BRD4-PRC2 represses transcription of T-helper 2-specific negative regulators during T-cell differentiation.

BRD4 is a well-recognized transcriptional activator, but how it regulates gene transcriptional repression in a cell type-specific manner has remained elusive. In this study, we report that BRD4 works with Polycomb repressive complex 2 (PRC2) to repress transcriptional expression of the T-helper 2 (Th2)-negative regulators Foxp3 and E3-ubiqutin ligase Fbxw7 during lineage-specific differentiation of Th2 cells from mouse primary naïve CD4+ T cells. Brd4 binds to the lysine-acetylated-EED subunit of the PRC2 complex via its second bromodomain (BD2) to facilitate histone H3 lysine 27 trimethylation (H3K27me3) at target gene loci and thereby transcriptional repression. We found that Foxp3 represses transcription of Th2-specific transcription factor Gata3, while Fbxw7 promotes its ubiquitination-directed protein degradation. BRD4-mediated repression of Foxp3 and Fbxw7 in turn promotes BRD4- and Gata3-mediated transcriptional activation of Th2 cytokines including Il4, Il5, and Il13. Chemical inhibition of the BRD4 BD2 induces transcriptional de-repression of Foxp3 and Fbxw7, and thus transcriptional downregulation of Il4, Il5, and Il13, resulting in inhibition of Th2 cell lineage differentiation. Our study presents a previously unappreciated mechanism of BRD4's role in orchestrating a Th2-specific transcriptional program that coordinates gene repression and activation, and safeguards cell lineage differentiation.

BET degrader exhibits lower antiproliferative activity than its inhibitor via EGR1 recruiting septins to promote E2F1-3 transcription in triple-negative breast cancer.

The bromodomain and extraterminal domain (BET) family proteins serve as primary readers of acetylated lysine residues and play crucial roles in cell proliferation and differentiation. Dysregulation of BET proteins has been implicated in tumorigenesis, making them important therapeutic targets. BET-bromodomain (BD) inhibitors and BET-targeting degraders have been developed to inhibit BET proteins. In this study, we found that the BET inhibitor MS645 exhibited superior antiproliferative activity than BET degraders including ARV771, AT1, MZ1 and dBET1 in triple-negative breast cancer (TNBC) cells. Treatment with MS645 led to the dissociation of BETs, MED1 and RNA polymerase II from the E2F1-3 promoter, resulting in the suppression of E2F1-3 transcription and subsequent inhibition of cell growth in TNBC. In contrast, while ARV771 displaced BET proteins from chromatin, it did not significantly alter E2F1-3 expression. Mechanistically, ARV771 induced BRD4 depletion at protein level, which markedly increased EGR1 expression. This elevation of EGR1 subsequently recruited septin 2 and septin 9 to E2F1-3 promoters, enhancing E2F1-3 transcription and promoting cell proliferation rate in vitro and in vivo. Our findings provide valuable insights into differential mechanisms of BET inhibition and highlight potential of developing BET-targeting molecules as therapeutic strategies for TNBC.

Spatially constrained tandem bromodomain inhibition bolsters sustained repression of BRD4 transcriptional activity for TNBC cell growth.

The importance of BET protein BRD4 in gene transcription is well recognized through the study of chemical modulation of its characteristic tandem bromodomain (BrD) binding to lysine-acetylated histones and transcription factors. However, while monovalent inhibition of BRD4 by BET BrD inhibitors such as JQ1 blocks growth of hematopoietic cancers, it is much less effective generally in solid tumors. Here, we report a thienodiazepine-based bivalent BrD inhibitor, MS645, that affords spatially constrained tandem BrD inhibition and consequently sustained repression of BRD4 transcriptional activity in blocking proliferation of solid-tumor cells including a panel of triple-negative breast cancer (TNBC) cells. MS645 blocks BRD4 binding to transcription enhancer/mediator proteins MED1 and YY1 with potency superior to monovalent BET inhibitors, resulting in down-regulation of proinflammatory cytokines and genes for cell-cycle control and DNA damage repair that are largely unaffected by monovalent BrD inhibition. Our study suggests a therapeutic strategy to maximally control BRD4 activity for rapid growth of solid-tumor TNBC cells.

Discovery of new thienopyrimidine derivatives as potent and orally efficacious phosphoinositide 3-kinase inhibitors.

