IDO1 can impair NK cells function against non-small cell lung cancer by downregulation of NKG2D Ligand via ADAM10.

Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the rate-limiting step in tryptophan catabolism along the kynurenine (Kyn) pathway and exerts immunosuppressive properties mainly via activation of transcription factor aryl hydrocarbon receptor (AhR) pathway. IDO1 induces NK cells dysfunction via downregulation of the activating receptor NKG2D on NK cells, but whether and how it affects the expression of NKG2D Ligand (NKG2DL) on tumor cells remains unclear. Since a disintegrin and metalloprotease 10 (ADAM10) plays a potential role in the shedding of NKG2DL and the releasing of soluble NKG2DL (sNKG2DL), we investigated how IDO1 modulates the expression of NKG2DL via ADAM10 in non-small cell lung cancer (NSCLC). We found that IDO1 expression was negatively correlated with NKG2DL expression while positively correlated with ADAM10 expression with human lung cancer brain metastasis tissue, NSCLC cells and LLC tumor-bearing mice. IDO1 could regulate ADAM10 expression via IDO1-Kyn-AhR signaling pathway and subsequently regulate NKG2DL expression. IDO1 deficiency led to retarded tumor growth and improved NK cells function in NSCLC mice. IDO1 inhibitors improved NK cells function in vitro and in vivo. The combo of IDO1 inhibitor and NK cells exhibited more therapeutic efficacy than either of the single IDO1 inhibitor or NK cells treatment.

Copper-Promoted One-Pot Sandmeyer-Type Reaction for the Synthesis of N-Aryltriazoles.

Herein, we report the copper-catalyzed one-pot Sandmeyer-type reaction of aromatic amines with triazoles to afford N-aryl-1,2,3-triazoles. Diazonium salts, formed from aromatic amines and tert-butyl nitrite in the presence of fluoroboric acid, reacted with triazoles in a copper-catalyzed Sandmeyer-type reaction. The reaction proceeded under mild conditions to afford N-aryltriazoles in moderate to good yields. This method is amenable to a wide range of aromatic amines and triazoles and shows diverse functional group tolerance. Inhibition of the reaction upon the addition of free radical scavengers suggested a radical pathway, in which the aryl radical, copper, and triazole formed a complex that underwent reductive elimination to give aryltriazole compounds; this is consistent with the mechanism underlying the Sandmeyer reaction. Thus, we demonstrate a new effective strategy for the construction of C-N bonds via Sandmeyer-type reactions and a valuable alternative approach for the synthesis of aryltriazole derivatives.

Synthesis of novel tryptanthrin derivatives as dual inhibitors of indoleamine 2,3-dioxygenase 1 and tryptophan 2,3-dioxygenase.

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are promising drug development targets due to their implications in pathologies such as cancer and neurodegenerative diseases. The search for IDO1 inhibitor has been intensely pursued but there is a paucity of potent TDO and IDO1/TDO dual inhibitors. Natural product tryptanthrin has been confirmed to bear IDO1 and/or TDO inhibitory activities. Herein, twelve novel tryptanthrin derivatives were synthesized and evaluated for the IDO1 and TDO inhibitory potency. All of the compounds were found to be IDO1/TDO dual inhibitors, in particular, compound 9a and 9b bore IDO1 inhibitory activity similar to that of INCB024360, and compound 5a and 9b had remarkable TDO inhibitory activity superior to that of the well-known TDO inhibitor LM10. This work enriches the collection of IDO1/TDO dual inhibitors and provides chemical molecules for potential development into drugs.

Evaluation and comparison of the commonly used bioassays of human indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO).

Inhibitors of indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are potential drugs for the treatment of tumor and neurological diseases. A variety of bioassays have been developed to evaluate IDO1/TDO (IDO1 and/or TDO) inhibitors, with uncertainty regarding how the differences in the assay methods or protocols may influence the assay outcomes. The enzymatic assays of IDO1/TDO are usually performed with NFK assay and Kyn adduct assay while the cellular assays of IDO1 are carried out with Hela assay and HEK293 assay. The present study focused on the comparison of the most common bioassays of IDO1/TDO. In addition, the effects of major factors of bioassays such as reaction time and culture medium on the assay outcomes were evaluated. The study will provide reference for the researchers to select IDO1/TDO inhibitors with bioassays, and promote the development of IDO1/TDO inhibitors.

