The cellular prion protein (PrP) is a highly conserved, widely expressed, glycosylphosphatidylinositolanchored (GPI-anchored) cell surface glycoprotein. Since its discovery, most studies on PrP have focused on its role in neurodegenerative prion diseases, whereas its function outside the nervous system remains unclear. Here, we report that human pancreatic ductal adenocarcinoma (PDAC) cell lines expressed PrP. However, the PrP was neither glycosylated nor GPI-anchored, existing as pro-PrP and retaining its GPI anchor peptide signal sequence (GPI-PSS). We also showed that the PrP GPI-PSS has a filamin A-binding (

May is designated as Hepatitis Awareness Month, and May 19 is Hepatitis Testing Day. Hepatitis B and hepatitis C, the most common types of viral hepatitis in the United States, can cause chronic infections, and many persons remain unaware of their infection until serious complications occur. In 2016, an estimated 862,000 and 2.4 million persons were living with hepatitis B and hepatitis C, respectively, despite availability of a vaccine and effective treatment for hepatitis B and a cure for hepatitis C (1,2). Although hepatitis A is preventable through vaccination, multiple states have had outbreaks since 2016, with unprecedented large numbers of cases and person-toperson spread (primarily among persons who use drugs or experience homelessness). A report in this issue of MMWR summarizes this resurgence of hepatitis A among unvaccinated adults at risk (3). New cases of hepatitis C are also increasing; during 2010-2016, they increased 3.5-fold, mostly among young adults (4). Recent increases in viral hepatitis infections, many attributed to surges in injection-drug use (4), highlight the importance of acknowledging and combatting the infectious disease consequences of the nation's opioid crisis.

Purpose: Hypoxia inducible factor-1 (HIF-1), the central mediator of the cellular response to low oxygen, functions as a transcription factor for a broad range of genes that provide adaptive responses to oxygen deprivation. HIF-1 is overexpressed in cancer and has become an important therapeutic target in solid tumors. In this study, a novel HIF-1α inhibitor was identified and its molecular mechanism was investigated. Experimental Design: Using a HIF-responsive reporter cell-based assay, a 10,000-member natural product-like chemical compound library was screened to identify novel HIF-1 inhibitors. This led us to discover KC7F2, a lead compound with a central structure of cystamine. The effects of KC7F2 on HIF-1 transcription, translation, and protein degradation processes were analyzed. Results: KC7F2 markedly inhibited HIF-mediated transcription in cells derived from different tumor types, including glioma, breast, and prostate cancers, and exhibited enhanced cytotoxicity under hypoxia. KC7F2 prevented the activation of HIF-target genes such as carbonic anhydrase IX, matrix metalloproteinase 2 (MMP2), endothelin 1, and enolase 1. An investigation into the mechanism of action of KC7F2 showed that it worked through the down-regulation of HIF-1α protein synthesis, an effect accompanied by the suppression of the phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 and p70 S6 kinase, key regulators of HIF-1α protein synthesis. Conclusion: These results show that KC7F2 is a potent HIF-1 pathway inhibitor and its potential as a cancer therapy agent warrants further study. (Clin Cancer Res 2009;15 (19):6128-36) Hypoxia, a reduction in partial oxygen pressure, is a major hindrance to effective solid tumor therapy. The microenvironment of rapidly growing solid tumors shows increased energy demand and diminished vascular supply, resulting in focal areas of prominent hypoxia (1). The hypoxic fraction of tumors is resistant to traditional therapies. Radiotherapy is compromised because of the reduced reaction of oxygen with radiationinduced DNA free radicals (2). Chemotherapy is hampered by the diffusion-limited drug delivery to hypoxic regions from distant vasculature. Moreover, many anticancer drugs are most effective against rapidly proliferating cells, and hypoxia (and deficiencies in other nutrients such as glucose) can cause a reduction in cell proliferation rate (3). This is compounded by the induction of the multidrug resistance (MDR1) gene product P-glycoprotein in hypoxic tissue (4), further reducing drug efficacy. Hypoxic tumor regions also impede immune responses, and may promote the growth of cancer stem cells (5,6).Hypoxia drives malignant tumor progression. Tumor hypoxia increases malignant progression and metastasis by promoting angiogenesis through the induction of proangiogenic proteins such as vascular endothelial growth factor (VEGF) and metabolic adaptation through elevation of glycolytic enzymes (7,8). Hypoxia also generates selective pressure for cells to acquir...

