It is increasingly clear that hepatocellular carcinoma (HCC) has a distinct microRNA (miRNA) expression profile that is involved in malignancy; however, little is known about how functional miRNA modulates the metastasis of hepatitis B virus (HBV)-related HCC (HBV-HCC). In the present study, we demonstrate that the levels of miRNA-143 (miR-143) are dramatically increased in metastatic HBV-HCC of both p21-HBx transgenic mice and HCC patients. Moreover, we show that overexpression of this miRNA is transcribed by nuclear factor kappa B (NF-B) and favors liver tumor cell invasive and metastatic behavior. H epatocellular carcinoma (HCC) is a common and aggressive cancer that is strongly associated with chronic infection by the hepatitis B virus (HBV). 1 Poor prognosis and patient survival with HCC are largely due to invasion/metastasis and postsurgical recurrence. 2 The HBV X protein (HBx), a protein encoded by HBV, is thought to play a key role in the molecular pathogenesis of HBV-related HCC (HBV-HCC). 2,3 Invasion and metastasis are fundamental properties of HBV-HCC, which has a very high mortality rate. Alteration of some adhesion molecules in HBV-HCC has been described, including up-regulation of matrix metalloproteinases 1-3 and down-regulation of E-cadherin. Both of these changes indicate that HBx contributes to the metastatic spread of liver tumors. 2,4 Metastasis is a complex cascade, however, and the underlying molecular mechanisms are far from being fully understood.MicroRNAs (miRNAs) are evolutionarily endogenous regulatory noncoding RNAs that play critical roles in gene regulation. 5 Recent studies implicate miRNAs in several cancers, and altered miRNA levels can result in aberrant expression of gene products that may contribute to cancer biology, including tumor metastasis. [5][6][7][8] These findings suggest that expression profiling of miRNAs is an alternative method for cancer subtype classification, prognostication, and treatment. 5,7,8 It is known that HCC develops several years after HBV infection. 2,9 A p21-HBx transgenic mouse model was established by introducing the HBx gene into the p21 locus. About 60% of p21-HBx transgenic mice develop hepato-

BackgroundRecent evidences showed that long noncoding RNAs (lncRNAs) are frequently dysregulated and play important roles in various cancers. Clear cell renal cell carcinoma (ccRCC) is one of the leading cause of cancer-related death, largely due to the metastasis of ccRCC. However, the clinical significances and roles of lncRNAs in metastatic ccRCC are still unknown.MethodslncRNA expression microarray analysis was performed to search the dysregulated lncRNA in metastatic ccRCC. quantitative real-time PCR was performed to measure the expression of lncRNAs in human ccRCC samples. Gain-of-function and loss-of-function experiments were performed to investigate the biological roles of lncRNAs on ccRCC cell proliferation, migration, invasion and in vivo metastasis. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and western blot were performed to explore the molecular mechanisms underlying the functions of lncRNAs.ResultsThe microarray analysis identified a novel lncRNA termed metastatic renal cell carcinoma-associated transcript 1 (MRCCAT1), which is highly expressed in metastatic ccRCC tissues and associated with the metastatic properties of ccRCC. Multivariate Cox regression analysis revealed that MRCCAT1 is an independent prognostic factor for ccRCC patients. Overexpression of MRCCAT1 promotes ccRCC cells proliferation, migration, and invasion. Depletion of MRCCAT1 inhibites ccRCC cells proliferation, migration, and invasion in vitro, and ccRCC metastasis in vivo. Mechanistically, MRCCAT1 represses NPR3 transcription by recruiting PRC2 to NPR3 promoter, and subsequently activates p38-MAPK signaling pathway.ConclusionsMRCCAT1 is a critical lncRNA that promotes ccRCC metastasis via inhibiting NPR3 and activating p38-MAPK signaling. Our results imply that MRCCAT1 could serve as a prognostic biomarker and therapeutic target for ccRCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-017-0681-0) contains supplementary material, which is available to authorized users.

