Highly penetrable nanoparticles co-loading doxorubicin and IDO1 siRNA enhance tumor immunotherapy / 药学学报

There are two serious obstacles to tumor immunotherapy. Firstly, the immune response of the tumor is seriously reduced due to immunosuppressive tumor microenvironment (ITM) and low immunogenicity of tumor. The second obstacle is the dense and complex heterogeneous structures, which seriously prevent the nanoparticles (NPs) from penetrating deeper into tumor tissue. Immunogenic cell death (ICD) induced by doxorubicin (DOX) is an effective method to enhance tumor immune activity. However, interferon-γ (IFN-γ) secreted by cytotoxic T lymphocytes (CTL) after ICD induction would increase the expression of indoleamine 2,3-dioxygenase 1 (IDO1) and enhance ITM. IDO1 siRNA would reduce the expression of IDO1 protein, regulate the tumor immunosuppressive microenvironment and regulate ITM, so as to enhance the ICD effect of DOX. In this paper, a novel charge conversional, particle size reduction and highly penetrable NPs based on a pH sensitive copolymer poly(ethylene glycol)-poly-L-lysine-2,3-dimethylmaleic anhydride (mPEG-PLL-DMA, PLD) and polyamidoamine (PAMAM) dendrimers to achieve deep delivery of tumor tissue. DOX and IDO1 siRNA were encapsulated to achieve efficient tumor immunotherapy. Preparation and cell level experiments showed that PLD material had significant pH sensitivity. Results of 3D tumor penetrable experiment in vitro showed that adding the pH sensitive material PLD significantly improved the permeability of the preparation. In addition, 4T1 tumor model was established for BALB/c mice and all animal experiments were displayed in according with the requirements of the Animal Experiment Ethics Committee of Shenyang Pharmaceutical University. The results of in vivo efficacy experiments and tissue experiments evaluated that IDO1 siRNA significantly improved the ICD effect owing to DOX, so as to significantly inhibit tumor growth.

Anti-tumor activity and mechanisms of IDO1 inhibitor in combined treatment with temozolomide on human glioma cell lines / 药学学报

We analyzed the anticancer effect and mechanism of the novel indoleamine 2,‍3-dioxygenase 1 (IDO1) inhibitor NLG-919 combined with temozolomide (TMZ) on human glioma cell lines. The anti-tumor activity of NLG-919 and temozolomide after single and combined treatments was detected by MTT assay. Colony formation assay, invasion assay and migration assays were used to detect the effects of NLG-919 and temozolomide alone or in combination on proliferation, invasion and migration of human glioma cells. A flow cytometry assay was used to detect cell apoptosis, cell cycle arrest, reactive oxygen species (ROS) production and mitochondrial membrane potential damage (JC-1). An immunofluorescence assay was used to detect the expression level of IDO1 and HPLC was used to detect the expression level of L-kynurenine (Kyn) to explore the anti-tumor mechanism of NLG-919 and temozolomide. The results show that NLG-919 had a weak in vitro inhibitory effect compared to that of temozolomide. The IC50 of NLG-919 on U251 cells and U87 after 72 h was 26.9 and 30.7 μmol·L-1, respectively. However, when NLG-919 was used in combination with temozolomide, its anti-glioma activity was significantly increased. Compared with the single treatment, the combination treatment had a potent ability to inhibit proliferation, invasion and migration of glioma cells. Combination treatment improved the capacity of temozolomide to induce cell cycle arrest and inhibit the growth of glioma cells. NLG-919 significantly down-regulated the expression and activity of IDO1 in glioma cells, and the inhibitory effect was improved after combination with temozolomide, and effectively blocked the production of Kyn through the metabolism of L-tryptophan (Trp). In conclusion, the IDO1 inhibitor NLG-919 and temozolomide showed synergistic effects in the anticancer therapy of human glioma cell lines.

