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Host cells infected with dengue virus (DENV) often trigger endoplasmic reticulum (ER) stress, a key process that allows viral reproduction, without killing the host cells until the late stage of the virus life-cycle. However, little is known regarding which DENV viral proteins interact with the ER machinery to support viral replication. In this study, we identified and characterized a novel host factor, stress-associated ER protein 1 (SERP1), which interacts with the DENV type 2 (DENV-2) NS4B protein by several assays, for example, yeast two-hybrid, subcellular localization, NanoBiT complementation, and co-immunoprecipitation. A drastic increase (34.5-fold) in the SERP1 gene expression was observed in the DENV-2-infected or replicon-transfected Huh7.5 cells. The SERP1 overexpression inhibited viral yields (37-fold) in the DENV-2-infected Huh7.5 cells. In contrast, shRNAi-knockdown and the knockout of SERP1 increased the viral yields (3.4- and 16-fold, respectively) in DENV-2-infected HEK-293 and Huh7.5 cells, respectively. DENV-2 viral RNA replication was severely reduced in stable SERP1-expressing Huh7.5 cells transfected with DENV-2 replicon plasmids. The overexpression of DENV-2 NS4B alleviated the inhibitory effect of SERP1 on DENV-2 RNA replication. Taking these results together, we hypothesized that SERP1 may serve as an antiviral player during ER stress to restrict DENV-2 infection. Our studies revealed novel anti-DENV drug targets that may facilitate anti-DENV drug discovery. [ABSTRACT FROM AUTHOR]

Treatment of hyperglycemia with drugs that block renal glucose reabsorption via inhibition of sodium-dependent glucose cotransporter 2 (SGLT2) is a novel approach to diabetes management. In this study, twenty-seven aryl C -glycosides bearing a C=N/C−N linkage at the glucosyl C6 position were designed, synthesized and evaluated for their inhibitory activity against human SGLT2 (hSGLT2). Compounds with good hSGLT2 inhibition were further investigated to determine their selectivity over hSGLT1. Of these, five representative aryl C -glycosides were chosen for pharmacokinetic analysis. Oxime 2a was determined to have the most promising pharmacokinetic properties and was selected for in vivo glucosuria and plasma glucose level studies, which found it to exhibit comparable efficacy to dapagliflozin ( 1 ). Furthermore, 2a was not found to exhibit either significant cytotoxicity (CC 50 > 50 μM) or human ether-a-go-go related gene (hERG) inhibition (2% inhibition at 10 μM). Taken together, these efforts culminated in the discovery of oxime 2a as a potential SGLT2 inhibitor. [ABSTRACT FROM AUTHOR]

• Long-term exposure of peritoneal dialysate and chronic inflammation were risk factors of encapsulating peritoneal sclerosis. • The miRNA-based model could be useful to assist to determine the possibility of encapsulating peritoneal sclerosis. • 5 miRNAs were key regulators of TGF-β signal pathway in mesothelial-mesenchymal transition and immune systems. • The interaction network of miRNAs and compounds indicated these these miRNAs have the therapeutic potential targets. Encapsulating peritoneal sclerosis (EPS) is a catastrophic complication of peritoneal dialysis (PD) with high mortality. Our aim is to develop a novel noninvasive microRNA (miRNA) test for EPS. We collected 142 PD effluents (EPS: 62 and non-EPS:80). MiRNA profiles of PD effluents were examined by a high-throughput real-time polymerase chain reaction (PCR) array to first screen. Candidate miRNAs were verified by single real-time PCR. The model for EPS prediction was evaluated by multiple logistic regression and machine learning. Seven candidate miRNAs were identified from the screening of PCR-array of 377 miRNAs. The top five area under the curve (AUC) values with 5 miRNA-ratios were selected using 127 samples (EPS: 56 vs non-EPS: 71) to produce a receiver operating characteristic curve. After considering clinical characteristics and 5 miRNA-ratios, the accuracies of the machine learning model of Random Forest and multiple logistic regression were boosted to AUC 0.97 and 0.99, respectively. Furthermore, the pathway analysis of miRNA associated targeting genes and miRNA-compound interaction network revealed that these five miRNAs played the roles in TGF-β signaling pathway. The model-based miRNA expressions in PD effluents may help determine the probability of EPS and provide further therapeutic opinion for EPS. [ABSTRACT FROM AUTHOR]

CXCR4 antagonists have been claimed to reduce mortality after myocardial infarction in myocardial infarction (MI) animals, presumably due to suppressing inflammatory responses caused by myocardial ischemia-reperfusion injury, thus, subsequently facilitating tissue repair and cardiac function recovery. This study aims to determine whether a newly designed CXCR4 antagonist DBPR807 could exert better vascular-protective effects than other clinical counterparts (e.g., AMD3100) to alleviate cardiac damage further exacerbated by reperfusion. Consequently, we find that instead of traditional continuous treatment or multiple-dose treatment at different intervals of time, a single-dose treatment of DBPR807 before reperfusion in MI animals could attenuate inflammation via protecting oxidative stress damage and preserve vascular/capillary density and integrity via mobilizing endothelial progenitor cells, leading to a desirable fibrosis reduction and recovery of cardiac function, as evaluated with the LVEF (left ventricular ejection fraction) in infarcted hearts in rats and mini-pigs, respectively. Thus, it is highly suggested that CXCR4 antagonists should be given at a single high dose prior to reperfusion to provide the maximal cardiac functional improvement. Based on its favorable efficacy and safety profiles indicated in tested animals, DBPR807 has a great potential to serve as an adjunctive medicine for percutaneous coronary intervention (PCI) therapies in acute MI patients. [ABSTRACT FROM AUTHOR]

Ciclesonide is an inhaled corticosteroid used to treat asthma and has been repurposed as a treatment for mildly ill COVID-19 patients, but its precise mechanism of action is unclear. Herein, we report that ciclesonide blocks the coronavirus-induced production of the cytokines IL-6, IL-8, and MCP-1 by increasing IκBα protein levels and significantly decreasing p65 nuclear translocation. Furthermore, we found that the combination of ciclesonide and dbq33b, a potent tylophorine-based coronavirus inhibitor that affects coronavirus-induced NF-κB activation a little, additively and synergistically decreased coronavirus-induced IL-6, IL-8, and MCP-1 cytokine levels, and synergistically inhibited the replication of both HCoV-OC43 and SARS-CoV-2. Collectively, the combination of ciclesonide and dbq33b merits consideration as a treatment for COVID-19 patients who may otherwise be overwhelmed by high viral loads and an NF-κB-mediated cytokine storm. [ABSTRACT FROM AUTHOR]

Ligand-targeting drug conjugates are a class of clinically validated biopharmaceutical drugs constructed by conjugating cytotoxic drugs with specific disease antigen targeting ligands through appropriate linkers. The integrated linker-drug motif embedded within such a system can prevent the premature release during systemic circulation, thereby allowing the targeting ligand to engage with the disease antigen and selective accumulation. We have designed and synthesized new thioester-linked maytansinoid conjugates. By performing in vitro cytotoxicity, targeting ligand binding assay, and in vivo pharmacokinetic studies, we investigated the utility of this new linker-drug moiety in the small molecule drug conjugate (SMDC) system. In particular, we conjugated the thioester-linked maytansinoids to the phosphatidylserine-targeting small molecule zinc dipicolylamine and showed that Zn8_DM1 induced tumor regression in the HCC1806 triple-negative breast cancer xenograft model. Moreover, in a spontaneous sorafenib-resistant liver cancer model, Zn8_DM1 exhibited potent antitumor growth efficacy. From quantitative mRNA analysis of Zn8_DM1 treated-tumor tissues, we observed the elevation of gene expressions associated with a "hot inflamed tumor" state. With the identification and validation of a plethora of cancer-associated antigens in the "omics" era, this work provided the insight that antibody- or small molecule-based targeting ligands can be conjugated similarly to generate new ligand-targeting drug conjugates. [ABSTRACT FROM AUTHOR]

