Association between hemorrhage and direct oral anticoagulants in combination with verapamil: Analysis of Japanese Adverse Drug Event Report database and electronic medical record data.

OBJECTIVE: The aim of this study was to investigate the risk of hemorrhage in concomitant therapy with direct oral anticoagulants (DOACs) and class IV antiarrhythmic drugs. MATERIALS AND METHODS: First, disproportionality analysis (DPA) was performed using the Japanese Adverse Drug Event Report (JADER) database to investigate the risk of hemorrhage with DOACs. Second, a cohort study was performed using electronic medical record data to confirm the results of the JADER analysis. RESULTS: In the JADER analysis, hemorrhage was significantly associated with treatment with edoxaban and verapamil (reporting odds ratio = 1.66; 95% confidence interval (CI) = 1.04 - 2.67). The cohort study revealed that hemorrhage incidence significantly differed between the verapamil-treated group and the bepridil-treated group, with a higher risk for hemorrhage in the verapamil group (log-rank test: p < 0.001). The multivariate Cox proportional hazards model also showed that the verapamil and DOAC combination was significantly associated with hemorrhage events compared with the bepridil and DOAC combination (hazard ratio (HR): 2.87, 95% CI: 1.17 - 7.07, p = 0.022). Furthermore, creatinine clearance (Ccr) ≥ 50 mL/min was significantly associated with hemorrhage events (HR: 2.72, 95% CI: 1.03 - 7.18, p = 0.043), and verapamil was significantly associated with hemorrhage in patients with Ccr ≥ 50 mL/min (HR: 3.58, 95% CI: 1.36 - 9.39, p = 0.010) but not in patients with Ccr < 50 mL/min. CONCLUSION: Verapamil increases the risk of hemorrhage in patients on DOACs. Dose adjustment of DOACs based on renal function may prevent hemorrhage when verapamil is concomitantly administered.

Effects of bepridil on early cardiac development of zebrafish.

Bepridil is a commonly used medication for arrhythmia and heart failure. It primarily exerts hemodynamic effects by inhibiting Na+/K+ movement and regulating the Na+/Ca2+ exchange. In comparison to other Ca2+ inhibitors, bepridil has a long half-life and a complex pharmacology. Additionally, it is widely used in antiviral research and the treatment of various diseases. However, the toxicity of this compound and its other possible effects on embryonic development are unknown. In this study, we investigated the toxicity of bepridil on rat myocardial H9c2 cells. After treatment with bepridil, the cells became overloaded with Ca2+ and entered a state of cytoplasmic vacuolization and nuclear abnormality. Bepridil treatment resulted in several morphological abnormalities in zebrafish embryo models, including pericardium enlargement, yolk sac swelling, and growth stunting. The hemodynamic effects on fetal development resulted in abnormal cardiovascular circulation and myocardial weakness. After inhibiting the Ca2+ transmembrane, the liver of zebrafish larvae also displayed an ectopic and deficient spatial location. Additionally, the results of the RNA-seq analysis revealed the detailed gene expression profiles and metabolic responses to bepridil treatment in zebrafish embryonic development. Taken together, our study provides an important evaluation of antiarrhythmic agents for clinical use in prenatal heart patients.

Proarrhythmia Risk Assessment Using Electro-Mechanical Window in Human iPS Cell-Derived Cardiomyocytes.

Evaluation of drug-induced cardiotoxicity is still challenging to avoid adverse effects, such as torsade de pointes (TdP), in non-clinical and clinical studies. Numerous studies have suggested that human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a useful platform for detecting drug-induced TdP risks. Comprehensive in vitro Proarrhythmia Assay (CiPA) validation study suggested that hiPSC-CMs can assess clinical TdP risk more accurately than the human ether-a-go-go-related assay and QT interval prolongation. However, there were still some outliers, such as bepridil, mexiletine, and ranolazine, among the CiPA 28 compounds in the CiPA international multi-site study using hiPSC-CMs. In this study, we assessed the effects of the positive compound dofetilide, the negative compound aspirin, and several CiPA compounds (bepridil, mexiletine, and ranolazine) on the electromechanical window (E-M window), which were evaluated using multi-electrode array assay and motion analysis, in hiPSC-CMs. Similar to previous in vivo studies, dofetilide, which has a high TdP risk, decreased the E-M window in hiPSC-CMs, whereas aspirin, which has a low TdP risk, had little effect. Bepridil, classified in the high TdP-risk group in CiPA, decreased the E-M window in hiPSC-CMs, whereas ranolazine and mexiletine, which are classified in the low TdP-risk group in CiPA, slightly decreased or had little effect on the E-M window of hiPSC-CMs. Thus, the E-M window in hiPSC-CMs can be used to classify drugs into high and low TdP risk.

