PROTACs in Ovarian Cancer: Current Advancements and Future Perspectives.

Ovarian cancer is the deadliest gynecologic malignancy. The majority of patients diagnosed with advanced ovarian cancer will relapse, at which point additional therapies can be administered but, for the most part, these are not curative. As such, a need exists for the development of novel therapeutic options for ovarian cancer patients. Research in the field of targeted protein degradation (TPD) through the use of proteolysis-targeting chimeras (PROTACs) has significantly increased in recent years. The ability of PROTACs to target proteins of interest (POI) for degradation, overcoming limitations such as the incomplete inhibition of POI function and the development of resistance seen with other inhibitors, is of particular interest in cancer research, including ovarian cancer research. This review provides a synopsis of PROTACs tested in ovarian cancer models and highlights PROTACs characterized in other types of cancers with potential high utility in ovarian cancer. Finally, we discuss methods that will help to enable the selective delivery of PROTACs to ovarian cancer and improve the pharmacodynamic properties of these agents.

Medicinal chemistry curriculum and pedagogical practices at Canadian pharmacy schools: Towards standardization of practice.

INTRODUCTION: Medicinal chemistry instruction in PharmD programs at Canadian universities is considered an important foundational science. However, with few guidelines for the required content most programs have observed a decrease in hours of medicinal chemistry instruction. A Medicinal Chemistry Special Interest Group (SIG) was formed to address these issues nationally and initiated a pan-Canadian environmental scan to better understand the depth and breadth of medicinal chemistry instruction. METHODS: The SIG carried out an environmental scan to identify medicinal chemistry content, delivery and assessments in PharmD programs in Canada. RESULTS: Core medicinal chemistry concepts across the PharmD programs are in general agreement with those listed by the Accreditation Council for Pharmacy Education. Medicinal chemistry was typically taught as didactic lectures either as a standalone course or within a pharmacology course, although one program integrated some medicinal chemistry within therapeutics focused problem-based learning. There was no consistent time in program where medicinal chemistry occurred. CONCLUSIONS: The SIG found that similar medicinal chemistry content is taught across all Canadian PharmD programs, but incorporation of medicinal chemistry in therapeutics courses was minimal. Core concepts within six high-level overarching themes that guide our collective instruction were identified. The core concepts require developing high-level cognitive processes such as knowledge application and synthesis that practicing pharmacists are expected to possess for entry to practice. We the authors posit that in addition to providing a unique tool for pharmacists to employ in therapeutic decision-making, medicinal chemistry also provides early practice of important problem-solving and critical thinking skills.

The Antipsychotic Dopamine 2 Receptor Antagonist Diphenylbutylpiperidines Improve Glycemia in Experimental Obesity by Inhibiting Succinyl-CoA:3-Ketoacid CoA Transferase.

Despite significant progress in understanding the pathogenesis of type 2 diabetes (T2D), the condition remains difficult to manage. Hence, new therapeutic options targeting unique mechanisms of action are required. We have previously observed that elevated skeletal muscle succinyl CoA:3-ketoacid CoA transferase (SCOT) activity, the rate-limiting enzyme of ketone oxidation, contributes to the hyperglycemia characterizing obesity and T2D. Moreover, we identified that the typical antipsychotic agent pimozide is a SCOT inhibitor that can alleviate obesity-induced hyperglycemia. We now extend those observations here, using computer-assisted in silico modeling and in vivo pharmacology studies that highlight SCOT as a noncanonical target shared among the diphenylbutylpiperidine (DPBP) drug class, which includes penfluridol and fluspirilene. All three DPBPs tested (pimozide, penfluridol, and fluspirilene) improved glycemia in obese mice. While the canonical target of the DPBPs is the dopamine 2 receptor, studies in obese mice demonstrated that acute or chronic treatment with a structurally unrelated antipsychotic dopamine 2 receptor antagonist, lurasidone, was devoid of glucose-lowering actions. We further observed that the DPBPs improved glycemia in a SCOT-dependent manner in skeletal muscle, suggesting that this older class of antipsychotic agents may have utility in being repurposed for the treatment of T2D.

