Warfare arsenicals are potent blistering agents and cause severe inflammation following their skin exposure. Data from our group (unpublished) show that these chemicals act by activating bromodomain-4 and RIPK signaling. To develop a dual inhibitor of the bromodomain-containing protein 4 (BRD4) and the receptor-interacting serine/threonine-protein kinase 3 (RIPK3), we conducted a high-throughput screening (HTS) campaign for inhibitors of BRD4 and RIPK3 activity to identify anti-inflammatory agent candidates that could alleviate arsenicals-induced injury. Our primary assays were adapted to 384-well microplates and used to screen a collection of 4074 compounds consisting of FDA-approved drugs and other bioactive compounds. The BRD4 primary screen had an average Z' value of 0.93 and a signal-to-background (S/B) ratio of 3018, while the RIPK3 primary screen had an average Z' value of 0.86 and S/B = 12.6. A counter screen assay was used to ensure activity was due to target engagement and not assay interference. Hits that inhibited BRD4 binding by > 54.6 % and kinase activity by > 22.4 % in the primary screen and were not statistical outliers in the counter screen assays, were confirmed in concentration-response format. Hits were also tested in a cell-based IL-6 assay to determine corresponding inflammatory inhibitory activity. Eighteen compounds were active in both BRD4 and RIPK3 assays, of which three displayed IC50 values < 10 μM with promising IL-6 inhibition. These compounds could serve as good candidates for further chemical optimization for the development of small-molecule medical counter measure agents against arsenicals.

analyzer.After normalization to cell number, basal OCR results indicated that 16hBE cells with delF508-CFTR exhibited lower adenosine triphosphate-linked respiration than wt-CFTR cells.16hBE cells with delF508-CFTR had lower maximal respiration as well, especially than that of wt.VX-770 alone, without a corrector, significantly improved oxidative phosphorylation in 16hBE cells with delF508-CFTR but not in wt-CFTR cells.CB-839, the glutaminase-1 inhibitor, exerted a corrective effect on 16hBE cells with delF508-CFTR but not on cells with wt-CFTR.Our Ussing chamber data confirmed the results from the Seahorse analysis.We found that acute inhibition of glutaminase-1 by CB-839 slightly potentiates the function of CFTR.These data suggest that inhibition of specific metabolic pathways such as glutaminolysis could be beneficial to PwCF.Conclusions: Our study has established a rationale for testing the effect of glutaminase-1 inhibitors, particularly CB-839, in primary airway epithelial cells bearing mutant CFTR.

The nonsteroidal anti-inflammatory drug (NSAID) sulindac demonstrates attractive anticancer activity, but the toxicity resulting from cyclooxygenase (COX) inhibition and the suppression of physiologically important prostaglandins precludes its long-term, high dose use in the clinic for cancer prevention or treatment. While inflammation is a known tumorigenic driver, evidence suggests that sulindac’s antineoplastic activity is partially or fully independent of its COX inhibitory activity. One COX-independent target proposed for sulindac is cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) isozymes. Sulindac metabolites, i.e., sulfide and sulfone, inhibit cGMP PDE enzymatic activity at concentrations comparable with those associated with cancer cell growth inhibitory activity. Additionally, the cGMP PDE isozymes PDE5 and PDE10 are overexpressed during the early stages of carcinogenesis and appear essential for cancer cell proliferation and survival based on gene silencing experiments. Here, we describe a novel amide derivative of sulindac, sulindac sulfide amide (SSA), which was rationally designed to eliminate COX-inhibitory activity while enhancing cGMP PDE inhibitory activity. SSA was 68-fold and 10-fold less potent than sulindac sulfide (SS) in inhibiting COX-1 and COX-2, respectively, but 10-fold more potent in inhibiting growth and inducing apoptosis in breast cancer cells. The pro-apoptotic activity of SSA was associated with inhibition of cGMP PDE activity, elevation of intracellular cGMP levels, and activation of cGMP-dependent protein kinase (PKG) signaling, as well as the inhibition of β-catenin/Tcf transcriptional activity. SSA displayed promising in vivo anticancer activity, resulting in a 57% reduction in the incidence and a 62% reduction in the multiplicity of tumors in the N-methyl-N-nitrosourea (MNU)-induced model of breast carcinogenesis. These findings provide strong evidence for cGMP/PKG signaling as a target for breast cancer prevention or treatment and the COX-independent anticancer properties of sulindac. Furthermore, this study validates the approach of optimizing off-target effects by reducing the COX-inhibitory activity of sulindac for future targeted drug discovery efforts to enhance both safety and efficacy.