Palladium-catalyzed ortho-C-H alkenylation of 2-benzyl-1,2,3-triazoles.

A mild and efficient method for the direct alkenylation of 2-benzyl-1,2,3-triazoles via Pd-catalyzed C-H bond activation was developed. This protocol was compatible with various substrates and gave the corresponding products in good to excellent yields. Thus, the present study provides a novel and valuable method for the synthesis of 2-benzyl-1,2,3-triazole derivatives.

Palladium-catalyzed oxidative C-H/C-H cross-coupling of 1-substituted 1,2,3-triazoles with furans and thiophenes.

Palladium-catalyzed heteroarylation of 1-substituted 1,2,3-triazoles with furans and thiophenes has been developed in the presence of pyridine and Ag2CO3. The procedure is suitable for the regioselective preparation of 1,5-disubstituted 1,2,3-triazoles through conventional heating at reaction temperatures of 90-100 °C for 18 h.

Palladium-catalyzed ortho-alkoxylation of 2-aryl-1,2,3-triazoles.

Palladium-catalyzed alkoxylation of 2-aryl-1,2,3-triazoles was described in the presence of various groups in the aromatic rings. In addition, some other directing groups of heterocycles containing nitrogen were explored.

Palladium-catalyzed ortho-acylation of 2-benzyl-1,2,3-triazoles with aldehydes.

A palladium-catalyzed ortho-acylation of 2-benzyl-1,2,3-triazoles with aldehydes as an acyl source was developed. A wide variety of ketones containing 1,2,3-triazoles were obtained in good to excellent yields. This methodology provides a convenient access to the acylation of 2-substituted-1,2,3-triazoles.

Copper-catalyzed arylsulfonylation of N-arylsulfonyl-acrylamides with arylsulfonohydrazides: synthesis of sulfonated oxindoles.

A copper-catalyzed arylsulfonylation of N-arylsulfonyl-acrylamides with sulfonylhydrazides through a tandem radical process was developed. This methodology provided an alternative strategy for the synthesis of sulfonated oxindoles by forming C-S, C-N and C-C bonds in a single operation.

An easy arylation of 2-substituted 1,2,3-triazoles.

A selective, efficient and catalytic ligand-free method for the direct arylation of 2-aryl-1,2,3-triazoles via Pd-catalyzed C-H bond activation is described. The process smoothly proceeds in moderate to excellent yields.

IDO1 Inhibitor RY103 Suppresses Trp-GCN2-Mediated Angiogenesis and Counters Immunosuppression in Glioblastoma.

Glioma is characterized by strong immunosuppression and excessive angiogenesis. Based on existing reports, it can be speculated that the resistance to anti-angiogenic drug vascular endothelial growth factor A (VEGFA) antibody correlates to the induction of novel immune checkpoint indoleamine 2,3-dioxygenase 1 (IDO1), while IDO1 has also been suggested to be related to tumor angiogenesis. Herein, we aim to clarify the potential role of IDO1 in glioma angiogenesis and the mechanism behind it. Bioinformatic analyses showed that the expressions of IDO1 and angiogenesis markers VEGFA and CD34 were positively correlated and increased with pathological grade in glioma. IDO1-overexpression-derived-tryptophan depletion activated the general control nonderepressible 2 (GCN2) pathway and upregulated VEGFA in glioma cells. The tube formation ability of angiogenesis model cells could be inhibited by IDO1 inhibitors and influenced by the activity and expression of IDO1 in condition medium. A significant increase in serum VEGFA concentration and tumor CD34 expression was observed in IDO1-overexpressing GL261 subcutaneous glioma-bearing mice. IDO1 inhibitor RY103 showed positive anti-tumor efficacy, including the anti-angiogenesis effect and upregulation of natural killer cells in GL261 glioma-bearing mice. As expected, the combination of RY103 and anti-angiogenesis agent sunitinib was proved to be a better therapeutic strategy than either monotherapy.

Tryptophan deficiency induced by indoleamine 2,3-dioxygenase 1 results in glucose transporter 1-dependent promotion of aerobic glycolysis in pancreatic cancer.