Abstract: Chitosan (CS) and its derivatives have been investigated as paracellular permeation enhancers for facilitating the oral bioavailability of hydrophilic macromolecules. As is well known, CS can transiently open the tight junctions (TJs) between epithelial cells, thus enhancing the paracellular permeability. However, the signaling mechanism that is related to the effect of CS on TJs remains unclear. Therefore, this study elucidates the potential transduction cascade of TJ opening in Caco-2 cell monolayers subsequent to CS exposure. Experimental results indicate that activation of integrin receptors on cell membranes significantly contributes to CS-mediated TJ disruption, initiating the cascade of TJ opening. Additionally, treatment of Caco-2 cell monolayers with CS leads to the clustering of integrins along the cell border, phosphorylation of FAK and Src tyrosine kinases, and results in the regulation of TJ permeability via the redistribution of TJ protein CLDN4 from the cell membrane to the cytosol. Elucidating the signaling mechanism of CS-induced TJ opening in intestinal cells significantly contributes to efforts to use CS and its derivatives as paracellular permeation enhancers. [Copyright &y& Elsevier]

Abstract: Sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors are the current focus on the indication for the management of hyperglycemia in diabetes. Here, a novel series of C-linked indolylxyloside-based inhibitors of SGLT2 has been discovered. Structure–activity relationship studies revealed that substituents at the 7-position of the indole moiety and a p-cyclopropylphenyl group in the distal position were necessary for optimum inhibitory activity. The pharmacokinetic study demonstrates that the most potent compound 1i is metabolically stable with a low clearance in rats. In further efficacy study, 1i is found to significantly lower blood glucose levels of streptozotocin (STZ)-induced diabetic rats. [Copyright &y& Elsevier]

Abstract: A series of trans-2-aryl-cyclopropylamine derived compounds were synthesized and evaluated their biological activities against DPP-IV. The structure-activity relationships (SAR) led to the discovery of novel series of DPP-IV inhibitors, having IC50 values of <100 nM with excellent selectivity over the closely related enzymes, DPP8, DPP-II and FAP. The studies identified a potent and selective DPP-IV inhibitor 24b, which exhibited the ability to both significantly inhibit plasma DPP-IV activity in rats and improve glucose tolerance in lean mice and diet induced obese mice. [Copyright &y& Elsevier]

Abstract: Shengmai San (SMS), which is comprised of the medicinal herbs of Panax ginseng C.A. Meyer, Schisandra chinensis Baill., and Ophiopogon japonicus Ker-Gawl (2:1:2)., is a traditional Chinese medicine being used for treating coronary heart disease. The aim of this study was to investigate the effects of SMS on the plasma and liver lipids, lipid peroxidation and antioxidant systems in liver and heart of cholesterol-fed rats. Rats were fed on a high-cholesterol (0.5%) diet (control group), high-cholesterol diet containing 2% SMS (2% SMS group) and 4% SMS (4% SMS group) for four weeks. The oxidative stress marker (thiobarbituric acid reactive substances, TBARS) and antioxidant defense systems including glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities in rat liver and heart were evaluated. Results showed that rats fed with SMS-containing diet had reduced the H2O2-induced erythrocytes susceptibility to hemolysis, and 4% SMS feeding rats had higher plasma GSH concentration compared to the animals fed with the control diet. However, SMS had no effect on plasma lipids (total cholesterol, triglyceride and high-density lipoprotein cholesterol) and TBARS concentration. On the other hand, rats fed with the 4% SMS diet reduced the hepatic cholesterol and triglyceride contents. Fecal bile acid excretion was significantly increased in rats fed with the SMS-containing diet. Higher hepatic GSH and lower TBARS concentrations were observed in rats fed with the 4% SMS diet compared with the rats fed with the control diet. No significant difference in activities of GSH-Px, GST and SOD was found in liver and heart after the SMS treatment. Results from this study indicate that the SMS may reduce hepatic lipids and lipid peroxidation in rats. [Copyright &y& Elsevier]

[Display omitted] • Fucoidan targets viral spike and host furin to block coronaviral entry. • Fucoidan inhibits viral entry and infection of HCoV-OC43 in vitro. • Fucoidan inhibits viral entry and infection of SARS-CoV-2 in vitro. • Fucoidan effectively inhibits infection by SARS-CoV-2 in vivo. Fucoidans are a class of long chain sulfated polysaccharides and have multiple biological functions. Herein, four natural fucoidans extracted from Fucus vesiculosus , F. serratus, Laminaria japonica and Undaria pinnatifida , were tested for their HCoV-OC43 inhibition and found to demonstrate EC 50 values ranging from 0.15 to 0.61 µg/mL. That from U. pinnatifida exhibited the most potent anti-HCoV-OC43 activity with an EC 50 value of 0.15 ± 0.02 µg/mL, a potency largely independent of its sulfate content. Comparison of the gene expression profiles of fucoidan-treated and untreated cells infected with HCoV-OC43 revealed that fucoidan treatment effectively diminished HCoV-OC43 gene expressions associated with induced chemokines, cytokines and viral activities. Further studies using a highly fucoidan-resistant HCoV-OC43 determined that fucoidan inhibited HCoV-OC43 infection via interfering with viral entry and led to the identification of the specific site on the N-terminal region of spike protein, that located adjacent to the host cell receptor binding domain, targeted by the virus. Furthermore, in a SARS-CoV-2 pseudovirus neutralization assay, fucoidan also blocked SARS-CoV-2 entry. In vitro and in vivo, fucoidan decreased SARS-CoV-2 viral loads and inhibited viral infection in Calu-3 or Vero E6 cells and SARS-CoV-2 infected hamsters, respectively. Fucoidan was also found to inhibit furin activity, and reported furin inhibitors were found to inhibit viral infection by wild type HCoV-OC43 or SARS-CoV-2. Accordingly, we conclude that fucoidans inhibit coronaviral infection by targeting viral spike protein and host cell furin to interfere with viral entry. [ABSTRACT FROM AUTHOR]

Abstract A medicinal chemistry program based on the small-molecule HCV NS5A inhibitor daclatasvir has led to the discovery of dimeric phenylthiazole compound 8 , a novel and potent HCV NS5A inhibitor. The subsequent SAR studies and optimization revealed that the cycloalkyl amide derivatives 27a - 29a exhibited superior potency against GT1b with GT1b EC 50 values at picomolar concentration. Interestingly, high diastereospecificity for HCV inhibition was observed in this class with the (1 R ,2 S ,1′ R ,2′ S) diastereomer displaying the highest GT1b inhibitory activity. The best inhibitor 27a was found to be 3-fold more potent (GT1b EC 50 = 0.003 nM) than daclatasvir (GT1b EC 50 = 0.009 nM) against GT1b, and no detectable in vitro cytotoxicity was observed (CC 50 > 50 μM). Pharmacokinetic studies demonstrated that compound 27a had an excellent pharmacokinetic profiles with a superior oral exposure and desired bioavailability after oral administration in both rats and dogs, and therefore it was selected as a developmental candidate for the treatment of HCV infection. Graphical abstract Image 1 Highlights • A novel class of dimeric phenylthiazole derivatives was identified as potent HCV NS5A inhibitors. • Several inhibitors showed GT1b potency at picomolar concentrations. • Compound 27a showed superior GT1b potency and promising pharmacokinetic properties in both rats and dogs. [ABSTRACT FROM AUTHOR]