Arsenicals belong to the class of chemical warfare agents known as vesicants, which are highly reactive, toxic and cause robust inflammatory response. Cutaneous exposure to arsenicals causes a wide range of systemic organ damage, beginning with cutaneous injuries, and later manifest multi-organ damage and death. Thus, the development of suitable antidotes that can effectively block injury following exposure to these agents is of great importance. Bromodomain 4 (BRD4), a member of the bromodomain and extra terminal domain (BET) family, plays crucial role in regulating transcription of inflammatory, proliferation and cell cycle genes. In this context, the development of potent small molecule inhibitors of BRD4 could serve as potential antidotes for arsenicals. Herein, we describe the synthesis and biological evaluation of a series of compounds.

Acute kidney injury (AKI) is a major public health concern with significant morbidity and mortality and no current treatments beyond supportive care and dialysis. Preclinical studies have suggested that heme-oxygenase-1 (HO-1), an enzyme that catalyzes the breakdown of heme, has promise as a potential therapeutic target for AKI. Clinical trials involving HO-1 products (biliverdin, carbon monoxide, and iron), however, have not progressed beyond the Phase ½ level. We identified small-molecule inducers of HO-1 that enable us to exploit the full therapeutic potential of HO-1, the combination of its products, and yet-undefined effects of the enzyme system. Through cell-based, high-throughput screens for induction of HO-1 driven by the human HO-1 promoter/enhancer, we identified two novel small molecules and broxaldine (an FDA-approved drug) for further consideration as candidate compounds exhibiting an Emax ≥70% of 5 µM hemin and EC50 <10 µM. RNA sequencing identified shared binding motifs to NRF2, a transcription factor known to regulate antioxidant genes, including HMOX1. In vitro, the cytoprotective function of the candidates was assessed against cisplatin-induced cytotoxicity and apoptosis. In vivo, delivery of a candidate compound induced HO-1 expression in the kidneys of mice. This study serves as the basis for further development of small-molecule HO-1 inducers as preventative or therapeutic interventions for a variety of pathologies, including AKI.

Premature termination codons (PTCs) prevent translation of a full-length protein and trigger nonsense-mediated mRNA decay (NMD). Nonsense suppression (also termed readthrough) therapy restores protein function by selectively suppressing translation termination at PTCs. Poor efficacy of current readthrough agents prompted us to search for better compounds. An NMD-sensitive NanoLuc readthrough reporter was used to screen 771,345 compounds. Among the 180 compounds identified with readthrough activity, SRI-37240 and its more potent derivative SRI-41315, induce a prolonged pause at stop codons and suppress PTCs associated with cystic fibrosis in immortalized and primary human bronchial epithelial cells, restoring CFTR expression and function. SRI-41315 suppresses PTCs by reducing the abundance of the termination factor eRF1. SRI-41315 also potentiates aminoglycoside-mediated readthrough, leading to synergistic increases in CFTR activity. Combining readthrough agents that target distinct components of the translation machinery is a promising treatment strategy for diseases caused by PTCs.