Indoleamine 2,3-dioxygenase 1 (IDO1), the key enzyme in the catabolism of the essential amino acid tryptophan (Trp) through kynurenine pathway, induces immune tolerance and is considered as a critical immune checkpoint, but its impacts as a metabolism enzyme on glucose and lipid metabolism are overlooked. We aim to clarify the potential role of IDO1 in aerobic glycolysis in pancreatic cancer (PC). Analysis of database revealed the positive correlation in PC between the expressions of IDO1 and genes encoding important glycolytic enzyme hexokinase 2 (HK2), pyruvate kinase (PK), lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1). It was found that IDO1 could modulate glycolysis and glucose uptake in PC cells, Trp deficiency caused by IDO1 overexpression enhanced glucose uptake by stimulating GLUT1 translocation to the plasma membrane of PC cells. Besides, Trp deficiency caused by IDO1 overexpression suppressed the apoptosis of PC cells via promoting glycolysis, which reveals the presence of IDO1-glycolysis-apoptosis axis in PC. IDO1 inhibitors could inhibit glycolysis, promote apoptosis, and exhibit robust therapeutic efficacy when combined with GLUT1 inhibitor in PC mice. Our study reveals the function of IDO1 in the glucose metabolism of PC and provides new insights into the therapeutic strategy for PC.

Regioselective halogenation of 2-substituted-1,2,3-triazoles via sp2 C-H activation.

A highly regioselective halogenation of 2-substituted-1,2,3-triazoles was developed via sp(2) C-H activation. This method is compatible with halogen atoms, as well as electron-donating and electron-withdrawing groups. Meanwhile, the strategy is also efficient for the synthesis of a key intermediate of Suvorexant.

[A preliminary study of the inhibitive efficacy of iodized linoleic acid and its fluorodeoxyuridine ester in hepatocellular cancer].

OBJECTIVE: To explore the potential of iodized linoleic acid (ILA) and its 5-fluoro-deoxyuridine ester (IFU) to inhibit hepatocellular carcinoma (HCC) cells in vitro and tumors in vivo. METHODS: ILA and its constituent component IFU were chemically synthesized, purified, and confirmed by 1H-NMR. The HCC cell lines, QGY-7703 (5-fluorouracil (5-FU) treatment sensitive) and SMMC-7721 (5-FU resistant), were treated with ILA, IFU, 5-FU, or traditional lipiodol for 72 hours. Survival rates of the treated cells were assessed by the methyl thiazolyl tetrazolium method, and used to calculate the IC50 and IC90. In addition, thirty nude mice were subcutaneously inoculated with SMMC-7721 cells and randomly divided two weeks later into four treatment groups (n = 6 each) for intra-tumoral injection of ILA, IFU, 5-FU, lipiodol or DMSO (controls). The rate of tumor inhibition (RTI) was calculated for each group at week 4 after treatment. RESULTS: For the cultured SMMC-7721 cells, the inhibitory concentrations for ILA, IFU, and 5-FU were: IC50: 134.38 mumol/L, 17.55 mumol/L, and 7.38 mumol/L; IC90: 192.88 mumol/L, 97.63 mumol/L, and more than 200 mumol/L. For the cultured QGY-7703 cells, the inhibitory concentrations for ILA, IFU, and 5-FU were: IC50: 109.55 mumol/L, 44.79 mumol/L, and 98.06 mumol/L; IC90: all, more than 200 mumol/L. In both cell types, the IC50 of lipiodol was more than 400 mumol/L. Compared with the RTI of the control mice (100%), the RTI of ILA-treated mice was 31.9% (t = 2.37, P less than 0.05), of IFU-treated mice was 56.9% (t = 4.91, P less than 0.01), and of 5-FU-treated mice was 31.0% (t = 2.59, P less than 0.05). The RTI of IFU was significantly stronger than that of either ILA or 5-FU (P less than 0.05). The lipiodol treatment showed no inhibition effect on tumors (P more than 0.05). CONCLUSION: ILA and IFU can effectively inhibit the growth of HCC cells in vitro and tumors in vivo. Furthermore, IFU outperforms ILA in inhibiting HCC growth.

An easy direct arylation of 5-pyrazolones.

A mild, efficient and catalytic ligand-free method for the direct arylation of 5-pyrazolones by Pd-catalyzed C-H bond activation is reported. The process smoothly proceeds and yields are moderate to excellent.

The Protective Effect of IDO1 Inhibition in Aß-Treated Neurons and APP/PS1 Mice.

