Upregulated FoxM1 expression induced by hepatitis B virus X protein promotes tumor metastasis and indicates poor prognosis in hepatitis B virus-related hepatocellular carcinoma.

Forkhead box M1 (FoxM1) is a master regulator of tumor metastasis that plays an important role in the development of hepatocellular carcinoma (HCC). However, whether or not FoxM1 contributes to the progression of HBV-associated HCC (HBV-HCC) remains unknown. Therefore, we aimed at investigating the clinicopathologic significance of FoxM1 in HBV-HCC and the potential role of FoxM1 in hepatitis B virus X (HBx)-mediated invasiveness and metastasis. The expression of FoxM1 and its functional targets matrix metalloproteinase-7 (MMP-7), RhoC, and Rho-kinase 1 (ROCK1) in human HBV-HCC tissues was detected by immunohistochemistry. Luciferase reporter, chromatin immunoprecipitation, and electrophoretic mobility shift assays were used to measure the transcriptional regulation of FoxM1 promoter by HBx. The effect of FoxM1 on HBx-mediated invasiveness and metastasis was analyzed by transwell assays and an orthotopic metastatic model. FoxM1 overexpression correlated with multiple malignant characteristics and indicated poor prognosis of HBV-HCC patients. FoxM1 expression was an independent factor affecting the recurrence and survival of patients with HBV-HCC after surgical resection. FoxM1 promoted hepatoma cell invasion and metastasis by promoting MMP-7, RhoC, and ROCK1 expression, while FoxM1 overexpression was associated with elevated expressions of these proteins in HBV-HCC tissues. HBx upregulated FoxM1 expression through the ERK/CREB pathway, and FoxM1 inhibition significantly decreased HBx-enhanced hepatoma cell invasion in vitro and lung metastasis in vivo. We report a new molecular mechanism for HBV-associated hepatocarcinogenesis that involves the activation of FoxM1 expression by HBx through the ERK/CREB pathway, thereby leading to invasion and metastasis of hepatoma cells.

Xia L ，Huang W ，Tian D ，Zhu H ，Zhang Y ，Hu H ，Fan D ，Nie Y ，Wu K ... -  《-》

FoxM1 overexpression promotes epithelial-mesenchymal transition and metastasis of hepatocellular carcinoma.

Meng FD ，Wei JC ，Qu K ，Wang ZX ，Wu QF ，Tai MH ，Liu HC ，Zhang RY ，Liu C ... -  《-》

Hepatitis B virus X protein stimulates high mobility group box 1 secretion and enhances hepatocellular carcinoma metastasis.

Hepatitis B virus X protein (HBx) plays an important role in the progression of hepatocellular carcinoma. Here we reported that overexpression of HBx in hepatocellular carcinoma (HCC) cells could induce the secretion of high-mobility group box 1 (HMGB1) to promote invasion and metastasis of HCC in an autocrine/paracrine manner. HBx triggered an increase of cytoplasmic calcium and activated CAMKK/CAMKIV pathway, leading to subsequent translocation and release of HMGB1. HMGB1 neutralizing antibody, as well as calcium chelator or inhibitors of CAMKK/CAMKIV, could remarkably reduce invasion and metastasis of HCC cells in vitro and in a murine HCC metastasis model in vivo. Furthermore, the level of HMGB1 in patient serum and tumor tissues was positively correlated with HBV DNA load. We demonstrate an inverse relationship between HMGB1 in tumor cytoplasm and overall prognosis of HCC patients. HBx promotes the progression of HCC through translocation and secretion of HMGB1 from tumor cells via calcium dependent cascades. These data indicates that HMGB1 could serve as a novel prognostic biomarker and potential therapeutic target for HBV-related HCC.

Chen S ，Dong Z ，Yang P ，Wang X ，Jin G ，Yu H ，Chen L ，Li L ，Tang L ，Bai S ，Yan H ，Shen F ，Cong W ，Wen W ，Wang H ... -  《-》

Hepatitis B virus X protein modulates oncogene Yes-associated protein by CREB to promote growth of hepatoma cells.

