1 wileyonlinelibrary.com recoverability and self-healing property, due to their intrinsic structural heterogeneity and/or lack of effi cient energydissipation mechanisms, [ 13 ] which greatly limit their uses for other applications requiring highly mechanical properties such as cartilage, tendon, muscle, and blood vessel.Many efforts have been made to develop tough hydrogels with new microstructures and toughening mechanisms, such as double network hydrogels, [ 14 ] nanocomposite hydrogels, [ 15 ] sliding-ring hydrogels, [ 16 ] macromolecular microsphere composite hydrogels, [ 17 ] tetrapolyethylene glycol hydrogels, [ 18 ] hydrophobically associated hydrogels, [ 19,20 ] and dipole-dipole or hydrogen bonding enhanced hydrogels. [ 21,22 ] Among them, double network (DN) hydrogels have demonstrated their excellent mechanical properties. The existing knowledge of DN gels from synthesis methods, network structures, to toughening mechanisms mainly comes from chemically cross-linked DN gels. [ 23 ] Both networks with contrasting structures in DN gels are separately crosslinked by covalent bonds, [ 24 ] and the interpenetration of two contrasting networks makes the chemically linked DN gels both tough and soft, as evidenced by stiffness (elastic modulus of 0.1-1.0 MPa), strength (failure tensile stress of 1-10 MPa, strain 1000%-2000%, failure compressive stress 20-60 MPa, strain 90%-95%), and toughness (tearing fracture energy of 10 2 -10 3 J m −2 ). [ 23 ] Chemically linked DN gels have comparable toughness to cartilage and rubber. The toughening mechanisms are largely based on "sacrifi cial bonds" that break from the fi rst network to effectively dissipate energy, protect the second network, sustain stress, and store elastic energy, thus to reinforce the gels. However, the fracture of the fi rst network also causes irreversible and permanent bond breaks, making the gels very diffi cult to be repaired and recovered from damages and fatigues. [ 25 ] Thus, the internal fracture process of the fi rst network is considered to be critical for toughness enhancement, because relatively large damage zones formed in the fi rst network allow for more accumulated damage before macroscopic crack propagation occurs throughout whole networks. [ 26,27 ] Double network (DN) hydrogels with two strong asymmetric networks being chemically linked have demonstrated their excellent mechanical properties as the toughest hydrogels, but chemically linked DN gels often exhibit negligible fatigue resistance and poor self-healing property due to the irreversible chain breaks in covalent-linked networks. Here, a new design strategy is proposed and demonstrated to improve both fatigue resistance and self-healing property of DN gels by introducing a ductile, nonsoft gel with strong hydrophobic interactions as the second network. Based on this design strategy, a new type of fully physically cross-linked Agar/hydrophobically associated polyacrylamide (HPAAm) DN gels are synthesized by a simple one-pot method. Agar/ HPAAm DN gels exhibit excellent mech...

We here report that miR-17-92 cluster is a novel target for p53-mediated transcriptional repression under hypoxia. We found the expression levels of miR-17-92 cluster were reduced in hypoxia-treated cells containing wild-type p53, but were unchanged in hypoxia-treated p53-deficient cells. The repression of miR-17-92 cluster under hypoxia is independent of c-Myc. Luciferase reporter assays mapped the region responding to p53-mediated repression to a p53-binding site in the proximal region of the miR-17-92 promoter. Chromatin immunoprecipitation (ChIP), Re-ChIP and gel retardation assays revealed that the binding sites for p53-and the TATA-binding protein (TBP) overlap within the miR-17-92 promoter; these proteins were found to compete for binding. Finally, we show that pri-miR-17-92 expression correlated well with p53 status in colorectal carcinomas. Over-express miR-17-92 cluster markedly inhibits hypoxia-induced apoptosis, whereas blocked miR-17-5p and miR-20a sensitize the cells to hypoxia-induced apoptosis. These data indicated that p53-mediated repression of miR-17-92 expression likely has an important function in hypoxia-induced apoptosis, and thus further our understanding of the tumour suppressive function of p53.