Abstract Morphine is widely used for the treatment of severe pain. This analgesic effect is mediated principally by the activation of μ-opioid receptors (MOR). However, prolonged activation of MOR also results in tolerance, dependence, addiction, constipation, nausea, sedation, and respiratory depression. To address this problem, we sought alternative ways to activate MOR – either by use of novel ligands, or via a novel activation mechanism. To this end, a series of compounds were screened using a sensitive CHO-K1/MOR/Gα15 cell-based FLIPR® calcium high-throughput screening (HTS) assay, and the bithiazole compound 5a was identified as being able activate MOR in combination with naloxone. Structural modifications of 5a resulted in the discovery of lead compound 5j , which could effectively activate MOR in combination with the MOR antagonist naloxone or naltrexone. I n vivo , naloxone in combination with 100 mg/kg of compound 5j elicited antinociception in a mouse tail-flick model with an ED 50 of 17.5 ± 4 mg/kg. These results strongly suggest that the mechanism by which the 5j /naloxone combination activates MOR is worthy of further study, as its discovery has the potential to yield an entirely novel class of analgesics. Graphical abstract Image 1 Highlights • A HTS assay identified 5a as being able to activate MOR in combination with naloxone. • Compound 5j /naloxone demonstrated anti-nociceptive effect in B6 mice. • This finding has the potential to open up a new area in pain treatment. [ABSTRACT FROM AUTHOR]

Nuclear factor erythroid-2-related factor 2 (NRF2) mainly regulates transcriptional activation through antioxidant-responsive elements (AREs) present in the promoters of NRF2 target genes. Recently, we found that NRF2 was overexpressed in a KB-derived drug-resistant cancer cell panel. In this panel, KB-7D cells, which show acquired resistance to topoisomerase II (Top II) poisons, exhibited the highest NRF2 activation. To investigate whether NRF2 directly contributed to acquired resistance against Top II poisons, we manipulated NRF2 by genetic and pharmacological approaches. The result demonstrated that silencing of NRF2 by RNA interference increased the sensitivity and treatment with NRF2 activator decreased the sensitivity of KB and KB-7D cells toward Top II poisons. Further, increased B-Raf – mediated NRF2 gene transcription and HATs – mediated NRF2 protein acetylation activated NRF2 signaling in KB-7D cells. Moreover, increased binding of NRF2 to an ARE in the promoter of ATP-binding cassette subfamily C member 1 ( ABCC1 ) directly contributed to Top II poison resistance. In addition, activation of NRF2 increased glutathione level and antioxidant capacity in KB-7D cells compared with that in KB cells; moreover, high glutathione level provided survival advantage to KB-7D cells. Our study is the first to show that aberrant NRF2 activation is via increased B-Raf–mediated NRF2 gene transcription and HATs–mediated NRF2 protein acetylation, which increases the acquired resistance and promote the survival of Top II poison-resistant cancer cells. Importantly, NRF2 downstream effectors ABCC1 and glutathione directly contribute to acquired resistance and survival, respectively. These results suggest that blockade of NRF2 signaling may enhance therapeutic efficacy and reduce the survival of Top II poison-refractory tumors in clinical. [ABSTRACT FROM AUTHOR]

The Synergistic Inhibition of Coronavirus Replication and Induced Cytokine Production by Ciclesonide and the Tylophorine-Based Compound Dbq33b. B Changes to "authors who contributed equally" b In the original publication [[1]], the authors who had "contributed equally" were not listed. Reference 1 Lee Y.-Z., Hsu H.-Y., Yang C.-W., Lin Y.-L., Chang S.-Y., Yang R.-B., Liang J.-J., Chao T.-L., Liao C.-C., Kao H.-C. The Synergistic Inhibition of Coronavirus Replication and Induced Cytokine Production by Ciclesonide and the Tylophorine-Based Compound Dbq33b. [Extracted from the article]

Currently, there is a significant unmet need for novel analgesics with fewer side effects. In this study, we carried out structural modification of a hit compound previously identified in an artificial-intelligence (AI) virtual screening and discovered the potent analgesic, benzo[b]thiophene-2-carboxamide analog (compound 25) with new structural scaffold. We investigated the signaling pathways of opioid receptors mediated by compound 25 , and found this racemic compound activated mu-opioid receptor through the cyclic adenosine monophosphate (cAMP) and β-arrestin-2-mediated pathways with strong potency and efficacy, and accompanying nociceptin-orphanin FQ opioid peptide and delta-opioid receptors through the cAMP pathway with weak potencies. Compound 25 elicited potent antinociception in thermal-stimulated pain (ED 50 value of 127.1 ± 34.65 μg/kg) and inflammatory-induced allodynia models with less gastrointestinal transit inhibition and antinociceptive tolerance than morphine. Overall, this study revealed a novel analgesic with reduced risks of side effects. [Display omitted] • Benzo[b]thiophene-2-carboxamides were identified as potent opioid receptor agonists. • Compound 25 demonstrates potent antinociception in thermal nociceptive mouse model. • Compound 25 exerts less potent constipation than antinociception. • Compound 25 demonstrates less antinociceptive tolerance than morphine. [ABSTRACT FROM AUTHOR]

[Display omitted] • A HTS assay identified 1 as being able to activate MOR in combination with naloxone. • Compound 21 -naloxone did not affect activity of morphine in activation of MOR. • This phenomenon was antagonist dependent. We identified, via high-throughput screening using a FLIPR® calcium assay, compound 1 , which incorporated a dihydroquinolinyl-2-oxoethylsulfanyl-(1H,5H)-pyrimidinedione core and activated the μ-opioid receptor (MOR) in the presence of naloxone or naltrexone. A structure-activity relationship study of the analogs of 1 led to the design of compound 21 , which activated MOR in the presence of naloxone with an EC 50 of 3.3 ± 0.2 μM. MOR activation by the compound 21 -antagonist pair was antagonist-dependent. Compound 21 did not affect the potency of the orthosteric agonist, morphine, toward MOR, indicating that it affected the function of MOR antagonists rather than that of the agonists. Computer modeling of the compound 21 -MOR-naloxone complex revealed major interactions between compound 21 and MOR, including hydrogen bonding with Ser196, π-π stacking with Tyr149, and sulfur-aromatic interaction with Trp192. This study may pave the way for developing agents capable of safe and effective MOR modulation. [ABSTRACT FROM AUTHOR]

Suppression of glucose reabsorption through the inhibition of sodium-dependent glucose co-transporter 2 (SGLT2) is a promising therapeutic approach for the treatment of type 2 diabetes. To investigate the effect of C6-substitution on inhibition of SGLT2 by N -indolylglucosides, a small library of 6-triazole, 6-amide, 6-urea, and 6-thiourea N -indolylglycosides were synthesized and tested. A detailed structure–activity relationship (SAR) study culminated in the identification of 6-amide derivatives 6a and 6o as potent SGLT2 inhibitors, which were further tested for inhibitory activity against SGLT1. The data obtained indicated that 6a and 6o are mildly to moderately selective for SGLT2 over SGLT1. Both compounds were also evaluated in a urinary glucose excretion test and pharmacokinetic study; 6a was found capable of inducing urinary glucose excretion in normal SD rats. [ABSTRACT FROM AUTHOR]