High throughput measurement of hERG drug block kinetics using the CiPA dynamic protocol.

The Comprehensive in vitro Proarrhythmic Assay (CiPA) has promoted use of in silico models of drug effects on cardiac repolarization to improve proarrhythmic risk prediction. These models contain a pharmacodynamic component describing drug binding to hERG channels that required in vitro data for kinetics of block, in addition to potency, to constrain them. To date, development and validation has been undertaken using data from manual patch-clamp. The application of this approach at scale requires the development of a high-throughput, automated patch-clamp (APC) implementation. Here, we present a comprehensive analysis of the implementation of the Milnes, or CiPA dynamic protocol, on an APC platform, including quality control and data analysis. Kinetics and potency of block were assessed for bepridil, cisapride, terfenadine and verapamil with data retention/QC pass rate of 21.8% overall, or as high as 50.4% when only appropriate sweep lengths were considered for drugs with faster kinetics. The variability in IC50 and kinetics between manual and APC was comparable to that seen between sites/platforms in previous APC studies of potency. Whilst the experimental success is less than observed in screens of potency alone, it is still significantly greater than manual patch. With the modifications to protocol design, including sweep length, number of repetitions, and leak correction recommended in this study, this protocol can be applied on APC to acquire data comparable to manual patch clamp.

Different voltage dependence of ICaL blockade in nonselective IKr blockers causes their opposite effects on early afterdepolarization in drug-induced arrhythmia.

Several false-positive results in the human ether-à-gogo-related gene test suggest that blockers of the rapid component of delayed rectifier K+ current (IKr) do not necessarily produce drug-induced arrhythmias. Specifically, the occurrence of early afterdepolarization (EAD) differs among IKr blockers, even if the prolonged action potential duration is in the same range. To predict EAD in drug-induced arrhythmias, we proposed a prediction method based on the mechanisms underlying the difference in frequency of EAD among nonselective IKr blockers. The mechanisms were elucidated by examining how different blockade kinetics of L-type Ca2+ current (ICaL) affect the frequency of EAD, using mathematical models of human ventricular myocytes. Addition of voltage-independent ICaL blockade resulted in the suppression of EAD. However, when voltage-dependent ICaL blockade kinetics of amiodarone, bepridil, and terfenadine were incorporated into ICaL in the model, bepridil and terfenadine induced EAD more than the voltage-independent ICaL blockade, while amiodarone suppressed EAD more effectively. Opposite effects were accounted for by the difference in ICaL blockade at negatively polarized potential. EAD occurrence was found to be associated with ICaL blockade measured at -20 mV. These results suggest that voltage dependence of ICaL blockade may be useful in predicting the different risks of nonselective IKr blockers.

Effect of preprocedural pharmacologic cardioversion on pulmonary vein isolation in patients with persistent atrial fibrillation.

BACKGROUND: The optimal strategy for catheter ablation of persistent atrial fibrillation (PeAF) remains unknown. A preprocedural additive treatment for patients undergoing pulmonary vein isolation (PVI) alone to optimize catheter ablation should be investigated. OBJECTIVE: The purpose of this study was to determine whether pharmacologic cardioversion with a fixed low-dose antiarrhythmic drug (AAD) before ablation could stratify the long-term outcome of a PVI-alone strategy. METHODS: We conducted a prospective cohort study of PeAF patients who underwent PVI using contact force-sensing catheters. No substrate modification was performed. Fixed low-dose bepridil was administered before ablation for cardioversion and patients were classified into 2 groups based on obtaining sinus rhythm (SR). The rate of recurrence of atrial fibrillation (AF) and/or atrial tachycardia (AT) within 36 months was compared between the 2 groups. RESULTS: Among the 303 PeAF patients who received the AAD, 102 returned to SR (SR group), and the other 201 had persistence of AF (non-SR group). AF persistence duration at baseline and during bepridil administration was similar between the 2 groups. The SR group had a significantly lower 36-month AF/AT recurrence rate than the non-SR group (17 [22.2%] vs 55 [34.0%], log-rank P = .022). AT-type recurrence was observed in 16 patients (2 [3.3%] in the SR group vs 14 [8.9%] in the non-SR group; log-rank P = .051). Nonresponse to AAD was an independent predictor of AF/AT recurrence after adjusting for other risk factors (hazard ratio 1.34; 95% confidence interval 1.01-1.77; P = .040). CONCLUSION: Preprocedural pharmacologic cardioversion could be a useful determinant for patients with treatable PeAF by PVI alone.