Recently, a large number of long non-coding RNAs (lncRNAs) have been reported in mammalian genomes and are evolutionarily conserved and presumably function in many biological events, especially in the pathogenesis of diverse human cancers. A lncRNA, named HOST2 (human ovarian cancer-specific transcript 2), was once reported to specifically be expressed at high level in human ovarian cancer. However, how HOST2 acts to regulate gene functions in ovarian carcinogenesis has remained enigmatic. Here we report, for the first time, that HOST2 promotes tumor cell migration, invasion and proliferation in epithelial ovarian cancer by working in key aspects of biological behaviors. In the present study, bioinformatics analysis indicated that HOST2 binds with microRNA let-7b, a potent tumor suppressor, which was then verified to target HOST2. Our results showed that HOST2 harbors a let-7b binding site and modulates let-7b availability by acting as a molecular sponge. HOST2 inhibits let-7b functions, which post-transcriptionally suppress the expression of targets, including some oncogenes that regulate cell growth and motility. Additionally, understanding HOST2/let-7b-dependent regulation may lead to alternative approaches for the diagnosis and cure of this deadly disease.

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Purpose: Portal vein tumor thrombus (PVTT) is a major complication of hepatocellular carcinoma (HCC) and is associated with poor survival. Long noncoding RNAs (lncRNA) contribute to HCC metastasis, but whether and how lncRNAs affect PVTT development remains unclear. In the present study, a novel highly expressed lncRNA (ICAM-1-related, ICR) was identified in ICAM-1 þ cancer stem cells (CSC) in HCC. This lncRNA regulated CSC properties and contributed to PVTT development.Experimental Design: We used microarray and bioinformatics analyses to identify differentially expressed lncRNAs. Realtime PCR and Western blotting were used to assess gene expression in cell lines and tumors. Sphere formation assays were performed to investigate stem cell properties of tumor cells in vitro. Retrospective and prospective studies were used to investigate the relationship between ICR expression and clinical outcomes. Conclusions: Our study demonstrates that ICR specifically regulates CSC properties of ICAM-1 þ HCC cells and that ICR contributes to PVTT development. Therefore, ICR may be a promising target for HCC therapy.

Wasp stings have been arising to be a severe public health problem in China in recent years. However, molecular information about lethal or toxic factors in wasp venom is extremely lacking. In this study, we used two pyrosequencing platforms to analyze the transcriptome of Vespa velutina, the most common wasp species native in China. Besides the substantial amount of transcripts encoding for allergens usually regarded as the major lethal factor of wasp sting, a greater abundance of hemostasis-impairing toxins and neurotoxins in the venom of V. velutina were identified, implying that toxic reactions and allergic effects are envenoming strategy for the dangerous outcomes. The pattern of differentially expressed genes before and after venom extraction clearly indicates that the manifestation of V. velutina stings depends on subtle regulations in the metabolic pathway required for toxin recruitment. This comparative analysis offers timely clues for developing clinical treatments for wasp envenoming in China and around the world.

Portal vein tumor thrombus (PVTT) is a type of intrahepatic metastasis arising from hepatocellular carcinoma (HCC) and is highly correlated with a poor prognosis. Hypoxia is common in solider tumors, including HCC, where it alters the behavior of HCC cells. We asked whether and how hypoxia contributes to PVTT formation. We demonstrated that increased intratumoral hypoxia is strongly associated with PVTT formation in HCC. We also showed that 14-3-3ζ is induced by hypoxia in HCC cells and correlates with PVTT formation in clinical HCC samples. In addition, 14-3-3ζ up-regulates HIF-1α expression by recruiting HDAC4, which prevents HIF-1α acetylation, thereby stabilizing the protein. Under hypoxic conditions in vitro, 14-3-3ζ knockdown inhibits hypoxia-induced HCC invasion by the HIF-1α/EMT pathway. Blockade of 14-3-3ζ in HCC cells reduces PVTT formation and distant lung metastasis in vivo. Moreover, a combination of 14-3-3ζ and HIF-1α expression is more prognostic for HCC patients than either protein alone. These results suggest that the hypoxia/14-3-3ζ/HIF-1α pathway plays an important role in PVTT formation and HCC metastasis.