SHMT1 通过抑制 NOX1 介导的 ROS 产生抑制 HCC 的转移。
SHMT1 inhibits the metastasis of HCC by repressing NOX1-mediated ROS production.
机构信息
Department of Hepatopancreatobiliary Surgery & Minimally Invasive Surgery, Zhejiang Provincial People's Hospital (People's Hospital of Hangzhou Medical College), Hangzhou, 310014, Zhejiang Province, China.
Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital (People's Hospital of Hangzhou Medical College), Hangzhou, 310014, Zhejiang Province, China.
出版信息
J Exp Clin Cancer Res. 2019 Feb 12;38(1):70. doi: 10.1186/s13046-019-1067-5.
BACKGROUND
Hepatocellular carcinoma (HCC) is the most major type of primary hepatic cancer. Serine hydroxymethyltransferase 1 (SHMT1) is recently found to play critical roles in human cancers including lung cancer, ovarian cancer and intestinal cancer. However, the expression, function and the underlying mechanisms of SHMT1 in HCC remain uncovered.
METHODS
qRT-PCR, immunohistochemistry and immunoblotting were performed to detect the expression of SHMT1 in HCC tissues and cell lines. HCC cell migration and invasion were determined by Boyden chamber and Transwell assay in vitro, and tumor metastasis was assessed via lung metastasis model in mice. The expression of key factors involved in epithelial-to-mesenchymal transition (EMT) process was evaluated by western blotting.
RESULTS
In this study, data mining of public databases and analysis of clinical specimens demonstrated that SHMT1 expression was decreased in HCC. Reduced SHMT1 level was correlated with unfavorable clinicopathological features and poor prognosis of HCC patients. Gain- and loss-of-function experiments showed that SHMT1 overexpression inhibited the migration and invasion of HCCLM3 cells while SHMT1 knockdown enhanced the metastatic ability of Hep3B cells. Furthermore, qRT-PCR and western blotting showed that SHMT1 inhibited EMT and matrix metallopeptidase 2 (MMP2) expression. In vivo experiments showed that SHMT1 suppressed the lung metastasis of HCC cells in mice. Mechanistically, SHMT1 knockdown enhanced reactive oxygen species (ROS) production, and thus promoted the motility, EMT and MMP2 expression in Hep3B cells. Furthermore, NADPH oxidase 1 (NOX1) was identified to be the downstream target of SHMT1 in HCC. NOX1 expression was negatively correlated with SHMT1 expression in HCC. Rescue experiments revealed that NOX1 mediated the functional influence of SHMT1 on HCC cells.
CONCLUSIONS
These data indicate that SHMT1 inhibits the metastasis of HCC by repressing NOX1 mediated ROS production.
背景
肝细胞癌（HCC）是原发性肝癌中最主要的类型。丝氨酸羟甲基转移酶 1（SHMT1）最近被发现于肺癌、卵巢癌和肠癌等人类癌症中发挥关键作用。然而，SHMT1 在 HCC 中的表达、功能及其潜在机制仍未被揭示。
方法
采用 qRT-PCR、免疫组化和免疫印迹法检测 HCC 组织和细胞系中 SHMT1 的表达。体外通过 Boyden 室和 Transwell 测定 HCC 细胞的迁移和侵袭，通过小鼠肺转移模型评估肿瘤转移。通过 Western 印迹评估参与上皮间质转化（EMT）过程的关键因子的表达。
结果
本研究通过公共数据库的数据挖掘和临床标本分析表明，SHMT1 在 HCC 中表达下调。降低的 SHMT1 水平与 HCC 患者不良的临床病理特征和预后相关。过表达和敲低实验表明，SHMT1 过表达抑制 HCCLM3 细胞的迁移和侵袭，而 SHMT1 敲低增强 Hep3B 细胞的转移能力。此外，qRT-PCR 和 Western 印迹表明，SHMT1 抑制 EMT 和基质金属蛋白酶 2（MMP2）的表达。体内实验表明，SHMT1 抑制 HCC 细胞在小鼠中的肺转移。机制上，SHMT1 敲低增强活性氧（ROS）的产生，从而促进 Hep3B 细胞的运动、EMT 和 MMP2 的表达。此外，NOX1 被鉴定为 HCC 中 SHMT1 的下游靶点。NOX1 的表达与 HCC 中 SHMT1 的表达呈负相关。挽救实验表明，NOX1 介导了 SHMT1 对 HCC 细胞的功能影响。
结论
这些数据表明，SHMT1 通过抑制 NOX1 介导的 ROS 产生来抑制 HCC 的转移。
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