Effects of Bepridil and Pimozide, Existing Medicines Capable of Blocking T-Type Ca2+ Channels, on Visceral Pain in Mice.

T-Type Ca2+ channels (T-channels), particularly Cav3.2, are now considered as therapeutic targets for treatment of intractable pain including visceral pain. Among existing medicines, bepridil, a multi-channel blocker, used for treatment of arrhythmia and angina, and pimozide, a dopamine D2 receptor antagonist, known as a typical antipsychotic, have potent T-channel blocking activity. We thus tested whether bepridil and pimozide could suppress visceral pain in mice. Colonic and bladder pain were induced by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) and systemic administration of cyclophosphamide (CPA), respectively. Referred hyperalgesia was assessed by von Frey test, and colonic hypersensitivity to distension by a volume load with intracolonic water injection and spontaneous bladder pain were evaluated by observing nociceptive behaviors in conscious mice. The mice exhibited referred hyperalgesia and colonic hypersensitivity to distension on day 6 after TNBS treatment. Systemic administration of bepridil at 10-20 mg/kg or pimozide at 0.1-0.5 mg/kg strongly reduced the referred hyperalgesia on the TNBS-induced referred hyperalgesia and colonic hypersensitivity to distension. CPA treatment caused bladder pain-like nociceptive behavior and referred hyperalgesia, which were reversed by bepridil at 10-20 mg/kg or pimozide at 0.5-1 mg/kg. Our data thus suggest that bepridil and pimozide, existing medicines capable of blocking T-channels, are useful for treatment of colonic and bladder pain, and serve as seeds for the development of new medicines for visceral pain treatment.

Bepridil is potent against SARS-CoV-2 in vitro.

Guided by a computational docking analysis, about 30 Food and Drug Administration/European Medicines Agency (FDA/EMA)-approved small-molecule medicines were characterized on their inhibition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro). Of these small molecules tested, six displayed a concentration that inhibits response by 50% (IC50) value below 100 µM in inhibiting Mpro, and, importantly, three, that is, pimozide, ebastine, and bepridil, are basic molecules that potentiate dual functions by both raising endosomal pH to interfere with SARS-CoV-2 entry into the human cell host and inhibiting Mpro in infected cells. A live virus-based modified microneutralization assay revealed that bepridil possesses significant anti-SARS-CoV-2 activity in both Vero E6 and A459/ACE2 cells in a dose-dependent manner with low micromolar effective concentration, 50% (EC50) values. Therefore, the current study urges serious considerations of using bepridil in COVID-19 clinical tests.

Torsadogenic Action of Cisapride, dl-Sotalol, Bepridil, and Verapamil Analyzed by the Chronic Atrioventricular Block Cynomolgus Monkeys: Comparison With That Reported in the CiPA In Silico Mechanistic Model.

