No abstract

Deregulation of microRNAs (miRNAs) is common in advanced human hepatocellular carcinoma (HCC); however, the ones involved in early carcinogenesis have not yet been investigated. By examining the expression of 22 HCC-related miRNAs between precancerous and cancerous liver tissues, we found miR-216a and miR-224 were significantly up-regulated, starting from the precancerous stage. Furthermore, the elevation of miR-216a was mainly identified in male patients. To study this gender difference, we demonstrated that pri-miR-216a is activated transcriptionally by the androgen pathway in a ligand-dependent manner and is further enhanced by the hepatitis B virus X protein. The transcription initiation site for pri-miR-216a was delineated, and one putative androgen-responsive element site was identified within its promoter region. Mutation of this site abolished the elevation of pri-miR-216a by the androgen pathway. One target of miR-216a was shown to be the tumor suppressor in lung cancer-1 gene (TSLC1) messenger RNA (mRNA) through the three target sites at its 3 0 untranslated region. Finally, the androgen receptor level increased in male liver tissues during hepatocarcinogenesis, starting from the precancerous stage, with a concomitant elevation of miR-216a but a decrease of TSLC1. Conclusion: The current study discovered the up-regulation of miRNA-216a by the androgen pathway and a subsequent suppression of TSLC1 as a new mechanism for the androgen pathway in early hepatocarcinogenesis. (HEPATOLOGY 2012;56:632-643) T he incidence of hepatocellular carcinoma (HCC) ranks fifth for cancers worldwide and causes about half a million deaths every year. 1 HCC is usually the ultimate outcome of chronic hepatitis caused by persistent viral infection (hepatitis B or C virus [HBV/HCV]) or by alcoholic/metabolic etiologies. After decades of chronic hepatitis, which might induce persistent necrosis and regeneration and accumulate the carcinogenic events in the hepatocytes, about 30%-40% of patients will progress into liver cirrhosis, and those will subsequently develop HCC with an annual incidence around 1%-5%. 2 Due to the multistep characteristic of cancer development, on average six to seven successive mutations are generally believed to be required to convert a normal hepatocyte into an invasive HCC. 3 As every mutation contributes to the formation of an expanded clone and thus presents a larger target population of cells for the next mutation, the cells surrounding the HCC could be considered precancerous cells, retaining the potential to become the subsequent HCC. 4 This

No abstract

The estrogen pathway has long been implicated as a tumor protector in female hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Our previous study identified that estrogen receptor alpha (ERa) protein is downregulated in 60% of female HCC cases, via a miR-18a elevation mediated suppression of ERa translation. This study aims to delineate the mechanism underlying the upregulation of miR-18a in female HCC. The analysis of 77 female HCC specimens revealed that miR-18a levels were associated with pre-miR-18a rather than pri-miR-18a levels, suggesting an enhanced processing of pri-to pre-miR-18a. Among a panel of factors involved in microRNA processing, p53 was identified as a novel regulator for miR-18a maturation process. Knockdown of p53 by si-RNA decreased the level of miR-18a, whereas overexpression of either wild-type or mutant p53 increased its level. The association between the elevation of miR-18a and the accumulation of p53, mainly caused by somatic mutations, was confirmed in the clinical specimens of HBV-related female HCC. By analyzing the association with clinicopathological features, activation of this p53/miR-18a pathway mainly occurs in younger or noncirrhosis female HCC patients and associated with a trend of worse overall survival. Therefore, this study demonstrated a novel function of elevated/mutant p53 in regulating the amount of ERa protein through its promoting the biogenesis of miR-18a, which could lead to decrease the tumor-protective function of the estrogen pathway in female hepatocarcinogenesis.Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and its strong association with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is well known.1 Among the nonviral risk factors, the male sex factor has long been considered as a major risk factor of HCC, 2,3 as the incidence of HCC in male patients is 2-to 11-fold higher than that observed in females; this is even more evident in HBV-related HCC. 4 The sex hormones, including both the androgen and estrogen axes, are involved in the regulation of this gender difference in HCC. 4,5 The serial cohort studies performed by Yu et al. showed that an elevation in the activity of the androgen pathway was associated with higher HCC risk in male HBV carriers, whereas an elevation in the activity of the estrogen pathway was associated with lower HCC risk in female HBV carriers. 6 These results suggested opposite roles of the androgen and estrogen pathways in hepatocarcinogenesis, which might contribute to the gender difference of HCC.At the molecular level, recent studies have identified several mechanisms underlying the function of androgen and estrogen in the hepatocarcinogenic process. Regarding the androgen pathway, we found a positive regulatory loop between the viral Hepatitis B virus X protein and ligandactivated androgen receptor (AR) transcriptional activation in HBV-infected hepatocytes. This loop leads to persistently elevated AR activity and increased HBV mRNA transcription, which contribute to the ...