Abstract: Chemotherapy-induced neutropenia often increases the likelihood of life-threatening infections. In this study, a nanoparticle (NP) system composed of chitosan and poly(γ-glutamic acid) conjugated with diethylene triamine pentaacetic acid (γPGA-DTPA) was prepared for oral delivery of granulocyte colony-stimulating factor (G-CSF), a hematopoietic growth factor. The therapeutic potential of this NP system for daily administration of G-CSF to treat neutropenia associated with chemotherapy was evaluated in a rat model. In vitro results indicate that the procedures of NP loading and release preserved the structural integrity and bioactivity of the G-CSF molecules adequately. Those results further demonstrated the enzymatic inhibition activity of γPGA-DTPA towards G-CSF against intestinal proteases. Additionally, the in vivo biodistribution study clearly identified accumulations of G-CSF in the heart, liver, bone marrow, and urinary bladder, an indication of systemic absorption of G-CSF; its relative bioavailability was approximately 13.6%. Moreover, significant glucose uptake was observed in bone marrow during G-CSF treatment, suggesting increased bone marrow metabolism and neutrophil production. Consequently, neutrophil count in the blood increased in a sustained manner; this fact may help a patient's immune system recover from the side effects of chemotherapy. [Copyright &y& Elsevier]

Abstract: This work examined the feasibility of preparing a pH-responsive nanoparticle (NP) system composed of chitosan and poly(γ-glutamic acid) conjugated with ethylene glycol tetraacetic acid (γPGA–EGTA) for oral insulin delivery in diabetic rats during an oral glucose tolerance test (OGTT). OGTT has been used largely as a model to mimic the period that comprises and follows a meal, which is often associated with postprandial hyperglycemia. Based on Förster resonance energy transfer (FRET), this work also demonstrated the ability of γPGA–EGTA to protect insulin from an intestinal proteolytic attack in living rats, owing to its ability to deprive the environmental calcium. Additionally, EGTA-conjugated NPs were effective in disrupting the epithelial tight junctions, consequently facilitating the paracellular permeation of insulin throughout the entire small intestine. Moreover, results of positron emission tomography and computer tomography demonstrated the effective absorption of the permeated insulin into the systemic circulation as well as promotion of the glucose utilization in the myocardium, and skeletal muscles of the chest wall, forelimbs and hindlimbs, resulting in a significant glucose-lowering effect. Above results indicate that as-prepared EGTA-conjugated NPs are a promising oral insulin delivery system to control postprandial hyperglycemia and thus may potentially prevent the related diabetic complications. [Copyright &y& Elsevier]

Abstract: Current insulin therapy via subcutaneous administration can lead to occasional hypoglycemia and peripheral hyperinsulinemia, due to its nonphysiological route. This study evaluates the feasibility of using bovine insulin and exendin-4 in a form of combination therapy, as orally delivered by nanoparticles composed of chitosan and poly(γ-glutamic acid) (CS/γPGA NPs), to control blood glucose levels in rats with type 2 diabetes mellitus (T2DM) undergoing the oral glucose tolerance test. Experimental results indicate that CS/γPGA NPs could enhance the intestinal paracellular permeation; consequently, the exogenous bovine insulin and exendin-4 could be delivered into the liver and pancreas, where they could elicit their glucoregulatory activities. In response to the stimulus of exogenously delivered bovine insulin and the endogenously secreted rat insulin stimulated by the ingested exendin-4, significant glucose utilizations were found in the cardiac and skeletal muscles, resulting in the glucose-lowering effect. Owing to its synergic stimulation effects, the hypoglycemic effect of oral ingestion of NPs containing bovine insulin and exendin-4 was significantly greater than that of the group solely treated with insulin NPs. Above results demonstrate that oral combination therapy with bovine insulin and exendin-4 improves the modulation of blood glucose levels in T2DM rats, making it highly promising for treating those T2DM patients not adequately controlled by the current insulin therapy. [Copyright &y& Elsevier]

Abstract: Preclinical investigations and early clinical trials suggest that FLT3 inhibitors are a viable therapy for acute myeloid leukemia. However, early clinical data have been underwhelming due to incomplete inhibition of FLT3. We have developed 3-phenyl-1H-5-pyrazolylamine as an efficient template for kinase inhibitors. Structure–activity relationships led to the discovery of sulfonamide, carbamate and urea series of FLT3 inhibitors. Previous studies showed that the sulfonamide 4 and carbamate 5 series were potent and selective FLT3 inhibitors with good in vivo efficacy. Herein, we describe the urea series, which we found to be potent inhibitors of FLT3 and VEGFR2. Some inhibited growth of FLT3-mutated MOLM-13 cells more strongly than the FLT3 inhibitors sorafenib (2) and ABT-869 (3). In preliminary in vivo toxicity studies of the four most active compounds, 10f was found to be the least toxic. A further in vivo efficacy study demonstrated that 10f achieved complete tumor regression in a higher proportion of MOLM-13 xenograft mice than 4 and 5 (70% vs 10% and 40%). These results show that compound 10f possesses improved pharmacologic and selectivity profiles and could be more effective than previously disclosed FLT3 inhibitors in the treatment of acute myeloid leukemia. [Copyright &y& Elsevier]

Abstract: Chitosan (CS) is a potential paracellular permeation enhancer for trans-epithelial drug delivery; however, its ability to enhance epithelial permeability in a pH-dependent manner remains unclear. This study was designed to explore the underlying molecular mechanisms with regard to the effect of CS on tight junction (TJ) disruption at different pH environments in Caco-2 cell monolayers. The experimental results revealed that the direct interaction between CS and integrin αVβ3 on cell surfaces has a crucial role in CS-induced TJ opening, an indication of receptor activation. The mechanism of action appeared to be the electrostatic interaction between the positively-charged CS and the negatively-charged integrin αVβ3. This electrostatic interaction led to the conformation change of integrin αVβ3 and its clustering along the cell border, F-actin reorganization, and CLDN4 down-regulation, eventually resulting in the disruption of TJs and an increase in paracellular permeability. The above observations were all in a pH-dependent manner. As pH increased, CS became less positively charged, thereby losing its capability to interact with integrin αVβ3 and failing to induce the TJ opening. These consequences might help to better understand the molecular mechanism of TJ opening mediated by CS, thereby facilitating the use of CS for trans-epithelial drug delivery. [Copyright &y& Elsevier]

Abstract: Recently, we reported a pH-responsive nanoparticle (NP) system shelled with chitosan (CS), which could effectively increase the oral absorption of insulin and produce a hypoglycemic effect, presumably due to the CS-mediated tight junction (TJ) opening. It has been often questioned whether CS can also enhance the absorption of endotoxins present in the small intestine. To address this concern, we studied the effect of CS NPs on the absorption of lipopolysaccharide (LPS), the most commonly found toxin in the gastrointestinal tract. To follow their biodistribution by the single-photon emission computed tomography/computed tomography, LPS and insulin were labeled with 99mTc-pertechnetate (99mTc-LPS) and 123iodine (123I-insulin), respectively. The 99mTc-LPS was ingested 1 h prior to the administration of the 123I-insulin-loaded NPs to mimic the physiological conditions. The confocal and TEM micrographs show that the orally administered CS NPs were able to adhere and infiltrate through the mucus layer, approach the epithelial cells and mediate to open their TJs. The radioactivity associated with LPS was mainly restricted to the gastrointestinal tract, whereas 123I-insulin started to appear in the urinary bladder at 3 h post administration. This observation indicates that the insulin-loaded in CS NPs can traverse across the intestinal epithelium and enter the systemic circulation, whereas LPS was unable to do so, probably because of the charge repulsion between the anionic LPS in the form of micelles and the negatively charged mucus layer. Our in vivo toxicity study further confirms that the enhancement of paracellular permeation by CS NPs did not promote the absorption of LPS. These results suggest that CS NPs can be used as a safe carrier for oral delivery of protein drugs. [Copyright &y& Elsevier]

