Journal of Pharmacology and Experimental Therapeutics最新文献

ICH established S7B and E14 guidelines in 2005 to prevent drug-induced torsade de pointes (TdP), effectively preventing the development of high-risk drugs. However, those guidelines unfortunately hampered the development of some potentially valuable drug candidates despite not being proven to be proarrhythmic. In response, Comprehensive In Vitro Proarrhythmia Assay (CiPA) and Exposure-Response Modeling were proposed in 2013 to reinforce proarrhythmic risk assessment. In 2022, ICH released E14/S7B Q&As (Stage 1), emphasizing a "double negative" nonclinical scenario for low-risk compounds. For "non-double negative" compounds, new Q&As are expected to be enacted as Stage 2 shortly, in which more detailed recommendations for proarrhythmia models and proarrhythmic surrogate markers will be provided. This review details the onset mechanisms of drug-induced TdP, including I_Kr inhibition, pharmacokinetic factors, autonomic regulation and reduced repolarization reserve. It also explores the utility of proarrhythmic surrogate markers (J-T_peak, T_peak-T_end and terminal repolarization period) besides QT interval. Finally, it presents various in silico, in vitro, ex vivo and in vivo models for proarrhythmic risk prediction, such as CiPA in silico model, iPS cell-derived cardiomyocyte sheet, Langendorff perfused heart preparation, chronic atrioventricular block animals (dogs, monkeys, pigs and rabbits), acute atrioventricular block rabbits, methoxamine-sensitized rabbits, and genetically engineered rabbits for specific long QT syndromes. Those models along with the surrogate markers can play important roles in quantifying TdP risk of new compounds, impacting late-phase clinical design and regulatory decision-making, and preventing adverse events on post-marketing clinical use. Significance Statement Since ICH S7B/E14 guidelines unfortunately hampered the development of some potentially valuable compounds with unproven proarrhythmic risk, Comprehensive In Vitro Proarrhythmia Assay and Exposure-Response Modeling were proposed in 2013 to reinforce proarrhythmic risk assessment of new compounds. In 2022, ICH released Q&As (Stage 1) emphasizing "double negative" nonclinical scenario for low-risk compounds, and new Q&As (Stage 2) for "non-double negative" compounds are expected. This review delves into proarrhythmic mechanisms with surrogate markers, and explores various models for proarrhythmic risk prediction.

XELOX therapy, which comprises capecitabine and oxaliplatin, is the standard first-line chemotherapeutic regimen for colorectal cancer. However, its myelosuppressive effects pose challenges for its clinical management. Mathematical modeling combining pharmacokinetics (PK) and toxicodynamics (TD) is a promising approach for optimizing dosing strategies and reducing toxicity. This study aimed to develop a translational PK-TD model using rat data to inform dosing strategies and TD implications in humans. The rats were administered capecitabine, oxaliplatin, or XELOX combination regimen, and PK and TD data were collected. PK parameters were analyzed using sequential compartment analysis, whereas TD responses were assessed using Friberg's semiphysiological model. A toxicity intensity-based nomogram recommends optimal dosing strategies. Translational modeling techniques using the hybrid PK-TD model were employed to predict clinical responses. The PK-TD model successfully predicted the time-course profiles of hematological responses in rats following monotherapy and XELOX combination treatment. Interactive effects on lymphocytopenia were identified with the coadministration of capecitabine and oxaliplatin. A model-based recommended combination of the dose reduction rate for escaping severe lymphocytopenia was proposed as 40% and 60% doses of capecitabine and oxaliplatin, respectively. The current translational model techniques successfully simulated the time-course profiles of blood cell counts with confidence intervals in patients using rat data. Our study provides valuable insights into dose optimization strategies for each individual drug within the XELOX regimen and underscores the potential of translational modeling to improve patient outcomes. In addition to dose determination, these data will lay the groundwork for advancing drug development processes in oncology. SIGNIFICANCE STATEMENT: This study introduced a novel translational modeling approach rooted in a rat PK-TD model to optimize dosing strategies for the XELOX regimen for colorectal cancer treatment. Our findings highlight the interactive effects on lymphocytopenia and suggest a toxicity intensity-based nomogram for dose reduction, thus advancing precision medicine. This translational modeling paradigm enhances our understanding of drug interactions, offering a tool to tailor dosing, minimize hematological toxicity, and improve therapeutic outcomes in patients undergoing XELOX therapy.

