Parallel Synthesis of Pyrazolone-Fused Cinnolines by the Palladium-Catalyzed [4 + 2] Annulation of Pyrazol-3-ones with Substituted Allenoates.

The synthesis of pyrazolone-fused cinnolines from pyrazol-3-ones and α,γ-substituted allenoates via a palladium-catalyzed C-H activation/annulation cascade was developed. Mechanistic studies revealed the course of the reaction. Initially, N-acyl-valine ligand-assisted ortho-C-H activation gives ortho-alkenylated intermediate. Subsequent cyclopalladation and migratory insertion of allenoate give a seven-membered palladacycle. Reductive elimination finally furnishes pyrazolone-fused cinnolines.

Rh(III)-Catalyzed (4 + 1) Annulation of Pyrazol-3-ones with Alkynoates via Ortho-Alkenylation/Cyclization Cascade: Synthesis of Indazole-Fused Pyrazoles.

A facile synthesis of novel indazole-fused pyrazoles from pyrazol-3-ones and alkynoate esters/amides via Rh(III)-catalyzed sequential C-H activation/ortho-alkenylation/intramolecular cyclization cascade is reported. The important characteristic of this method is that the resulting scaffold bearing quaternary carbon has been obtained through unusual [4 + 1] rather than expected [4 + 2] addition where alkynoate acts as a one-carbon unit.

Substrate-controlled Rh(III)-catalyzed regiodivergent annulation towards fused and spiro benzimidazoles.

A Rh(III)-catalyzed cascade C-H activation and cyclization of 2-aryl benzimidazoles with maleimides for the synthesis of benzimidazole-fused isoquinolines and benzimidazole-spiro isoindoles is reported. Switchable selectivity towards the formation of these two distinct products can be achieved using unsubstituted and substituted benzimidazoles at the ortho-position of the phenyl ring. Mechanistically, C-H activation followed by migratory insertion of maleimide forms a Heck-type intermediate. Unsubstituted benzimidazole undergoes aza-Michael addition to form a (4 + 2) fused product, whereas ortho-substituted phenyl benzimidazole causes steric clash to deliver a (4 + 1) spiro-adduct favorably via acid-catalyzed intramolecular annulation.

LIF-STAT signaling in decidual cells: a possible role in embryo implantation and early pregnancy.

In this study, we investigate the effects of miRNA-138-5p and probable G-protein coupled receptor 124 (GPR124)-regulated inflammasome and downstream leukemia inhibitory factor (LIF)-STAT and adhesion molecule signaling in human decidual stromal cells. After informed consent was obtained from women aged 25-38 years undergoing surgical termination of the normal pregnancy and spontaneous miscarriage after 6-9 weeks of gestation, human decidual stromal cells were extracted from the decidual tissue. Extracellular vesicles (EVs) with microRNA (miRNA) between cells have been regarded as critical factors for embryo-maternal interactions on embryo implantation and programming of human pregnancy. MicroRNA-138-5p acts as the transcriptional regulator of GPR124 and the mediator of downstream inflammasome. LIF-regulated STAT activation and expression of integrins might influence embryo implantation. Hence, a better understanding of LIF-STAT and adhesion molecule signaling would elucidate the mechanism of microRNA-138-5p- and GPR124-regulated inflammasome activation on embryo implantation and pregnancy. Our results show that microRNA-138-5p, purified from the EVs of decidual stromal cells, inhibits the expression of GPR124 and the inflammasome, and activates the expression of LIF-STAT and adhesion molecules in human decidual stromal cells. Additionally, the knockdown of GPR124 and NLRP3 through siRNA increases the expression of LIF-STAT and adhesion molecules. The findings of this study help us gain a better understanding the role of EVs, microRNA-138-5p, GPR124, inflammasomes, LIF-STAT, and adhesion molecules in embryo implantation and programming of human pregnancy.

Kisspeptin Regulates Cell Invasion and Migration in Endometrial Cancer.