ALS is a rare type of progressive neurological disease with unknown etiology. It results in the gradual degeneration and death of motor neurons responsible for controlling the voluntary muscles. Identification of mutations in the superoxide dismutase (SOD) 1 gene has been the most significant finding in ALS research. SOD1 abnormalities have been associated with both familial as well as sporadic ALS cases. SOD2 is a highly inducible SOD that performs in concurrence with SOD1 to detoxify ROS. Induction of SOD2 can be obtained through activation of NF-ҡBs. We previously reported that SRI-22819 increases NF-ҡB expression and activation in vitro, but it has poor ADME properties in general and has no oral bioavailability. Our initial studies were focused on direct modifications of SRI-22819. There were active compounds identified but no improvement in microsomal stability was observed. In this context, we focused on making more significant structural changes in the core of the molecule. Ataluren, an oxadiazole compound that promotes read-through and expression of dystrophin in patients with Duchenne muscular dystrophy, bears some structural similarity to SRI-22819. Thus, we synthesized a series of SRI-22819 and Ataluren (PTC124) hybrid compounds. Several compounds from this series exhibited improved activity, microsomal stability and lower calculated polar surface area (PSA). This manuscript describes the synthesis and biological evaluation of SRI-22819 analogs and its hybrid combination with Ataluren.

Amyotrophic lateral sclerosis (ALS) is a rare and progressive neurodegenerative disease with unknown etiology. It is caused by the degeneration of motor neurons responsible for controlling voluntary muscles. It has been reported that mutations in the superoxide dismutase (SOD) 1 gene can lead to ALS. SOD1 abnormalities have been identified in both familial, as well as sporadic ALS cases. SOD2 is a highly inducible SOD that works in conjunction with SOD1. SOD2 can be induced through activation of NF-κBs. We previously reported that the novel small molecule, SRI-22818, increases NF-κB expression and activation and SOD2 levels in vitro and has activity in vivo in the SOD1-G93A reference model of ALS. We report herein the synthesis and biological evaluation of SRI-22818 analogs.

Disruptor of Telomeric Silencing 1-Like (DOT1L), the sole histone H3 lysine 79 (H3K79) methyltransferase, is required for leukemogenic transformation in a subset of leukemias bearing chromosomal translocations of the Mixed Lineage Leukemia (MLL) gene, as well as other cancers. Thus, DOT1L is an attractive therapeutic target and discovery of small molecule inhibitors remain of high interest. Herein, we are presenting screening results for a unique focused library of 1200 nucleoside analogs originally produced under the aegis of the NIH Pilot Scale Library Program. The complete nucleoside set was screened virtually against DOT1L, resulting in 210 putative hits. In vitro screening of the virtual hits resulted in validation of 11 compounds as DOT1L inhibitors clustered into two distinct chemical classes, adenosine-based inhibitors and a new chemotype that lacks adenosine. Based on the developed DOT1L ligand binding model, a structure-based design strategy was applied and a second-generation of non-nucleoside DOT1L inhibitors was developed. Newly synthesized compound 25 was the most potent DOT1L inhibitor in the new series with an IC50 of 1.0 μM, showing 40-fold improvement in comparison with hit 9 and exhibiting reasonable on target effects in a DOT1L dependent murine cell line. These compounds represent novel chemical probes with a unique non-nucleoside scaffold that bind and compete with the SAM binding site of DOT1L, thus providing foundation for further medicinal chemistry efforts to develop more potent compounds.

TGF-β has been a target of interest for the treatment of fibrotic diseases and certain cancers. Approaches to target TGF-β include antagonists of the active ligand or TGF-β receptor kinase activity. These approaches have failed in clinical trials due to a lack of effectiveness and a limited therapeutic window. In this context, newer and more selective approaches to target TGF-β are needed. We previously reported that the matricellular protein, thrombospondin 1, activates the latent TGF-β complex and that antagonism of this pathway using tri/tetrapeptides in various animal models reduces fibrosis. The tripeptide, SRI-31277 (1), is effective in vivo but has a short plasma half life (0.2 h). Herein we describe the design and synthesis SRI-31277 analogs, specifically smaller peptides that retain potency and have improved bioavailability. We identified SRI-35241 (36) with a single chiral center, which blocks TGF-β activation (pIC50 = 8.12 nM) and has a plasma half life of 1.8 h (iv).