Alzheimer's disease (AD) is an inflammatory associated disease, in which dysregulated kynurenine pathway (KP) plays a key role. Through KP, L-tryptophan is catabolized into neurotoxic and neuroprotective metabolites. The overactivation of indolamine 2,3-dioxygenase1 (IDO1), the first rate-limiting enzyme of KP, and the abnormal accumulation of KP metabolites have been noted in AD, and blocking IDO1 has been suggested as a therapeutic strategy. However, the expression patterns of KP enzymes in AD, and whether these enzymes are related to AD pathogenesis, have not been fully studied. Herein, we examined the expression patterns of inflammatory cytokines, neurotrophic factors and KP enzymes, and the activity of IDO1 and IDO1 effector pathway AhR (aryl hydrocarbon receptor) in AD mice. We studied the effects of IDO1 inhibitors on Aß-related neuroinflammation in rat primary neurons, mouse hippocampal neuronal cells, and APP/PS1 mice. The results further demonstrated the importance of IDO1-catalyzed KP in neuroinflammation in Alzheimer's disease.

The relationship among amyloid-ß deposition, sphingomyelin level, and the expression and function of P-glycoprotein in Alzheimer's disease pathological process.

In Alzheimer's disease, the transporter P-glycoprotein is responsible for the clearance of amyloid-ß in the brain. Amyloid-ß correlates with the sphingomyelin metabolism, and sphingomyelin participates in the regulation of P-glycoprotein. The amyloid cascade hypothesis describes amyloid-ß as the central cause of Alzheimer's disease neuropathology. Better understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-ß and their potential association in the pathological process of Alzheimer's disease is critical. Herein, we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable age. The functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of age. Decreased sphingomyelin levels, increased ceramide levels, and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type mice. Similar results were observed in the Alzheimer's disease mouse model induced by intracerebroventricular injection of amyloid-ß1-42 and human cerebral microvascular endothelial cells treated with amyloid-ß1-42. In human cerebral microvascular endothelial cells, neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-ß1-42 treatment. Neutral sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ceramide. Together, these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide pathway. These studies may serve as new pursuits for the development of anti-Alzheimer's disease drugs.

Efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles from 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes.

An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-halo-1H-pyrazoles are found to be important intermediates that can easily be converted into 1,2,5-triaryl-substituted pyrazoles via Pd-catalyzed C-H bond activation.

Synthesis of vinyl-1,2,3-triazole derivatives under transition metal-free conditions.

Herein, we describe a novel and green route for the direct synthesis of vinyl triazole derivatives with alkynes and triazoles promoted by an inorganic base under transition metal-free conditions. The base shows great catalytic activity for the anti-Markovnikov stereoselective hydroamination of alkynes. Moreover, good yields with excellent functional group tolerance are successfully achieved for a range of substrates, including aryl and heteroaryl groups, terminal alkynes and internal alkynes, and various triazole derivatives. This work presents an advanced concept for the synthesis of alkenyl triazole with a versatile and cost-efficient approach.

IDO1/TDO dual inhibitor RY103 targets Kyn-AhR pathway and exhibits preclinical efficacy on pancreatic cancer.

Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzing the conversion of tryptophan (Trp) to kynurenine (Kyn) in kynurenine pathway (KP) is involved in the immunosuppression in pancreatic cancer (PC), but the value of IDO1 as an independent prognostic marker for PC is uncertain. Moreover, the correlation between tryptophan 2,3-dioxygenase (TDO), an isozyme of IDO1, and PC is largely unknown. Using TCGA database, the correlation between IDO1 and/or TDO expression and PC patients' survival was analyzed. The expressions of IDO1 and TDO in PC cells and PC mice were examined. The effects of IDO1, TDO or dual inhibition on IDO1 and TDO effector pathway (Aryl hydrocarbon receptor, AhR) and on migration and invasion of PC cells were investigated. The block effect of IDO1/TDO dual inhibitor RY103 on KP was evaluated. The preclinical efficacy of RY103 and its immunomodulatory effect on KPIC orthotopic PC mice and Pan02 tumor-bearing mice were explored. Results showed that IDO1/TDO co-expression is an independent prognostic marker for PC. RY103 can significantly block KP and target Kyn-AhR pathway to blunt the migration and invasion of PC cells, exhibit preclinical efficacy and ameliorate IDO1/TDO-mediated immunosuppression in PC mice.