Hepatitis B virus X protein (HBx) plays critical roles in the development of hepatocellular carcinogenesis (HCC). Yes-associated protein (YAP), a downstream effector of the Hippo-signaling pathway, is an important human oncogene. In the present article, we report that YAP is involved in the hepatocarcinogenesis mediated by HBx. We demonstrated that the expression of YAP was dramatically elevated in clinical HCC samples, hepatitis B virus (HBV)-infected hepatoma HepG2.2.15 cell line, and liver cancer tissues of HBx-transgenic mice. Meanwhile, we found that overexpression of HBx resulted in the up-regulation of YAP in stably HBx-transfected HepG2/H7402 hepatoma cell lines, whereas HBx RNA interference reduced YAP expression in a dose-dependent manner in the above-mentioned cell lines, suggesting that HBx up-regulates YAP. Then, we investigated the mechanism underlying the up-regulation of YAP by HBx. Luciferase reporter gene assays revealed that the promoter region of YAP regulated by HBx was located at nt -232/+115 containing cyclic adenosine monophosphate response element-binding protein (CREB) element. Chromatin immunoprecipitation (ChIP) demonstrated that HBx was able to bind to the promoter of YAP, whereas it failed to work when CREB was silenced. Moreover, we confirmed that HBx activated the YAP promoter through CREB by electrophoretic mobility shift assay and luciferase reporter gene assays. Surprisingly, we found that YAP short interfering RNA was able to remarkably block the HBx-enhanced growth of hepatoma cells in vivo and in vitro. YAP is a key driver gene in HBx-induced hepatocarcinogenesis in a CREB-dependent manner. YAP may serve as a novel target in HBV-associated HCC therapy.

Zhang T ，Zhang J ，You X ，Liu Q ，Du Y ，Gao Y ，Shan C ，Kong G ，Wang Y ，Yang X ，Ye L ，Zhang X ... -  《-》

Linc00152 promotes cancer progression in hepatitis B virus-associated hepatocellular carcinoma.

The X protein (HBx) plays as a key role in hepatocarcinogenesis associated with hepatitis B virus (HBV) infections. The study aimed to figure out the role of Linc00152 in hepatocellular carcinoma (HCC) and the association between the expression levels of Linc00152 and HBx. QRT-PCR assays were applied to analyzed the expression levels of Linc00152 and HBx. Kaplan-Meier survival curve was performed to identify the association between LINC00152 and the over survival time (OS) in HCC patients. Cell growth and invasion ability was evaluated by CCK8 cell proliferation and transwell invasion assays. Western-blot analysis was detected the protein expression. RNA immunoprecipitation (RIP), RNA-pull down and chromatin Immunoprecipitation (ChIP) assays was also been carried out. We demonstrated that LINC00152 expression in hepatocellular carcinoma (HCC) patients was significantly higher compared with adjacent non-tumour tissues and positively correlated with tumor size, HBV infection (HBsAg) and tumor number. Patient with hepatitis B virus (HBV) infection HCC was higher expression than that without HBV. Furthermore, the expression levels of Linc00152 were positively correlated with HBx expression in HCC tissues and higher Linc00152 expression levels were correlated with poor prognosis of HCC patients. In vitro, Linc00152 was up-regulated in Huh-7 and SM7721 cells after overexpression of HBx and down-regulated after silencing HBx. Furthermore, silencing Linc00152 suppressed the cell proliferation and invasion. Moreover, we found that Linc00152 inhibited the E-cadherin expression via interacting with EZH2 and promoted the Epithelial-mesenchymal transition (EMT) phenomenon in HCC cells. These results suggested that HBx enhanced LINC00152 expression and inhibition of LINC00152 could provide a therapeutic target for HCC.

Deng X ，Zhao XF ，Liang XQ ，Chen R ，Pan YF ，Liang J ... -  《-》