5-(4-Fluoro­phen­yl)-3-[5-methyl-1-(4-methyl­phen­yl)-1H-1,2,3-triazol-4-yl]-4,5-dihydro-1H-pyrazole-1-carbothio­amide

In the title compound, C20H19FN6S, the pyrazole ring has an envelope conformation, with the methine C atom being the flap atom. The dihedral angle between the least-squares plane through the pyrazole and triazole rings is 7.59 (9)°, and the triazole and attached benzene ring form a dihedral angle of 74.79 (9)°. The thio­urea group is coplanar with the pyrazole ring [N—N—C—S torsion angle = −179.93 (11)°], which enables the formation of an intra­molecular N—H⋯N hydrogen bond. In the crystal, inversion-related mol­ecules associate via N—H⋯S hydrogen bonds and eight-membered {⋯HNCS}2 synthons feature in the crystal packing. These synthons are connected into supra­molecular chains along the a axis via N—H⋯F hydrogen bonds, and the chains are consolidated into layers in the ab plane via C—H⋯S and C—H⋯F contacts

TGF-β1 enhances cardiomyogenic differentiation of skeletal muscle-derived adult primitive cells

The optimal medium for cardiac differentiation of adult primitive cells remains to be established. We quantitatively compared the efficacy of IGF-1, dynorphin B, insulin, oxytocin, bFGF, and TGF-beta1 in inducing cardiomyogenic differentiation. Adult mouse skeletal muscle-derived Sca1+/CD45-/c-kit-/Thy-1+ (SM+) and Sca1-/CD45-/c-kit-/Thy-1+ (SM-) cells were cultured in basic medium (BM; DMEM, FBS, IGF-1, dynorphin B) alone and BM supplemented with insulin, oxytocin, bFGF, or TGF-beta1. Cardiac differentiation was evaluated by the expression of cardiac-specific markers at the mRNA (qRT-PCR) and protein (immunocytochemistry) levels. BM+TGF-beta1 upregulated mRNA expression of Nkx2.5 and GATA-4 after 4 days and Myl2 after 9 days. After 30 days, BM+TGF-beta1 induced the greatest extent of cardiac differentiation (by morphology and expression of cardiac markers) in SM- cells. We conclude that TGF-beta1 enhances cardiomyogenic differentiation in skeletal muscle-derived adult primitive cells. This strategy may be utilized to induce cardiac differentiation as well as to examine the cardiomyogenic potential of adult tissue-derived stem/progenitor cells

Design, Synthesis and Biological Evaluation of Syn and Anti-like Double Warhead Quinolinones Bearing Dihydroxy Naphthalene Moiety as Epidermal Growth Factor Receptor Inhibitors with Potential Apoptotic Antiproliferative Action

Our investigation includes the synthesis of new naphthalene-bis-triazole-bis-quinolin-2(1H)-ones 4a–e and 7a–e via Cu-catalyzed [3 + 2] cycloadditions of 4-azidoquinolin-2(1H)-ones 3a–e with 1,5-/or 1,8-bis(prop-2-yn-1-yloxy)naphthalene (2) or (6). All structures of the obtained products have been confirmed with different spectroscopic analyses. Additionally, a mild and versatile method based on copper-catalyzed [3 + 2] cycloaddition (Meldal–Sharpless reaction) was developed to tether quinolinones to O-atoms of 1,5- or 1,8-dinaphthols. The triazolo linkers could be considered as anti and syn products, which are interesting precursors for functionalized epidermal growth factor receptor (EGFR) inhibitors with potential apoptotic antiproliferative action. The antiproliferative activities of the 4a–e and 7a–e were evaluated. Compounds 4a–e and 7a–e demonstrated strong antiproliferative activity against the four tested cancer cell lines, with mean GI50 ranging from 34 nM to 134 nM compared to the reference erlotinib, which had a GI50 of 33 nM. The most potent derivatives as antiproliferative agents, compounds 4a, 4b, and 7d, were investigated for their efficacy as EGFR inhibitors, with IC50 values ranging from 64 nM to 97 nM. Compounds 4a, 4b, and 7d demonstrated potent apoptotic effects via their effects on caspases 3, 8, 9, Cytochrome C, Bax, and Bcl2. Finally, docking studies show the relevance of the free amino group of the quinoline moiety for antiproliferative action via hydrogen bond formation with essential amino acids

Bioactive Hydroperoxyl Cembranoids from the Red Sea Soft Coral Sarcophyton glaucum

A chemical investigation of an ethyl acetate extract of the Red Sea soft coral Sarcophyton glaucum has led to the isolation of two peroxide diterpenes, 11(S) hydroperoxylsarcoph-12(20)-ene (1), and 12(S)-hydroperoxylsarcoph-10-ene (2), as well as 8-epi-sarcophinone (3). In addition to these three new compounds, two known structures were identified including: ent-sarcophine (4) and sarcophine (5). Structures were elucidated by spectroscopic analysis, with the relative configuration of 1 and 2 confirmed by X-ray diffraction. Isolated compounds were found to be inhibitors of cytochrome P450 1A activity as well as inducers of glutathione S-transferases (GST), quinone reductase (QR), and epoxide hydrolase (mEH) establishing chemo-preventive and tumor anti-initiating activity for these characterized metabolites

