Lineage plasticity mediates resistance to androgen receptor pathway inhibitors (ARPIs) and progression from adenocarcinoma to neuroendocrine prostate cancer (NEPC), a highly aggressive and poorly understood subtype. Neuronal transcription factor ASCL1 has emerged as a central regulator of the lineage plasticity driving neuroendocrine differentiation. Here, we showed that ASCL1 was reprogrammed in ARPI-induced transition to terminal NEPC and identified that the ASCL1 binding pattern tailored the expression of lineage-determinant transcription factor combinations that underlie discrete terminal NEPC identity.
View Article and Find Full Text PDFLineage plasticity is a form of therapy-induced drug resistance. In prostate cancer, androgen receptor (AR) pathway inhibitors potentially lead to the accretion of tumor relapse with loss of AR signaling and a shift from a luminal state to an alternate program. However, the molecular and signaling mechanisms orchestrating the development of lineage plasticity under the pressure of AR-targeted therapies are not fully understood.
View Article and Find Full Text PDFTreatment with androgen receptor pathway inhibitors (ARPIs) in prostate cancer leads to the emergence of resistant tumors characterized by lineage plasticity and differentiation toward neuroendocrine lineage. Here, we find that ARPIs induce a rapid epigenetic alteration mediated by large-scale chromatin remodeling to support activation of stem/neuronal transcriptional programs. We identify the proneuronal transcription factor ASCL1 motif to be enriched in hyper-accessible regions.
View Article and Find Full Text PDFCancers adapt to increasingly potent targeted therapies by reprogramming their phenotype. Here we investigated such a phenomenon in prostate cancer, in which tumours can escape epithelial lineage confinement and transition to a high-plasticity state as an adaptive response to potent androgen receptor (AR) antagonism. We found that AR activity can be maintained as tumours adopt alternative lineage identities, with changes in chromatin architecture guiding AR transcriptional rerouting.
View Article and Find Full Text PDFNonsense mutations leading to premature stop codons are common occurring in approximately 12% of all human genetic diseases. Thus, pharmacological nonsense mutation suppression strategies would be beneficial to a large number of patients if the drugs could be targeted to the affected tissues at the appropriate time. Here, we used nonsense suppression to manipulate Pax6 dosage at different developmental times in the eye of the small eye (Pax6; G194X) mouse model of aniridia.
View Article and Find Full Text PDFThere has been an escalating interest in the medicinal use of Cannabis sativa in recent years. Cannabis is often administered orally with fat-containing foods, or in lipid-based pharmaceutical preparations. However, the impact of lipids on the exposure of patients to cannabis components has not been explored.
View Article and Find Full Text PDFThe molecular signaling leading to cell death in hereditary neurological diseases such as retinal degeneration is incompletely understood. Previous neuroprotective studies have focused on apoptotic pathways; however, incomplete suppression of cell death with apoptosis inhibitors suggests that other mechanisms are at play. Here, we report that different signaling pathways are activated in rod and cone photoreceptors in the P23H rhodopsin mutant rat, a model representing one of the commonest forms of retinal degeneration.
View Article and Find Full Text PDFA super-saturated self-nanoemulsifying drug delivery system (super-SNEDDS), containing the poorly water-soluble drug halofantrine (Hf) at 150% of equilibrium solubility (S eq), was compared in vitro and in vivo with a conventional SNEDDS (75% of S eq) with respect to bioavailability and digestibility. Further, the effect of digestion on oral absorption of Hf from SNEDDS and super-SNEDDS was assessed by incorporation of the lipase inhibitor tetrahydrolipstatin (orlistat) into the SNEDDS. The SNEDDS contained soybean oil/Maisine 34-I (1:1), Kolliphor RH40, and ethanol at a ratio of 55:35:10, w/w percent.
View Article and Find Full Text PDFPurpose: To evaluate the antifungal activity of amphotericin B (AmB) in a mouse model of systemic candidiasis following administration of a novel oral AmB formulation (iCo-010) that has been pre-exposed to tropical temperatures.
Methods: Amphotericin B (AmB) was prepared as a 5 mg/mL dispersion in a mixture of Peceol, Gelucire 44/14 and VitE-TPGS 2,3 (iCo-010). The formulation was protected from light and incubated in a sealed container at 43 °C for 60 days.
Objective: An oral lipid based formulation that exhibits tropical stability (iCo-010) was developed to enhance the absorption of orally administered amphotericin B (AmB). iCo-010 has previously shown high efficacy in an acute model of systemic candidiasis in rats, directing the focus of this study to be its efficacy in a chronic model of systemic candidiasis in mice.
Methods: Mice were infected with 0.
Protonated nanostructured aluminum silicate (NSAS) is a protonated montmorillonite clay that was shown to be effective as an inhibitor of intestinal cholesterol absorption. The effect of NSAS on the intestinal absorption of nutrients is unknown. An in vitro lipolysis model was adapted to test the intraluminal processing of vitamin D3 and K1 in the presence of various amounts of NSAS.
View Article and Find Full Text PDFPurpose: To develop and to validate a simple but sensitive method for determination of vitamins D3 and K1 in rat plasma.
Methods: The sample treatment included protein precipitation by cold acetonitrile, evaporation, reconstitution with methanol and filtration. The chromatography conditions included Xterra RP18 3.
The objective of this study was to assess the pharmacokinetics and tissue distribution of amphotericin B (AmB) in rats following oral administration of three lipid-based formulations (iCo-009, iCo-010 and iCo-011). The lipid-based formulations were administered to rats at a dose of 10 mg/kg and blood samples were withdrawn at predose, 1, 2, 4, 6, 8, 10, 12, 24, 48 and 72 h, after which the animals were sacrificed and the body organs were collected for AmB quantification using a validated HPLC method. Plasma pharmacokinetics parameters were determined using non-compartmental analysis.