In order to bridge the gap of information between the in silico model and human subjects, we evaluated torsadogenic risk of cisapride, dl-sotalol, bepridil and verapamil selected from 12 training compounds in the comprehensive in vitro proarrhythmia assay using the chronic atrioventricular block monkeys. Cisapride (0, 1, and 5 mg/kg, n = 5 for each dose), dl-sotalol (0, 1, 3, and 10 mg/kg, n = 5 for each dose), bepridil (0, 10, and 100 mg/kg, n = 4 for each dose), verapamil (0, 1.5, 15, and 75 mg/kg, n = 4 for each dose) were orally administered to the monkeys in conscious state. Five mg/kg of cisapride, 1, 3, and 10 mg/kg of dl-sotalol and 100 mg/kg of bepridil prolonged ΔΔQTcF, which was not observed by verapamil. Torsade de pointes was induced by 5 mg/kg of cisapride in 2 out of 5 animals, by 10 mg/kg of dl-sotalol in 5 out of 5 and by 100 mg/kg of bepridil in 2 out of 4, which was not induced by verapamil. These torsadogenic doses were normalized by their maximum clinical daily ones to estimate torsadogenic risk. The order of risk was dl-sotalol >bepridil ≥cisapride >verapamil in our study. Since the order was bepridil ≥dl-sotalol >cisapride >verapamil in comprehensive in vitro proarrhythmia assay (CiPA) in silico mechanistic model validation, sympathetic regulation on the heart may play a pivotal role in the onset of torsade de pointes in vivo.

Relationship between serum bepridil concentration and corrected QT interval.

OBJECTIVE: Bepridil prolongs the QT interval and can induce torsade de pointes. Although increased bepridil concentration may be a primary cause of prolonged QT, the relationship between serum bepridil concentration and prolonged QT remains unclear. We investigated the relationship between serum bepridil concentration and the corrected QT (QTc) interval in patients treated with bepridil. MATERIALS AND METHODS: A retrospective study was performed at the National Cerebral and Cardiovascular Center in Japan. Patients with atrial fibrillation who were treated with bepridil from January 2014 to December 2015 were enrolled in the study. Serum bepridil concentrations and electrocardiogram data collected more than 21 days after the initiation of bepridil were used for analysis. RESULTS: A total of 60 patients were included in this study. There was a significant difference in mean QTc interval before and after initiation of bepridil (p < 0.0001). A significant relationship was observed between bepridil dose (p = 0.014) or serum bepridil concentration (p < 0.001) and QTc interval. Additionally, a significant relationship was observed between serum bepridil concentration and ΔQTc (p = 0.034). In the study, 4 patients developed QTc prolongation ≥ 500 ms after the initiation of bepridil. Serum bepridil concentration in this group was significantly higher compared with the group that did not display prolonged QTc (973 ± 651 vs. 526 ± 310 ng/mL, p = 0.01). CONCLUSION: This study revealed that the QTc interval was significantly associated with serum bepridil concentration. Serum bepridil concentration beyond a therapeutic range may be a critical risk factor for developing QTc prolongation.

Characterization of microminipig as a laboratory animal for pharmacological study by analyzing bepridil-induced cardiovascular responses.

Since microminipig is becoming attractive model for various cardiac electropharmacological applications, which may meet consideration of 3Rs. We characterized microminipigs by analyzing how multi-ionic channel inhibitor bepridil may affect their in situ hearts in comparison with dogs. Bepridil in doses of 0.3 and 3.0 mg/kg were intravenously administered over 10 min under halothane anesthesia (n = 4). Microminipigs may be less sensitive for ICaT inhibition of bepridil, whereas they are more responsive to INa, IKr and IKs suppression than dogs. This information would help predict cardiovascular effects of a drug in patients with the remodeled hearts having similar electrophysiological profile to microminipigs.

Bepridil Inhibits Premature Ventricular Complexes Induced by Cardio-Sympathetic Nerve Stimulation in a Canine Experimental Model.