Genetic tractability and easy manipulation make Caenorhabditis elegans a good model to study host-pathogen interactions. Dozens of different bacterial species can pathogenically infect C. elegans under laboratory conditions, and all of these microbes are extracellular pathogens to nematodes. Viruses, on the other hand, are obligate intracellular parasites, and yet no viral infections have been reported for C. elegans. We established a procedure allowing vaccinia virus to enter and subsequently replicate in C. elegans. Virus replication was significantly enhanced in ced-3, ced-4, ced-9(gf), and egl-1(lf) mutants, demonstrating that the core programmed cell death (PCD) genes ced-3, ced-4, ced-9, and egl-1 control vaccinia virus replication in C. elegans. The ability of ced-3 and ced-4 alleles to restrict virus replication is correlated with their cell-killing activities. Moreover, the increase in vaccinia virus replication levels in the PCD-defective mutants was not likely to be caused by the extra live cells, as neither the inhibition of PCD by icd-1 overexpression nor the presence of extra cells after extra cell divisions in cul-1 or lin-23 mutants had any significant effect on vaccinia virus replication. Therefore, the core PCD genes possess a unique function in controlling vaccinia virus replication in C. elegans.programmed cell death ͉ virus-host interaction

Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may be saved and copied for your personal and scholarly purposes. You are not to copy documents for public or commercial purposes, to exhibit the documents publicly, to make them publicly available on the internet, or to distribute or otherwise use the documents in public. If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence.

Epidemics and outbreaks caused by infections of several subgenotypes of EV71 and other serotypes of coxsackie A viruses have raised serious public health concerns in the Asia-Pacific region. These concerns highlight the urgent need to develop a scalable manufacturing platform for producing an effective and sufficient quantity of vaccines against deadly enteroviruses. In this report, we present a platform for the large-scale production of a vaccine based on the inactivated EV71(E59-B4) virus. The viruses were produced in Vero cells in a 200 L bioreactor with serum-free medium, and the viral titer reached 107 TCID50/mL 10 days after infection when using an MOI of 10−4. The EV71 virus particles were harvested and purified by sucrose density gradient centrifugation. Fractions containing viral particles were pooled based on ELISA and SDS-PAGE. TEM was used to characterize the morphologies of the viral particles. To evaluate the cross-protective efficacy of the EV71 vaccine, the pooled antigens were combined with squalene-based adjuvant (AddaVAX) or aluminum phosphate (AlPO4) and tested in human SCARB2 transgenic (Tg) mice. The Tg mice immunized with either the AddaVAX- or AlPO4-adjuvanted EV71 vaccine were fully protected from challenges by the subgenotype C2 and C4 viruses, and surviving animals did not show any degree of neurological paralysis symptoms or muscle damage. Vaccine treatments significantly reduced virus antigen presented in the central nervous system of Tg mice and alleviated the virus-associated inflammatory response. These results strongly suggest that this preparation results in an efficacious vaccine and that the microcarrier/bioreactor platform offers a superior alternative to the previously described roller-bottle system.

Over the past decade the scale of higher education in China has expanded substantially. Regional development policies have attempted to make use of scale expansion as a tool to reduce inequality of higher education among regions with different development levels by providing poor regions with preferential treatment and support. This paper analyzes a provincial dataset (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008), aiming to provide comprehensive quantitative evidence for the development of inequality of opportunity in higher education across provinces in China over the period of scale expansion. Results show that, for higher education, regional inequality relative to provincial population size clearly decreased over the research period. Accompanying the reduction in overall inequality across provinces, inequality between poor and rich regions actually increased over the same period. However, the increase was realized in favor of the poor region. The empirical results are consistent with the policy orientation of reforming the higher education system and of promoting regional development in China over the past decade.