Allosteric inhibitor of β-catenin selectively targets oncogenic Wnt signaling in colon cancer.

Abnormal regulation of β-catenin initiates an oncogenic program that serves as a main driver of many cancers. Albeit challenging, β-catenin is an attractive drug target due to its role in maintenance of cancer stem cells and potential to eliminate cancer relapse. We have identified C2, a novel β-catenin inhibitor, which is a small molecule that binds to a novel allosteric site on the surface of β-catenin. C2 selectively inhibits β-catenin, lowers its cellular load and significantly reduces viability of β-catenin-driven cancer cells. Through direct binding to β-catenin, C2 renders the target inactive that eventually activates proteasome system for its removal. Here we report a novel pharmacologic approach for selective inhibition of β-catenin via targeting a cryptic allosteric modulation site. Our findings may provide a new perspective for therapeutic targeting of β-catenin

New Details of HCV NS3/4A Proteinase Functionality Revealed by a High-Throughput Cleavage Assay

Background: The hepatitis C virus (HCV) genome encodes a long polyprotein, which is processed by host cell and viral proteases to the individual structural and non-structural (NS) proteins. HCV NS3/4A serine proteinase (NS3/4A) is a noncovalent heterodimer of the N-terminal,,180-residue portion of the 631-residue NS3 protein with the NS4A co-factor. NS3/ 4A cleaves the polyprotein sequence at four specific regions. NS3/4A is essential for viral replication and has been considered an attractive drug target. Methodology/Principal Findings: Using a novel multiplex cleavage assay and over 2,660 peptide sequences derived from the polyprotein and from introducing mutations into the known NS3/4A cleavage sites, we obtained the first detailed fingerprint of NS3/4A cleavage preferences. Our data identified structural requirements illuminating the importance of both the short-range (P1–P19) and long-range (P6-P5) interactions in defining the NS3/4A substrate cleavage specificity. A newly observed feature of NS3/4A was a high frequency of either Asp or Glu at both P5 and P6 positions in a subset of the most efficient NS3/4A substrates. In turn, aberrations of this negatively charged sequence such as an insertion of a positively charged or hydrophobic residue between the negatively charged residues resulted in inefficient substrates. Because NS5B misincorporates bases at a high rate, HCV constantly mutates as it replicates. Our analysis revealed that mutations do not interfere with polyprotein processing in over 5,000 HCV isolates indicating a pivotal role of NS3/4A proteolysis in the viru

Multi-Omics Studies towards Novel Modulators of Influenza A Virus-Host Interaction

Human influenza A viruses (IAVs) cause global pandemics and epidemics. These viruses evolve rapidly, making current treatment options ineffective. To identify novel modulators of IAV-host interactions, we re-analyzed our recent transcriptomics, metabolomics, proteomics, phosphoproteomics, and genomics/virtual ligand screening data. We identified 713 potential modulators targeting 199 cellular and two viral proteins. Anti-influenza activity for 48 of them has been reported previously, whereas the antiviral efficacy of the 665 remains unknown. Studying anti-influenza efficacy and immuno/neuro-modulating properties of these compounds and their combinations as well as potential viral and host resistance to them may lead to the discovery of novel modulators of IAV-host interactions, which might be more effective than the currently available anti-influenza therapeutics.Peer reviewe

Probing of Exosites Leads to Novel Inhibitor Scaffolds of HCV NS3/4A Proteinase

Hepatitis C is a treatment-resistant disease affecting millions of people worldwide. The hepatitis C virus (HCV) genome is a single-stranded RNA molecule. After infection of the host cell, viral RNA is translated into a polyprotein that is cleaved by host and viral proteinases into functional, structural and non-structural, viral proteins. Cleavage of the polyprotein involves the viral NS3/4A proteinase, a proven drug target. HCV mutates as it replicates and, as a result, multiple emerging quasispecies become rapidly resistant to anti-virals, including NS3/4A inhibitors.To circumvent drug resistance and complement the existing anti-virals, NS3/4A inhibitors, which are additional and distinct from the FDA-approved telaprevir and boceprevir α-ketoamide inhibitors, are required. To test potential new avenues for inhibitor development, we have probed several distinct exosites of NS3/4A which are either outside of or partially overlapping with the active site groove of the proteinase. For this purpose, we employed virtual ligand screening using the 275,000 compound library of the Developmental Therapeutics Program (NCI/NIH) and the X-ray crystal structure of NS3/4A as a ligand source and a target, respectively. As a result, we identified several novel, previously uncharacterized, nanomolar range inhibitory scaffolds, which suppressed of the NS3/4A activity in vitro and replication of a sub-genomic HCV RNA replicon with a luciferase reporter in human hepatocarcinoma cells. The binding sites of these novel inhibitors do not significantly overlap with those of α-ketoamides. As a result, the most common resistant mutations, including V36M, R155K, A156T, D168A and V170A, did not considerably diminish the inhibitory potency of certain novel inhibitor scaffolds we identified.Overall, the further optimization of both the in silico strategy and software platform we developed and lead compounds we identified may lead to advances in novel anti-virals

Kombinasi Format Factory, U-lead dan Microsoft Office Powerpoint dalam Upaya Meningkatkan Kualitas Media Pembelajaran

