chiniofon and 5-carboxy-8-hydroxyquinoline

Cholera remains a major cause of infectious diarrhea globally. Despite the increased availability of cholera vaccines, there is still an urgent need for other effective interventions to reduce morbidity and mortality. Furthermore, increased prevalence of antibiotic-resistant Vibrio cholerae threatens the use of many drugs commonly used to treat cholera. We developed iOWH032, a synthetic small molecule inhibitor of the cystic fibrosis transmembrane conductance regulator chloride channel, as an antisecretory, host-directed therapeutic for cholera. In the study reported here, we tested iOWH032 in a Phase 2a cholera controlled human infection model. Forty-seven subjects were experimentally infected with V. cholerae El Tor Inaba strain N16961 in an inpatient setting and randomized to receive 500 mg iOWH032 or placebo by mouth every 8 hours for 3 days to determine the safety and efficacy of the compound as a potential treatment for cholera. We found that iOWH032 was generally safe and achieved a mean (± standard deviation) plasma level of 4,270 ng/mL (±2,170) after 3 days of oral dosing. However, the median (95% confidence interval) diarrheal stool output rate for the iOWH032 group was 25.4 mL/hour (8.9, 58.3), compared to 32.6 mL/hour (15.8, 48.2) for the placebo group, a reduction of 23%, which was not statistically significant. There was also no significant decrease in diarrhea severity and number or frequency of stools associated with iOWH032 treatment. We conclude that iOWH032 does not merit future development for treatment of cholera and offer lessons learned for others developing antisecretory therapeutic candidates that seek to demonstrate proof of principle in a cholera controlled human infection model study. Trial registration: This study is registered with ClinicalTrials.gov as NCT04150250.

Topics: Administration, Oral; Adolescent; Adult; Cholera; Cystic Fibrosis Transmembrane Conductance Regulator; Diarrhea; Double-Blind Method; Female; Humans; Hydroxyquinolines; Male; Oxadiazoles; Vibrio cholerae; Young Adult

Natural killer (NK) cells are a potent weapon against tumor and viral infection. Finding active compounds with the capacity of enhancing NK cell effector functions will be effective to develop new anti-cancer drugs. In this study, we initially screened 287 commercially available active compounds by co-culturing with peripheral blood mononuclear cells (PBMCs). We found that five compounds, namely, Daphnetin, MK-8617, LW6, JIB-04, and IOX1, increased the IFN-γ

Topics: Acetanilides; Adamantane; Adolescent; Adult; Aminopyridines; Cytotoxicity, Immunologic; Drug Evaluation, Preclinical; Enzyme Inhibitors; Female; Humans; Hydrazones; Hydroxyquinolines; Interferon-gamma; Interleukin-12; K562 Cells; Killer Cells, Natural; Leukocytes, Mononuclear; Lymphocyte Activation; Male; Middle Aged; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyridazines; Pyrimidines; Signal Transduction; TOR Serine-Threonine Kinases; Umbelliferones; Young Adult

Epigenetic activation of Wnt/β-catenin signaling plays a critical role in Wnt-induced tumorigenesis, notably in colorectal cancers. KDM3 and KDM4 histone demethylases have been reported to promote oncogenic Wnt signaling through demethylation of H3K9 on Wnt target gene promoters and are suggested to be potential therapeutic targets. However, potent inhibitors for these regulators are still not available. In addition, which family is most responsible for activation of Wnt target genes and Wnt-induced oncogenesis is not well documented, specifically in colorectal cancer. In this study, we characterized the functional redundancy and differences between KDM3 and KDM4 in regard to regulating Wnt signaling. Our data suggest that KDM3 may play a more essential role than KDM4 in regulating oncogenic Wnt signaling in human colorectal cancer. We also identified that IOX1, a known histone demethylase inhibitor, significantly suppresses Wnt target gene transcription and colorectal cancer tumorigenesis. Mechanistically, IOX1 inhibits the enzymatic activity of KDM3 by binding to the Jumonji C domain and thereby preventing the demethylation of H3K9 on Wnt target gene promoters. Taken together, our data not only identified the critical mechanisms by which IOX1 suppressed Wnt/β-catenin signaling and colorectal cancer tumorigenesis through inhibition of KDM3, but also suggested that IOX1 may represent an attractive small molecule lead for future drug design and discovery.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Hydroxyquinolines; Jumonji Domain-Containing Histone Demethylases; Mice, Nude; Neoplasm Invasiveness; Neoplastic Stem Cells; Transcription, Genetic; Wnt Proteins; Wnt Signaling Pathway

