Let-7b Inhibits Human Cancer Phenotype by Targeting Cytochrome P450 Epoxygenase 2J2

BACKGROUND: MicroRNAs (miRNAs) are small, noncoding RNA molecules of 20 to 22 nucleotides that regulate gene expression by binding to their 3' untranslated region (3'UTR). Increasing data implicate altered miRNA participation in the progress of cancer. We previously reported that CYP2J2 epoxygenase promotes human cancer phenotypes. But whether and how CYP2J2 is regulated by miRNA is not understood. METHODS AND RESULTS: Using bioinformatics analysis, we found potential target sites for miRNA let-7b in 3'UTR of human CYP2J2. Luciferase and western blot assays revealed that CYP2J2 was regulated by let-7b. In addition, let-7b decreased the enzymatic activity of endogenous CYP2J2. Furthermore, let-7b may diminish cell proliferation and promote cell apoptosis of tumor cells via posttranscriptional repression of CYP2J2. Tumor xenografts were induced in nude mice by subcutaneous injection of MDA-MB-435 cells. The let-7b expression vector, pSilencer-let-7b, was injected through tail vein every 3 weeks. Let-7b significantly inhibited the tumor phenotype by targeting CYP2J2. Moreover, quantitative real-time polymerase chain reaction and western blotting were used to determine the expression levels of let-7b and CYP2J2 protein from 18 matched lung squamous cell cancer and adjacent normal lung tissues; the expression level of CYP2J2 was inversely proportional to that of let-7b. CONCLUSIONS: Our results demonstrated that the decreased expression of let-7b could lead to the high expression of CYP2J2 protein in cancerous tissues. These findings suggest that miRNA let-7b reduces CYP2J2 expression, which may contribute to inhibiting tumor phenotypes

Investigation of utilization of nanosuspension formulation to enhance exposure of 1,3-dicyclohexylurea in rats: Preparation for PK/PD study via subcutaneous route of nanosuspension drug delivery

1,3-Dicyclohexylurea (DCU), a potent soluble epoxide hydrolase (sEH) inhibitor has been reported to lower systemic blood pressure in spontaneously hypertensive rats. One limitation of continual administration of DCU for in vivo studies is the compound's poor oral bioavailability. This phenomenon is mainly attributed to its poor dissolution rate and low aqueous solubility. Previously, wet-milled DCU nanosuspension has been reported to enhance the bioavailability of DCU. However, the prosperities and limitations of wet-milled nanosuspension have not been fully evaluated. Furthermore, the oral pharmacokinetics of DCU in rodent are such that the use of DCU to understand PK/PD relationships of sEH inhibitors in preclinical efficacy model is less than ideal. In this study, the limitation of orally delivered DCU nanosuspension was assessed by a surface area sensitive absorption model and pharmacokinetic modeling. It was found that dosing DCU nanosuspension did not provide the desired plasma profile needed for PK/PD investigation. Based on the model and in vivo data, a subcutaneous route of delivery of nanosuspension of DCU was evaluated and demonstrated to be appropriate for future PK/PD studies

The Epoxygenases CYP2J2 Activates the Nuclear Receptor PPARα In Vitro and In Vivo

Peroxisome proliferator-activated receptors (PPARs) are a family of three (PPARalpha, -beta/delta, and -gamma) nuclear receptors. In particular, PPARalpha is involved in regulation of fatty acid metabolism, cell growth and inflammation. PPARalpha mediates the cardiac fasting response, increasing fatty acid metabolism, decreasing glucose utilisation, and is the target for the fibrate lipid-lowering class of drugs. However, little is known regarding the endogenous generation of PPAR ligands. CYP2J2 is a lipid metabolising cytochrome P450, which produces anti-inflammatory mediators, and is considered the major epoxygenase in the human heart.Expression of CYP2J2 in vitro results in an activation of PPAR responses with a particular preference for PPARalpha. The CYP2J2 products 8,9- and 11-12-EET also activate PPARalpha. In vitro, PPARalpha activation by its selective ligand induces the PPARalpha target gene pyruvate dehydrogenase kinase (PDK)4 in cardiac tissue. In vivo, in cardiac-specific CYP2J2 transgenic mice, fasting selectively augments the expression of PDK4.Our results establish that CYP2J2 produces PPARalpha ligands in vitro and in vivo, and suggests that lipid metabolising CYPs are prime candidates for the integration of global lipid changes to transcriptional signalling events

Atorvastatin Therapy during the Peri-Infarct Period Attenuates Left Ventricular Dysfunction and Remodeling after Myocardial Infarction

Although statins impart a number of cardiovascular benefits, whether statin therapy during the peri-infarct period improves subsequent myocardial structure and function remains unclear. Thus, we evaluated the effects of atorvastatin on cardiac function, remodeling, fibrosis, and apoptosis after myocardial infarction (MI). Two groups of rats were subjected to permanent coronary occlusion. Group II (n = 14) received oral atorvastatin (10 mg/kg/d) daily for 3 wk before and 4 wk after MI, while group I (n = 12) received equivalent doses of vehicle. Infarct size (Masson's trichrome-stained sections) was similar in both groups. Compared with group I, echocardiographic left ventricular ejection fraction (LVEF) and fractional area change (FAC) were higher while LV end-diastolic volume (LVEDV) and LV end-systolic and end-diastolic diameters (LVESD and LVEDD) were lower in treated rats. Hemodynamically, atorvastatin-treated rats exhibited significantly higher dP/dtmax, end-systolic elastance (Ees), and preload recruitable stroke work (PRSW) and lower LV end-diastolic pressure (LVEDP). Morphometrically, infarct wall thickness was greater in treated rats. The improvement of LV function by atorvastatin was associated with a decrease in hydroxyproline content and in the number of apoptotic cardiomyocyte nuclei. We conclude that atorvastatin therapy during the peri-infarct period significantly improves LV function and limits adverse LV remodeling following MI independent of a reduction in infarct size. These salubrious effects may be due in part to a decrease in myocardial fibrosis and apoptosis

