Unveiling the Impact of Hemodynamics on Endothelial Inflammation-Mediated Hepatocellular Carcinoma Metastasis Using a Biomimetic Vascular Flow Model.

Hepatocellular carcinoma (HCC) hematogenous dissemination is a leading cause of HCC-related deaths. The inflammatory facilitates this process by promoting the adhesion and invasion of tumor cells in the circulatory system. But the contribution of hemodynamics to this process remains poorly understood due to the lack of a suitable vascular flow model for investigation. This study develops a vascular flow model to examine the impact of hemodynamics on endothelial inflammation-mediated HCC metastasis. This work finds the increasing shear stress will reduce the recruitment of HCC cells by disturbing adhesion forces between endothelium and HCC cells. However, this reduction will be restored by the inflammation. When applying high FSS (4-6 dyn cm-2) to the inflammatory endothelium, there will be a 4.8-fold increase in HCC cell adhesions compared to normal condition. Nevertheless, the increase fold of cell adhesions is inapparent, around 1.5-fold, with low and medium FSS. This effect can be attributed to the FSS-induced upregulation of ICAM-1 and VCAM-1 of the inflammatory endothelium, which serve to strengthen cell binding forces. These findings indicate that hemodynamics plays a key role in HCC metastasis during endothelial inflammation by regulating the expression of adhesion-related factors.

Andrographolide anti-proliferation and metastasis of hepatocellular carcinoma through LncRNA MIR22HG regulation.

Hepatocellular carcinoma (HCC) treatment is a major challenge. Although andrographolide (Andro) has an anti-proliferation effect on HCC, its underlying mechanism is not yet elucidated, and whether Andro can inhibit HCC metastasis has not been reported. The present study aimed to clarify whether Andro inhibits SK-Hep-1 cell proliferation and HCC metastasis, and the mechanisms. The results showed that Andro significantly reduced the survival of HCC cells and tumor weight and volume in tumor-bearing nude mice. Andro also triggered apoptosis of HCC cells and upregulated MIR22HG, Cleaved Caspase 9/7/3 expression levels, and downregulated BCL-2 mRNA, BCL-2 expression levels. Knockdown of MIR22HG or overexpression of HuR attenuated the effects of Andro on the signal transduction of mitochondrial apoptotic pathway and proliferation ability in HCC cells. Moreover, Andro significantly reduced the invasive ability of the cells and the level of HCC cell lung metastasis, upregulated miR-22-3p expression level and downregulated HMGB1 and MMP-9 expression levels. MIR22HG or miR-22-3p knockdown attenuated the effects of Andro on the signaling of HMGB1/MMP-9 pathway and invasive ability in HCC cells, while the overexpression of HMGB1 attenuated the inhibitory effects of Andro on the MMP-9 expression level and invasive ability in HCC cells. Thus, the regulation of MIR22HG-HuR/BCL-2 and MIR22HG/HMGB1 signaling pathways is involved in the anti-HCC proliferation and metastasis effects of Andro. This study provided a new pharmacological basis for Andro in HCC treatment and, for the first time, identified a natural product molecule capable of positively regulating MIR22HG, which has a robust biological function.

Platelets promote primary hepatocellular carcinoma metastasis through TGF-ß1-mediated cancer cell autophagy.

Previous research has revealed that platelets promote tumor metastasis by binding to circulating tumor cells (CTCs). However, the role of platelets in epithelial-mesenchymal transition (EMT) of cancer cells at the primary tumor site, the crucial initial step of tumor metastasis, remains to be elucidated. Here, we found that platelet releasate enhanced EMT and motility of hepatocellular carcinoma (HCC) cells via AMPK/mTOR-induced autophagy. RNA-seq indicated that platelet releasate altered TGF-ß signaling pathway of cancer cells. Inhibiting TGFBR or deleting platelet TGF-ß1 suppressed AMPK/mTOR pathway activation and autophagy induced by platelet releasate. Compared with Pf4cre-; Tgfb1fl/fl mice, HCC orthotopic models established on Pf4cre+; Tgfb1fl/fl mice showed reduced TGF-ß1 in primary tumors, which corresponded with decreased cancer cell EMT, autophagy, migration ability and tumor metastasis. Inhibition of autophagy via Atg5 knockdown in cancer cells negated EMT and metastasis induced by platelet-released TGF-ß1. Clinically, higher platelet count correlated with increased TGF-ß1, LC3 and N-cad expression in primary tumors of HCC patients, suggesting a link between platelets and HCC progression. Our study indicates that platelets promote cancer cell EMT in the primary tumor and HCC metastasis through TGF-ß1-induced HCC cell autophagy via the AMPK/mTOR pathway. These findings offer novel insights into the role of platelets in HCC metastasis and the potential therapeutic targets for HCC metastasis.

Dysregulated glucuronic acid metabolism exacerbates hepatocellular carcinoma progression and metastasis through the TGFß signalling pathway.

