A chemical strategy toward novel brain-penetrant EZH2 inhibitors

Aberrant gene-silencing through dysregulation of polycomb protein activity has emerged as an important oncogenic mechanism in cancer, implicating polycomb proteins as important therapeutic targets. Recently, an inhibitor targeting EZH2, the methyltransferase component of PRC2, received FDA approval following promising clinical responses in cancer patients. However, the current array of EZH2 inhibitors have poor brain-penetrance limiting their use in patients with CNS malignancies, a number of which have been shown to be sensitive to EZH2 inhibition. To address this need, we have identified a chemical strategy, based on computational modeling of pyridone-containing EZH2 inhibitor scaffolds, to minimize P-glycoprotein activity and here we report the first brain-penetrant EZH2 inhibitor, TDI-6118 (compound 5). Additionally, in the course of our attempts to optimize this compound we discovered TDI-011904 (compound 21); a novel, highly-potent, and peripherally active EZH2 inhibitor based on a 7 member ring structure.

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INFLUENCE OF POLYSACCHARIDE COMPLEXES OF PLANTS OF CENTRAL RUSSIA ON THE P-GLYCOPROTEIN ACTIVITY IN VITRO

chemistry of plant raw material ◽

10.14258/jcprm.2020047444 ◽

2020 ◽

pp. 73-81

Author(s):

Ivan Vladimirovich Chernykh ◽

Aleksey Vladimirovich Shchul'kin ◽

Yekaterina Yevgen'yevna Kirichenko ◽

Sergey Konstantinovich Pravkin ◽

Yelena Nikolayevna Yakusheva

Keyword(s):

High Performance ◽

Protein Activity ◽

Apparent Permeability ◽

Melilotus Officinalis ◽

Polysaccharide Complex ◽

Transport Medium ◽

Transporter Protein ◽

Central Russia ◽

P Glycoprotein

The purpose of this work was to study the effect of polysaccharide complexes isolated from tansy flowers (Tanacetum vulgare L., fam. Asteraceae) and melilotus herb (Melilotus officinalis L., fam. Fabaceae) on P-glycoprotein (Pgp, ABCB1 protein) activity in vitro. On Caco-2 cell line the effect of polysaccharide complex isolated from tansy flowers and melilotus herb on Pgp activity was studied. In vitro Pgp activity was assessed by the transport of fexofenadine in the transwell system. High performance liquid chromatography with UV detection at wavelength 220 nm was used to determine fexofenadine concentration in the transport medium. It was revealed that when polysaccharide isolated from tansy flowers was added to the transport medium in concentrations 10 and 100 μM the ratio of the apparent permeability coefficients of fexofenadine b-a/a-b decreased by 1.81 and 2.65 times, respectively, compared with the series of isolated transport of fexofenadine, which indicated decreased Pgp functional activity under the polysaccharide action. The polysaccharide complex of the melilotus herb did not change the b-a/a-b ratio in any of the applied concentrations, thus it did not affect the activity of this transporter. It is advisable to continue the study of tansy flower polysaccharide complex as an inhibitor of Pgp transporter protein in order to assess the possibility of its clinical use for the treatment of pharmacoresistant forms of cancer by overcoming the phenomenon of multidrug resistance of cells.

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Influence of female hormones on the P-glycoprotein functioning

Problems of Endocrinology ◽

10.14341/probl9545 ◽

2018 ◽

Vol 64 (3) ◽

pp. 144-150 ◽

Cited By ~ 1

Author(s):

Alexey V. Shchulkin ◽

Ivan V. Chernykh ◽

Pavel Yu. Mylnikov ◽

Dmitry O. Utkin ◽

Elena N. Yakusheva

Keyword(s):

