BACKGROUNDStudies have shown that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) plays critical roles in the genesis and development of human cancers.AIMTo investigate the clinical significance and role of IGF2BP1 in pancreatic cancer.METHODSExpression 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.RESULTSWe 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.CONCLUSIONOur 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.

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 a (TNF-a) 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-jB (NF-jB) protein p65 in nuclei, and NF-jB promoter activity, suggesting that orexin A suppresses JNK and NF-jB pathway activation. In conclusion, our study demonstrates that orexin A peptide possesses a protective role against HBx-mediated cytotoxicity and inflammation in hepatocytes.

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.

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