Nicotinamide in Combination with EGFR-TKIs for the Treatment of Stage IV Lung Adenocarcinoma with EGFR Mutations: A Randomized Double-Blind (Phase IIb) Trial.

Purpose: RUNX3 is a tumor suppressor gene, which is inactivated in approximately 70% of lung adenocarcinomas. Nicotinamide, a sirtuin inhibitor, has demonstrated potential in re-activating epigenetically silenced RUNX3 in cancer cells. This study assessed the therapeutic benefits of combining nicotinamide with first-generation EGFR-tyrosine kinase inhibitors (TKI) for patients with stage IV lung cancer carrying EGFR mutations.

Small-molecule inhibitors of ferrochelatase are antiangiogenic agents.

Activity of the heme synthesis enzyme ferrochelatase (FECH) is implicated in multiple diseases. In particular, it is a mediator of neovascularization in the eye and thus an appealing therapeutic target for preventing blindness. However, no drug-like direct FECH inhibitors are known.

Co-Spray Dried Nafamostat Mesylate with Lecithin and Mannitol as Respirable Microparticles for Targeted Pulmonary Delivery: Pharmacokinetics and Lung Distribution in Rats.

Coronavirus disease 2019 (COVID-19), caused by a new strain of coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly worldwide. Nafamostat mesylate (NFM) suppresses transmembrane serine protease 2 and SARS-CoV-2 S protein-mediated fusion. In this study, pharmacokinetics and lung distribution of NFM, administered via intravenous and intratracheal routes, were determined using high performance liquid chromatography analysis of blood plasma, lung lumen using bronchoalveolar lavage fluid, and lung tissue.

RUNX3 regulates cell cycle-dependent chromatin dynamics by functioning as a pioneer factor of the restriction-point.

The cellular decision regarding whether to undergo proliferation or death is made at the restriction (R)-point, which is disrupted in nearly all tumors. The identity of the molecular mechanisms that govern the R-point decision is one of the fundamental issues in cell biology. We found that early after mitogenic stimulation, RUNX3 binds to its target loci, where it opens chromatin structure by sequential recruitment of Trithorax group proteins and cell-cycle regulators to drive cells to the R-point.

Structural Basis for Selective Binding of Export Cargoes by Exportin-5.

In the nucleus, RanGTP binding to importin dissociates the cargo. On the other hand, RanGTP enables exportin to bind export cargo and form the export complex by each exportin's own cargo selection mechanism. Here, we present two X-ray structures for Exportin-5 (Exp-5) alone and Exp-5:RanGTP intermediate complex.

Low pH-driven folding of WW45-SARAH domain leads to stabilization of the WW45-Mst2 complex.

The scaffolding protein Salvador (Sav) plays a key role in the Hippo (Hpo) signalling pathway, which controls tissue growth by inhibiting cell proliferation and promoting apoptosis. Dysregulation of the Hippo pathway contributes to cancer development. Since the identification of the first Sav gene in 2002, very little is known regarding the molecular basis of Sav-SARAH mediating interactions due to its insolubility.

Structural and functional analysis of Hikeshi, a new nuclear transport receptor of Hsp70s.

Hikeshi is a nuclear transport receptor required for cell survival after stress. It mediates heat-shock-induced nuclear import of 70 kDa heat-shock proteins (Hsp70s) through interactions with FG-nucleoporins (FG-Nups), which are proteins in nuclear pore complexes (NPCs). Here, the crystal structure of human Hikeshi is presented at 1.

Structural basis for the selective nuclear import of the C2H2 zinc-finger protein Snail by importin β.

Snail contributes to the epithelial-mesenchymal transition by suppressing E-cadherin in transcription processes. The Snail C2H2-type zinc-finger (ZF) domain functions both as a nuclear localization signal which binds to importin β directly and as a DNA-binding domain. Here, a 2.

X-ray structure of prephenate dehydratase from Streptococcus mutans.

Prephenate dehydratase is a key enzyme of the biosynthesis of L-phenylalanine in the organisms that utilize shikimate pathway. Since this enzymatic pathway does not exist in mammals, prephenate dehydratase can provide a new drug targets for antibiotics or herbicide. Prephenate dehydratase is an allosteric enzyme regulated by its end product.

Crystallization and preliminary X-ray diffraction analysis of human importin β-Snail zinc finger domain complex.

Snail is a C2H2-type zinc finger transcriptional repressor that induces epithelial-mesenchymal transition by repression of E-cadherin expression levels during embryonic development and tumour progression. Snail is imported into the nucleus by importin β through direct binding with its four zinc finger domain. The complex between importin β and Snail four zinc finger domain was crystallized in order to understand the nuclear transport mechanism of Snail.