Abstract: Preclinical investigations and early clinical trial studies suggest that FLT3 inhibitors offer a viable therapy for acute myeloid leukemia. However, early clinical data for direct FLT3 inhibitors provided only modest results because of the failure to fully inhibit FLT3. We have designed and synthesized a novel class of 3-phenyl-1H-5-pyrazolylamine-derived compounds as FLT3 inhibitors which exhibit potent FLT3 inhibition and high selectivity toward different receptor tyrosine kinases. The structure–activity relationships led to the discovery of two series of FLT3 inhibitors, and some potent compounds within these two series exhibited comparable potency to FLT3 inhibitors sorafenib (3) and ABT-869 (4) in both wt-FLT3 enzyme inhibition and FLT3-ITD inhibition on cell growth (MOLM-13 and MV4;11 cells). In particular, the selected compound 12a exhibited the ability to regress tumors in mouse xenograft models using MOLM-13 and MV4;11 cells. [Copyright &y& Elsevier]

Abstract: DB-67 and its lactone homolog DB-91 are derivatives of topoisomerase I inhibitor camptothecin (CPT) with silyl moiety, which may exhibit a slower inactivation process by changed kinetics of protein binding and/or hydrolysis of its lactone ring and result in increased antitumor activity and decreased toxicity. Pharmacokinetic properties and antitumor activities of the two silatecans were studied and compared. The lactone ring of DB-91 is more stable than those of all the other CPT derivatives in mouse plasma. Both silatecans were metabolized faster than CPT in mouse and human liver microsomes. Pharmacokinetic study revealed a plasma elimination half-life (t 1/2) of 33 and 94min for DB-67 and DB-91, respectively; similar systemic exposure in plasma between DB-67 and DB-91; and similar volume of distribution at the steady state between DB-67 and DB-91, approximately 15-fold smaller than that of CPT. While DB-91 showed limited activities, DB-67 exhibited activities against the growth of in vivo-like histocultured human tumors and s.c. xenografted human tumors in nude mice. In conclusion, DB-67 is more effective, compared to DB-91, against human tumor growth in in vitro, in vivo-like and in vivo systems. Further pre-clinical and clinical investigations of DB-67 are warranted. [Copyright &y& Elsevier]

Abstract: A variety of approaches have been studied in the past to overcome the problems encountered with the oral delivery of insulin, but with little success. In this study, self-assembled nanoparticles (NPs) with a pH-sensitive characteristic were prepared by mixing the anionic poly-γ-glutamic acid solution with the cationic chitosan solution in the presence of MgSO4 and sodium tripolyphosphate. The in vitro results found that the transport of insulin across Caco-2 cell monolayers by NPs appeared to be pH-dependent; with increasing pH, the amount of insulin transported decreased significantly. An in vivo toxicity study was performed to establish the safety of the prepared NPs after oral administration. Additionally, the impact of orally administered NPs on the pharmacodynamics (PD) and pharmacokinetics (PK) of insulin was evaluated in a diabetic rat model. The in vivo results indicated that the prepared NPs could effectively adhere on the mucosal surface and their constituted components were able to infiltrate into the mucosal cell membrane. The toxicity study indicated that the NPs were well tolerated even at a dose 18 times higher than that used in the PD/PK study. Oral administration of insulin-loaded NPs demonstrated a significant hypoglycemic action for at least 10h in diabetic rats and the corresponding relative bioavailability of insulin was found to be 15.1±0.9%. These findings suggest that the NPs prepared in the study are a promising vehicle for oral delivery of insulin. [Copyright &y& Elsevier]

Rare oncogenic NTRK gene fusions result in uncontrolled TRK signaling leading to various adult and pediatric solid tumors. Based on the architecture of our multi-targeted clinical candidate BPR1K871 (10), we designed and synthesized a series of quinazoline compounds as selective and orally bioavailable type II TRK inhibitors. Property-driven and lead optimization strategies informed by structure-activity relationship studies led to the identification of 39 , which showed higher (about 15-fold) selectivity for TRKA over AURA and AURB, as well as potent cellular activity (IC 50 = 56.4 nM) against the KM12 human colorectal cancer cell line. 39 also displayed good AUC and oral bioavailability (F = 27%), excellent in vivo efficacy (TGI = 64%) in a KM12 xenograft model, and broad-spectrum anti -TRK mutant potency (IC 50 = 3.74–151.4 nM), especially in the double-mutant TRKA enzymatic assays. 39 is therefore proposed for further development as a next-generation, selective, and orally-administered type II TRK inhibitor. [Display omitted] • A next-generation orally selective type II TRK inhibitor was discovered. • Twenty-nine quinazoline-based analogues were designed and synthesized. • Property-driven strategy guided lead-to-candidate optimization. • 39 is a potent TRK inhibitor against both wild-type and mutant TRKs. • 39 demonstrated antitumor effectiveness in KM-12 xenograft model. [ABSTRACT FROM AUTHOR]

Abstract: Previously, we demonstrated that 5,5-diphenyl-2-thiohydantoin (DPTH) exerts an anti-proliferation effect on subcultured human umbilical vein endothelial cells (HUVEC). In the present study, we show that 2(naphthalen-2-ylmethylsulfanyl)-5,5-diphenyl-1,5-dihydro-imidazol-4-one (DPTH-N10), a derivative compound of DPTH, exerts a 5 times stronger inhibition of [3H]thymidine incorporation into HUVEC as compared with DPTH and at very low concentrations (0–20μM) inhibited DNA synthesis and decreased cell number in cultured HUVEC in a concentration- and time-dependent manner, but not in human fibroblasts. [3H]thymidine incorporation analysis demonstrated that treatment of HUVEC with DPTH-N10 arrested the cell at the G0/G1 phase of the cell cycle. Western blot analysis revealed that the protein level of p21 in HUVEC increased after DPTH-N10 treatment. In contrast, the protein levels of p27, p53, cyclins A, D1, D3 and E, cyclin-dependent kinase (CDK)2, and CDK4 in HUVEC were not changed significantly after DPTH-N10 treatment. Immunoprecipitation showed that the formation of the CDK2–p21 complex, but not the CDK2–p27, CDK4–p21, and CDK4–p27 complex, was increased in the DPTH-N10-treated HUVEC. Kinase assay further demonstrated that CDK2, but not CDK4, kinase activity was decreased in the DPTH-N10-treated HUVEC. Pretreatment of HUVEC with a p21, but not p27, antisense oligonucleotide reversed the DPTH-N10-induced inhibition of [3H]thymidine incorporation into HUVEC. Taken together, these data suggest that DPTH-N10 inhibits HUVEC proliferation by increasing the level of p21 protein, which in turn inhibits CDK2 kinase activity, and finally interrupts the cell cycle. Capillary-like tube formation, aortic ring culture, and chick embryo chorioallantoic membrane (CAM) assays further demonstrated the anti-angiogenic effect of DPTH-N10. [Copyright &y& Elsevier]