MJN110 inhibits the enzyme monoacylglycerol lipase (MAGL) to increase levels of the endocannabinoid 2-arachidonoylglycerol , an endogenous high-efficacy agonist of cannabinoid 1 and 2 receptors (CB_1/2R). MAGL inhibitors are under consideration as candidate analgesics, and we reported previously that acute MJN110 produced partial antinociception in an assay of pain-related behavioral depression in mice. Given the need for repeated analgesic administration in many pain patients and the potential for analgesic tolerance during repeated treatment, this study examined antinociceptive effects of repeated MJN110 on pain-related behavioral depression and CB₁R-mediated G-protein function. Male and female ICR mice were treated daily for 7 days in a 2 × 2 design with (a) 1.0 mg/kg/d MJN110 or its vehicle followed by (b) intraperitoneal injection of dilute lactic acid (IP acid) or its vehicle as a visceral noxious stimulus to depress nesting behavior. After behavioral testing, G-protein activity was assessed in lumbar spinal cord (LSC) and five brain regions using an assay of CP55,940-stimulated [³⁵S]GTPɣS activation. As reported previously, acute MJN110 produced partial but significant relief of IP acid-induced nesting depression on day 1. After 7 days, MJN110 continued to produce significant but partial antinociception in males, while antinociceptive tolerance developed in females. Repeated MJN110 also produced modest decreases in maximum levels of CP55,940-induced [³⁵S]GTPɣS binding in spinal cord and most brain regions. These results indicate that repeated treatment with a relatively low antinociceptive MJN110 dose produces only partial and sex-dependent transient antinociception associated with the emergence of CB₁R desensitization in this model of IP acid-induced nesting depression. SIGNIFICANCE STATEMENT: The drug MJN110 inhibits monoacylglycerol lipase (MAGL) to increase levels of the endogenous cannabinoid 2-arachidonoylglycerol and produce potentially useful therapeutic effects including analgesia. This study used an assay of pain-related behavioral depression in mice to show that repeated MJN110 treatment produced (1) weak but sustained antinociception in male mice, (2) antinociceptive tolerance in females, and (3) modest cannabinoid-receptor desensitization that varied by region and sex. Antinociceptive tolerance may limit the utility of MJN110 for treatment of pain.

Ischemia with non-obstructive coronary arteries (INOCA), caused by coronary artery spasm, has gained increasing attention owing to the poor quality of life of impacted patients. Therapeutic options to address INOCA remain limited, and developing new therapeutic agents is desirable. Here, we examined whether soluble guanylate cyclase (sGC) activators could be beneficial in preventing coronary spasms. In organ chamber experiments with isolated canine coronary arteries, prostaglandin F_{2 α} -induced, endothelin-1-induced, 5-hydroxytryptamine-induced, and potassium chloride-induced contractions were suppressed by the sGC activator BAY 60-2770 (0.1, 1, and 10 nM). In isolated pig coronary arteries, BAY 60-2770 (0.1, 1, and 10 nM) could prolong the cycle length of phasic contractions induced by 3,4-diaminopyridine, as well as lower the peak and bottom tension of the contraction in a concentration-dependent manner. Additionally, BAY 60-2770 (1 pM-0.1 µM) evoked a concentration-related relaxation to a greater extent in small (first diagonal branch) coronary arteries than in large (left anterior descending) coronary arteries. In vasopressin-induced angina model rats, pretreatment with BAY 60-2770 (3 µg/kg) suppressed electrocardiogram S-wave depression induced by arginine vasopressin without affecting changes in mean blood pressure and heart rate. These findings suggest that BAY 60-2770 could be valuable in preventing both large and small coronary spasms. Therefore, sGC activators could represent a novel and efficacious therapeutic option for INOCA. SIGNIFICANCE STATEMENT: The soluble guanylate cyclase (sGC) activator BAY 60-2770 exerted antispastic effects on the coronary arteries in animal vasospasm models as proof-of-concept studies. These data can help to support potential clinical development with sGC activators, suitable for human use in patients with vasospastic angina.

Cannabis sativa L. has a long history of medicinal use, particularly for gastrointestinal diseases. Patients with inflammatory bowel disease (IBD) report using cannabis to manage their symptoms, despite little data to support the use of cannabis or cannabis products to treat the disease. In this study, we use the well-described dextran sodium sulfate (DSS) model of colitis in mice to assess the impact of commercially available, noneuphorigenic, high cannabigerol (CBG) hemp extract (20 mg/mL cannabigerol, 20.7 mg/mL cannabidiol, 1 mg/mL cannabichromene) on IBD activity and the colonic microbiome. Mice were given 2% DSS in drinking water for 5 days, followed by 2 days of regular drinking water. Over the 7 days, mice were dosed daily with either high CBG hemp extract or matched vehicle control. Daily treatment with high CBG hemp extract dramatically reduces the severity of disease at the histological and organismal levels as measured by decreased disease activity index, increased colon length, and decreases in percent colon tissue damage. 16S rRNA gene sequencing of the fecal microbiota reveals high CBG hemp extract treatment results in alterations in the microbiota that may be beneficial for colitis. Finally, using metabolomic analysis of fecal pellets, we find that mice treated with high CBG hemp extract have a normalization of several metabolic pathways, including those involved in inflammation. Taken together, these data suggest that high CBG hemp extracts may offer a novel treatment option for patients. SIGNIFICANCE STATEMENT: Using the dextran sodium sulfate model of colitis, the authors show that treatment with high cannabigerol hemp extract reduces the severity of symptoms associated with colitis. Additionally, they show that treatment modulates both the fecal microbiota and metabolome with potential functional significance.