A series of new thienopyrimidine derivatives has been discovered as potent PI3K inhibitors. The systematic SAR studies for these analogues are described. Among them, 8a and 9a exhibit nanomolar enzymatic potencies and sub-micromolar cellular anti-proliferative activities. 8a displays favorable pharmacokinetic profiles, while 9a easily undergoes deacetylation to yield a major metabolite 8a. Furthermore, 8a and 9a potently inhibit tumor growth in a dose-dependent manner in the NCI-H460 xenograft model with an acceptable safety profile.

Synthesis and structure-activity relationships of PI3K/mTOR dual inhibitors from a series of 2-amino-4-methylpyrido[2,3-d]pyrimidine derivatives.

Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway by PI3K/mTOR dual inhibitors provides a promising new approach to the treatment of cancers. In this Letter, we identified structurally novel and potent PI3K/mTOR dual inhibitors from a series of 2-amino-4-methylpyrido[2,3-d]pyrimidine derivatives. Their synthesis and structure-activity relationships are reported.

Identification of novel 7-amino-5-methyl-1,6-naphthyridin-2(1H)-one derivatives as potent PI3K/mTOR dual inhibitors.

Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most intensively studied approaches to cancer therapy. Rational design led to the identification of novel 7-amino-5-methyl-1,6-naphthyridin-2(1H)-one derivatives as potent PI3K/mTOR dual inhibitors. Design, synthesis and structure activity relationship are reported.

Do the asymmetric effects of eco-digitalization amidst energy transition make or mar the strides toward environmental sustainability in the USA?

The present era faces adverse effects of the strides recorded in economic advancements of the prior generations thus leading the present generation to growth dilemma. Consequently, there is a conscientious consideration for the ecological effects of economic growth. To resolve the preceding issue, due consideration must be given to harmless growth of which eco-digitalization, green financing, green technology, energy transition, and regularity quality are key determinants. Despite the aforesaid importance, empirical studies advancing this nexus are scarce. Hence, this study contributes to environment empirics by providing empirical evidence for the impacts of the highlighted indicators on sustainable environment in the USA. The study explores quarterly data from 1996Q1 to 2019Q4 based on the novel non-linear autoregressive distributed lag (ARDL) model. The pretests' outcomes show that long-run nexus exists among the variables, whereas the Zivot-Andrew uncovers breakpoint years in the observations. The main findings show that eco-digitalization, green financing, green technology, and renewable energy promote sustainable environment. On the flip side, non-renewable energy and regulatory quality hinder the pathways to sustaining the environment in the USA. Robustness analyses conducted based on FMOL, DOLS, and CCR provide substantial support and validity for the main results. Furthermore, the causality nexus lends empirical support for the existence of bidirectional and unidirectional causalities in the empirical model. Policy insights that drive the paths to sustainability in the US are suggested based on the findings.

Discovery of thiadiazole amides as potent, S1P3-sparing agonists of sphingosine-1-phosphate 1 (S1P1) receptor.

High-throughput screening of GSK compound collection led to the discovery of a novel series of thiadiazole amides as potent and S1P(3)-sparing sphingosine-1-phosphate 1 (S1P(1)) receptor agonists. Synthesis, structure and activity relationship, selectivity, and some developability properties are described.

Small Molecules with Big Promises for Curing Demyelinating Diseases.

Myelin regeneration by myelinating oligodendrocytes is key to neuronal damage repair for treatment of neurological disorders such as multiple sclerosis. In this issue of Cell Chemical Biology, Allimuthu et al. (2019) report new small molecule inhibitors of cholesterol biosynthesis enzymes that enhance oligodendrocyte formation and subsequent remyelination.

Studies on the metabolism of 4-methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride in rats by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

4-Methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride(TM208) is a newly synthesized compound, which has shown excellent in vivo and in vitro anticancer activity and low toxicity. In this study, the metabolism of TM208 in rats was studied for the first time by high-performance liquid chromatography coupled with tandem mass spectrometry. Following a single oral administration to rats, TM208 was metabolized to eight metabolites (M1-M8). M1 is the desmethyl metabolite and the acylation of M1 with N-acetyl transferase results in M6 (N-acetyl metabolite), M5 is N-formyl metabolite; M4 is phenyl monohydroxylation metabolite, M2 is the sulfine metabolite of TM208, and M3 is also an odd-oxygen added products which the possible oxidation site has described in this paper; M8 is the metabolite resulting from the replacement of '-C=S' with '-C=O', M7 is a ring-opened piperazine oxidation products to a kind of acid.

Discovery of a Novel Series of Thienopyrimidine as Highly Potent and Selective PI3K Inhibitors.

Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway provides a promising new approach for cancer therapy. Through a rational design, a novel series of thienopyrimidine was discovered as highly potent and selective PI3K inhibitors. These thienopyrimidine derivatives were demonstrated to bear nanomolar PI3Kα inhibitory potency with over 100-fold selectivity against mTOR kinase. The lead compounds 6g and 6k showed good developability profiles in cell-based proliferation and ADME assays. In this communication, their design, synthesis, structure-activity relationship, selectivity, and some developability properties are described.

Discovery of Biaryl Amides as Potent, Orally Bioavailable, and CNS Penetrant RORγt Inhibitors.

A novel series of biaryl amides was identified as RORγt inhibitors through core replacement of a starting hit 1. Structure-activity relationship exploration on the biaryl moiety led to discovery of potent RORγt inhibitors with good oral bioavailability and CNS penetration. Compounds 9a and 9g demonstrated excellent in vivo efficacy in EAE mice dose dependently with once daily oral administration.

Simultaneous determination of 4-methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride and its major metabolite in rats by HPLC.

A method for the simultaneous determination of TM208 and its major metabolite (sulfine 4-methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester, TM208-SO) was developed and validated for the first time. The analytes were extracted from plasma samples by liquid-liquid extraction and analyzed using high-performance liquid chromatography. Flunarizine hydrochloride was used as the internal standard. Chromatographic separations were performed on a Diamonsil C(18) analytical column. The mobile phases consisted of 20 mM ammonium acetate adjusted to pH 4.20 with acetic acid (solvent A) and acetonitrile (solvent B). The analytes were detected at 254 nm after linear gradient elution. The flow rate was 0.8 mL/min. Linearity was obtained over the concentration range of 0.104-5.20 microg/mL for TM208 and 0.145-5.80 microg/mL for TM208-SO in rat plasma. The limit of quantification was 0.104 microg/mL for TM208 and 0.145 microg/mL for TM208-SO, respectively. The inter- and intra-day precision was less than 12.8% for TM208 and 14.1% for TM208-SO. And the accuracy was 96.2-111.1% for TM208 and 95.5-108.6% for TM208-SO. This analytic procedure was applied to a pharmacokinetic study of TM208 and TM208-SO in rats, and the pharmacokinetic parameters were calculated.

Analysis of 4-methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenyl-propyl ester hydrochloride and its major metabolites in rat plasma and tissues by LC-MS/MS.

4-Methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM-208) is a newly synthesized compound, which has shown excellent in vivo and in vitro anticancer activity and low toxicity. To investigate the metabolism of TM-208 in rats, in the present study, we administered TM-208 orally to rats and analyzed its metabolites existing in rat plasma and central tissues by LC-MS/MS. Rat plasma and tissue samples were collected before or after a single oral dose (250 mg/kg) of TM-208, then the analytes were extracted from samples by liquid-liquid extraction and analyzed using LC-MS/MS. The structures of proposed metabolites were elucidated according to the rules of drug metabolism and disposition in vivo and the characteristic fragmentation behaviors of TM-208 in ESI-ITMS(n). Five metabolites (M1-M5) were tentatively or assuredly identified: (2-amino-ethyl)-dithiocarbamic acid 3-cyano-3,3-diphenyl-propyl ester (M1), (2-methylamino-ethyl)-dithiocarbamic acid 3-cyano-3,3-diphenyl-propyl ester (M2), 4-methyl-piperazine-1-carbothioic acid S-(3-cyano-3,3-diphenyl-propyl) ester (M3), piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester (M4), and sulfine of (4-methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester) (M5).

Studies on the metabolism of 4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3- diphenylpropyl ester hydrochloride in rat bile by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

4-Methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208) is a newly synthesized compound which has shown excellent in vivo and in vitro anticancer activity and low toxicity. In the present study, the major metabolites of TM208 in rat bile were studied by high-performance liquid chromatography/tandem mass spectrometry with an electrospray ionization (ESI) interface. It was demonstrated that TM208 was extensively metabolized in rat bile and nine metabolites (M1-M9) were definitely or tentatively identified: (2-aminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M1), (2-methylaminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M2), 4-[(4-methylpiperazin-1-yl)thioxomethanesulfinyl]-2,2-diphenylbutyronitrile (M3), 4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester(M4), the sulfine of (4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester) (M5), 4-methylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M6), piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester (M7), 4-hydroxymethylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M8) and the sulfine of [4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester] (M9).