Objective: Human ZR75-1 cells were among the first few characterized estrogen-dependent mammary gland carcinoma cell lines and had been utilized in various studies for the pro- or antitumor effect of xenoestrogens and antiestrogens. The objective of this study was to establish a breast tumor model in ZR75-1 cells bearing multimodal reporter genes to allow noninvasive imaging of tumor growth using fluorescence and nuclear imaging platforms.Methods and Results: Enhanced green fluorescent protein (eGFP) cDNA was fused at the C-terminus with herpes simplex virus type 1 thymidine kinase (HSV1-tk) to form the fusion reporter gene (eGFP-tk). In vitro proliferation, migration, and invasion assays revealed that eGFP-tk-transfected ZR75-1 cells exhibited decreased proliferation rate, migratory activity, and invasion ability compared to the wild-type cells. The functional HSV1-tk enzymatic activity in stably transfected cells were confirmed by in vitro ganciclovir (GCV) sensitivity and [123I]2-fluoro-2-deoxy-1-beta-D-arabinofuranosyl-5-iodouracil (FIAU) accumulation assays. In vivo fluorescence and nuclear imaging were performed on nude mice bearing multiple subcutaneous xenografts established from ZR75-1-eGFP-tk and wild-type cells. Optical imaging was able to detect the green fluorescence of eGFP-tk tumor. The eGFP-tk reporter gene-specific imaging was achieved by single photon emission computed tomography (SPECT) using [123I]FIAU as a radiotracer and demonstrated decreased FIAU uptake in eGFP-tk tumor by GCV treatment. Probably due to a flare reaction after GCV treatment, micro-positron emission tomography (micro-PET) imaging using 2-deoxy-2-[18F]fluoro-D-glucose (FDG) could not demonstrate decreases in FDG uptake. However, in vitro metabolic assay also revealed that eGFP-tk cells transiently increased [3H]-deoxyglucose uptake in response to GCV treatment.Conclusions: This study confirmed the usefulness of eGFP-tk in many applications by providing, in vitro and in vivo, the sensitive and reporter gene-specific imaging. ZR75-1-eGFP-tk cells that are ready to incorporate in various imaging platforms constitute a useful model in breast cancer research. [ABSTRACT FROM AUTHOR]

Abstract: Paclitaxel is widely used to treat several types of solid tumors. The commercially available paclitaxel formulation contains Cremophor/ethanol as solubilizers. This study evaluated the effects of d-α-tocopheryl polyethylene glycol 400 succinate (TPGS 400) on the oral absorption of paclitaxel in mice. Mice were given an intravenous (18mg/kg) or oral (100mg/kg) dose of paclitaxel solubilized in Cremophor/ethanol or in TPGS 400/ethanol formulations. Paclitaxel plasma concentrations and pharmacokinetic parameters were determined. The maximal plasma concentrations of paclitaxel after an oral dose were 1.77±0.17 and 3.39±0.49μg/ml for Cremophor/ethanol and TPGS 400/ethanol formulations, respectively, with a similar time at 40–47min to reach the maximal plasma concentrations. The oral bioavailability of paclitaxel in TPGS 400/ethanol (7.8%) was 3-fold higher than that in Cremophor/ethanol (2.5%). On the other hand, the plasma pharmacokinetic profiles of intravenous paclitaxel demonstrated a superimposition for the two formulations. Furthermore, TPGS 400 concentration-dependently increased the intracellular retention of Rhodamine 123 in Caco-2 cells and enhanced paclitaxel permeability in monolayer Caco-2 cultures. TPGS 400 at concentrations up to 1mM did not inhibit testosterone 6β-hydroxylase, a cytochrome P450 isozyme 3A in liver microsomes metabolizing paclitaxel. Our results indicated that TPGS 400 enhances the oral bioavailability of paclitaxel in mice and the enhancement may result from an increase in intestinal absorption of paclitaxel. [Copyright &y& Elsevier]

Abstract: A rapid and sensitive liquid chromatography–tandem mass spectrometric method (LC–MS/MS) had been developed and validated to determine the concentrations of BPR0L075 in rat plasma. After a simple protein precipitation of plasma samples by acetonitrile, BPR0L075 was analyzed on a C8 column at a flow rate of 0.5mL/min. The mobile phase consisted of a mixture of 10mM ammonium acetate containing 0.1% formic acid and acetonitrile (20:80, v/v). Both BPR0L075 (analyte) and the internal standard (BPR0L092) were determined using electro-spray ionization and the MS data acquisition was via multiple reactions monitoring (MRM) in positive scanning model. The MS/MS ion transitions monitored are m/z 342.2/195.2 and 312.5/165.2 for BPR0L075 and BPR0L092, respectively. The low limit of quantitation was 0.5ng/mL. Each plasma sample was chromatographed within 5min. The method was validated with respect to linearity, accuracy, precision, recovery, and stability. A good linear relationship was observed over the concentration range of 0.5–1000ng/mL (r >0.9994). Absolute recoveries ranged from 63.45 to 68.34% in plasma at the concentrations of 2, 40, 400, and 800ng/mL. The intra- and inter-day accuracy ranged from 92.04 to 111.80%. Intra- and inter-day relative standard deviations were 1.08–3.29% and 1.96–5.46%, respectively. This developed and validated assay method had been successfully applied to a pharmacokinetic study after intravenous injection of BPR0L075 in rats at a dose of 5mg/kg. [Copyright &y& Elsevier]

Abstract: The inhibitory effect of saturated fatty acids (SFAs): palmitic acid (PA), stearic acid (SA) and polyunsaturated fatty acids (PUFAs): linoleic acid (LA), linolenic acid (LN), arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on six human drug-metabolizing enzymes (CYP1A2, 2C9, 2C19, 2D6, 2E1 and 3A4) was studied. Supersomes from baculovirus-expressing single isoforms were used as the enzyme source. Phenacetin O-deethylation (CYP1A2), diclofenac 4-hydroxylation (CYP2C9), mephenytoin 4-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1) and midazolam 1-hydroxylation (CYP3A4) were used as the probes. Results show that all the five examined PUFAs competitively inhibited CYP2C9- and CYP2C19-catalyzed metabolic reactions, with Ki values ranging from 1.7 to 4.7 μM and 2.3 to 7.4 μM, respectively. Among these, AA, EPA and DHA tended to have greater inhibitory potencies (lower IC50 and Ki values) than LA and LN. In addition, these five PUFAs also competitively inhibited the metabolic reactions catalyzed by CYP1A2, 2E1 and 3A4 to a lesser extent (Ki values>10 μM). On the other hand, palmitic and stearic acids, the saturated fatty acids, had no inhibitory effect on the activities of six human CYP isozymes at concentrations up to 200 μM. Incubation of PUFAs with CYP2C9 or CYP2C19 in the presence of NADPH resulted in the decrease of PUFA concentrations in the incubation mixtures. These results indicate that the PUFAs are potent inhibitors as well as the substrates of CYP2C9 and CYP2C19. [Copyright &y& Elsevier]

