UCHL5 promotes hepatocellular carcinoma progression by promoting glycolysis through activating Wnt/ß-catenin pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is highly malignant with a dismal prognosis, although the available therapies are insufficient. No efficient ubiquitinase has been identified as a therapeutic target for HCC despite the complicating role that of proteins ubiquitination plays in the malignant development of HCC. METHODS: The expression of ubiquitin carboxyl terminal hydrolase L5 (UCHL5) in HCC tumor tissue and adjacent normal tissue was determined using the cancer genome atlas (TCGA) database and was validated using real-time quantitative polymerase chain reaction (RT-qRCR), Western blot and immunohistochemistry (IHC), and the relation of UCHL5 with patient clinical prognosis was explored. The expression of UCHL5 was knocked down and validated, and the effect of UCHL5 on the biological course of HCC was explored using cellular assays. To clarify the molecular mechanism of action of UCHL5 affecting HCC, expression studies of Adenosine triphosphate adenosine triphosphate (ATP), extracellular acidification (ECAR), and glycolysis-related enzymes were performed. The effects of UCHL5 on ß-catenin ubiquitination and Wnt signaling pathways were explored in depth and validated using cellular functionalities. Validation was also performed in vivo. RESULTS: In the course of this investigation, we discovered that UCHL5 was strongly expressed in HCC at both cellular and tissue levels. The prognosis of patients with high UCHL5 expression is considerably worse than that of those with low UCHL5 expression. UCHL5 has been shown to increase the degree of glycolysis in HCC cells with the impact of stimulating the proliferation and metastasis of HCC cells in both in vivo and in vitro. UCHL5 downregulates its degree of ubiquitination by binding to ß-catenin, which activates the Wnt/ß-catenin pathway and accelerates HCC cell glycolysis. Thereby promoting the growth of the HCC. CONCLUSIONS: In summary, we have demonstrated for the first time that UCHL5 is a target of HCC and promotes the progression of hepatocellular carcinoma by promoting glycolysis through the activation of the Wnt/ß-catenin pathway. UCHL5 may thus serve as a novel prognostic marker and therapeutic target for the treatment of HCC.

lncRNA-XLOC_012370 Promotes the Development of Pancreatic Cancer and Inactivates the NF-κB Pathway Through miR-140-5p.

Pancreatic cancer is a high incidence, high degree of malignancy, and high mortality in the digestive system tumor. The incidence of pancreatic cancer in China has increased nearly six folds in the past 20 years, ranking fifth in the mortality rate of malignant tumors, so it is particularly important to actively explore clinical indicators with better diagnostic significance for pancreatic cancer. LncRNA performs an essential regulatory function in the occurrence, development, and metastasis of many kinds of tumors, playing both a carcinogenic role and a tumor suppressor gene. Here, we demonstrated the function and mechanism of LncRNA-XLOC_012370 in the development of pancreatic cancer. In our research, the abnormal upregulation of XLOC_012370 was observed in pancreatic cancer patients' tumor tissues. XLOC_012370 was related to tumor stage, lymph node metastasis, and overall survival. Silencing of XLOC_012370 prevented the proliferation, migration, and invasion via the NF-κB signal pathway. Further, miR-140-5p was identified as the target and downstream of XLOC_012370 and involved in pancreatic cancer progression. In vivo, knockdown of XLOC_012370 inhibited tumor growth via the NF-κB signal pathway. In conclusion, lncRNA-XLOC_012370 is closely related to some malignant clinicopathological features and prognosis of pancreatic cancer. Thus the miR-140-5p/NF-κB signal pathway might represent a promising treatment strategy to combat pancreatic cancer.

GPR43 regulates HBV X protein (HBx)-induced inflammatory response in human LO2 hepatocytes.

