Phosphatidylserine (PS) receptors contribute to two crucial biological processes: apoptotic clearance and entry of many enveloped viruses. In both cases, they recognize PS exposed on the plasma membrane. Here we demonstrate that phosphatidylethanolamine (PE) is also a ligand for PS receptors and that this phospholipid mediates phagocytosis and viral entry. We show that a subset of PS receptors, including T-cell immunoglobulin (Ig) mucin domain protein 1 (TIM1), efficiently bind PE. We further show that PE is present in the virions of flaviviruses and filoviruses, and that the PE-specific cyclic peptide lantibiotic agent Duramycin efficiently inhibits the entry of West Nile, dengue, and Ebola viruses. The inhibitory effect of Duramycin is specific: it inhibits TIM1-mediated, but not L-SIGNmediated, virus infection, and it does so by blocking virus attachment to TIM1. We further demonstrate that PE is exposed on the surface of apoptotic cells, and promotes their phagocytic uptake by TIM1-expressing cells. Together, our data show that PE plays a key role in TIM1-mediated virus entry, suggest that disrupting PE association with PS receptors is a promising broad-spectrum antiviral strategy, and deepen our understanding of the process by which apoptotic cells are cleared. M embers of the filovirus and flavivirus families are the causative agents of life-threatening diseases. Ebola virus (EBOV), a filovirus, causes hemorrhagic fever with an average case fatality rate as high as 65% (1). Although there are EBOV vaccine candidates (2, 3), there is currently no licensed vaccine or treatment. Dengue virus (DENV) and West Nile virus (WNV) belong to the flavivirus family. Both are transmitted to humans through mosquito bites and can cause lethal hemorrhagic fever (in the case of DENV) or severe neurological diseases (in the case of WNV) (4, 5). Flaviviruses are emerging as major health concerns in tropical and subtropical areas worldwide. More than one third of the world's population is estimated to be at risk for DENV infection, with approximately 400 million people infected yearly (6). There are currently no approved vaccines or therapeutic agents against DENV or WNV.Virus entry into host cells typically initiates with the interaction between viral entry glycoproteins (GPs) and a receptor or coreceptor expressed at the surface of the target cell. Viruses also use less specific mechanisms to localize to target cell membranes, for example through GP association with various attachment factors (7). During the past few years, it has been increasingly recognized that many viruses also use a strategy known as apoptotic mimicry to promote their association with, and internalization into their target cells (8). Receptors for phospholipids, specifically phosphatidylserine (PS), normally involved in the clearance of apoptotic cells, markedly enhance the infection of a number of enveloped viruses. These PS receptors are presumed to engage PS on the virion membrane rather than the viral entry protein (9, 10). Enveloped viruses acquire...

SUMMARY Androgen deprivation therapy is the most effective treatment for advanced prostate cancer, however, almost all cancer eventually become castration-resistant, and the underlying mechanisms are largely unknown. Here, we show that an intrinsic constitutively activated feed-forward signaling circuit composed of IκBα/NF-κB(p65), miR-196b-3p, Meis2, PPP3CC is formed during the emergence of castration-resistant prostate cancer (CRPC). This circuit controls the expression of stem cell transcription factors that drives the high tumorigenicity of CRPC cells. Interrupting the circuit by targeting its individual components significantly impairs the tumorigenicity and CRPC development. Notably, constitutive activation of IκBα/NF-κB(p65) in this circuit is not dependent on the activation of traditional IKKβ/NF-κB pathways that are important in normal immune responses. Therefore, our studies present deep insight into the bona fide mechanisms underlying castration-resistance and provide the foundation for the development of CRPC therapeutic strategies that would be highly efficient while avoiding indiscriminate IKK/NF-κB inhibition in normal cells.

The Panax ginseng C.A. Meyer belonging to the Araliaceae has long been used as an herbal medicine. Although public databases are presently available for this family, no methyl jasmonate (MeJA) elicited transcriptomic information was previously reported on this species, with the exception of a few expressed sequence tags (ESTs) using the traditional Sanger method. Here, approximately 53 million clean reads of adventitious root transcriptome were separately filtered via Illumina HiSeq™2000 from two samples treated with MeJA (Pg-MeJA) and equal volumes of solvent, ethanol (Pg-Con). Jointly, a total of 71,095 all-unigenes from both samples were assembled and annotated, and based on sequence similarity search with known proteins, a total of 56,668 unigenes was obtained. Out of these annotated unigenes, 54,920 were assigned to the NCBI non-redundant protein (Nr) database, 35,448 to the Swiss-prot database, 43,051 to gene ontology (GO), and 19,986 to clusters of orthologous groups (COG). Searching in the Kyoto encyclopedia of genes and genomes (KEGG) pathway database indicated that 32,200 unigenes were mapped to 128 KEGG pathways. Moreover, we obtained several genes showing a wide range of expression levels. We also identified a total of 749 ginsenoside biosynthetic enzyme genes and 12 promising pleiotropic drug resistance (PDR) genes related to ginsenoside transport.

Increasing evidence suggests that the non-canonical IKKs play critical roles in tumor genesis and development, leading to the notion that non-canonical IKKs may be good targets for cancer therapy. Here, we demonstrate that although TBK1 is not over-expressed or constitutively activated in some tumor cells, targeting IKKi induces the activation of TBK1. Therefore, simultaneously targeting both kinases is necessary to efficiently suppress tumor cell proliferation. We show that three TBK1/IKKi dual inhibitors, which are based on a structurally rigid 2-amino-4-(3′-cyano-4′-pyrrolidine)phenyl-pyrimidine scaffold, potently inhibit cell viability in human breast, prostate, and oral cancer cell lines. Treatment with these TBK1/IKKi dual inhibitors significantly impairs tumor development in xenograft and allograft mouse models. The anti-cancer function of these inhibitors may be due partially to their suppression of TBK1/IKKi-mediated AKT phosphorylation and VEGF expression. Most importantly, these TBK1/IKKi dual inhibitors have drug-like properties including low molecular weight, low Cytochrome P450 inhibition, and high metabolic stability. Therefore, our studies provide proof of concept for further drug discovery efforts that may lead to novel strategies and new therapeutics for the treatment of human cancer.

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