Dipeptidyl peptidase 4 (DPP-4) is a valid molecular drug target from which its inhibitors have been developed as medicines for treating diabetes. The present study evaluated a new synthetic DPP-4-specific inhibitor of small molecule DBPR108 for pharmacology and pharmacokinetic profiles. DBPR108 of various doses was orally administered to rats, diabetic mice, and dogs and the systemic circulating DPP-4 activities in the animals were measured to demonstrate the pharmacological mechanisms of action via DPP-4 inhibition. Upon an oral administration of DBPR108, the serum active GLP-1 and insulin levels of the rats challenged with an oral glucose ingestion were measured. Oral glucose tolerance test in diet-induced obese mice was performed to examine if DBPR108 increases the glucose tolerability in animals. Orally administered DBPR108 inhibited the systemic plasma DPP-4 activities in rats, dogs and diabetic mice in a dose-dependent manner. DBPR108 caused elevated serum levels of active GLP-1 and insulin in the rats. DBPR108 dose-dependently increased the glucose tolerability in diet-induced obese (DIO) mice and, furthermore, DIO mice treated with DBPR108 (0.1 mg/kg) in combination with metformin (50 or 100 mg/kg) showed a prominently strong increase in the glucose tolerability. DBPR108 is a novel DPP-4-selective inhibitor of small molecule that demonstrated potent in vivo pharmacological effects and good safety profiles in animals. DBPR108 is now a drug candidate being further developed in the clinical studies as therapeutics for treating diabetes. [ABSTRACT FROM AUTHOR]

Reactivation of fetal hemoglobin (HbF) expression by therapeutic agents has been suggested as an alternative treatment to modulate anemia and the related symptoms of severe β-thalassemia and sickle cell disease (SCD). Hydroxyurea (HU) is the first US FDA-approved HbF inducer for treating SCD. However, approximately 25% of the patients with SCD do not respond to HU. A previous study identified TN1 (1) as a small-molecule HbF inducer. However, this study found that the poor potency and oral bioavailability of compound 1 limits the development of this inducer for clinical use. To develop drug-like compounds, further structure-activity relationship studies on the purine-based structure of 1 were conducted. Herein, we report our discovery of a more potent inducer, compound 13a , that can efficiently induce γ-globin gene expression at non-cytotoxic concentrations. The molecular mechanism of 13a, for the regulation HbF expression, was also investigated. In addition, we demonstrated that oral administration of 13a can ameliorate anemia and the related symptoms in SCD mice. The results of this study suggest that 13a can be further developed as a novel agent for treating hemoglobinopathies, such as β-thalassemia and SCD. Image 1 • Compound 13a displays potent antianemic activity. • Compound 13a overcomes resistance to hydroxyurea in primary human erythroid cells. • Compound 13a is not a histone deacetylase inhibitor. • Oral 13a treatments yield dose-dependent relief of anemia symptoms in SCD mice. [ABSTRACT FROM AUTHOR]

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC patients with overexpressed or mutated epidermal growth factor receptor (EGFR) related to disease progression are treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Acquired drug resistance after TKI treatments has been a major focus for development of NSCLC therapies. This study aimed to establish afatinib-resistant cell lines from which afatinib resistance-associated genes are identified and the underlying mechanisms of multiple-TKI resistance in NSCLC can be further investigated. Nude mice bearing subcutaneous NSCLC HCC827 tumors were administered with afatinib at different dose intensities (5–100 mg/kg). We established three HCC827 sublines resistant to afatinib (IC 50 > 1 μM) with cross-resistance to gefitinib (IC 50 > 5 μM). cDNA microarray revealed several of these sublines shared 27 up- and 13 down-regulated genes. The mRNA expression of selective novel genes — such as transmembrane 4 L six family member 19 (TM4SF19), suppressor of cytokine signaling 2 (SOCS2), and quinolinate phosphoribosyltransferase (QPRT) — are responsive to afatinib treatments only at high concentrations. Furthermore, c-MET amplification and activations of a subset of tyrosine kinase receptors were observed in all three resistant cells. PHA665752, a c-MET inhibitor, remarkably increased the sensitivity of these resistant cells to afatinib (IC 50 = 12–123 nM). We established afatinib-resistant lung cancer cell lines and here report genes associated with afatinib resistance in human NSCLC. These cell lines and the identified genes serve as useful investigational tools, prognostic biomarkers of TKI therapies, and promising molecule targets for development of human NSCLC therapeutics. [ABSTRACT FROM AUTHOR]

The therapeutic outcome of pancreatic cancer remains unsatisfactory, despite many attempts to improve it. To address this challenge, an oral drug delivery system that spontaneously initiates an effervescent reaction to form gas-bubble carriers is proposed. These carriers concurrently deliver lipophilic paclitaxel (PTX) and hydrophilic gemcitabine (GEM) in the small intestine. The bursting of the bubbles promotes the intestinal absorption of the drugs. The antitumor efficacy of this proposed oral drug delivery system is evaluated in rats with experimentally created orthotopic pancreatic tumors. The combined administration of equivalent amounts of PTX and GEM via the intravenous (i.v.) route, which is clinically used for treating pancreatic cancer, serves as a control. Following oral administration, the lipophilic PTX is initially absorbed through the intestinal lymphatic system and then enters systemic circulation, whereas the hydrophilic GEM is directly taken up into the blood circulation, ultimately accumulating in the tumorous pancreatic tissues. A pharmacokinetic study reveals that the orally delivered formulation has none of the toxic side-effects that are associated with the i.v. injected formulation; changes the pharmacokinetic profiles of the drugs; and increases the bioavailability of PTX. The oral formulation has a greater impact than the i.v. formulation on tumor-specific stromal depletion, resulting in greater inhibition of tumor growth with no evidence of metastatic spread. As well as enhancing the therapeutic efficacy, this unique approach of oral chemotherapy has potential for use on outpatients, greatly improving their quality of life. [ABSTRACT FROM AUTHOR]

Dengue virus (DENV) is a global health problem that affects approximately 3.9 billion people worldwide. Since safety concerns were raised for the only licensed vaccine, Dengvaxia, and since the present treatment is only supportive care, the development of more effective therapeutic anti-DENV agents is urgently needed. In this report, we identified a potential small-molecule inhibitor, BP34610, via cell-based high-throughput screening (HTS) of 12,000 compounds using DENV-2 reporter viruses. BP34610 reduced the virus yields of type 2 DENV-infected cells with a 50% effective concentration (EC 50) and selectivity index value of 0.48 ± 0.06 μM and 197, respectively. Without detectable cytotoxicity, the compound inhibited not only all four serotypes of DENV but also Japanese encephalitis virus (JEV). Time-of-addition experiments suggested that BP34610 may act at an early stage of DENV virus infection. Sequencing analyses of several individual clones derived from BP34610-resistant viruses revealed a consensus amino acid substitution (S397P) in the N-terminal stem region of the E protein. Introduction of S397P into the DENV reporter viruses conferred an over 14.8-fold EC 90 shift for BP34610. Importantly, the combination of BP34610 with a viral replication inhibitor, ribavirin, displayed synergistic enhancement of anti-DENV-2 activity. Our results identify an effective small-molecule inhibitor, BP34610, which likely targets the DENV E protein. BP34610 could be developed as an anti-flavivirus agent in the future. • BP34610 displayed an inhibitory effect to DNEV-1, 2, 3, 4, and JEV in vitro. • Time-of-addition experiments suggested BP34610 may affect the early stage of viral entry. • Drug resistant studies indicted BP34610 targets at DENV-2 E protein. • BP34610 displayed the synergistic effect against DENV-2 with ribavirin. [ABSTRACT FROM AUTHOR]