Crystallization and preliminary X-ray crystallographic study of the human MST2 SARAH domain.

The SARAH domain at the C-terminus of human MST2 (residues 436-484) was overproduced and purified using an Escherichia coli expression system. The purified domain was crystallized using the hanging-drop vapour-diffusion technique. Two crystal forms were obtained.

Crystal structure of tuguaconitine, a diterpene alkaloid from Aconitum sibiricum.

The three-dimensional structure of a natural product, tuguaconitine (C23H35NO7) from Aconitumrn sibiricum was determined by single crystal X-ray diffraction analysis. The compound was recrystallized from a methanol solution into orthorhombic crystal system, with a = 18.093(4), b = 12.

Interaction between cardiac calsequestrin and drugs with known cardiotoxicity.

Ca(2+) regulation is coupled to critical signals in eucaryotic cells, and calsequestrin is one of the crucial components for this calcium regulation. Our previous observations of calsequestrins revealed the existence of three thioredoxin-like folds, a basic motif that often provides the platform for small molecule binding. Therefore, we have examined the previously reported trifluoperazine and other pharmaceuticals that have similar heart-related side effects (such as tachycardia; bradycardia; palpitation; changing PR, QRS, QTc intervals in electrocardiogram; heart failure) for their binding affinity to cardiac calsequestrin (cCSQ) using isothermal titration calorimetry.

Crystallographic studies of V44 mutants of Clostridium pasteurianum rubredoxin: effects of side-chain size on reduction potential.

Understanding the structural origins of differences in reduction potentials is crucial to understanding how various electron transfer proteins modulate their reduction potentials and how they evolve for diverse functional roles. Here, the high-resolution structures of several Clostridium pasteurianum rubredoxin (Cp Rd) variants with changes in the vicinity of the redox site are reported in order to increase this understanding. Our crystal structures of [V44L] (at 1.

The unique hydrogen bonded water in the reduced form of Clostridium pasteurianum rubredoxin and its possible role in electron transfer.

Rubredoxin is a small iron-sulfur (FeS4) protein involved in oxidation-reduction reactions. The side chain of Leu41 near the iron-sulfur center has two conformations, which we suggested previously serve as a gate for a water molecule during the electron transfer process. To establish the role of residue 41 in electron transfer, an [L41A] mutant of Clostridium pasteurianum rubredoxin was constructed and crystallized in both oxidation states.

Comparing skeletal and cardiac calsequestrin structures and their calcium binding: a proposed mechanism for coupled calcium binding and protein polymerization.

Calsequestrin, the major calcium storage protein of both cardiac and skeletal muscle, binds and releases large numbers of Ca(2+) ions for each contraction and relaxation cycle. Here we show that two crystal structures for skeletal and cardiac calsequestrin are nearly superimposable not only for their subunits but also their front-to-front-type dimers. Ca(2+) binding curves were measured using atomic absorption spectroscopy.

An unusual electronic effect of an aromatic-F in phase-transfer catalysts derived from cinchona-alkaloid.

[structure: see text] Various N-benzylcinchonidinium salts were prepared to study electronic factors in the catalytic enantioselective phase-transfer alkylation of glycine anion equivalent. An ortho-fluoro substituent on the benzyl group in the quaternary ammonium salt dramatically increased the enantioselectivity in the alkylation. O(9)-Allyl-N-2',3',4'-trifluorobenzylhydrocinchonidinium bromide (27), which gave the highest enantioselectivity of the catalysts studied, was used to prepare 12 alpha-alkylated amino acid derivatives in 94 approximately >99% ee.

Molecular modeling of 3-arylisoquinoline antitumor agents active against A-549. A comparative molecular field analysis study.

A series of 58 3-arylisoquinoline antitumor agents were investigated for defining the pharmacophore model using comparative molecular field analysis (CoMFA) program. The studied compounds related to bioisostere of benzophenanthridine alkaloid were synthesized and evaluated for antitumor cytotoxicity against human lung tumor cell (A 549). In order to perform the systematic molecular modeling study of these compounds, the conformational search was carried out based on the single X-ray crystallographic structure of 7,8-dimethoxy-3-phenylisoquinolin-(2H)-one (2).

Isolation and structures of guaianolides from Carpesium macrocephalum.

Two new guaianolides, 4alpha,10alpha-dihydroxy-1beta(H),5beta(H)-guai-11(13)-en-8alpha,12-olide (2) and 4beta,10beta-dihydroxy-5alpha(H)-1,11(13)-guaidien-8alpha,12-olide (3), from Carpesium macrocephalum were isolated, and their structures were elucidated on the basis of spectroscopic studies.