Early-onset hepatocellular carcinoma (HCC) accounts for 15%-20% of total HCC cases in Asia, and the incidence is increasing. The low frequency of cirrhosis and poor prognosis of early-onset HCC suggests that its mechanisms may differ from late-onset HCC. Although hepatitis B virus (HBV) infection is epidemiologically associated with HCC, the role of HBV in early-onset HCC remains poorly understood. Here, we report a comparative study of HBV subgenotypes and integration in early-( £ 30) and late-onset (70) HBV-associated HCC using a novel high-throughput viral integration detection method. We report that HBV B2 is predominantly present in early-onset HCC. HBV integration is a common phenomenon, both in early-and late-onset HCC, which favors integrating into human repeat regions. Moreover, we found a breakpoint in 8q24 located between c-Myc and plasmocytoma variant translocation 1 (PVT1), which was detected in 12.4% (14 of 113) of early-onset HCCs, but only 1.4% (2 of 145) in lateonset HCCs. HBV integrating this site results in c-MYC, PVT1, and microRNA-1204 overexpression in tumors, thereby potentially contributing to the development of earlyonset HCC. Conclusion: HBV genotype and integration patterns may be distinct in early-onset HCC. Our results may shed light on HCC risk factors in young HBV carriers. Further studies are needed to elucidate at which time in tumor development this integration event occurs and whether it plays an important, causative role in HCC development or progression. (HEPATOLOGY 2015;61:1821-1831 H epatocellular carcinoma (HCC) is a common solid tumor and the third leading cause of cancer death worldwide.1 Hepatitis B virus (HBV) is a major etiological agent in China, Southeast Asia, and sub-Saharan Africa, and individuals with chronic HBV infection are at increased risk of developing HCC, particularly those with chronic liver disease and cirrhosis.2 Average age at onset of HBVassociated HCC is 50 years 3,4 ; thus, the recommendations advise HCC screening for Asian male HBV patients older than 40 and Asian female HBV patients older than 50.5 Nonetheless, incidence of HCC in patients younger than 40, especially in high-risk populations, is relatively high. 6,7 Recent studies have reported a significant prevalence and worse prognosis in early-onset HCC patients, 8,9 suggesting that there Abbreviations: ALB, albumin; bp, base pairs; DR1/2, direct repeat 1 and 2; FN1, fibronectin 1; GATM, glycine amidinotransferase; gDNA, genomic DNA; HBV, hepatitis B virus; Hbx, HBV x gene; HCC, hepatocellular carcinoma; HIVID, high-throughput viral integration detection; kb, kilobase; LC, liver cirrhosis; LINE, long interspersed nuclear elements; miR, microRNA; MLL4, myeloid/lymphoid or mixed-lineage leukemia 4; PVT1, plasmocytoma variant translocation 1; RT-PCR, reverse-transcription polymerase chain reaction; SINE, short interspersed nuclear elements; ST18, suppression of tumorigenicity 18; STAT1, signal transducer and activator of transcription 1; SYT12, synaptotagmin XII; TERT, telomerase reverse transc...