Sepsis is caused by organ dysfunction initiated by an unrestrained host immune response to infection. The emergence of antibiotic-resistant bacteria has rapidly increased in the last decades and has stimulated a firm research platform to combat infections caused by antibiotic-resistant bacteria that cannot be eradicated with conventional antibiotics. Strategies like epigenetic regulators such as lysine demethylase (Kdm) has received attention as a new target. Thus, we sought to investigate the epigenetic mechanisms in sepsis pathophysiology with the aim of discovering new concepts for treatment. A transcriptome analysis of dendritic cells during their inflammatory state identified Kdm as a critical molecule in sepsis regulation. Next, 8-hydroxyquinoline-5-carboxylic acid (IOX1) ability to control endotoxemia induced by Lipopolysaccharide and bacterial sepsis was demonstrated. IOX1 has been shown to regulate endotoxemia and sepsis caused by Escherichia coli and carbapenem-resistant Acinetobacter baumannii and has also contributed to the suppression of multidrug-resistant bacterial growth through the inhibition of DNA Gyrase. These findings show that IOX1 could be a component agent against bacterial sepsis by functioning as a broad-spectrum antibiotic with dual effects.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Anti-Bacterial Agents; Dendritic Cells; Disease Models, Animal; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Histone Demethylases; Humans; Hydroxyquinolines; Mice; Microbial Sensitivity Tests; Molecular Docking Simulation; Sepsis

Anti-programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) antibodies are currently used in the clinic to interupt the PD-1/PD-L1 immune checkpoint, which reverses T cell dysfunction/exhaustion and shows success in treating cancer. Here, we report a histone demethylase inhibitor, 5-carboxy-8-hydroxyquinoline (IOX1), which inhibits tumour histone demethylase Jumonji domain-containing 1A (JMJD1A) and thus downregulates its downstream β-catenin and subsequent PD-L1, providing an antibody-independent paradigm interrupting the PD-1/PD-L1 checkpoint. Synergistically, IOX1 inhibits cancer cells' P-glycoproteins (P-gp) through the JMJD1A/β-catenin/P-gp pathway and greatly enhances doxorubicin (DOX)-induced immune-stimulatory immunogenic cell death. As a result, the IOX1 and DOX combination greatly promotes T cell infiltration and activity and significantly reduces tumour immunosuppressive factors. Their liposomal combination reduces the growth of various murine tumours, including subcutaneous, orthotopic, and lung metastasis tumours, and offers a long-term immunological memory function against tumour rechallenging. This work provides a small molecule-based potent cancer chemo-immunotherapy.

Topics: Animals; Antibodies; Antineoplastic Combined Chemotherapy Protocols; B7-H1 Antigen; Cell Line, Tumor; Cell Survival; Doxorubicin; HCT116 Cells; Humans; Hydroxyquinolines; Immunotherapy; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Neoplasms, Experimental; NIH 3T3 Cells; Programmed Cell Death 1 Receptor; T-Lymphocytes; Tumor Burden

Topics: A549 Cells; AC133 Antigen; Apoptosis; ATP Binding Cassette Transporter, Subfamily B; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Glutathione Transferase; Humans; Hydroxyquinolines; Low Density Lipoprotein Receptor-Related Protein-1; Neoplastic Stem Cells; NF-kappa B; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Spheroids, Cellular; TOR Serine-Threonine Kinases

Esophageal squamous cell carcinoma (ESCC), the most frequent esophageal cancer (EC) subtype, entails dismal prognosis. Hypoxia, a common feature of advanced ESCC, is involved in resistance to radiotherapy (RT). RT response in hypoxia might be modulated through epigenetic mechanisms, constituting novel targets to improve patient outcome. Post-translational methylation in histone can be partially modulated by histone lysine demethylases (KDMs), which specifically removes methyl groups in certain lysine residues. KDMs deregulation was associated with tumor aggressiveness and therapy failure. Thus, we sought to unveil the role of Jumonji C domain histone lysine demethylases (JmjC-KDMs) in ESCC radioresistance acquisition. The effectiveness of RT upon ESCC cells under hypoxic conditions was assessed by colony formation assay. KDM3A/KDM6B expression, and respective H3K9me2 and H3K27me3 target marks, were evaluated by RT-qPCR, Western blot, and immunofluorescence. Effect of JmjC-KDM inhibitor IOX1, as well as KDM3A knockdown, in in vitro functional cell behavior and RT response was assessed in ESCC under hypoxic conditions. In vivo effect of combined IOX1 and ionizing radiation treatment was evaluated in ESCC cells using CAM assay. KDM3A, KDM6B, HIF-1α, and CAIX immunoexpression was assessed in primary ESCC and normal esophagus. Herein, we found that hypoxia promoted ESCC radioresistance through increased KDM3A/KDM6B expression, enhancing cell survival and migration and decreasing DNA damage and apoptosis, in vitro. Exposure to IOX1 reverted these features, increasing ESCC radiosensitivity and decreasing ESCC microtumors size, in vivo. KDM3A was upregulated in ESCC tissues compared to the normal esophagus, associating and colocalizing with hypoxic markers (HIF-1α and CAIX). Therefore, KDM3A upregulation in ESCC cell lines and primary tumors associated with hypoxia, playing a critical role in EC aggressiveness and radioresistance. KDM3A targeting, concomitant with conventional RT, constitutes a promising strategy to improve ESCC patients' survival.