Research progress on indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is the rate-limiting enzyme in the degradation of tryptophan to kynurenine. IDO1 is highly expressed in some tumor tissues. IDO1 can deplete tryptophan in tumor microenvironment, inhibit T cell function, and mediate the immune escape of tumor cells. Thus, IDO1 is considered a potential target of tumor immunotherapy. Currently, there are several IDO1 inhibitors in clinical research studies. The mechanism of IDO1-mediated tumor immune escape and the structure of IDO1 inhibitors are summarized in this review.

Advances in research on inhibitors based on targets: IDO1 and TDO / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) catalyze the initial and rate limiting step in the catabolism of tryptophan, which is related to tumor immune tolerance and poor prognosis in patients. In this regard, two enzymes have become important therapeutic targets for tumor immunotherapy. So far, nine IDO1 inhibitors and three IDO1/TDO dual inhibitors have entered clinical trials. This review summarizes the research progress of IDO1 inhibitors, TDO inhibitors and IDO1/TDO dual inhibitors from the perspective of medicinal chemistry.

Myricetin inhibits interferon-γ-induced programmed death ligand-1 and indoleamine 2, 3-dioxygenase 1 expression in lung cancer cells / 中国药理学与毒理学杂志

OBJECTIVE Programmed death ligand-1 (PD-L1) and indoleamine 2, 3-dioxygenase 1 (IDO1) are immune checkpoints which can be induced by interferon-γ(IFN-γ) in the tumor microenvironment, leading to immune escape of tumors. Myricetin (MY) is a flavonoid distributed in many edible and medicinal plants. The aim of this study is to clarify the effect and the mechanism of MY on inhibiting IFN-γ-induced PD-L1 and IDO1 in lung cancer cells. METHODS Expressions of PD-L1 and major histocompatibility complex-I (MHC-I) were evaluated by flow cytometry and Western blotting, and the expression of IDO1 was measured by Western blotting. qRT-PCR was used to detect their mRNA levels. The function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line that overexpressing PD-1. Molecular docking analysis, Western blotting and immunofluorescence were used for mechanism study. RESULTS MY potently inhibited IFN-γ-induced PD-L1 and IDO1 expression in human lung cancer cells, while didn't show obvious effect on the expression of MHC-I. In addition, MY restored the survival, proliferation, CD69 expression and interleukin-2 (IL-2) secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells in the co-culture system. Mechanistically, IFN-γ up-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis, which was targeted and inhibited by MY. CONCLUSION Our research revealed a new insight into the anti-tumor effects of MY which inhibited IFN-γ-induced PD-L1 and IDO1 expression, supporting the potential of MY in anti-tumor immunotherapy.

Enzima indolamina-2,3-dioxigenasa 1: implicaciones fisiopatológicas durante la gestación en condiciones de obesidad / Enzyme indoleamine 2,3-dioxygenase 1: physiopathological implications during gestation in obesity conditions

RESUMEN En las gestantes obesas se han observado complicaciones, incluyendo prevalencia de abortos espontáneos y preeclampsia. Se ha propuesto que en parte estas complicaciones podrían explicarse por el ambiente inflamatorio que predomina en la obesidad. La enzima indolami-na-2,3-dioxigenasa 1 (IDO1) es inducida por la citoquina pro-inflamatoria IFN-y, por lo que se ha sugerido un incremento en su expresión en pacientes obesos. IDO1 desempeña funciones claves durante el embarazo, entre las que se encuentra el establecimiento de la tolerancia materno-fetal, la placentación y la regulación del flujo sanguíneo en la placenta. Hasta el momento los estudios que evalúan la expresión de IDO1 en la gestación en condiciones de obesidad son escasos. Por lo tanto, en esta revisión se propuso explorar las implicaciones derivadas de la alteración en la expresión de esta enzima en gestantes obesas. Según la evidencia disponible en la literatura, es posible que en gestantes obesas se presente un aumento en la expresión y la actividad de IDO1. Estas modificaciones podrían tener efectos deletéreos sobre la gestación y estar relacionada con las complicaciones que se observan en gestantes obesas.