Structure-Activity Relationship of N-Phenylthieno[2,3-b]pyridine-2-carboxamide Derivatives Designed as Forkhead Box M1 Inhibitors: The Effect of Electron-Withdrawing and Donating Substituents on the Phenyl Ring.

We report synthesis, characterization, biological evaluation, and molecular-docking studies of 18 thieno[2,3-b]pyridines with a phenylacetamide moiety at position 2, which is disubstituted with F, Cl, Br, or I at position 4, and with electron-withdrawing and electron-donating groups (-CN, -NO2, -CF3, and -CH3) at position 2, to study how the electronic properties of the substituents affected the FOXM1-inhibitory activity. Among compounds 1-18, only those bearing a -CN (regardless of the halogen) decreased FOXM1 expression in a triple-negative breast cancer cell line (MDA-MB-231), as shown by Western blotting. However, only compounds 6 and 16 decreased the relative expression of FOXM1 to a level lower than 50%, and hence, we determined their anti-proliferative activity (IC50) in MDA-MB-231 cells using the MTT assay, which was comparable to that observed with FDI-6, in contrast to compound 1, which was inactive according to both Western blot and MTT assays. We employed molecular docking to calculate the binding interactions of compounds 1-18 in the FOXM1 DNA-binding site. The results suggest a key role for residues Val296 and Leu289 in this binding. Furthermore, we used molecular electrostatic potential maps showing the effects of different substituents on the overall electron density.

Targeting of the FOXM1 Oncoprotein by E3 Ligase-Assisted Degradation.

The transcription factor FOXM1 that regulates multiple proliferation-related genes through selective protein-DNA and protein-protein interactions is now considered an attractive oncotarget. There are several small-molecule inhibitors that indirectly suppress the expression of FOXM1 or block its DNA binding domain (FOXM1-DBD). However, insufficient specificity or/and efficacy are two potential drawbacks. Here, we employed in silico modeling of FOXM1-DBD with inhibitors to enable the design of an effective CRBN-recruiting molecule that induced significant FOXM1 protein degradation and exerted promising in vivo antitumor activity against TNBC xenograft models. This study is the first of its kind showcasing the use of an approach described in the literature as protein-targeting chimeras to degrade the elusive FOXM1, providing an alternative strategy to counter the pathological effects resulting from the increased transcriptional activity of FOXM1 observed in cancer cells.

FOXM1 Inhibitors as Potential Diagnostic Agents: First Generation of a PET Probe Targeting FOXM1 To Detect Triple-Negative Breast Cancer in†vitro and in†vivo.

The FOXM1 protein controls the expression of essential genes related to cancer cell cycle progression, metastasis, and chemoresistance. We hypothesize that FOXM1 inhibitors could represent a novel approach to develop 18 F-based radiotracers for Positron Emission Tomography (PET). Therefore, in this report we describe the first attempt to use 18 F-labeled FOXM1 inhibitors to detect triple-negative breast cancer (TNBC). Briefly, we replaced the original amide group in the parent drug FDI-6 for a ketone group in the novel AF-FDI molecule, to carry out an aromatic nucleophilic (18 F)-fluorination. AF-FDI dissociated the FOXM1-DNA complex, decreased FOXM1 levels, and inhibited cell proliferation in a TNBC cell line (MDA-MB-231). [18 F]AF-FDI was internalized in MDA-MB-231 cells. Cell uptake inhibition experiments showed that AF-FDI and FDI-6 significantly decreased the maximum uptake of [18 F]AF-FDI, suggesting specificity towards FOXM1. [18 F]AF-FDI reached a tumor uptake of SUV=0.31 in MDA-MB-231 tumor-bearing mice and was metabolically stable 60 min post-injection. These results provide preliminary evidence supporting the potential role of FOXM1 to develop PET radiotracers.