Advanced-stage endometrial cancer patients typically receive a combination of platinum and paclitaxel chemotherapy. However, limited treatment options are available for those with recurrent disease, and there is a need to identify alternative treatment options for the advanced setting. Our goal was to evaluate the pre-clinical efficacy and mechanism of action of Oklahoma Nitrone 007 (OKN-007) alone and in combination with carboplatin and paclitaxel in endometrial cancer. The effect of OKN-007 on the metabolic viability of endometrial cancer cells in both two- and three-dimensional (2D and 3D) cultures, as well as on clonogenic growth, in vitro was assessed. We also evaluated OKN-007 in vivo using an intraperitoneal xenograft model and targeted gene expression profiling to determine the molecular mechanism and gene expression programs altered by OKN-007. Our results showed that endometrial cancer cells were generally sensitive to OKN-007 in both 2D and 3D cultures. OKN-007 displayed a reduction in 3D spheroid and clonogenic growth. Subsequent targeted gene expression profiling revealed that OKN-007 significantly downregulated the immunosuppressive and immunometabolic enzyme indolamine 2,3-dioxygenase 1 (IDO1) (-11.27-fold change) and modulated upstream inflammatory pathways that regulate IDO1 expression (interferon- (IFN-), Jak-STAT, TGF-β, and NF-kB), downstream IDO1 effector pathways (mTOR and aryl hydrocarbon receptor (AhR)) and altered T-cell co-signaling pathways. OKN-007 treatment reduced IDO1, SULF2, and TGF-β protein expression in vivo, and inhibited TGF-β, NF-kB, and AhR- receptor-mediated nuclear signaling in vitro. These findings indicate that OKN-007 surmounts pro-inflammatory, immunosuppressive, and pro-tumorigenic pathways and is a promising approach for the effective treat endometrial cancer. Significance Statement Women with advanced and recurrent endometrial cancer have limited therapeutic options. OKN-007, which has minimal toxicity and is currently being evaluated in early-phase clinical trials for the treatment of cancer, is a potential new strategy for the treatment of endometrial cancer.

Cancer patients have an increased risk of venous thromboembolism (VTE) which is their second cause of death after disease progression itself. Several thrombotic risk factors coexist in cancer patients, including the ability of both cancer and tumoral microenvironment's cells to directly or indirectly activate platelets and the enzymes of the coagulation cascade, resulting in a hyper-coagulable state of blood. This narrative review gives an overview of the main mechanisms leading to VTE in cancer patients, including the role that platelets and the clotting proteins may have in tumor growth and metastasis. Noteworthy, the haemostatic balance is altered in cancer patients who may, next to a thrombosis tendency, also have an increased risk of bleeding. To highlight the complexity and the precariousness of the haemostatic balance of these patients, we discuss two specific gastrointestinal malignancies: hepatocellular carcinoma, which is frequently associated with liver cirrhosis, a condition that causes profound alterations of haemostasis, and colorectal cancer, which is characterized by a fragile mucosa that is prone to bleeding. Understanding the molecular mechanisms of cancer-associated thrombosis may give a unique opportunity to develop new innovative drugs, acting differently on distinct pathways and potentially allowing to reduce the risk of bleeding related to antithrombotic therapies. Significance Statement The topic is significant because understanding the molecular mechanisms leading to cancer associated thrombosis and bleeding, focusing on gastrointestinal malignancies, enables the development of more rationale and innovative antithrombotic strategies for cancer associated thrombosis. Eventually, this will support an improved and patient-tailored antithrombotic management in vulnerable oncologic patients.

Cardiovascular disease (CVD) remains one of leading causes of death worldwide. Aberrant platelet function mediate fibrin(ogen) rich thrombi that lead to occlusive thrombi associated with mortality. The receptor, TREM-like transcript-1 (TLT-1), stored in the platelet a-granules and released upon platelet activation, binds fibrinogen and von Willebrand factor. Once it is released from platelets TLT-1 is a potential therapeutic target to prevent the thrombosis associated with CVD. Here we design an assay to screen a compound library of small molecules inhibitors. HEK-293 cells stably transfected with a full length human treml-1 construct were used to screen library of 800 compounds, for inhibition of TLT-1 to fibrinogen binding in an attachment assay using crystal violet staining. The possible cytotoxicity of the best compounds was determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide MTT and calcein AM staining assays. Here we demonstrate that the addition of TLT-1 to HEK-293 cells increases cell adhesion by more than 2-fold. We identified ~80 compounds that inhibit binding by more than 80%. We further tested the top compounds and confirmed that reduction of hTLT-1 to fibrinogen bound in the top compounds was not caused by cytotoxicity, as per colorimetric and fluorescent viability assays. Four compounds were identified as potential small molecule inhibitors one of which, BM-8372, demonstrated significant effect in platelet aggregation assays. Significance Statement TLT-1 is a key platelet receptor that binds fibrinogen and mediates clot formation The developed assay successfully screens 800 small molecules, pinpointing ~80 potent inhibitors that reduce TLT-1 binding by over 80%. Importantly, the study rigorously rules out cytotoxicity concerns, affirming the therapeutic potential of the identified compounds. By elucidating TLT-1's role and presenting promising inhibitors, this research offers a significant stride toward developing novel strategies to combat CVD-related thrombosis.