Morphinan antagonists, which block opioid effects at mu-opioid receptors, have been studied for their analgesic potential. Previous studies have suggested that these antagonists elicit analgesia with fewer adverse effects in the presence of the mutant mu-opioid receptor (MOR; S196A). However, introducing a mutant receptor for medical applications represents significant challenges. We hypothesize that binding a chemical compound to the MOR may elicit a comparable effect to the S196A mutation. Through high-throughput screening and structure-activity relationship studies, we identified a modulator, 4-(2-(4-fluorophenyl)-4-oxothiazolidin-3-yl)-3-methylbenzoic acid (BPRMU191), which confers agonistic properties to small-molecule morphinan antagonists, which induce G protein-dependent MOR activation. Co-application of BPRMU191 and morphinan antagonists resulted in MOR-dependent analgesia with diminished side effects, including gastrointestinal dysfunction, antinociceptive tolerance, and physical and psychological dependence. Combining BPRMU191 and morphinan antagonists could serve as a potential therapeutic strategy for severe pain with reduced adverse effects and provide an avenue for studying G protein-coupled receptor modulation., Competing Interests: Declaration of interests S.-H.U., S.-H.Y., S.-Y.L., H.H.L., and C.S. have a granted patent (no. US10544113 B2) covering BPRMU191., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aurora kinase inhibitors, such as alisertib, can destabilize MYC-family oncoproteins and have demonstrated compelling antitumor efficacy. In this study, we report 6K465, a novel pyrimidine-based Aurora A inhibitor, that reduces levels of c-MYC and N-MYC oncoproteins more potently than alisertib. In an analysis of the antiproliferative effect of 6K465, the sensitivities of small cell lung cancer (SCLC) and breast cancer cell lines to 6K465 were strongly associated with the protein levels of c-MYC and/or N-MYC. We also report DBPR728, an acyl-based prodrug of 6K465 bearing fewer hydrogen-bond donors, that exhibited 10-fold improved oral bioavailability. DBPR728 induced durable tumor regression of c-MYC- and/or N-MYC-overexpressing xenografts including SCLC, triple-negative breast cancer, hepatocellular carcinoma, and medulloblastoma using a 5-on-2-off or once-a-week dosing regimen on a 21-day cycle. A single oral dose of DBPR728 at 300 mg/kg induced c-MYC reduction and cell apoptosis in the tumor xenografts for more than 7 days. The inhibitory effect of DBPR728 at a reduced dosing frequency was attributed to its uniquely high tumor/plasma ratio (3.6-fold within 7 days) and the long tumor half-life of active moiety 6K465. Furthermore, DBPR728 was found to synergize with the mTOR inhibitor everolimus to suppress c-MYC- or N-MYC-driven SCLC. Collectively, these results suggest DBPR728 has the potential to treat cancers overexpressing c-MYC and/or N-MYC., (©2024 American Association for Cancer Research.)

The development of orally bioavailable, furanopyrimidine-based double-mutant (L858R/T790M) EGFR inhibitors is described. First, selectivity for mutant EGFR was accomplished by replacing the ( S )-2-phenylglycinol moiety of 12 with either an ethanol or an alkyl substituent. Then, the cellular potency and physicochemical properties were optimized through insights from molecular modeling studies by implanting various solubilizing groups in phenyl rings A and B. Optimized lead 52 shows 8-fold selective inhibition of H1975 (EGFR L858R/T790M overexpressing) cancer cells over A431 (EGFR WT overexpressing) cancer cells; western blot analysis further confirmed EGFR mutant-selective target modulation inside the cancer cells by 52 . Notably, 52 displayed in vivo antitumor effects in two different mouse xenograft models (BaF3 transfected with mutant EGFR and H1975 tumors) with TGI = 74.9 and 97.5% after oral administration ( F = 27%), respectively. With an extraordinary kinome selectivity ( S (10) score of 0.017), 52 undergoes detailed preclinical development.

The major challenge in COVID-19 vaccine effectiveness is immune escape by SARS-CoV-2 variants. To overcome this, an Omicron-specific messenger RNA (mRNA) vaccine was designed. The extracellular domain of the spike of the Omicron variant was fused with a modified GCN4 trimerization domain with low immunogenicity (TSomi). After immunization with TSomi mRNA in hamsters, animals were challenged with SARS-CoV-2 virus. The raised nonneutralizing antibodies or cytokine secretion responses can recognize both Wuhan S and Omicron S. However, the raised antibodies neutralized SARS-CoV-2 Omicron virus infection but failed to generate Wuhan virus neutralizing antibodies. Surprisingly, TSomi mRNA immunization protected animals from Wuhan virus challenge. These data indicated that non-neutralizing antibodies or cellular immunity may play a more important role in vaccine-induced protection than previously believed. Next-generation COVID-19 vaccines using the Omicron S antigen may provide sufficient protection against ancestral or current SARS-CoV-2 variants., (© 2022 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC.)

(1) Destabilization of microtubule dynamics is a primary strategy to inhibit fast growing tumor cells. The low cytotoxic derivative of microtubule inhibitor D-24851, named BPR0C261 exhibits antitumor activity via oral administration. In this study, we investigated if BPR0C261 could modulate the radiation response of human non-small cell lung cancer (NSCLC) cells with or without p53 expression. (2) Different doses of BPR0C261 was used to treat human NSCLC A549 (p53+/+) cells and H1299 (p53-/-) cells. The cytotoxicity, radiosensitivity, cell cycle distribution, DNA damage, and protein expression were evaluated using an MTT assay, a colony formation assay, flow cytometry, a comet assay, and an immunoblotting analysis, respectively. (3) BPR0C261 showed a dose-dependent cytotoxicity on A549 cells and H1299 cells with IC 50 at 0.38 μM and 0.86 μM, respectively. BPR0C261 also induced maximum G 2 /M phase arrest and apoptosis in both cell lines after 24 h of treatment with a dose-dependent manner. The colony formation analysis demonstrated that a combination of low concentration of BPR0C261 and X-rays caused a synergistic radiosensitizing effect on NSCLC cells. Additionally, we found that a low concentration of BPR0C261 was sufficient to induce DNA damage in these cells, and it increased the level of DNA damage induced by a fractionation radiation dose (2 Gy) of conventional radiotherapy. Furthermore, the p53 protein level of A549 cell line was upregulated by BPR0C261. On the other hand, the expression of PTEN tumor suppressor was found to be upregulated in H1299 cells but not in A549 cells under the same treatment. Although radiation could not induce PTEN in H1299 cells, a combination of low concentration of BPR0C261 and radiation could reverse this situation. (4) BPR0C261 exhibits specific anticancer effects on NSCLC cells by the enhancement of DNA damage and radiosensitivity with p53-dependent and p53-independent/PTEN-dependent manners. The combination of radiation and BPR0C261 may provide an important strategy for the improvement of radiotherapeutic treatment.

Ligand-targeting drug delivery systems have made significant strides for disease treatments with numerous clinical approvals in this era of precision medicine. Herein, we report a class of small molecule-based immune checkpoint-targeting maytansinoid conjugates. From the ligand targeting ability, pharmacokinetics profiling, in vivo anti-pancreatic cancer, triple-negative breast cancer, and sorafenib-resistant liver cancer efficacies with quantitative mRNA analysis of treated-tumor tissues, we demonstrated that conjugate 40a not only induced lasting regression of tumor growth, but it also rejuvenated the once immunosuppressive tumor microenvironment to an "inflamed hot tumor" with significant elevation of gene expressions that were not accessible in the vehicle-treated tumor. In turn, the immune checkpoint-targeting small molecule drug conjugate from this work represents a new pharmacodelivery strategy that can be expanded with combination therapy with existing immune-oncology treatment options.