Oxidative Stress-Induced JNK/AP-1 Signaling is a Major Pathway Involved in Selective Apoptosis of Myelodysplastic Syndrome Cells by Withaferin-A

Myelodysplastic syndromes (MDS) are a diverse group of malignant clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, dysplastic cell morphology in one or more hematopoietic lineages, and a risk of progression to acute myeloid leukemia (AML). Approximately 50% of MDS patients respond to current FDA-approved drug therapies but a majority of responders relapse within 2-3 years. There is therefore a compelling need to identify potential new therapies for MDS treatment. We utilized the MDS-L cell line to investigate the anticancer potential and mechanisms of action of a plant-derived compound, Withaferin A (WFA), in MDS. WFA was potently cytotoxic to MDS-L cells but had no significant effect on the viability of normal human primary bone marrow cells. WFA also significantly reduced engraftment of MDS-L cells in a xenotransplantation model. Through transcriptome analysis, we identified reactive oxygen species (ROS)-activated JNK/AP-1 signaling as a major pathway mediating apoptosis of MDS-L cells by WFA. We conclude that the molecular mechanism mediating selective cytotoxicity of WFA on MDS-L cells is strongly associated with induction of ROS. Therefore, pharmacologic manipulation of redox biology could be exploited as a selective therapeutic target in MDS

Rational design of autotaxin inhibitors by structural evolution of endogenous modulators

Autotaxin produces the bioactive lipid lysophosphatidic acid (LPA), and is a drug target of considerable interest for numerous pathologies. We report the expedient, structure-guided evolution of weak physiological allosteric inhibitors (bile salts) into potent competitive Autotaxin inhibitors that do not interact with the catalytic site. Functional data confirms that our lead compound attenuates LPA mediated signalling in cells, and reduces LPA synthesis in vivo, providing a promising natural product derived scaffold for drug discovery

Deoxycholate induces COX-2 expression via Erk1/2-, p38-MAPK and AP-1-dependent mechanisms in esophageal cancer cells

<p>Abstract</p> <p>Background</p> <p>The progression from Barrett's metaplasia to adenocarcinoma is associated with the acquirement of an apoptosis-resistant phenotype. The bile acid deoxycholate (DCA) has been proposed to play an important role in the development of esophageal adenocarcinoma, but the precise molecular mechanisms remain undefined. The aim of this study was to investigate DCA-stimulated COX-2 signaling pathways and their possible contribution to deregulated cell survival and apoptosis in esophageal adenocarcinoma cells.</p> <p>Methods</p> <p>Following exposure of SKGT-4 cells to DCA, protein levels of COX-2, MAPK and PARP were examined by immunoblotting. AP-1 activity was assessed by mobility shift assay. DCA-induced toxicity was assessed by DNA fragmentation and MTT assay.</p> <p>Results</p> <p>DCA induced persistent activation of the AP-1 transcription factor with Fra-1 and JunB identified as the predominant components of the DCA-induced AP-1 complex. DCA activated Fra-1 via the Erk1/2- and p38 MAPK while Erk1/2 is upstream of JunB. Moreover, DCA stimulation mediated inhibition of proliferation with concomitant low levels of caspase-3-dependent PARP cleavage and DNA fragmentation. Induction of the anti-apoptotic protein COX-2 by DCA, via MAPK/AP-1 pathway appeared to balance the DCA mediated activation of pro-apoptotic markers such as PARP cleavage and DNA fragmentation. Both of these markers were increased upon COX-2 suppression by aspirin pretreatment prior to DCA exposure.</p> <p>Conclusion</p> <p>DCA regulates both apoptosis and COX-2-regulated cell survival in esophageal cells suggesting that the balance between these two opposing signals may determine the transformation potential of DCA as a component of the refluxate.</p

Characterization of anti-NF-κB RNA aptamer-binding specificity in vitro and in the yeast three-hybrid system

RNA aptamers offer a potential therapeutic approach to the competitive inhibition of DNA-binding transcription factors. In previous reports we described in vitro selection and characterization of anti-NF-κB p50 and p65 RNA aptamers. We now describe the further characterization of these aptamers in vitro and in vivo. We show that sub-saturating concentrations of certain anti-p50 RNA aptamers promote complex formation with NF-κB p50 tetramers, whereas anti-p65 R1 RNA aptamers bind NF-κB dimers under all conditions tested. Yeast three-hybrid RNA aptamer specificity studies corroborate previous in vitro results, verifying that anti-p50 and anti-p65 R1 RNA aptamers are highly specific for NF-κB p502 and p652, respectively. These studies introduce a novel T-cassette RNA transcript that improves RNA display from a four-way RNA junction. Mutagenesis of the anti-p65 R1 aptamer reveals tolerated substitutions, suggesting a complex tertiary structure. We describe in vivo selections from a yeast three-hybrid RNA library containing sequences present early in the R1 SELEX process to identify novel anti-p65 RNA aptamers, termed Y1 and Y3. These aptamers appear to be compact bulged hairpins, reminiscent of anti-p50. Y1 competitively inhibits the DNA-binding domain of NF-κB p652 in vitro