS2 的种系敲除显示 HCC 转移显着减少，我们进一步开发了肝靶向重组腺相关病毒载体，以敲低 SPNS2 表达并抑制铁调节的 HCC 转移。我们的观察表明铁在 HCC 肺转移中的作用，并表明 SPNS2 作为预防 HCC 肺转移的潜在治疗靶点。