SP1-independent inhibition of FOXM1 by modified thiazolidinediones.

This research article describes an approach to modify the thiazolidinedione scaffold to produce test drugs capable of binding to, and inhibit, the in vitro transcriptional activity of the oncogenic protein FOXM1. This approach allowed us to obtain FOXM1 inhibitors that bind directly to the FOXM1-DNA binding domain without targeting the expression levels of Sp1, an upstream transcription factor protein known to activate the expression of FOXM1. Briefly, we modified the chemical structure of the thiazolidinedione scaffold present in anti-diabetic medications such as pioglitazone, rosiglitazone and the former anti-diabetic drug troglitazone, because these drugs have been reported to exert inhibition of FOXM1 but hit other targets as well. After the chemical synthesis of 11 derivatives possessing a modified thiazolidinedione moiety, we screened all test compounds using in vitro protocols to measure their ability to (a) dissociate a FOXM1-DNA complex (EMSA assay); (b) decrease the expression of FOXM1 in triple negative-breast cancer cells (WB assay); (c) downregulate the expression of FOXM1 downstream targets (luciferase reporter assays and qPCR); and inhibit the formation of colonies of MDA-MB-231 cancer cells (colony formation assay). We also identified a potential binding mode associated with these compounds in which compound TFI-10, one of the most active molecules, exerts binding interactions with Arg289, Trp308, and His287. Unlike the parent drug, troglitazone, compound TFI-10 does not target the in vitro expression of Sp1, suggesting that it is possible to design FOXM1 inhibitors with a better selectivity profile.

Pimozide Alleviates Hyperglycemia in Diet-Induced Obesity by Inhibiting Skeletal Muscle Ketone Oxidation.

Perturbations in carbohydrate, lipid, and protein metabolism contribute to obesity-induced type 2 diabetes (T2D), though whether alterations in ketone body metabolism influence T2D pathology is unknown. We report here that activity of the rate-limiting enzyme for ketone body oxidation, succinyl-CoA:3-ketoacid-CoA transferase (SCOT/Oxct1), is increased in muscles of obese mice. We also found that the diphenylbutylpiperidine pimozide, which is approved to suppress tics in individuals with Tourette syndrome, is a SCOT antagonist. Pimozide treatment reversed obesity-induced hyperglycemia in mice, which was phenocopied in mice with muscle-specific Oxct1/SCOT deficiency. These actions were dependent on pyruvate dehydrogenase (PDH/Pdha1) activity, the rate-limiting enzyme of glucose oxidation, as pimozide failed to alleviate hyperglycemia in obese mice with a muscle-specific Pdha1/PDH deficiency. This work defines a fundamental contribution of enhanced ketone body oxidation to the pathology of obesity-induced T2D, while suggesting pharmacological SCOT inhibition as a new class of anti-diabetes therapy.

A structure-activity relationship study of Forkhead Domain Inhibitors (FDI): The importance of halogen binding interactions.

The Forkhead boX M1 (FOXM1) protein is an essential transcription factor required for the normal activation of human cell cycle. However, increasing evidence supports a correlation between FOXM1 overexpression and the onset of several types of cancer. Based on a previously reported molecular modeling and molecular dynamics simulations (MD) study, we hypothesized the role of an essential halogen-bonding interaction between the 4-fluorophenyl group in the forkhead domain inhibitor-6 (FDI-6) and an Arg297 residue inside the FOXM1-DNA binding domain (DBD). To prove the importance of this binding interaction, we synthesized and screened ten FDI-6 derivatives possessing different groups at the 4-fluorophenyl position of the lead molecule. Briefly, we found that derivatives possessing a 4-chlorophenyl, 4-bromophenyl, or a 4-iodophenyl group, were equipotent to the original 4-fluorophenyl moiety present in FDI-6, whereas derivatives without this 4-halogen moiety were inactive. We also observed that positional isomers in which the halogen was relocated to positions 2- or 3- on the phenyl group were significantly less active. These results provide evidence to support the essential role of a 4-halophenyl bonding interaction, with the Arg297 residue in the FOXM1-DBD, to exert inhibition of transcriptional activity.