Sympathetic nerve activity has arrhythmogenic potential for ventricular arrhythmias associated with structural heart diseases. However, a sufficient amount of beta-blockers occasionally cannot be prescribed in some patients.An experimental study was performed to clarify the therapeutic effects of bepridil, a multiple ionic current inhibitor that does not affect beta-adrenergic receptors, for premature beats occurring during enhanced sympathetic nerve activity. Cardio-sympathetic nerve activity was augmented via stellate-ganglion (SG) stimulation in a canine model (n = 8), and the arrhythmogenic potential and anti-arrhythmic effects of bepridil (2 and 4 mg/kg intravenously) were assessed. For safe use, vagal-stimulation-induced slow HR and programmed electrical stimulation were applied to evaluate possible pro-arrhythmic effects of the drug. Heart rate variability (HRV) indexes were used to estimate cardio-autonomic nerve activity.Either side of the SG-stimulation increased BP and HR. Premature beats were induced in 10/16 SG-stimulations and it was more frequent in left (8/8) rather than right stimulation (2/8). Following 2 mg/kg drug administration, premature beats were still inducible in 8/16 stimulations (7/8 in left and 1/8 in right), but burden of the premature beats decreased from 87.1 ± 46.8 to 62.1 ± 42.6 beats. After 4 mg/kg administration, premature beats were inducible in one SG-stimulation. Proarrhythmic effects were not observed in all experiments. Steady-state HRV indexes and percent increases in SG-stimulation-induced BP-elevation and HR-acceleration were similar among the 3 periods (before, 2 and 4 mg/kg of the drug).Bepridil may be an option for ventricular arrhythmias developed during enhanced cardio-sympathetic nerve activity with minimal effect on autonomic nerve responses.

Efficacy of hybrid therapy using prior administration of bepridil hydrochloride and cryoballoon ablation in patients with persistent atrial fibrillation.

BACKGROUND: Rhythm control before catheter ablation for persistent atrial fibrillation (PeAF) can improve clinical outcomes. We sought to investigate the efficacy of pretreatment with bepridil prior to cryoballoon ablation (CBA) with respect to clinical outcomes in patients with PeAF. METHODS: We retrospectively analyzed 65 consecutive patients with PeAF who underwent CBA following pretreatment with bepridil hydrochloride (bepridil). Electrical cardioversion was additionally performed in cases involving failure of pharmacological sinus restoration before CBA. The primary endpoint was survival free from atrial tachyarrhythmia at the one-year follow-up, and the secondary endpoints were changes in P-wave morphology and left atrium diameter (LAD) before CBA. RESULTS: At the one-year follow-up, 51 patients (78.5%) achieved the primary endpoint (non-recurrence group). Compared to the P-wave duration (Pdur) and dispersion at the time of sinus restoration, they significantly shortened at the time of CBA in the non-recurrence group, while they did not change in the recurrence group. There were no changes in LAD in both groups. Multivariate analysis revealed that refractoriness of bepridil (p = 0.03, odds ratio = 4.72, 95% confidence interval = 1.18-18.92), and longer Pdur at admission for CBA (p = 0.003, odds ratio = 1.08, 95% confidence interval = 1.01-1.14) were independent predictors of recurrence. CONCLUSIONS: Rhythm control with bepridil induced electrical reverse remodeling; bepridil may improve clinical outcomes after CBA.

Electropharmacological profile of an atrial-selective sodium channel blocker acehytisine assessed in the isoflurane-anesthetized guinea-pig model.

Experimental evidence regarding the risk of proarrhythmic potential of acehytisine is limited. We assessed its electropharmacological effect together with proarrhythmic potential at intravenous doses of 4 and 10 mg/kg (n = 6) using isoflurane-anesthetized guinea pigs in comparison with that of bepridil at 1 and 3 mg/kg, intravenously (n = 6). Acehytisine at therapeutic dose (4 mg/kg) decreased the heart rate, prolonged P wave duration, QRS width, QT interval, QTc, MAP90(sinus), MAP90(CL300) and MAP90(CL250). At supratherapeutic dose (10 mg/kg), it prolonged the PR interval besides enhancing the changes induced by the therapeutic dose. Quantitative assessment showed that peak changes in P wave duration by acehytisine at 10 mg/kg were 1.7 times longer than bepridil, and in MAP90(sinus), MAP90(CL300) and MAP90(CL250) by acehytisine were 1.9, 1.5 and 1.5 times shorter than bepridil, respectively. Importantly, qualitative assessment indicated that bepridil increased beat-to-beat variability and J-Tpeakc in a dose-related manner, confirming a higher proarrhythmic risk, whereas such dose-related responses were not observed in acehytisine, suggesting a lower proarrhythmic risk. These results suggest that acehytisine exhibits favorable pharmacological characters, i.e. potent atrial inhibition and lower proarrhythmic toxicity compared with bepridil, being a promising candidate for the treatment of paroxysmal supraventricular tachycardia.

A simple and sensitive LC-MS/MS method for quantification of Bepridil in rat plasma and its application to pharmacokinetic studies.