The present study investigated the role of G coupled-protein receptor 43 (GPR43), also known as free fatty acid receptor 2 (FFAR2), in regulating the cytotoxic effects of hepatitis B virus (HBV) by transfecting hepatitis B protein X (HBx) into human LO2 hepatocytes. To our knowledge, this study is the first to demonstrate the role of GPR43 in LO2 hepatocytes and to show that transfection with HBx suppresses GPR43 expression. HBx contributes to inflammation by triggering the release of proinflammatory cytokines including interleukin-6 (IL-6), monocyte chemoattractant protein (MCP-1), (C-X-C motif) ligand 2 (CXCL2), and high mobility group box 1 protein (HMGB1). Additionally, HBx induces oxidative stress by upregulating the production of ROS. We performed a series of experiments using the human LO2 cell line and the specific GPR43 agonist (S)-2-(4-chlorophenyl)-3,3-dimethyl-N-(5-phenyl thiazole-2-yl) butanamide (PA). We found that agonism of GPR43 significantly ameliorated HBx-induced expression of proinflammatory cytokines and chemokines, and lowered the level of oxidative stress. Notably, we demonstrate that these effects of PA are mediated through inhitibing the phosphorylation of p38 and activation of the IκBα/nuclear factor-κB (NF-κB) pathway. Together, our findings provide compelling evidence of the potential for GPR43 as a treatment target against HBx-induced inflammatory response.

Insulin-like growth factor 2 mRNA-binding protein 1 promotes cell proliferation via activation of AKT and is directly targeted by microRNA-494 in pancreatic cancer.

BACKGROUND: Studies have shown that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) plays critical roles in the genesis and development of human cancers. AIM: To investigate the clinical significance and role of IGF2BP1 in pancreatic cancer. METHODS: Expression levels of IGF2BP1 and microRNA-494 (miR-494) were mined based on Gene Expression Omnibus datasets and validated in both clinical samples and cell lines by quantitative real-time polymerase chain reaction and Western blot. The relationship between IGF2BP1 expression and clinicopathological factors of pancreatic cancer patients was analyzed. The effect and mechanism of IGF2BP1 on pancreatic cancer cell proliferation were investigated in vitro and in vivo. Analyses were performed to explore underlying mechanisms of IGF2BP1 upregulation in pancreatic cancer and assays were carried out to verify the post-transcriptional regulation of IGF2BP1 by miR-494. RESULTS: We found that IGF2BP1 was upregulated and associated with a poor prognosis in pancreatic cancer patients. We showed that downregulation of IGF2BP1 inhibited pancreatic cancer cell growth in vitro and in vivo via the AKT signaling pathway. Mechanistically, we showed that the frequent upregulation of IGF2BP1 was attributed to the downregulation of miR-494 expression in pancreatic cancer. Furthermore, we discovered that reexpression of miR-494 could partially abrogate the oncogenic role of IGF2BP1. CONCLUSION: Our results revealed that upregulated IGF2BP1 promotes the proliferation of pancreatic cancer cells via the AKT signaling pathway and confirmed that the activation of IGF2BP1 is partly due to the silencing of miR-494.

Orexin A ameliorates HBV X protein-induced cytotoxicity and inflammatory response in human hepatocytes.

Hepatitis B virus is one of the main causes of hepatitis and hepatocellular carcinoma (HCC). Hepatitis B virus-encoded X protein (HBx) has been shown to be involved in many aspects of the pathogenicity of liver diseases. Orexin A is a small peptide produced in the hippocampus. Orexin A and its receptor have become important therapeutic targets for certain metabolic disorders. In this study, we show that orexin A has a protective role against HBx-induced cytotoxicity and inflammation in hepatocytes. The ectopic expression of HBx in hepatocytes reduces orexin A receptor 1 (OX1R) expression. When orexin A is added to the cells, it mitigates HBx-induced oxidative stress indicator 4-hydroxynonenal (4-HNE) and reactive oxygen species (ROS) as well the NADPH subunit NADPH oxidase 4 (NOX-4). Orexin A also ameliorates HBx-mediated mitochondrial membrane potential and adenosine triphosphate (ATP) reduction. Moreover, orexin A significantly inhibits HBx-induced production of pro-inflammatory cytokines including interleukin 8 (IL-8), tumour necrosis factor α (TNF-α) and chemokine ligand 2 (CXCL2). The presence of orexin A ameliorates HBx-induced lactate dehydrogenase (LDH) release, indicating that it could protect hepatocytes from cytotoxicity. Mechanistically, we found that orexin A suppresses c-Jun N-terminal kinase (JNK) phosphorylation, accumulation of nuclear factor-κB (NF-κB) protein p65 in nuclei, and NF-κB promoter activity, suggesting that orexin A suppresses JNK and NF-κB pathway activation. In conclusion, our study demonstrates that orexin A peptide possesses a protective role against HBx-mediated cytotoxicity and inflammation in hepatocytes.