Functional Activity ◽

Drug Dose ◽

Transport Protein ◽

Whole Body ◽

Cycle Phase ◽

Protein Activity ◽

P Glycoprotein ◽

Combined Administration ◽

Renal Tubular ◽

Small And Large Intestine

The P-glycoprotein (Pgp, ABCB1-protein) is a transport protein localized in the membrane of hepatocytes, small and large intestine enterocytes, renal tubular epitheliocytes, endothelial cells of histohematic barriers, and tumor cells. Aim — to study the effect of estradiol and progesterone physiological concentrations on the Pgp functional activity on the whole body. Material and methods. The work was performed on 17 adult female chinchilla rabbits. The first group of rabbits underwent a “false operation” (n=5); the second group (n=6) underwent ovariectomy. The third group (n=6) was ovariectomized and received estradiol (0.5 mg/rabbit) for 14 days (starting on the 14th postoperative day), followed by combined administration of estradiol (0.5 mg/rabbit) and progesterone (5 mg/rabbit) for 14 days. The Pgp functional activity was determined in rabbits of all groups using HPLC analysis of fexofenadine pharmacokinetics on day 7 before the study onset and on day 14, 28, and 42 after the operation. Accumulation of fexofenadine in rabbits indicates Pgp inhibition, and a decrease in its content means Pgp induction. Results. Ovariectomy led to a decrease in the Pgp functional activity. The estradiol introduction for 14 days after ovariectomy did not significantly affect the transport protein functional activity. Combined administration of estradiol and progesterone for 14 days resulted in an increase in the Pgp activity, compared to that in the ovariectomy series and baseline values. Conclusions. The dependence of the transport protein activity on the dynamics of physiological estradiol and progesterone concentrations suggests that the effectiveness of pharmacotherapy with Pgp substrates may depend on the menstrual cycle phase, and drug dose correction may be used to increase the pharmacotherapy effectiveness.

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A dynamic in-vitro model of the intestinal epithelium for the investigation of P-glycoprotein activity

10.21203/rs.3.rs-24178/v2 ◽

2020 ◽

Author(s):

Joana Costa ◽

Vanessa Almonti ◽

Ludovica Cacopardo ◽

Daniele Poli ◽

Simona Rapposelli ◽

...

Keyword(s):

Inhibitory Effect ◽

Therapeutic Effects ◽

Protein Activity ◽

Glycoprotein P ◽

Phenyl Derivative ◽

Natural Substances ◽

P Glycoprotein ◽

Pre Treatment ◽

Vitro Model

Abstract Multidrug resistance is still an obstacle for chemotherapeutic treatments. One of the proteins involved in this phenomenon is the P-glycoprotein, P-gp, which is known to be responsible for the efflux of therapeutic substances from the cell cytoplasm. To date, the identification of a drug that can efficiently inhibit P-gp activity remains a challenge, nevertheless some studies have identified natural compounds suitable for that purpose. Amongst them, curcumin has shown an inhibitory effect on the protein in in vitro studies using Caco-2 cells.To understand if physiological flow can modulate membrane protein activity, we studied the uptake of a P-gp substrate under static and dynamic conditions. Caco-2 cells were cultured in bioreactors and in Transwells and the basolateral transport of Rhodamine-123 assessed in the two systems as a function of P-gp activity. Experiments were performed with and without pre-treatment of the cells with an extract of curcumin or an arylmethyloxy-phenyl derivative to evaluate the inhibitory effect of the natural substance with respect to a synthetic compound.The results indicated that the P-gp activity of the cells cultured in the bioreactors was intrinsically lower, and that the effect of both natural and synthetic inhibitors was up modulated by the presence of flow. Our study underlies the fact that the use of more sophisticated and physiologically relevant in vitro models can bring new insights on the therapeutic effects of natural substances such as curcumin.

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Pharmacogenomics of methadone: a narrative review of the literature

Pharmacogenomics ◽

10.2217/pgs-2020-0040 ◽

2020 ◽

Vol 21 (12) ◽

pp. 871-887

Author(s):

Senthil Packiasabapathy ◽

Blessed W Aruldhas ◽

Nicole Horn ◽

Brian R Overholser ◽

Sara K Quinney ◽

...