Many factors have been proposed to contribute to the risk of recurrent tenosynovial giant cell tumours (TSGCT); however, we remain unable to predict those at risk, which formed the rationale for this multicentre retrospective case-control study of 28 patients with recurrence. We included cases of recurrence in a 1:1 ratio matched for age and sex with controls over 10 years. Using Cox regression, we present hazard ratios (HRs) for recurrence with 95% confidence intervals (CIs). Out of 285 cases, 28 individuals developed recurrence after a median of 2.4 years. Recurrent TSGCT had a higher mitotic count/mm2 in the primary tumour (median increase of 3 [IQR 1, 7]). Mitotic count in the primary tumour was associated with the risk of recurrence (adjusted HR 1.1 [95% CI 1.1, 1.2]) meaning that for every additional mitosis, the risk of recurrence increased by 10% per annum. We recommend a prospective cohort study to validate our findings.

Aim: Experimental and epidemiological studies and clinical trials suggest that nonsteroidal anti-inflammatory drugs possess antitumor potential. Sulindac, a widely used nonsteroidal anti-inflammatory drug, can prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA) is an amide-linked sulindac sulfide analog that showed in vivo antitumor activity in a human colon tumor xenograft model. Results/methodology: A new analog series with heterocyclic rings such as oxazole or thiazole at the C-2 position of sulindac was prepared and screened against prostate, colon and breast cancer cell lines to probe the effect of these novel substitutions on the activity of sulindac analogs. Conclusion: In general, replacement of the amide function of SSA analogs had a negative impact on the cell lines tested. A small number of hits incorporating rigid oxazole or thiazole groups in the sulindac scaffold in place of the amide linkage show comparable activity to our lead agent SSA.

Background:Sulindac belongs to the chemically diverse family of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) that effectively prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA), an amide analog of sulindac sulfide, shows insignificant COX-related activity and toxicity while enhancing anticancer activityin vitroand demonstratingin vivoxenograft activity.Objective:Develop structure-activity relationships in the sulindac amine series and identify analogs with promising anticancer activities.Method:A series of sulindac amine analogs were designed and synthesized and then further modified in a “libraries from libraries” approach to produce amide, sulfonamide and N,N-disubstituted sulindac amine sub-libraries. All analogs were screened against three cancer cell lines (prostate, colon and breast).Results:Several active compounds were identifiedviain vitrocancer cell line screening with the most potent compound (26) in the nanomolar range.Conclusion:Compound26and analogs showing the most potent inhibitory activity may be considered for further design and optimization efforts as anticancer hit scaffolds.

Non-steroidal anti-inflammatory drugs (NSAIDs) have a variety of potential indications that include management of pain and inflammation as well as chemoprevention and/or treatment of cancer. Furthermore, a specific form of ibuprofen, dexibuprofen or the S-(+) form, shows interesting neurological activities and has been proposed for the treatment of Alzheimer's disease. In a continuation of our work probing the anticancer activity of small sulindac libraries, we have prepared and screened a small diversity library of α-methyl substituted sulindac amides in the profen class. Several compounds of this series displayed promising activity compared with a lead sulindac analog.

As part of an ongoing program to study the anticancer activity of non-steroidal anti-inflammatory drugs (NSAIDs) through generating diversity libraries of multiple NSAID scaffolds, we synthesized a series of NSAID amide derivatives and screened these sets against three cancer cell lines (prostate, colon and breast) and Wnt/β-catenin signaling. The evaluated amide analog libraries show significant anticancer activity/cell proliferation inhibition, and specific members of the sets show inhibition of Wnt/β-catenin signaling.

Sulindac is a non-steroidal anti-inflammatory drug (NSAID) that has shown significant anticancer activity. Sulindac sulfide amide (1) possessing greatly reduced COX-related inhibition relative to sulindac displayed in vivo antitumor activity that was comparable to sulindac in a human colon tumor xenograft model. Inspired by these observations, a panel of diverse sulindac amide derivatives have been synthesized and their activity probed against three cancer cell lines (prostate, colon and breast). A neutral analog, compound 79 was identified with comparable potency relative to lead 1 and activity against a panel of lymphoblastic leukemia cell lines. Several new series also show good activity relative to the parent (1), including five analogs that also possess nanomolar inhibitory potencies against acute lymphoblastic leukemia cells. Several new analogs identified may serve as anticancer lead candidates for further development.