ABSTRACT
Blockade of immune checkpoint PD-1/PD-L1 has been a promising anticancer strategy; however, clinically available PD-1/PD-L1 small-molecule inhibitors are lacking. In view of the high potency of compound 2 (BMS-1002), structural fine tuning of the methoxy linkage together with diverse modification in the solvent interaction region was conducted. A series of novel derivatives featuring a difluoromethyleneoxy linkage were designed. Compound 43 was identified as the most promising PD-1/PD-L1 inhibitor with an IC50 value of 10.2 nM in the HTRF assay. This compound is capable of promoting CD8+ T cell activation through inhibiting PD-1/PD-L1 cellular signaling. Moreover, in the Hepa1-6 syngeneic mouse model, administration of compound 43 at 1 mg/kg dosage promoted CD8+ T cell activation and delayed the tumor growth with good tolerance. Notably, the tumor in one mouse of the compound 43-treated group was completely regressed. These results indicate that compound 43 is a promising candidate worthy of further investigation.
Subject(s)
B7-H1 Antigen/antagonists & inhibitors , Drug Design , Immune Checkpoint Inhibitors/chemistry , Immune Checkpoint Inhibitors/pharmacology , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Animals , CD8-Positive T-Lymphocytes/immunology , Cell Line, Tumor , Humans , Immune Checkpoint Inhibitors/chemical synthesis , Immune Checkpoint Inhibitors/pharmacokinetics , Interferon-gamma/metabolism , Mice , Mice, Inbred C57BL , Molecular Docking Simulation , Signal Transduction , Xenograft Model Antitumor AssaysABSTRACT
Starting from the antimalarial drugs chloroquine and hydroxychloroquine, we conducted a structural optimization on the side chain of chloroquine by introducing amino substituted longer chains thus leading to a series of novel aminochloroquine derivatives. Anti-infectious effects against SARS-Cov2 spike glycoprotein as well as immunosuppressive and anti-inflammatory activities of the new compounds were evaluated. Distinguished immunosuppressive activities on the responses of T cell, B cell and macrophages upon mitogen and pathogenic signaling were manifested. Compounds 9-11 displayed the most promising inhibitory effects both on cellular proliferation and on the production of multiple pro-inflammatory cytokines, including IL-17, IFN-γ, IL-6, IL-1ß and TNF-α, which might be insightful in the pursuit of treatment for immune disorders and inflammatory diseases.
Subject(s)
Amines/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antiviral Agents/pharmacology , Chloroquine/pharmacology , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Amines/chemistry , Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , B-Lymphocytes/immunology , Cell Proliferation/drug effects , Chloroquine/chemical synthesis , Chloroquine/chemistry , Cytokines/metabolism , Dose-Response Relationship, Drug , Humans , Macrophages/drug effects , Macrophages/immunology , Microbial Sensitivity Tests , Molecular Structure , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Structure-Activity Relationship , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
Activation of the stimulator of interferon gene (STING) has emerged as an exciting immuno-oncology therapeutic strategy; however, the first-generation STING agonists, cyclic dinucleotide (CDN) analogues, have suffered from many disadvantages and failed in clinical trials. Therefore, non-CDN small-molecule STING agonists are urgently needed. In view of the unique structure of the high potency of dimeric amidobenzimidazole STING agonist 5, a structural elaboration was conducted by modifying several structural hotspots of this scaffold. Triazole 40 was identified as a new potent STING activator, possessing EC50 values of 0.24 and 39.51 µM for h- and m-STING, respectively. This compound has a slightly better pharmacokinetic profile and is >20-fold more aqueously soluble than 5. It activated the STING signaling dramatically by directly binding and stabilizing all h-STING isoforms and m-STING. In vivo, intermittent administration of 40 was found to have significant antitumor efficacy with good tolerance in two mouse tumor models.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , Membrane Proteins/agonists , Animals , Antineoplastic Agents/pharmacokinetics , Benzimidazoles/pharmacokinetics , Humans , Mice , Mice, Inbred BALB C , Models, Molecular , Solubility , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
Starting from the recently launched FLT3/AXL multi-targeted inhibitor Gilteritinib (5), we conducted a side-chain ring closure medicinal chemistry approach leading to the identification of compound 15c as a highly potent AXL inhibitor in the biochemical and cellular anti-proliferative assays, with IC50 values of 1.2 and 0.3â¯nM, respectively. Compared with the reference compound 5, our new discovered AXL inhibitor 15c is more potent in both assays.