Keyword(s):

Genetic Variants ◽

Single Gene ◽

Predictive Ability ◽

Pharmacodynamic Modeling ◽

Population Pharmacokinetic ◽

Cytochrome P450 Enzymes ◽

Duration Of Action ◽

P Glycoprotein ◽

Surgical Pain ◽

Clinical Responses

Background: Methadone, a synthetic opioid with longer duration of action and lower abuse potential compared with morphine, is used to prevent opioid withdrawal, as well as to manage chronic and acute surgical pain. The variability in response to methadone has been widely recognized. The purpose of this article is to review the literature on the pharmacogenetic factors underlying this variability. Materials & methods: This is a narrative overview of the literature on the genetic variants affecting pharmacodynamics and pharmacokinetics of methadone, retrieved from searches of databases such as PubMed and google scholar. Discussion: Clinical responses to methadone may be affected by genetic variants in the opioidergic, dopaminergic and neurotrophic pathways. Polymorphisms in genes related to disposition and elimination of methadone alter the pharmacokinetics, and possibly pharmacodynamics of methadone. Cytochrome P450 enzymes and P-glycoprotein variants contribute to the interindividual variability in methadone pharmacokinetics. Evidence for single gene variants affecting methadone response remains weak. Multiple genetic variants must be considered in conjunction to improve predictive ability. Conclusion: Evidence remains scarce at this time, to recommend pharmacogenetic testing before methadone administration. Well-powered clinical studies are needed with population pharmacokinetic-pharmacodynamic modeling and multigenetic signature-based predictions to enable tailored use of methadone in clinical practice.

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Immunotherapy earns its spot in the ranks of cancer therapy

Journal of Experimental Medicine ◽

10.1084/jem.20112275 ◽

2012 ◽

Vol 209 (2) ◽

pp. 201-209 ◽

Cited By ~ 92

Author(s):

Drew Pardoll ◽

Charles Drake

Keyword(s):

Immune Responses ◽

Cancer Therapeutics ◽

Genetic Alterations ◽

Therapeutic Modality ◽

Scientific Principle ◽

Phase 3 ◽

Fda Approval ◽

Significant Survival ◽

Clinical Responses ◽

Exquisite Specificity

Since it became clear that all cancer cells express tumor-specific and tumor-selective antigens generated by genetic alterations and epigenetic dysregulation, the immunology community has embraced the possibility of designing therapies to induce targeted antitumor immune responses. The potential therapeutic specificity and efficacy of such treatments are obvious to anyone who studies the exquisite specificity and cytocidal potency of immune responses. However, the value assigned to a therapeutic modality by the oncology community at large does not depend on scientific principle; all that matters is how patients respond. The bar for the ultimate acceptance of a therapy requires more than anecdotal clinical responses; rather, the major modalities of cancer therapeutics, including surgery, chemotherapy, radiation therapy, and, more recently, drugs targeting oncogenes, have earned their place only after producing dramatic frequent clinical responses or demonstrating statistically significant survival benefits in large randomized phase 3 clinical trials, leading to FDA approval. Although tumor-targeted antibodies have certainly cleared this bar, immunotherapies aimed at harnessing antitumor cellular responses have not—until now.

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Pc2 and SUMOylation

Biochemical Society Transactions ◽

10.1042/bst0351401 ◽

2007 ◽

Vol 35 (6) ◽

pp. 1401-1404 ◽

Cited By ~ 41

Author(s):

D. Wotton ◽

J.C. Merrill

Keyword(s):

Recent Work ◽

Histone Deacetylase ◽

Chromatin Structure ◽

Mammalian Cells ◽

Protein Complexes ◽

E3 Ligase ◽

Histone Methyltransferase ◽

Polycomb Proteins ◽

Polycomb Protein ◽

Shed Light

Polycomb proteins are key regulators of transcription in metazoan organisms. Recent work has shed light on the nature of the polycomb protein complexes in flies and mammalian cells. Multiple enzymatic activities have been shown to associate with polycomb complexes, including histone methyltransferase, histone deacetylase and ubiquitination activities, which are primarily directed towards the modification of chromatin structure. In addition to these chromatin-based functions, other potential roles for polycomb proteins exist. Here, we present a comparison of vertebrate Pc2 (polycomb 2 protein) homologues, and review the known functions of the mammalian Pc2 focusing on its role as a SUMO (small ubiquitin-related modifier) E3 ligase. Pc2 is an E3 for several SUMO substrates, but still appears to have a more limited repertoire than other SUMO E3s, perhaps due to its association with polycomb complexes. One possibility is that Pc2 represents a relatively specialized polycomb protein, which has additional functions to those associated with other mammalian Pc (polycomb protein) paralogues.