RASSF7 promotes cell proliferation through activating MEK1/2-ERK1/2 signaling pathway in hepatocellular carcinoma.

The Ras-association domain family (RASSF) proteins have been involved in many important biological processes. RASSF7 is recently reported to be up-regulated in several types of cancer. However, the function of RASSF7 remain unknown in human cancers. To explore the role of RASSF7 in hepatocellular carcinoma (HCC) cells proliferation and molecular mechanism. RASSF7 expression was examined using public database TCGA, qRT-PCR and Western blot. The correlation between RASSF7 and clinicopathological features was measured. Overexpression and silencing of RASSF7 were performed to measure the impact on HCC cell proliferation, cell cycle and apoptosis. Futhermore, the molecular mechanism of MEK1/2-ERK1/2 signaling pathway regulation by RASSF7 was explored. RASSF7 was significantly up-regulated in HCC tissues and cell lines, and correlated with AFP, poor tumor histology and T stage. Overexpression of RASSF7 promoted HCC cell proliferation, drived G1-S phase cell cycle transition and inhibited apoptosis. Knockdown of RASSF7 suppressed cell growth, induced G1-S phase cell cycle arrest and cell apoptosis. Furthermore, our findings also demonstrated that RASSF7 promoted HCC cell proliferation through activating MEK1/2-ERK1/2 signaling pathway. Taken together, this study provides a novel evidence for clinical significance of RASSF7 as a potential biomarker, and demonstrates that RASSF7- MEK1/2-ERK1/2 signaling pathway might be a novel pathway involved in HCC progression.

[Stem cell factor enhances invasive ability of BxPC-3 cells via hypoxia-inducible factor 1α (HIF-1α)].

Objective To investigate the effect of stem cell factor (SCF)/c-KIT system on the invasion of BxPC-3 pancreatic cancer cells and the role of hypoxia-inducible factor 1 alpha (HIF-1α) in this effect. Methods BxPC-3 cells were cultured in normoxia and hypoxia. The cells cultured in normoxia were treated with SCF. Real-time quantitative PCR and Western blotting were used to investigate the expressions of HIF-1α mRNA and protein, respectively. Small interference RNA of HIF-1α (siHIF-1α) was designed and synthesized, and then transfected into BxPC-3 cells. The expressions of matrix metalloproteinase-2 (MMP2), MMP9, and urokinase type plasminogen activator (uPA) were detected by real-time quantitative PCR and Western blotting in BxPC-3 cells after treated with SCF or siHIF-1α. The effects of SCF/c-KIT and HIF-1α knockdown on BxPC-3 cell invasion were examined by TranswellTM assay. Results Either SCF or hypoxia could induce the protein expression of HIF-1α. The siHIF-1α down-regulated the expression of HIF-1α specifically in BxPC-3 cells. SCF up-regulated the mRNA and protein expressions of MMP2, MMP9 and uPA, while siHIF-1α down-regulated the expressions of these genes. The invasive ability of BxPC-3 cells were enhanced by SCF, while siHIF-1α played an opposite role. Conclusion SCF/c-KIT system up-regulates the mRNA and protein expressions of MMP2, MMP9 and uPA through HIF-1α, which enhances the invasive ability of pancreatic cancer cells. And siHIF-1α can effectively inhibit these effects.