Myeloperoxidase-mediated oxidation of edaravone produces an apparent non-toxic free radical metabolite and modulates hydrogen peroxide-mediated cytotoxicity in HL-60 cells.

Edaravone is considered to be a potent antioxidant drug known to scavenge free radical species and prevent free radical-induced lipid peroxidation. In this study, we investigated the effect of edaravone on the myeloperoxidase (MPO) activity, an enzyme responsible for the production of an array of neutrophil-derived oxidants that can cause cellular damage. The addition of edaravone to the reaction of MPO and hydrogen peroxide (H2O2) significantly enhanced the reduction of MPO Compound II back to native MPO. Interestingly, the MPO-mediated production of toxic hypochlorous acid exhibited a concentration-dependent biphasic effect, with the apparent optimal edaravone concentration at 10 µM. Oxidation of edaravone by MPO was examined by various analytical methods. An MPO-catalyzed product(s) of edaravone was identified at 350 nm by kinetic analysis of UV-Vis spectroscopy. Several MPO-catalyzed metabolites of edaravone were proposed from the LC-MS analyses, including oxidized dimers from edaravone radicals. Electron spin resonance (ESR) spin trapping detected a carbon-centred radical metabolite of edaravone. NMR studies revealed that there are two exchangeable hydrogens, one of which is on the α-carbon, justifying the carbon-centred edaravone radical produced from MPO. Despite the formation of an edaravone carbon-radical metabolite, it did not appear to effectively oxidize GSH (in comparison with phenoxyl radicals). Viability (ATP) and cytotoxicity (LDH release) assays showed a concentration-dependent effect of edaravone on HL-60 cells treated with either a bolus concentration of 30 µM H2O2 or a flux of H2O2 generated by 5 mM glucose and 10 mU/mL glucose oxidase. The H2O2-induced toxicity was ameliorated at high edaravone concentrations (100-200 µM). In contrast, low concentrations of edaravone (1-10 µM) exacerbated the H2O2-induced toxicity. However, the effect of edaravone at low concentration (0-10 µM) appeared more prominent with the LDH assay only. The cellular findings correlated with the biochemical studies with respect to hypochlorous acid formation. These findings provide interesting perspectives regarding the duality of edaravone as an antioxidant drug.

Identification and Characterization of Novel Receptor-Interacting Serine/Threonine-Protein Kinase 2 Inhibitors Using Structural Similarity Analysis.

Receptor-interacting protein kinase 2 (RIP2 or RICK, herein referred to as RIPK2) is linked to the pathogen pathway that activates nuclear factor κ-light-chain-enhancer of activated B cells (NFκB) and autophagic activation. Using molecular modeling (docking) and chemoinformatics analyses, we used the RIPK2/ponatinib crystal structure and searched in chemical databases for small molecules exerting binding interactions similar to those exerted by ponatinib. The identified RIPK2 inhibitors potently inhibited the proliferation of cancer cells by > 70% and also inhibited NFκB activity. More importantly, in vivo inhibition of intestinal and lung inflammation rodent models suggests effectiveness to resolve inflammation with low toxicity to the animals. Thus, our identified RIPK2 inhibitor may offer possible therapeutic control of inflammation in diseases such as inflammatory bowel disease, asthma, cystic fibrosis, primary sclerosing cholangitis, and pancreatitis.

Untying the knot of transcription factor druggability: Molecular modeling study of FOXM1 inhibitors.