Bepridil is potent inhibitor of Na+, K+ and Ca+ channel in cardiomyocytes. It has demonstrated strong antianginal effect with type I antiarrhythmic and with minimum antihypertensive therapeutic effect. Till date, a specific LC-MS/MS method to quantify Bepridil concentrations in biological matrix have not been reported yet. In current study, a highly sensitive, specific and simple LC-MS/MS method for quantification of antianginal drug Bepridil in rat plasma is presented. The LC-MS/MS method was validated in terms of selectivity, specificity, sensitivity, accuracy and precision, matrix effect, extraction recovery and stability as per USFDA's bioanalytical method validation guideline. The validated assay was applied for quantification of Bepridil from pharmacokinetic study in rats following oral and intravenous administration. The lower limit of quantification (LLOQ) of Bepridil was 1 ng/mL. The calibration curve ranges from 1 ng/mL to 1000 ng/mL with desirable linearity and r2 > 0.99. The method exhibited 10-fold dilution integrity. The intra-day and inter-day accuracy were within 101.32-96.80% and 102.87-95.35% with coefficient of variation 10.11-2.89% and 10.45-3.97% respectively. No significant interference observed by endogenous peak at the retention time of Bepridil and IS. The assay was free from any matrix effect, precise recovery across the calibration curve range and samples were stable under all experimental conditions. The validated assay was successfully applied to analyze plasma samples of pharmacokinetic study in rat to determine concentrations of Bepridil. In summary, a novel method for analyzing Bepridil in rat plasma has been successfully validated and is now being utilized for quantification of Bepridil from pre-clinical studies.

Blockade of the forward Na+ /Ca2+ exchanger suppresses the growth of glioblastoma cells through Ca2+ -mediated cell death.

BACKGROUND AND PURPOSE: The Na+ /Ca2+ exchanger (NCX) working in either forward or reverse mode participates in maintaining intracellular Ca2+ ([Ca2+ ]i ) homeostasis, which is essential for determining cell fate. Previously, numerous blockers targeting reverse or forward NCX have been developed and studied in ischaemic tissue injury but barely examined in glioblastoma for the purpose of anti-tumour therapy. We assessed the effect of NCX blockers on glioblastoma growth and whether NCX can become a therapeutic target. EXPERIMENTAL APPROACH: Patch-clamp recording, Ca2+ imaging, flow cytometry, and Western blot were used to study the effects of specific and non-specific NCX blockers on cultured glioblastoma cells. In vivo bioluminescent imaging was used to measure effects on grafted glioblastoma. KEY RESULTS: Selectively blocking the reverse NCX with SEA0400, SN-6, and YM-244769 did not affect tumour cell viability. Blocking the forward NCX with bepridil, CB-DMB, or KB-R7943 elevated [Ca2+ ]i and killed glioblastoma cells. Bepridil and CB-DMB caused Ca2+ -dependent cell cycle arrest together with apoptosis, which were all attenuated by a Ca2+ chelator BAPTA-AM. Systemic administration of bepridil inhibited growth of brain-grafted glioblastoma. Bepridil did not appear to have a cytotoxic effect on human astrocytes, which have higher functional expression of NCX than glioblastoma cells. CONCLUSIONS AND IMPLICATIONS: Low expression of the NCX makes glioblastoma cells sensitive to disturbance of [Ca2+ ]i . Interventions designed to block the forward NCX can cause Ca2+ -mediated injury to glioblastoma thus having therapeutic potential. Bepridil could be a lead compound for developing new anti-tumour drugs.

Novel drug candidate for the treatment of several soft­tissue sarcoma histologic subtypes: A computational method using survival­associated gene signatures for drug repurposing.

