SHMT1 inhibits the metastasis of HCC by repressing NOX1-mediated ROS production

Abstract

BackgroundHepatocellular 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.MethodsqRT-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.ResultsIn 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.ConclusionsThese data indicate that SHMT1 inhibits the metastasis of HCC by repressing NOX1 mediated ROS production.Electronic supplementary materialThe online version of this article (10.1186/s13046-019-1067-5) contains supplementary material, which is available to authorized users.

Bromodomain-containing protein 9 promotes the growth and metastasis of human hepatocellular carcinoma by activating the TUFT1/AKT pathway

“…RNA extraction and qRT-PCR were performed as previously described 18 . 18S RNA was used as an internal control.…”

“…Immunohistochemistry (IHC) staining was performed as described previously 18 . The following antibodies were used in the IHC staining: BRD9 antibody (1:50) and TUFT1 antibody (1:50).…”

Hypoxia-Inducible Ubiquitin Specific Peptidase 13 Contributes to Tumor Growth and Metastasis via Enhancing the Toll-Like Receptor 4/Myeloid Differentiation Primary Response Gene 88/Nuclear Factor-κB Pathway in Hepatocellular Carcinoma

“…Four-week BALB/c nude mice were purchased from Shanghai SLAC Laboratory Animal Company (Shanghai, China). The in vivo tumor growth and lung metastasis experiments were performed using Hep3B cells with or without USP13 knockdown according to the protocols as previously described (Dou et al, 2019a;Guo et al, 2019). The tumor volume (V) was calculated as follows: V = (L × D2)/2 where L and D represent the tumor length and width, respectively (in mm).…”

NOX1 Inhibition Attenuates the Development of a Pro-Tumorigenic Environment in Experimental Hepatocellular Carcinoma

“…In addition, when activated, liver resident Kupffer cells (KCs) release an 'oxidative burst' of superoxide and numerous other products with cytotoxic, pro-in ammatory and growthpromoting activity, and attract circulating immune cells to the liver; all contributing to the establishment of a tumor-promoting microenvironment. ROS also contribute to cancer development and progression, by acting as second messengers in disease-driven intracellular signaling pathways controlling cell proliferation, survival, motility and invasiveness, as well as by controlling the reactivity of stromal components that are fundamental for cancer development and dissemination, in ammation, tissue repair, and de novo angiogenesis (11)(12)(13)(14)(15)(16)(17)(18).…”

“…Recent research on human HCC samples showed that high NOX1 levels are correlated with a poor prognosis (24,25). The involvement of NOX1 in cell proliferation, tumor growth, cell motility, epithelial-mesenchymal transition (EMT) and matrix metalloproteinase-2 production has been shown in in vitro studies (13,14). NOX1-/-knockout mice and mice with myeloid NOX1 disruption were reported to develop fewer and smaller tumors following diethylnitrosamine (DEN) injection.…”