The FOXM1 protein is a relevant transcription factor involved in cancer cell proliferation. The direct or indirect inhibition of this protein's transcriptional activity by small molecule drugs correlates well with a potentially significant anti-cancer profile, making this macro molecule a promising drug target. There are a few drug molecules reported to interact with (and inhibit) the FOXM1 DNA binding domain (FOXM1-BD), causing downregulation of protein expression and cancer cell proliferation inhibition. Among these drug molecules are the proteasome inhibitor thiostrepton, the former antidiabetic drug troglitazone, and the new FDI-6 molecule. Despite their structural differences, these drugs exert a similar inhibitory profile, and this observation prompted us to study a possible similar mechanism of action. Using a series of molecular dynamics simulations and docking protocols, we identified essential binding interactions exerted by all three classes of drugs, among which, a π-sulfur interaction (between a His287 and a sulfur-containing heterocycle) was the most important. In this report, we describe the preliminary evidence suggesting the presence of a drug-binding pocket within FOXM1 DNA binding domain, in which inhibitors fit to dissociate the protein-DNA complex. This finding suggests a common mechanism of action and a basic framework to design new FOXM1 inhibitors.

Differential eNOS-signalling by platelet subpopulations regulates adhesion and aggregation.

AIMS: In addition to maintaining haemostasis, circulating blood platelets are the cellular culprits that form occlusive thrombi in arteries and veins. Compared to blood leucocytes, which exist as functionally distinct subtypes, platelets are considered to be relatively simple cell fragments that form vascular system plugs without a differentially regulated cellular response. Hence, investigation into platelet subpopulations with distinct functional roles in haemostasis/thrombosis has been limited. In our present study, we investigated whether functionally distinct platelet subpopulations exist based on their ability to generate and respond to nitric oxide (NO), an endogenous platelet inhibitor. METHODS AND RESULTS: Utilizing highly sensitive and selective flow cytometry protocols, we demonstrate that human platelet subpopulations exist based on the presence and absence of endothelial nitric oxide synthase (eNOS). Platelets lacking eNOS (approximately 20% of total platelets) fail to produce NO and have a down-regulated soluble guanylate cyclase-protein kinase G (sGC-PKG)-signalling pathway. In flow chamber and aggregation experiments eNOS-negative platelets primarily initiate adhesion to collagen, more readily activate integrin αIIbß3 and secrete matrix metalloproteinase-2, and form larger aggregates than their eNOS-positive counterparts. Conversely, platelets having an intact eNOS-sGC-PKG-signalling pathway (approximately 80% of total platelets) form the bulk of an aggregate via increased thromboxane synthesis and ultimately limit its size via NO generation. CONCLUSION: These findings reveal previously unrecognized characteristics and complexity of platelets and their regulation of adhesion/aggregation. The identification of platelet subpopulations also has potentially important consequences to human health and disease as impaired platelet NO-signalling has been identified in patients with coronary artery disease.

Synthesis and Biological Evaluation of New Tyrosol-Salicylate Derivatives as Potential Anti-Inflammatory Agents.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used medications in inflammatory illnesses. However, the gastrointestinal bleeding and toxicity associated with NSAIDs long term use prompted the quest towards investigations for new anti-inflammatory agents. Natural and natural-derived molecules proved its anti-inflammatory efficacy in vitro as well as in vivo. Given this background, the scope of this research involves structural changes of the natural polyphenol (tyrosol) generating two new salicylate derivatives and testing their biological properties, focusing on anti-inflammatory effects assessed in vitro and in vivo assays. The first molecular modification was the introduction of a carboxylic acid group adjacent to the phenol group present in this compound, which creates a new salicylate-like tyrosol. In addition, the acetylation of phenol group in this molecule produced an acetylsalicylate derivative, which may be regarded as aspirin-like natural polyphenol. Interestingly, tyrosol and its novel derivatives attenuated the edema in acute inflammatory response on carrageenan- induced local inflammation in mice. In addition, our results demonstrated that tyrosol and its novel derivatives were able to reduce the chemotaxis of neutrophil assessed in vitro model by chemo attractant (fMLP). Furthermore, only derivative 2 was able to reduce this effect in the acute inflammatory model. In (DPPH)- scavenging activity, tyrosol derivatives demonstrated a minor antioxidant activity, which may suggest that radical scavenging is not a major pathway involved in the anti-inflammatory effects of these derivatives. Salicylate-like tyrosol derivatives are of particular interest for future studies.