Background As an alternative biomarker of intrahepatic covalently closed circular DNA (cccDNA) transcriptional activity, hepatitis B virus (HBV) RNA may evolve during long-lasting virus-host interactions during chronic hepatitis B viral infection. The distribution pattern of serum HBV RNA levels in the natural course of chronic HBV infection remains unclear. The aim of this study was to evaluate the levels of HBV RNA during the natural course of CHB and the role in distinguishing the natural history of HBV infection. Methods A total of 291 treatment-naïve chronic HBV carriers were enrolled. Based on the clinical, biochemical, serological, and histological data as well as HBV DNA levels, patients were classified into the following four categories: the immune-tolerant phase (IT, n = 35), HBeAg-positive immune-active phase (EPIA, n = 121), inactive chronic hepatitis B(ICH, n = 58) and HBeAg-negative immune reactive hepatitis (ENH, n = 77). The parameters and distribution patterns of serum HBV RNA were evaluated in relation to viral replication status, immune phase, disease category and Child-Pugh class. The relationships between serum HBV RNA and other serum hepatitis B viral markers were also analyzed. Results Serum HBV RNA levels were significantly lower in the HBeAg-negative patients compared to those in the HBeAg-positive patients, with the lowest levels seen in inactive carriers. In HBeAg-negative patients, serum HBV RNA levels increased if there is reactivation to active hepatitis and showed obvious superiority for the combination of serum HBV DNA (cutoff>3.39 Log copies/mL) and HBsAg (cutoff>2.74 Log IU/mL) in discriminating between ‘HBeAg-negative immune reactive’ phase and inactive chronic hepatitis B phases of HBeAg-negative chronic HBV infection. Serum HBV RNA levels were positively correlated with serum HBV DNA and HBsAg levels in all chronic HBV-infected patients. A stratified analysis revealed that a correlation between serum HBV RNA and HBV DNA or HBsAg was present in HBeAg-positive patients; however, in HBeAg-negative patients, serum HBV RNA was positively correlated with HBV DNA only. Conclusion During the natural course of chronic HBV infection, serum HBV RNA levels vary. Serum HBV RNA can act as a biomarker to predict the natural history of disease in chronic hepatitis B patients. In treatment-naïve HBeAg-negative chronic HBV-infected individuals, serum HBV RNA shows superiority in differentiating the ‘HBeAg-negative reactive’ phase.

Given the adverse effects of drugs used for NAFLD treatment, identifying novel and effective natural compound to prevent NAFLD is urgently needed. In the present study, the effects of phytosterol esters (PSEs) on NAFLD were explored. Adult SD rats were randomized into five groups: normal chow diet (NC), high-fat diet (HF), low-, medium- and high-dose PSE treatment plus high-fat diet groups (PSEL, PSEM, and PSEH). Our results showed that the levels of LDL-C in the PSEL group and hepatic TG, TC, and FFA in the three PSEs groups were significantly decreased. Notably, the uric acid (UA) level was significantly decreased by PSEs intervention. The hepatic inflammatory stress was ameliorated via the inhibition of the cytokines, including TGF-β, IL-6, IL-10 and CRP in the PSEs intervention groups. Further, the oxidative status was improved by PSE treatment through adjusting the enzyme activity (SOD and XOD) and decreasing the MDA level. These beneficial effects of PSE may have been partly due to its regulation on the expression of TGF-β1, TGF-β2, TNF-α, UCP-2, PPAR-α and PPAR-γ in hepatic tissue at both mRNA and protein level. The results of this study suggest that PSEs may be used as therapeutic agents for the prevention and progression of NAFLD and that hyperuricemia is induced by high-fat diet consumption.

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Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells; eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. For the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 8 miRNAs were up-regulated by 5-aza-2′-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. In addition to reporting these findings, our study also provides a reliable, systematic strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data.

Background: Circular RNAs (circRNAs) play a critical regulatory role in cancer progression. However, the underlying mechanisms of circRNAs in hepatocellular carcinoma (HCC) metastasis remain mostly unknown. Methods: Has_circ_0003998 (circ0003998) was identified by RNAs sequencing in HCC patients with /without portal vein tumor thrombus (PVTT) metastasis. The expression level of circ0003998 was further detected by in situ hybridization on tissues microarray (ISH-TMA) and qRT-PCR in 25 HCC patients with PVTT metastasis. Moreover, the 25 HCC patients with PVTT metastasis and 50 HCC patients without PVTT metastasis were recruited together to analyze the correlation between circ0003998 expression and HCC clinical characteristics. Transwell, migration and CCK8 assays, as well as nude mice model of lung or liver metastasis were used to evaluate the role of circ0003998 in epithelial to mesenchymal transition (EMT) in HCC. The regulatory mechanisms of circ0003998 in miR-143-3p and PCBP1 were determined by dual-luciferase reporter assay, nuclear-cytoplasmic fractionation, fluorescent in situ hybridization, RNA pull-down, microRNA sequence, western blot and RNA immunoprecipitation.