ABSTRACT Women who have an obese body mass index are more likely to experience pregnancy complications, including spontaneous abortion and preeclampsia. It has been suggested that these complications are at least in part related to the pro-inflamatory environment that predominates in obesity. Indoleamine-2,3-dioxygenase 1 is an enzyme induced downstream IFN-y signalling, hence it has been suggested that it increases its expression and activity in obese patients. IDO1 exerts multiple functions in pregnancy, including its contribution to materno-fetal tolerance, placentation and regulation of placental blood flow. The evidence about IDO1 in pregnant obese women is scarce. Therefore, herein the implications of an overexpression of IDO1 in pregnant obese patients were explored. The evidence available at the moment suggests that it is possible that IDO1 increases its expression and activity in pregnant obese women contributing to the complications observed on these patients.

Establishment and optimization of an enzyme-cell based high-throughput screening platform for IDO1 inhibitors / 药学学报

In this study, we used the tumor immunotherapy protein indoleamine 2,3-dioxygenase 1 (IDO1) as the target, and proposed an enzyme-cell-based tertiary IDO1 inhibitor high throughput screening platform. Firstly, the recombinant human IDO1 protein was expressed by genetic engineering and efficient IDO enzymatic screening system was established. Secondly, A172 cells stimulated with interferon-γ (IFNγ) or constructed plasmid which could highly express human IDO1 protein in HEK293 cells with transient transfection were used to construct the specific IDO1 cell based screening system. Finally, the effect of the compound on kynurenine and tryptophan in mouse plasma was determined by LC/MS/MS method on C57 mice, which could further verify the inhibitory effect of the selected compounds on IDO1 in vivo. The established and optimized enzyme-cell based screening model in this study can efficiently and effectively obtain IDO1 inhibitors in vitro, which lays a good foundation for the rapid development of clinical drugs. Procedures for animal study were performed with approval of the Animal Care and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College.

Design, synthesis and inhibitory activity of indoleamine 2,3-dioxygenase 1 inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme in the human tryptophan metabolism pathway, which can mediate tumor immune response. An IDO1 inhibitor would be a potential cancer immunotherapy drug. Based on the recently reported crystal of an IDO1 protein-inhibitor complex (PDBID: 6AZV), the structure of reported inhibitor, and by analyzing the interaction mode between the inhibitor and IDO1, new inhibitor molecules were designed and synthesized. All structures were confirmed by spectral data. Preliminary activity studies showed that compounds containing an azabiphenyl tetrazole structure (B1 and B2) and biphenyl compounds containing a sulfonamide structure (D1, D2 and D3) had excellent inhibitory activity of IDO1 at the enzyme and cell level, and were comparable or even better than the control drug INCB24360.

Progress in research of Trp-IDO1,2/TDO2-Kyn metabolic pathway in the pathogenesis of rheumatoid arthritis / 药学学报

Rheumatoid arthritis (RA) is an autoimmune disease characterized by excessive activation of autoreactive T cells and B cells, abundant production of autoantibodies and multiple joint involvement. Under the influence of heredity and environment, the disorder of innate immunity and adaptive immunity is the fundamental cause of the disease. In recent years, with rapid development of immunometabolism, milestone has been made in regulating the differentiation and function of immune cells through different energy metabolism pathways and related molecules. Many studies have shown that Trp-IDO1,2/TDO2-Kyn metabolic pathway mediates the pathogenesis and development of autoimmune diseases such as RA. This review summarizes the role of tryptophan (Trp), kynurenine (Kyn) and other metabolites in this metabolic pathway, as well as the role of rate-limiting enzymes indoleamine 2,3-dioxygenase 1 (IDO1), indoleamine 2,3-dioxygenase 2 (IDO2) and tryptophan-2,3-dioxygenase 2 (TDO2) in mediating RA inflammatory immune response and synovitis inflammation. This provides an important basis for elucidating the new pathological mechanism of RA and discovering new drug targets.