Kisspeptin (a product of the KISS1 gene and its receptor) plays an important role in obstetrics, gynecology, and cancer cell metastasis and behavior. In hypothalamic-pituitary-gonadal axis and placentation, Kisspeptin/Kisspeptin receptor affects hormone release and represses trophoblast invasion into maternal deciduae. Endometrial cancer is one of the common gynecological cancers and is usually accompanied by metastasis, the risk factor that causes death. Recently, research has demonstrated that Kisspeptin/Kisspeptin receptor expression in aggressive-stage endometrial cancer tissues. However, the detailed mechanism of Kisspeptin/Kisspeptin receptor in regulating the motility of endometrial cancers is not well understood. In this study, we use endometrial cancer cell lines RL95-2, Ishikawa, HEC-1-A, and HEC-1-B as models to explore the molecular mechanism of Kisspeptin on cell motility. First, we discovered that Kisspeptin/Kisspeptin receptor was expressed in endometrial cancer cells, and Kisspeptin significantly regulated the migration and invasion of endometrial cancer cells. Furthermore, we explored the epithelial-mesenchymal transition marker expression and the underlying signals were regulated on Kisspeptin treatment. In conclusion, we suggest that Kisspeptin regulates endometrial cancer cell motility via FAK and Src expression and the ERK1/2, N-Cadherin, E-Cadherin, beta-Catenin, Twist, and matrix metalloproteinase signaling pathways. We expect these molecules could be candidates for the development of new approaches and therapeutic targets.

Pd(II)-Catalyzed [5 + 2] Cyclization of N-Triflyl Aryl Indoles and α,γ-Substituted Allenoates: A Route to Indole-Fused Benzodiazepines.

A Pd(II)-catalyzed [5 + 2] annulation between N-triflyl aryl indoles and α,γ-substituted allenoates for the synthesis of indole-fused benzodiazepines is reported. This protocol is highly efficient when N-acetylated valine amino acid and DMSO have been used as ligand and cosolvent, respectively. The substrate scope can be further extended to disubstituted allenoates. A reaction mechanism has been proposed based on the mechanistic studies. Mechanistically, the N-acetylated valine amino acid ligand accelerates C-H activation of the C(sp2)-H bond. Consequent cyclopalladation leads to the formation of a six-membered palladacycle. Subsequent coordination and migratory insertion of an allenoate forms the possible eight-membered intermediate. Reductive elimination followed by a [1,3]-H shift results in the indole-fused benzodiazepines.

The Anti-Cancer Activity of Pentamidine and Its Derivatives (WLC-4059) Is through Blocking the Interaction between S100A1 and RAGE V Domain.

The S100A1 protein in humans is a calcium-binding protein. Upon Ca2+ binding to S100A1 EF-hand motifs, the conformation of S100A1 changes and promotes interactions with target proteins. RAGE consists of three domains: the cytoplasmic, transmembrane, and extracellular domains. The extracellular domain consists of C1, C2, and V domains. V domains are the primary receptors for the S100 protein. It was reported several years ago that S100A1 and RAGE V domains interact in a pathway involving S100A1-RAGE signaling, whereby S100A1 binds to the V domain, resulting in RAGE dimerization. The autophosphorylation of the cytoplasmic domain initiates a signaling cascade that regulates cell proliferation, cell growth, and tumor formation. In this study, we used pentamidine and a newly synthesized pentamidine analog (WLC-4059) to inhibit the S100A1-RAGE V interaction. 1H-15N HSQC NMR titration was carried out to characterize the interaction between mS100A1 (mutant S100A1, C86S) and pentamidine analogs. We found that pentamidine analogs interact with S100A1 via 1H-15N HSQC NMR spectroscopy. Based on the results, we utilized the HADDOCK program to generate structures of the mS100A1-WLC-4059 binary complex. Interestingly, the binary complex overlapped with the complex crystal structure of the mS100A1-RAGE-V domain, proving that WLC-4059 blocks interaction sites between S100A1 and RAGE-V. A WST-1 cell proliferation assay also supported these results. We conclude that pentamidine analogs could potentially enhance therapeutic approaches against cancers.