BACKGROUND: Glucuronic acid metabolism participates in cellular detoxification, extracellular matrix remodeling and cell adhesion and migration. Here, we aimed to explore the crosstalk between dysregulated glucuronic acid metabolism and crucial metastatic signalling in glutathione S-transferase zeta 1 (GSTZ1)-deficient hepatocellular carcinoma (HCC). METHODS: Transwell, HCC xenograft and Gstz1-/- mouse models were used to examine the role of GSTZ1 in HCC metastasis. Non-targeted and targeted metabolomics and global transcriptomic analyses were performed to screen significantly altered metabolic and signalling pathways in GSTZ1 overexpressing hepatoma cells. Further, RNA-binding protein immunoprecipitation, Biotin-RNA pull-down, mRNA decay assays and luciferase reporter assays were used to explore the interaction between RNA and RNA-binding proteins. RESULTS: GSTZ1 was universally silenced in both human and murine HCC cells, and its deficiency contributed to HCC metastasis in vitro and in vivo. UDP-glucose 6-dehydrogenase (UGDH)-mediated UDP-glucuronic acid (UDP-GlcUA) accumulation promoted hepatoma cell migration upon GSTZ1 loss. UDP-GlcUA stabilized TGFßR1 mRNA by enhancing its binding to polypyrimidine tract binding protein 3, contributing to the activation of TGFß/Smad signalling. UGDH or TGFßR1 blockade impaired HCC metastasis. In addition, UGDH up-regulation and UDP-GlcUA accumulation correlated with increased metastatic potential and decreased patient survival in GSTZ1-deficient HCC. CONCLUSIONS: GSTZ1 deficiency and subsequent up-regulation of the glucuronic acid metabolic pathway promotes HCC metastasis by increasing the stability of TGFßR1 mRNA and activating TGFß/Smad signalling. UGDH and a key metabolite, UDP-GlcUA, may serve as prognostic markers. Targeting UGDH might be a promising strategy for HCC therapy.

Increased neutrophil extracellular traps promote metastasis potential of hepatocellular carcinoma via provoking tumorous inflammatory response.

BACKGROUND: The propensity of the activated neutrophils to form extracellular traps (NETs) is demonstrated in multiple inflammatory conditions. In this study, we investigated the roles of NETs in metastasis of hepatocellular carcinoma (HCC) and further explored the underlying mechanism of how NETs affect metastasis as well as the therapeutic value. METHODS: The neutrophils were isolated from the blood of human HCC patients and used to evaluate the formation of NETs. The expression of NET markers was detected in tumor specimens. A LPS-induced NET model was used to investigate the role of NETs on HCC metastasis. RNA-seq was performed to identify the key molecular event triggered by NETs, and their underlying mechanism and therapeutic significance were explored using both in vitro and in vivo assays. RESULTS: NET formation was enhanced in neutrophils derived from HCC patients, especially those with metastatic HCCs. NETs trapped HCC cells and subsequently induced cell-death resistance and enhanced invasiveness to trigger their metastatic potential, which was mediated by internalization of NETs into trapped HCC cells and activation of Toll-like receptors TLR4/9-COX2 signaling. Inhibition of TLR4/9-COX2 signaling abrogated the NET-aroused metastatic potential. A combination of DNase 1 directly wrecking NETs with anti-inflammation drugs aspirin/hydroxychloroquine effectively reduced HCC metastasis in mice model. CONCLUSIONS: NETs trigger tumorous inflammatory response and fuel HCC metastasis. Targeting NETs rather than neutrophils themselves can be a practice strategy against HCC metastasis.

Hepatocellular metastasis recurrence in liver transplant after treatment with direct antiviral agents.

Chronic HCV liver infection is considered one of the main causes of liver cirrhosis and hepatocellular carcinoma (HCC). For a selected group of patients, orthotopic liver transplantation (OLTx) is the most effective option to cure both liver diseases. After liver transplantation, patients may be at risk of viral infection reactivation and HCC recurrence. HCV recurrence on the transplanted organ can lead to graft cirrhosis and therefore the clearance of virus with antiviral therapies has a pivotal role on the prevention of graft damage. Nowadays, direct antiviral agents (DAAs) represent the choice treatment for HCV recurrence in liver transplanted patients, ensuring high eradication rates. We present the case of a liver transplant recipient who developed, 7 years after OLTx and immediately after a DAAs treatment, a subcutaneous abdominal mass with histological characteristics of HCC.

Deubiquitylase OTUD6B Governs pVHL Stability in an Enzyme-Independent Manner and Suppresses Hepatocellular Carcinoma Metastasis.

Hypoxia inducible factors (HIFs) are the key transcription factors that allow cancer cells to survive hypoxia. HIF's stability is mainly controlled by von Hippel-Lindau (pVHL)-mediated ubiquitylation. Unlike sporadic clear-cell renal carcinomas, VHL mutation is rarely observed in hepatocellular carcinoma (HCC) and the regulatory mechanisms of pVHL-HIF signaling remain elusive. Here, it is shown that deubiquitylase ovarian tumor domain-containing 6B (OTUD6B) suppresses HCC metastasis through inhibiting the HIF activity. OTUD6B directly interacts with pVHL, decreases its ubiquitylation and proteasomal degradation to reduce HIF-1α accumulation in HCC cells under hypoxia. Surprisingly, OTUD6B limits the ubiquitylation of pVHL independent of its deubiquitylase activity. OTUD6B couples pVHL and elongin B/C to form more CBCVHL ligase complex, which protects pVHL from proteasomal degradation. Depletion of OTUD6B results in the dissociation of CBCVHL complex and the degradation of pVHL by Trp Asp repeat and suppressors of cytokine signaling box-containing protein 1 (WSB1). In human HCC tissues, the protein level of OTUD6B is positively correlated with pVHL, but negatively with HIF-1α and vascular endothelial growth factor. Low expression of OTUD6B predicts poor patient survival. Furthermore, OTUD6B gene is a direct transcriptional target of HIF-1α and upregulated upon hypoxia. These results indicate a previously unrecognized feedback loop consisting of OTUD6B, pVHL, and HIF-1α, and provide insights into the targeted hypoxic microenvironment for HCC therapy.