Topics: Apoptosis; Biomarkers, Tumor; Cell Line, Tumor; Cell Movement; Cell Proliferation; DNA Damage; DNA Repair; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Gene Expression Regulation, Neoplastic; Humans; Hydroxyquinolines; Jumonji Domain-Containing Histone Demethylases; Radiation Tolerance; Radiation, Ionizing; Tumor Hypoxia

Topics: alpha-Globins; Antigens, CD34; beta-Thalassemia; Butyric Acid; Cell Culture Techniques; Enzyme Inhibitors; Erythroid Cells; Gene Expression Profiling; Gene Expression Regulation; Histone Demethylases; Histones; Humans; Hydroxamic Acids; Hydroxyquinolines; Hydroxyurea; Molecular Sequence Annotation; Piperazines; RNA, Small Interfering; Small Molecule Libraries; Tranylcypromine; Vorinostat

The epigenetic modification of vascular smooth muscle cell (VSMC) phenotypic switching, proliferation, migration, apoptosis and extracellular matrix synthesis is known to occur in atherosclerosis. The aim of the present study was to investigate the effects of IOX1, a Jumonji domain-containing 2A (JMJD2A) inhibitor, on regulation of the cell cycle in angiotensin II (Ang II)-stimulated VSMCs and to elucidate the possible mechanisms involved. The proliferation and migration of the Ang II-stimulated VSMCs in the presence or absence of IOX1 were evaluated in vitro. Flow cytometric analysis was used to determine the effects of IOX1 on cell cycle progression. RT-qPCR and western blot analysis were carried out to measure the expression levels of cell cycle-related genes. The trimethylation of histone H3 lysine 9 (H3K9me3) at the promoters of these genes was detected by chromatin immunoprecipitation (ChIP) assay. We confirmed that the JMJD2A levels were increased, whereas the H3K9me3 levels were decreased in the Ang II-stimulated VSMCs. The inhibition of JMJD2A by IOX1 suppressed the Ang II-induced cell proliferation, migration and cell cycle progression by inhibiting cyclin D1 expression and increasing p21 expression. The underlying mechanisms were related to the restoration of the H3K9me3 levels at the promoters of these genes. In conclusion, the findings of our study indicate that IOX1 exerts its anti-proliferative and anti-migratory effects by regulating the expression of the cell cycle-related proteins, cyclin D1 and p21.

Topics: Angiotensin II; Animals; Cell Cycle; Cell Cycle Proteins; Cell Movement; Cell Proliferation; Cells, Cultured; Gene Expression Regulation; Histone Demethylases; Hydroxyquinolines; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Rats, Sprague-Dawley

A series of JMJD2A inhibitors had been designed by analyzing the binding mode of 5-carboxy-8-hydroxyquinoline (5-carboxy-8-HQ) with JMJD2A. The inhibitory activity of the synthesized compounds against JMJD2A was determined, followed by docking simulations to understand the structure-activity relationships. Compounds with potent JMJD2A inhibitory activity demonstrated outstanding selectivity for JMJD2A over PHD2. Several potent compounds were selected to evaluate their anti-proliferative activity on tumor cell lines. Among them, compound 6p displayed the best anti-proliferative activity. Based on these in vitro biological data, seven compounds were chosen to determine their physicochemical properties. Compound 6p displayed good aqueous solubility and better permeability than 5-carboxy-8-HQ. Our data recognized that compound 6p could be considered as a starting point for development of new JmjC inhibitors.

Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Enzyme Inhibitors; HCT116 Cells; Humans; Hydroxyquinolines; Jumonji Domain-Containing Histone Demethylases; MCF-7 Cells; Molecular Dynamics Simulation; Molecular Structure; Structure-Activity Relationship

The 2-oxoglutarate (2OG)-dependent Jumonji C domain (JmjC) family is the largest family of histone lysine demethylases. There is interest in developing small-molecule probes that modulate JmjC activity to investigate their biological roles. 5-Carboxy-8-hydroxyquinoline (IOX1) is the most potent broad-spectrum inhibitor of 2OG oxygenases, including the JmjC demethylases, reported to date; however, it suffers from low cell permeability. Here, we describe structure-activity relationship studies leading to the discovery of an n-octyl ester form of IOX1 with improved cellular potency (EC50 value of 100 to 4 μM). These findings are supported by in vitro inhibition and selectivity studies, docking studies, activity versus toxicity analysis in cell cultures, and intracellular uptake measurements. The n-octyl ester was found to have improved cell permeability; it was found to inhibit some JmjC demethylases in its intact ester form and to be more selective than IOX1. The n-octyl ester of IOX1 should find utility as a starting point for the development of JmjC inhibitors and as a use as a cell-permeable tool compound for studies investigating the roles of 2OG oxygenases in epigenetic regulation.

Topics: Cell Membrane Permeability; Cell Survival; Dose-Response Relationship, Drug; Enzyme Inhibitors; Esters; HeLa Cells; Humans; Hydroxyquinolines; Jumonji Domain-Containing Histone Demethylases; Models, Molecular; Molecular Structure; Structure-Activity Relationship