The research progress of indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme of L-tryptophan metabolic oxidation pathway, in which the L-tryptophan is transformed into N-formyl kynurenine by oxidative cleavage. IDO1 is considered as a potential target for the development of cancer immunotherapeutic molecules. Up to now, at least 10 drug candidates have been advanced into clinical research. In this review, the binding mode and structure-activity relationships of the representative IDO1 small molecule inhibitors were summarized according the characteristics of chemical structures. Hopefully, this review could provide some insights for further development of novel IDO1 inhibitors.

Research progress of indoleamine 2,3-dioxygenase 1 in tumor immunotherapy / 药学学报

IDO1 (indoleamine 2,3-dioxygenase 1) is one of the most significant checkpoint in tumor immunology. Numerous studies indicates that IDO1 is abnormally expressed in breast cancer, colorectal cancer, liver cancer and other tumor tissues, participating in tumor immune escape through multiple pathways. This review is prepared to elucidate the biological function of IDO1, highlight its pivotal role in tumor evasion, and summarize IDO1 inhibitors in the clinical trials.

Screening of natural small molecule IDO-1 inhibitors with anti-tumor role / 药学学报

Fragments of the human indoleamine 2,3-dioxygenase 1 (IDO1) gene 5'-UTR (untranslated 1 245 bp region) promoters were amplified by PCR and cloned into pGL4.20 vector in the construction of reporter vector pGL4-IDO1-luc. A549 cells were transfected with the constructed plasmid and IDO1 inhibitor screening model was established with dual-luciferase reporter assay. Based on the model, we screened natural small molecules which could down-regulate the expression of IDO1 on tumor cells. The anti-tumor activities were examined by MTT, Western blotting and lactic dehydrogenase (LDH) release assays. Toosendanin (NS-180) down regulated the IDO1 expression and inhibited IFN-γ-induced STAT1 and STAT3 phosphorylation in A549 cells. Moreover, NS-180 significantly increased the cytotoxicity of co-cultured NK cells on A549 cells in LDH release assays. In summary, NS-180 is a novel and potent IDO1 inhibitor, which has an antitumor activity for cancer immunotherapies.

Advances in indoleamine 2, 3-dioxygenase 1 inhibitors / 中国药科大学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is the rate-limiting enzyme which catalyses the metabolism of L-tryptophan(L-Trp) in the kynurenine pathway.It is overexpressed in many tumor cells and antigen presenting cells.This enzyme inhibits local immune response and supports tumor cells to evade immune surveillance by depleting L-Trp and producing kynurenine metabolites,thus,it is an important target for cancer immunotherapy.There are several IDO1 inhibitors with different scarfold under investigation,three of which have already entered clinical stage.The role of IDO1 in tumor immune tolerance and the research progress on IDO1 inhibitors in recent years are summarized in this paper.

The Empirical Study of Indoleamine 2,3-dioxygenase in Contributing to the Immune Escape on Hepatoma Carcinoma Cell / 中国生物工程杂志

Objective:To investigate the mechanism of indoleamine 2,3-dioxygenase(IDO)in HepG2 cells contributing to tumor immune escape.Methods:T-lymphocyte and HepG2 cell were cocultured,and 1-methyl-tryptophan(1-MT)was added to make an intervening experiment.The expression of IDO mRNA in HepG2 cell cocultured with T-lymphocyte was detected by RT-PCR;the apoptosis rate of HepG2 cell cocultured with T-lymphocyte was analyzed by flow cytometer;The cytotoxicity of T-lymphocyte against HepG2 cell was examined by MTT assay.Results:In combine reaction system,the expression of IDO mRNA was strongly induced in HepG2 cell cocultured with T-lymphocyte and faintly induced when cultured with 1-MT;the earlier apoptosis rate of HepG2 cell in control group and experiment group(1-MT:1.25 mmol/l,2.5 mmol/l,5mmol/l)was respectively(3.48?0.34)%,(7.82?0.41)%,(18.62?0.42)%,(25.32?0.40)%(P