View Article and Find Full Text PDFThe objective of this work was to assess the antifungal activity of a tropically stable formulation of amphotericin B (AmB) (iCo-010) over short period of treatment in a rat model of invasive candidiasis. The rats were infected with Candida albicans (ATCC 18804); 48 h later, the animals were assigned either to a control group, AmBisome(®) group (5 mg/kg QD), or iCo-010 groups (0.5, 1, 2.
View Article and Find Full Text PDFEritoran, a synthetic analogue of lipid A, has been shown to bind to TLR4/MD-2 complex and thereby block the interaction of endotoxins with TLR4. We report here the results of a study conducted to assess the single-dose safety and tolerability, as well as the pharmacokinetics and pharmacodynamics, of eritoran infusion in Japanese and Caucasian healthy adult men. Sixty-four men (aged 20-45 years; body mass index 18-30 kg/m(2)) were randomized into four groups: 4-mg total dose (six Japanese and six Caucasian men); 12-mg total dose (12 Japanese and 12 Caucasian men); 28-mg total dose (six Japanese and six Caucasian men); and placebo (eight Japanese and eight Caucasian men).
View Article and Find Full Text PDFThe purpose of this study was to investigate the intraluminal processing of novel oral lipid-based formulations of amphotericin B using an in vitro lipolysis model. Amphotericin B (AmB) was formulated in three lipid-based formulations consisting of different lipid components: iCo-009, iCo-010 and iCo-011. Various lipid loads (0.
View Article and Find Full Text PDFPurpose: Currently, in vivo or in vitro(99m)Tc-radiolabelled red blood cells are the standard blood pool imaging agents. Due to risks associated with handling of blood and the problems with the current (99m)Tc shortage, we were interested in a long-circulating biocompatible synthetic macromolecule that would be simple to prepare and could also be used for PET imaging.
Methods: A high molecular weight hyperbranched polyglycerol (HPG) of 500 kDa was derivatized to coordinate radioactive gallium and to establish its labelling efficiency, stability and pharmacokinetics.
Protonated nanostructured aluminosilicate (NSAS) was previously reported as effective in decreasing intestinal absorption of cholesterol in rats. In this work, the effect of NSAS on modeled intraluminal distribution of cholesterol was assessed using an in vitro lipolysis model. In addition to NSAS, the effect of bile salt sequestrant cholestyramine on modeled intraluminal distribution of cholesterol was tested, as well as the effect of the absence of bile salts in the system.
View Article and Find Full Text PDFBackground: The purpose of this study was to evaluate the biodistribution and toxicity of amphotericin B (AmB) following multiple oral administrations of a novel tropically stable lipid-based formulation (iCo-010).
Methods: BALB/c mice were allocated into six groups: oral iCo-010 twice daily for 5 days in the dose of 20, 10, 5 and 2.5 mg/kg; vehicle control; and intravenous boluses of Fungizone 2 mg/kg once daily for 5 days.
Purpose: To develop an HPLC-UV method for determination of a novel antitrypanosomal compound (OSU-36) and its ester prodrug (OSU-40) in rat plasma and to apply the method for pharmacokinetic evaluation of both compounds in rats.
Methods: Since an attempt to assay for OSU-36 and OSU-40 in non-stabilized plasma resulted in highly non-linear calibration curves and poor sensitivity due to instability of the compounds, the plasma was stabilized using paraoxon and ascorbic acid. The sample treatment included protein precipitation by acetonitrile; evaporation; reconstitution with acetonitrile and filtration.
Objectives: The purpose of this study was to assess the biodistribution and toxicity of amphotericin B (AMB) following multiple dose administration of an oral lipid-based formulation (iCo-009).
Methods: BALB/c female mice were used. ICo-009 was administered twice daily for 5 days at doses of 2.
There is a long-term discussion in the literature concerning the possible link between the improved efficacy of clozapine treatment and elevated plasma triglyceride levels, but no mechanistic studies have been performed to date. The aim of this work was to investigate whether the postprandial hypertriglyceridemia affects the pharmacokinetics and brain distribution of clozapine and norclozapine. Experimental hypertriglyceridemia in rats was induced by oral administration of peanut oil and the pharmacokinetic parameters and brain penetration of clozapine and norclozapine following administration of clozapine were compared to normotriglyceridemic control animals.
View Article and Find Full Text PDFObjectives: To assess the impact of visceral leishmaniasis (VL) on the concentration of amphotericin B (AmB) recovered in the liver and spleen following either intravenous (AmBisome) or oral (iCo-009) AmB administration to mice.
Methods: Livers and spleens previously obtained from VL-infected BALB/c mice (following intravenous AmBisome or oral AmB treatments) were analysed for AmB concentrations. Then, non-infected BALB/c mice were divided into three treatment groups: a single dose of intravenous AmBisome (2 mg/kg, n = 5); and oral AmB every 12 h for 5 days (10 mg/kg, n = 6 and 20 mg/kg, n = 6).
The aim of this work was to assess the effect of chronic administration of protonated nanostructured aluminosilicate (NSAS) on the plasma cholesterol levels and development of atherosclerotic lesions in Apolipoprotein (ApoE) deficient mice fed a high cholesterol and high fat diet. Apolipoprotein E (ApoE) deficient mice were divided into the following treatment groups: protonated NSAS 1.4% (w/w), untreated control and 2% (w/w) stigmastanol mixed with high-cholesterol/high-fat diet.
View Article and Find Full Text PDF