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Epigenetics: New Insights into Mammary Gland Biology

Genes ◽

10.3390/genes12020231 ◽

2021 ◽

Vol 12 (2) ◽

pp. 231

Author(s):

Elitsa Ivanova ◽

Sandrine Le Guillou ◽

Cathy Hue-Beauvais ◽

Fabienne Le Provost

Keyword(s):

Mammary Gland ◽

Molecular Mechanisms ◽

Cell Types ◽

Physiological Changes ◽

Protein Activity ◽

Polycomb Protein ◽

Non Coding Rna ◽

Mammary Cell ◽

Milk Component ◽

Mammary Gland Biology

The mammary gland undergoes important anatomical and physiological changes from embryogenesis through puberty, pregnancy, lactation and involution. These steps are under the control of a complex network of molecular factors, in which epigenetic mechanisms play a role that is increasingly well described. Recently, studies investigating epigenetic modifications and their impacts on gene expression in the mammary gland have been performed at different physiological stages and in different mammary cell types. This has led to the establishment of a role for epigenetic marks in milk component biosynthesis. This review aims to summarize the available knowledge regarding the involvement of the four main molecular mechanisms in epigenetics: DNA methylation, histone modifications, polycomb protein activity and non-coding RNA functions.

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A dynamic in-vitro model of the intestinal epithelium for the investigation of P-glycoprotein activity

10.21203/rs.3.rs-24178/v1 ◽

2020 ◽

Author(s):

Joana Costa ◽

Vanessa Almonti ◽

Ludovica Cacopardo ◽

Daniele Poli ◽

Simona Rapposelli ◽

...

Keyword(s):

Inhibitory Effect ◽

Therapeutic Effects ◽

Protein Activity ◽

Synthetic Compound ◽

Phenyl Derivative ◽

Natural Substances ◽

P Glycoprotein ◽

Pre Treatment ◽

Vitro Model

Abstract Multidrug resistance is still an obstacle for chemotherapeutic treatments. One of the proteins involved in this phenomenon is the P-glycoprotein, P-gp, which is known to be responsible for the efflux of therapeutic substances from the cell cytoplasm. To date, the identification of a drug that can efficiently inhibit P-gp activity remains a challenge, nevertheless some studies have identified natural compounds suitable for that purpose. Amongst them, curcumin has shown an inhibitory effect on the protein in in vitro studies using Caco-2 cells. Aiming at understanding the role of physiological flow on the modulation of membrane protein activity, we studied the uptake of a P-gp substrate under static and dynamic conditions. Caco-2 cells were cultured in bioreactors and in Transwells and the basolateral transport of Rhodamine-123 assessed in the two systems as a function of P-gp activity. Experiments were performed with and without pre-treatment of the cells with an extract of curcumin or an arylmethyloxy-phenyl derivative to evaluate the inhibitory effect of the natural substance with respect to a synthetic compound. The results indicated that the P-gp activity of the cells cultured in the bioreactors was intrinsically lower, and that the effect of both natural and synthetic inhibitors was up modulated by the presence of flow. Our study underlies the fact that the use of more sophisticated and physiologically relevant in vitro models can bring new insights on the therapeutic effects of natural substances such as curcumin.

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Circular ANRIL isoforms switch from repressors to activators of p15/CDKN2B expression during RAF1 oncogene-induced senescence

10.1101/2020.04.28.065888 ◽

2020 ◽

Author(s):

Lisa Muniz ◽

Sandra Lazorthes ◽

Maxime Delmas ◽

Julien Ouvrard ◽

Marion Aguirrebengoa ◽

...