Anti-inflammatory and antioxidant properties of a novel resveratrol-salicylate hybrid analog.

Resveratrol is a natural compound with a plethora of activities as well as limitations. We recently reported a series of resveratrol-salicylate analogs with potential chemopreventive activity. Herein, we report the anti-inflammatory and antioxidant properties of these resveratrol derivatives. Using an in vitro COX inhibition assay, and two in vivo protocols (carrageenan-induced peritonitis and paw edema), we identified a novel compound (C10) as a potent anti-inflammatory agent. The enhanced potency of C10 was associated with the ability of C10 to decrease the activity of myeloperoxidase (MPO) enzyme at 10mg/kg, whereas resveratrol and it's natural analog (TMS) did not exert the same effect. Additionally, C10 significantly reduced the concentration of intracellular reactive oxygen species. Because of the proven association between cancer, inflammation, and oxidative stress, we believe that C10 is a promising chemopreventive molecule.

NSAIDs do not require the presence of a carboxylic acid to exert their anti-inflammatory effect - why do we keep using it?

The carboxylic acid group (-COOH) present in classical NSAIDs is partly responsible for the gastric toxicity associated with the administration of these drugs. This concept has been extensively proven using NSAID prodrugs. However, the screening of NSAIDs with no carboxylic acid at all has been neglected. The goal of this work was to determine if new NSAID derivatives devoid of acidic moieties would retain the anti-inflammatory activity of the parent compound, without causing gastric toxicity. To test this concept, we replaced the carboxylic acid group in ibuprofen, flurbiprofen, and naproxen with three ammonium moieties. We tested the resulting water-soluble NSAID derivatives for anti-inflammatory and ulcerogenic activity in vitro and in vivo. In this regard, we observed that all non-acidic NSAIDs exerted a potent anti-inflammatory activity, suggesting that the acid group in commercial 2-phenylpropionic acid NSAIDs not be an essential requirement for anti-inflammatory activity. These data provide complementary evidence supporting the discontinuation of ulcerogenic acidic NSAIDs.

Resveratrol-salicylate derivatives as selective DNMT3 inhibitors and anticancer agents.

Resveratrol is a natural polyphenol with plethora of biological activities. Resveratrol has previously shown to decrease DNA-methyltransferase (DNMT) enzymes expression and to reactivate silenced tumor suppressor genes. Currently, it seems that no resveratrol analogs have been developed as DNMT inhibitors. Recently, we reported the synthesis of resveratrol-salicylate derivatives and by examining the chemical structure of these analogs, we proposed that these compounds could exhibit DNMT inhibition especially that they resembled NSC 14778, a compound we previously identified as a DNMT inhibitor by virtual screening. Indeed, using in vitro DNMT inhibition assay, some of the resveratrol-salicylate analogs we screened in this work that showed selective inhibition against DNMT3 enzymes which were greater than resveratrol. A molecular docking study revealed key binding interactions with DNMT3A and DNMT3B enzymes. In addition, the most active analog, 10 showed considerable cytotoxicity against three human cancer cells; HT-29, HepG2 and SK-BR-3, which was greater than resveratrol. Further studies are needed to understand the anticancer mechanisms of these derivatives.

Synergistic effects of anethole and ibuprofen in acute inflammatory response.

This study assessed the effect of the combination of anethole and ibuprofen in comparison with monotherapy by either drug alone, using two in vivo inflammatory models, namely the pleurisy and paw edema in rats. We also measured the levels of the TNF protein in plasma, and the ability of anethole to inhibit, in vitro, the activity of the cyclooxygenase 1 and cyclooxygenase 2 enzymes. The test drugs (anethole; ibuprofen; anethole + ibuprofen), at different doses, were administered once (p.o.) 60 min before the induction of the inflammatory response. The association of anethole + ibuprofen inhibited the development of the inflammatory response in both models used. This effect can be partially explained by the inhibitory action on the production of TNF and of COX isoforms. The isobologram analysis evidenced a synergistic effect between ibuprofen and anethole, because the combination of drugs showed a higher inhibitory potential than either drug alone.