BackgroundHealth-related quality of life (HRQOL) is a multi-dimensional concept commonly used to examine the impact of health status on quality of life. HRQOL is often measured by four core questions that asked about general health status and number of unhealthy days in the Behavioral Risk Factor Surveillance System (BRFSS). Use of these measures individually, however, may not provide a cohesive picture of overall HRQOL. To address this concern, this study developed and tested a method for combining these four measures into a summary score.MethodsExploratory and confirmatory factor analyses were performed using BRFSS 2013 data to determine potential numerical relationships among the four HRQOL items. We also examined the stability of our proposed one-factor model over time by using BRFSS 2001–2010 and BRFSS 2011–2013 data sets.ResultsBoth exploratory factor analysis and goodness of fit tests supported the notion that one summary factor could capture overall HRQOL. Confirmatory factor analysis indicated acceptable goodness of fit of this model. The predicted factor score showed good validity with all of the four HRQOL items. In addition, use of the one-factor model showed stability, with no changes being detected from 2001 to 2013.ConclusionInstead of using four individual items to measure HRQOL, it is feasible to study overall HRQOL via factor analysis with one underlying construct. The resulting summary score of HRQOL may be used for health evaluation, subgroup comparison, trend monitoring, and risk factor identification.Electronic supplementary materialThe online version of this article (doi:10.1186/s12963-016-0091-3) contains supplementary material, which is available to authorized users.

Converting normal prion protein (PrP C ) to the pathogenic PrP Sc isoform is central to prion disease. We previously showed that, in the presence of lipids, recombinant mouse PrP (rPrP) can be converted into the highly infectious conformation, suggesting a crucial role of lipid-rPrP interaction in PrP conversion. To understand the mechanism of lipid-rPrP interaction, we analyzed the capability of various rPrP mutants to bind anionic lipids and to gain the lipid-induced proteinase K (PK)-resistance. We found that the N-terminal positively charged region contributes to the electrostatic rPrP-lipid binding, but does not affect lipid-induced PK-resistance. In contrast, the highly conserved middle region of PrP, consisting of a positively charged region and a hydrophobic domain, is essential for lipid-induced rPrP conversion. The hydrophobic domain deletion mutant significantly weakened the hydrophobic rPrP-lipid interaction and abolished the lipid-induced C-terminal PK-resistance. The rPrP mutant without positive charges in the middle region reduced the amount of lipid-induced PK-resistant rPrP form. Consistent with a critical role of the middle region in lipid-induced rPrP conversion, both disease-associated P105L and P102L mutations, localized between lysine residues in the positively charged region, significantly affected lipid-induced rPrP conversion. The hydrophobic domain localized 129 polymorphism altered the strength of hydrophobic rPrP-lipid interaction. Collectively, our results suggest that the interaction between the middle region of PrP and lipid is essential for the formation of PKresistant conformation. Moreover, the influence of disease-associated PrP mutations and 129 polymorphism on PrP-lipid interaction supports the relevance of PrP-lipid interaction to the pathogenesis of prion disease.Prion diseases are a group of transmissible neurodegenerative disorders including Creutzfeldt-Jakob Disease (CJD) and Gerstmann-Straussler-Scheinker syndrome (GSS) in humans, scrapie in sheep, and bovine spongiform encephalopathy in cows (1-3). The transmission of prion disease is mediated by an unusual infectious agent, which is composed of a pathogenic conformer of the normal prion protein (PrP) (1,(4)(5)(6). The conformational change of PrP, converting the normal protease sensitive PrP C to the pathogenic protease resistant PrP Sc form, is a critical pathogenic event in prion disease (7)(8)(9)(10)(11). We recently reported that in the presence of anionic phospholipid POPG (1-palmitoyl-2-oleoylphosphatidylglycerol) and total mouse liver RNA, bacterially expressed recombinant PrP (rPrP) can be converted in vitro into the infectious conformer, causing prion disease in wild type animals (12). The high prion infectivity associated with the recombinant prion (16). Notably, the purified PrP C used in that study contains a stoichiometric amount of co-purified lipid molecules, indicating a role of lipid in PrP conversion (16). The role of lipid in PrP conversion has also been implicated by several previous studi...