Keyword(s):

Gene Expression ◽

Cell Fate ◽

Protein Localization ◽

Polycomb Group ◽

Circular Rnas ◽

Polycomb Proteins ◽

Cycle Arrest ◽

Polycomb Protein ◽

Stable Species ◽

Non Coding Rnas

AbstractLong non-coding RNAs (ncRNAs) are major regulators of gene expression and cell fate. The INK4 locus encodes the tumour suppressor proteins p15INK4b, p16INK4a and p14ARF required for cell cycle arrest and whose expression increases during senescence. ANRIL is a ncRNA antisense to the p15 gene. In proliferative cells, ANRIL prevents senescence by repressing INK4 genes through the recruitment of Polycomb-group proteins. In models of replicative and RASval12 oncogene-induced senescence (OIS), the expression of ANRIL and Polycomb proteins decreases, thus allowing INK4 derepression. Here, we found in a model of RAF1 OIS that ANRIL expression rather increases, due in particular to an increased stability. This led us to search for circular ANRIL isoforms, as circular RNAs are rather stable species. We found that the expression of two circular ANRIL increases in several OIS models (RAF1, MEK1 and BRAF). In proliferative cells, they repress p15 expression, while in RAF1 OIS, they promote full induction of p15, p16 and p14ARF expression. Further analysis of one of these circular ANRIL shows that it interacts with Polycomb proteins and decreases EZH2 Polycomb protein localization and H3K27me3 at the p15 and p16 promoters, respectively. We propose that changes in the ratio between Polycomb proteins and circular ANRIL isoforms allow these isoforms to switch from repressors of p15 gene to activators of all INK4 genes in RAF1 OIS. Our data reveal that regulation of ANRIL expression depends on the senescence inducer and underline the importance of circular ANRIL in the regulation of INK4 gene expression and senescence.

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Temporospatial genomic profiling in glioblastoma identifies commonly altered core pathways underlying tumor progression

Neuro-Oncology Advances ◽

10.1093/noajnl/vdaa078 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Mylan R Blomquist ◽

Shannon Fortin Ensign ◽

Fulvio D’Angelo ◽

Joanna J Phillips ◽

Michele Ceccarelli ◽

...

Keyword(s):

Standard Of Care ◽

Resection Margins ◽

Protein Activity ◽

Transcriptional Signature ◽

Functional Studies ◽

Protein Levels ◽

Aberrant Gene Expression ◽

Whole Exome ◽

Standard Of Care Treatment ◽

Aberrant Gene

Abstract Background Tumor heterogeneity underlies resistance and disease progression in glioblastoma (GBM), and tumors most commonly recur adjacent to the surgical resection margins in contrast non-enhancing (NE) regions. To date, no targeted therapies have meaningfully altered overall patient survival in the up-front setting. The aim of this study was to characterize intratumoral heterogeneity in recurrent GBM using bulk samples from primary resection and recurrent samples taken from contrast-enhancing (EN) and contrast NE regions. Methods Whole exome and RNA sequencing were performed on matched bulk primary and multiple recurrent EN and NE tumor samples from 16 GBM patients who received standard of care treatment alone or in combination with investigational clinical trial regimens. Results Private mutations emerge across multi-region sampling in recurrent tumors. Genomic clonal analysis revealed increased enrichment in gene alterations regulating the G2M checkpoint, Kras signaling, Wnt signaling, and DNA repair in recurrent disease. Subsequent functional studies identified augmented PI3K/AKT transcriptional and protein activity throughout progression, validated by phospho-protein levels. Moreover, a mesenchymal transcriptional signature was observed in recurrent EN regions, which differed from the proneural signature in recurrent NE regions. Conclusions Subclonal populations observed within bulk resected primary GBMs transcriptionally evolve across tumor recurrence (EN and NE regions) and exhibit aberrant gene expression of common signaling pathways that persist despite standard or targeted therapy. Our findings provide evidence that there are both adaptive and clonally mediated dependencies of GBM on key pathways, such as the PI3K/AKT axis, for survival across recurrences.

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