Systemic treatment options for soft tissue sarcomas (STSs) have remained unchanged despite the need for novel drug candidates to improve STS outcomes. Drug repurposing involves the application of clinical drugs to different diseases, reducing development time, and cost. It has also become a fast and effective way to identify drug candidates. The present study used a computational method to screen three drug­gene interaction databases for novel drug candidates for the treatment of several common STS histologic subtypes through drug repurposing. STS survival­associated genes were generated by conducting a univariate cox regression analysis using The Cancer Genome Atlas survival data. These genes were then applied to three databases (the Connectivity Map, the Drug Gene Interaction Database and the L1000 Fireworks Display) to identify drug candidates for STS treatment. Additionally, pathway analysis and molecular docking were conducted to evaluate the molecular mechanisms of the candidate drug. Bepridil was identified as a potential candidate for several STS histologic subtype treatments by overlapping the screening results from three drug­gene interaction databases. The pathway analysis with the Kyoto Encyclopedia of Genes and Genomes predicted that Bepridil may target CRK, fibroblast growth factor receptor 4 (FGFR4), laminin subunit ß1 (LAMB1), phosphoinositide­3­kinase regulatory subunit 2 (PIK3R2), WNT5A, cluster of differentiation 47 (CD47), elastase, neutrophil expressed (ELANE), 15­hydroxyprostaglandin dehydrogenase (HPGD) and protein kinase cß (PRKCB) to suppress STS development. Further molecular docking simulation suggested a relatively stable binding selectivity between Bepridil and eight proteins (CRK, FGFR4, LAMB1, PIK3R2, CD47, ELANE, HPGD, and PRKCB). In conclusion, a computational method was used to identify Bepridil as a potential candidate for the treatment of several common STS histologic subtypes. Experimental validation of these in silico results is necessary before clinical translation can occur.

Drug repositioning in head and neck squamous cell carcinoma: An integrated pathway analysis based on connectivity map and differential gene expression.

The severe damage to health and social burden caused by head and neck squamous cell carcinoma (HNSCC) generated an urgent need to develop novel anti-cancer therapy. Currently, drug repositioning has risen in responses to the proper time as an efficient approach to invention of new anti-cancer therapies. In the present study, we aimed to screen candidate drugs for HNSCC by integrating HNSCC-related pathways from differentially expressed genes (DEGs) and drug-affected pathways from connectivity map (CMAP). We also endeavored to unveil the molecular mechanism of HNSCC through creating drug-target network and protein-to-protein (PPI) network of component DEGs in key overlapping pathways. As a result, a total of 401 DEGs were obtained from TCGA and GTEx mRNA-seq data. Taking the intersection part of 27 HNSCC-related Kyoto Encyclopedia of Genes and Genomes pathways and 33 drug-affected pathways, we retained 22 candidate drugs corresponding to two key pathways (cell cycle and p53 signaling pathways) of the five overlapping pathways. Two of the hub genes (PCNA and CCND1) identified from the PPI network of component DEGs in cell cycle and p53 signaling pathways were defined as the critical targets of candidate drugs with increased protein expression in HNSCC tissues, which was reported by the human protein atlas (HPA) database and cBioPortal. Finally, we validated via molecular docking analysis that two drugs with unknown effects in HNSCC: MG-262 and bepridil might perturb the development of HNSCC through targeting PCNA. These candidate drugs possessed broad application prospect as medication for HNSCC.

Identification of Novel Inhibitors of Auxin-Induced Ca2+ Signaling via a Plant-Based Chemical Screen.

Many signal perception mechanisms are connected to Ca2+-based second messenger signaling to modulate specific cellular responses. The well-characterized plant hormone auxin elicits a very rapid Ca2+ signal. However, the cellular targets of auxin-induced Ca2+ are largely unknown. Here, we screened a biologically annotated chemical library for inhibitors of auxin-induced Ca2+ entry in plant cell suspensions to better understand the molecular mechanism of auxin-induced Ca2+ and to explore the physiological relevance of Ca2+ in auxin signal transduction. Using this approach, we defined a set of diverse, small molecules that interfere with auxin-induced Ca2+ entry. Based on annotated biological activities of the hit molecules, we found that auxin-induced Ca2+ signaling is, among others, highly sensitive to disruption of membrane proton gradients and the mammalian Ca2+ channel inhibitor bepridil. Whereas protonophores nonselectively inhibited auxin-induced and osmotic stress-induced Ca2+ signals, bepridil specifically inhibited auxin-induced Ca2+ We found evidence that bepridil severely alters vacuolar morphology and antagonized auxin-induced vacuolar remodeling. Further exploration of this plant-tailored collection of inhibitors will lead to a better understanding of auxin-induced Ca2+ entry and its relevance for auxin responses.