Peserta didik mempunyai gaya belajar yang berbeda-beda. Gaya belajar tersebut meliputi auditori, visual dan kinestetik (VAK). Seorang guru harus mampu memenuhi kebutuhan masing-masing gaya belajar peserta didik tersebut. Salah satu cara yang dapat dilakukan adalah dengan menggunakan media pembelajaran berbasis VAK. Media pembelajaran berbasis VAK dapat dipenuhi dengan menyisipkan file video di dalamnya. Selain itu, penggunaan file video sebagai media pembelajaran mendukung implementasi pembelajaran saintifik pada kurikulum 2013. Namun, belum semua guru memiliki kemampuan untuk mengemas file video tersebut dalam bentuk media pembelajaran. Tujuan penelitian ini adalah untuk meningkatkan kemampuan guru-guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran berbasis VAK dengan kombinasi software Format Factory, U-Lead dan PowerPoint. Hasil penelitian menunjukkan bahwa terjadi peningkatan kemampuan para guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran. Peningkatan kemampuan guru-guru tersebut berada di atas target yang direncanakan. Rerata peningkatan kemampuan guru-guru di SMA Negeri 1 Teras 7,87% di atas target, sedangkan di SMA Negeri 1 Boyolali 9,58% di atas target. Kata kunci: Media Pembelajaran, Format Factory, U-Lead, PowerPoint Students have different learning styles. Learning styles include visual learners, auditory learners, and kinesthetic learners. A teacher must be able to fulfill the needs of individual students\u27 learning styles. One way that can be applied is using Visual, Audio and Kinesthetic (VAK) learning media based. VAK-learning media based can be created by inserting video files on it. In addition, using video file as a learning media can support the implementation of scientific learning on the 2013 curriculum. However, not all teachers have the ability to use video files into a learning media. The purpose of this study is to improve the teachers\u27 ability at SMA Negeri 1 Teras and SMAN 1 Boyolali on making VAK-learning media based with a combination of Format Factory, U-Lead and PowerPoint software. The results showed that the teachers\u27 ability on making VAK-learning media based was increased. Increased the teachers\u27 ability was above planned target score. The mean score of the teachers\u27 ability at SMA Negeri 1 Teras 7.87% above the target, while at SMAN 1 Boyolali 9.58% above the target

Targeting Mitochondria in Cancer Therapy Could Provide a Basis for the Selective Anticancer Activity

To determine the target of the recently identified lead compound NSC130362 that is responsible for its selective anti-cancer efficacy and safety in normal cells, structure-activity relationship (SAR) studies were conducted. First, NSC13062 was validated as a starting compound for the described SAR studies in a variety of cell-based viability assays. Then, a small library of 1,4-naphthoquinines (1,4-NQs) and quinoline-5,8-diones was tested in cell viability assays using pancreatic cancer MIA PaCa-2 cells and normal human hepatocytes. The obtained data allowed us to select a set of both non-toxic compounds that preferentially induced apoptosis in cancer cells and toxic compounds that induced apoptosis in both cancer and normal cells. Anti-cancer activity of the selected non-toxic compounds was confirmed in viability assays using breast cancer HCC1187 cells. Consequently, the two sets of compounds were tested in multiple cell-based and in vitro activity assays to identify key factors responsible for the observed activity. Inhibition of the mitochondrial electron transfer chain (ETC) is a key distinguishing activity between the non-toxic and toxic compounds. Finally, we developed a mathematical model that was able to distinguish these two sets of compounds. The development of this model supports our conclusion that appropriate quantitative SAR (QSAR) models have the potential to be employed to develop anti-cancer compounds with improved potency while maintaining non-toxicity to normal cells

Dual function of Zika virus NS2B-NS3 protease.

Zika virus (ZIKV) serine protease, indispensable for viral polyprotein processing and replication, is composed of the membrane-anchored NS2B polypeptide and the N-terminal domain of the NS3 polypeptide (NS3pro). The C-terminal domain of the NS3 polypeptide (NS3hel) is necessary for helicase activity and contains an ATP-binding site. We discovered that ZIKV NS2B-NS3pro binds single-stranded RNA with a Kd of ~0.3 μM, suggesting a novel function. We tested various structural modifications of NS2B-NS3pro and observed that constructs stabilized in the recently discovered "super-open" conformation do not bind RNA. Likewise, stabilizing NS2B-NS3pro in the "closed" (proteolytically active) conformation using substrate inhibitors abolished RNA binding. We posit that RNA binding occurs when ZIKV NS2B-NS3pro adopts the "open" conformation, which we modeled using highly homologous dengue NS2B-NS3pro crystallized in the open conformation. We identified two positively charged fork-like structures present only in the open conformation of NS3pro. These forks are conserved across Flaviviridae family and could be aligned with the positively charged grove on NS3hel, providing a contiguous binding surface for the negative RNA strand exiting helicase. We propose a "reverse inchworm" model for a tightly intertwined NS2B-NS3 helicase-protease machinery, which suggests that NS2B-NS3pro cycles between open and super-open conformations to bind and release RNA enabling long-range NS3hel processivity. The transition to the closed conformation, likely induced by the substrate, enables the classical protease activity of NS2B-NS3pro