NOSH-aspirin (NBS-1120), a novel nitric oxide- and hydrogen sulfide-releasing hybrid has enhanced chemo-preventive properties compared to aspirin, is gastrointestinal safe with all the classic therapeutic indications.

Aspirin is chemopreventive; however, side effects preclude its long-term use. NOSH-aspirin (NBS-1120), a novel hybrid that releases nitric oxide and hydrogen sulfide, was designed to be a safer alternative. Here we compare the gastrointestinal safety, anti-inflammatory, analgesic, anti-pyretic, anti-platelet, and chemopreventive properties of aspirin and NBS-1120 administered orally to rats at equimolar doses. Gastrointestinal safety: 6h post-administration, the number and size of hemorrhagic lesions in stomachs were counted; tissue samples were frozen for PGE2, SOD, and MDA determination. Anti-inflammatory: 1h after drug administration, the volume of carrageenan-induced rat paw edemas was measured for 5h. Anti-pyretic: fever was induced by LPS (ip) an hour before administration of the test drugs, core body temperature was measured hourly for 5h. Analgesic: time-dependent analgesic effects were evaluated by carrageenan-induced hyperalgesia. Antiplatelet: anti-aggregatory effects were studied on collagen-induced platelet aggregation of human platelet-rich plasma. Chemoprevention: nude mice were gavaged daily for 25 days with vehicle, aspirin or NBS-1120. After one week, each mouse was inoculated subcutaneously in the right flank with HT-29 human colon cancer cells. Both agents reduced PGE2 levels in stomach tissue; however, NBS-1120 did not cause any stomach ulcers, whereas aspirin caused significant bleeding. Lipid peroxidation induced by aspirin was higher than that exerted by NBS-1120. SOD activity was significantly inhibited by aspirin but increased by NBS-1120. Both agents showed similar anti-inflammatory, analgesic, anti-pyretic, and anti-platelet activities. Aspirin increased plasma TNFα more than NBS-1120-treated animals. NBS-1120 was better than aspirin as a chemopreventive agent; it dose-dependently inhibited tumor growth and tumor mass.

Hydrogen sulfide-releasing naproxen suppresses colon cancer cell growth and inhibits NF-κB signaling.

Colorectal cancer (CRC) is the second leading cause of death due to cancer and the third most common cancer in men and women in the USA. Nuclear factor kappa B (NF-κB) is known to be activated in CRC and is strongly implicated in its development and progression. Therefore, activated NF-κB constitutes a bona fide target for drug development in this type of malignancy. Many epidemiological and interventional studies have established nonsteroidal anti-inflammatory drugs (NSAIDs) as a viable chemopreventive strategy against CRC. Our previous studies have shown that several novel hydrogen sulfide-releasing NSAIDs are promising anticancer agents and are safer derivatives of NSAIDs. In this study, we examined the growth inhibitory effect of a novel H2S-releasing naproxen (HS-NAP), which has a repertoire as a cardiovascular-safe NSAID, for its effects on cell proliferation, cell cycle phase transitions, and apoptosis using HT-29 human colon cancer cells. We also investigated its effect as a chemo-preventive agent in a xenograft mouse model. HS-NAP suppressed the growth of HT-29 cells by induction of G0/G1 arrest and apoptosis and downregulated NF-κB. Tumor xenografts in mice were significantly reduced in volume. The decrease in tumor mass was associated with a reduction of cell proliferation, induction of apoptosis, and decreases in NF-κB levels in vivo. Therefore, HS-NAP demonstrates strong anticancer potential in CRC.