Cardiovascular and renal effectiveness of empagliflozin in routine care in East Asia: Results from the EMPRISE East Asia study

Aim: To evaluate the effectiveness of empagliflozin in clinical practice in East Asia in the Empagliflozin Comparative Effectiveness and Safety (EMPRISE) East Asia study. Materials and methods: Data were obtained from the Medical Data Vision database (Japan), National Health Insurance Service database (South Korea) and National Health Insurance database (Taiwan). Patients aged ≥ 18 years with type 2 diabetes initiating empagliflozin or a dipeptidyl peptidase-4 (DPP-4) inhibitor were 1:1 propensity score (PS) matched into sequentially built cohorts of new users naïve to both drug classes. This design reduces confounding due to switching treatments, time lag and immortal time biases. Outcomes included hospitalization for heart failure (HHF), end-stage renal disease (ESRD) and all-cause mortality. Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional models, controlling for > 130 baseline characteristics in each data source and pooled by random-effects meta-analysis. Results: Overall, 28 712 pairs of PS-matched patients were identified with mean follow-up of 5.7-6.8 months. Compared with DPP-4 inhibitors, the risk of HHF was reduced by 18% and all-cause mortality was reduced by 36% with empagliflozin (HR 0.82; 95% CI 0.71-0.94, and HR 0.64; 95% CI 0.50-0.81, respectively). Reductions were consistent across countries, and in patients with and without baseline cardiovascular disease. ESRD was also significantly reduced with empagliflozin versus DPP-4 inhibitors (HR 0.37; 95% CI 0.24-0.58). Conclusions: Empagliflozin treatment was associated with reduced risk for HHF, all-cause mortality and ESRD compared with DPP-4 inhibitors in routine clinical practice in Japan, South Korea and Taiwan

Healthcare resource utilization in patients treated with empagliflozin in East Asia

AIMS/INTRODUCTION: We investigated the utilization of healthcare resources in patients with type 2 diabetes treated with empagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, versus dipeptidyl peptidase-4 (DPP-4) inhibitors in clinical practice in Japan, South Korea, and Taiwan. MATERIALS AND METHODS: We analyzed the Japanese Medical Data Vision database (December 2014-April 2018), the South Korean National Health Information Database, and the Taiwanese National Health Insurance claims database (both May 2016-December 2017). Patients with type 2 diabetes starting empagliflozin, 10 or 25 mg, or a DPP-4 inhibitor were matched 1:1 via propensity scores (PS). We compared inpatient care needs, emergency room (ER) visits, and outpatient visits between the treatment groups using Poisson regression and Cox proportional hazards models, pooled across countries by random-effects meta-analysis. RESULTS: We identified 28,712 pairs of PS-matched patients; the mean follow-up was 5.7-6.8 months. Empagliflozin-treated patients had a 27% lower risk of all-cause hospitalization compared with DPP-4 inhibitor-treated patients (rate ratio [RR] 0.73, 95% CI 0.67-0.79), and 23% reduced risk for first hospitalization (hazard ratio 0.77, 95% CI 0.73-0.81). The risk for an ER visit was 12% lower with empagliflozin than with DPP-4 inhibitors (RR 0.88, 95% CI 0.83-0.94) while the risk for outpatient visit was 4% lower (RR 0.96, 95% CI 0.96-0.97). These findings were generally consistent across countries, regardless of baseline cardiovascular disease, and in the subgroup starting empagliflozin with the 10 mg dose. CONCLUSIONS: Empagliflozin treatment was associated with lower inpatient care needs and other healthcare resource utilization than DPP-4 inhibitors in routine clinical practice in East Asia in this study

Cytochrome P450-derived eicosanoids: the neglected pathway in cancer

Endogenously produced lipid autacoids are locally acting small molecule mediators that play a central role in the regulation of inflammation and tissue homeostasis. A well-studied group of autacoids are the products of arachidonic acid metabolism, among which the prostaglandins and leukotrienes are the best known. They are generated by two pathways controlled by the enzyme systems cyclooxygenase and lipoxygenase, respectively. However, arachidonic acid is also substrate for a third enzymatic pathway, the cytochrome P450 (CYP) system. This third eicosanoid pathway consists of two main branches: ω-hydroxylases convert arachidonic acid to hydroxyeicosatetraenoic acids (HETEs) and epoxygenases convert it to epoxyeicosatrienoic acids (EETs). This third CYP pathway was originally studied in conjunction with inflammatory and cardiovascular disease. Arachidonic acid and its metabolites have recently stimulated great interest in cancer biology; but, unlike prostaglandins and leukotrienes the link between cytochome P450 metabolites and cancer has received little attention. In this review, the emerging role in cancer of cytochrome P450 metabolites, notably 20-HETE and EETs, are discussed

The "Statinth" wonder of the world: a panacea for all illnesses or a bubble about to burst

After the introduction of statins in the market as effective lipid lowering agents, they were shown to have effects other than lipid lowering. These actions were collectively referred to as 'pleiotropic actions of statins.' Pleiotropism of statins formed the basis for evaluating statins for several indications other than lipid lowering. Evidence both in favour and against is available for several of these indications. The current review attempts to critically summarise the available data for each of these indications