Mutation in the prion gene PRNP accounts for 10 -15% of human prion diseases. However, little is known about the mechanisms by which mutant prion proteins (PrPs) cause disease. Here we investigated the effects of 10 different pathogenic mutations on the conformation and ligand-binding activity of recombinant human PrP (rPrP). We found that mutant rPrPs react more strongly with N terminus-specific antibodies, indicative of a more exposed N terminus. The N terminus of PrP contains a glycosaminoglycan (GAG)-binding motif. Binding of GAG is important in prion disease. Accordingly, all mutant rPrPs bind more GAG, and GAG promotes the aggregation of mutant rPrPs more efficiently than wild-type recombinant normal cellular PrP (rPrP C ). Furthermore, point mutations in PRNP also cause conformational changes in the region between residues 109 and 136, resulting in the exposure of a second, normally buried, GAG-binding motif. Importantly, brainderived PrP from transgenic mice, which express a pathogenic mutant with nine extra octapeptide repeats, also binds more strongly to GAG than wild-type PrP C . Thus, several rPrPs with distinct pathogenic mutations have common conformational changes, which enhance binding to GAG. These changes may contribute to the pathogenesis of inherited prion diseases.genetics ͉ structure

Purpose The hypoxia inducible factor-1 (HIF-1) plays a critical role in tumor adaptation to hypoxia, and its elevated expression correlates with poor prognosis and treatment failure in cancer patients. In this study, we determined whether 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide, KCN1, the lead inhibitor in a novel class of arylsulfonamide inhibitors of the HIF-1 pathway, had anti-tumorigenic properties in vivo and further defined its mechanism of action. Experimental Design We studied the inhibitory effect of systemic KCN1 delivery on the growth of human brain tumors in mice. To define mechanisms of KCN1 anti-HIF activities, we examined its influence on the assembly of a functional HIF1α/HIF1β/p300 transcription complex. Results KCN1 specifically inhibited HIF reporter gene activity in several glioma cell lines at the nanomolar level. KCN1 also downregulated transcription of endogenous HIF-1 target genes, such as VEGF, Glut-1 and carbonic anhydrase 9, in an HRE-dependent manner. KCN1 potently inhibited the growth of subcutaneous malignant glioma tumor xenografts with minimal adverse effects on the host. It also induced a temporary survival benefit in an intracranial model of glioma but had no effect in a model of melanoma metastasis to the brain. Mechanistically, KCN1 did not down-regulate levels of HIF-1α or other components of the HIF transcriptional complex; rather, it antagonized hypoxia-inducible transcription by disrupting the interaction of HIF-1α with transcriptional co-activators p300/CBP. Conclusions Our results suggest that the new HIF pathway inhibitor KCN1 has antitumor activity in mouse models, supporting its further translation for the treatment of human tumors displaying hypoxia or HIF overexpression.

BackgroundInsecticide-treated bed nets (ITNs), used extensively to reduce human exposure to malaria, work through physical and chemical means to block or deter host-seeking mosquitoes. Despite the importance of ITNs, very little is known about how host-seeking mosquitoes behave around occupied bed nets. As a result, evidence-based evaluations of the effects of physical damage on bed net effectiveness are not possible and there is a dearth of knowledge on which to base ITN design.MethodsThe dispersion of colony-raised female Anopheles gambiae and Anopheles albimanus was observed in 2-hr laboratory experiments in which up to 200 mosquitoes were released inside a mosquito-proof 3 m × 3 m tent housing a bed net arrayed with 18 30 cm × 30 cm sticky screen squares on the sides, ends and roof. Numbers of mosquitoes caught on the sticky squares were interpreted as the ‘mosquito pressure’ on that part of the net.ResultsPresence of a human subject in the bed net significantly increased total mosquito pressure on the net for both species and significantly re-oriented An. gambiae to the roof of the net. Anopheles albimanus pressure was greatest on the bed net roof in both host-present and no-host conditions. The effects of different human subjects in the bed net, of different ambient conditions (dry, cool conditions vs warm, humid conditions) and of bed net treatment (deltamethrin-treated or no insecticide) on mosquito pressure patterns were tested for both species. Species-specific pressure patterns did not vary greatly as a result of any of these factors though some differences were noted that may be due the size of the different human subjects.ConclusionsAs a result of the interaction between host-seeking responses and the convective plume from the net occupant, species-specific mosquito pressure patterns manifest more or less predictably on the bed net. This has implications for bed net design and suggests that current methods of assessing damaged bed nets, which do not take damage location into account, should be modified.