Preclinical pharmacokinetic studies of 3-deazaneplanocin A, a potent epigenetic anticancer agent, and its human pharmacokinetic prediction using GastroPlus™

3-Deazaneplanocin A (DZNep): A Drug That Deserves a Second Look

The emerging data compiled during the past five years on 3-deazaneplanocin (DZNep) provide compelling evidence to reevaluate this drug as a better alternative over the specific catalytic inhibitors of histone methyl transferases (HTMs). The indirect mechanism of DZNep via inhibition of AdoHcy-ase, once considered a liability due to possible side effects, has now shown to be rather beneficial as additional pathways targeted by DZNep are important contributors to its superior anticancer properties. Furthermore, DZNep has demonstrated the ability to induce proteasomal degradation of its target and reduce toxicity in combination with well-established antitumor therapies in animal models. In addition, DZNep has shown important effects in suppressing fibrosis and inflammation in liver, kidney, peritoneum, and airways. Finally, inhibition of mRNA m6A methylation by DZNep suppresses the synthesis of the viral genome in SARS-Cov-2 infection and promises to have important therapeutic value when combined with its potent antiviral efficacy and anti-inflammatory effects.

Image-based predictive modelling frameworks for personalised drug delivery in cancer therapy

Personalised drug delivery enables a tailored treatment plan for each patient compared to conventional drug delivery, where a generic strategy is commonly employed. It can not only achieve precise treatment to improve effectiveness but also reduce the risk of adverse effects to improve patients' quality of life. Drug delivery involves multiple interconnected physiological and physicochemical processes, which span a wide range of time and length scales. How to consider the impact of individual differences on these processes becomes critical. Multiphysics models are an open system that allows well-controlled studies on the individual and combined effects of influencing factors on drug delivery outcomes while accommodating the patient-specific in vivo environment, which is not economically feasible through experimental means. Extensive modelling frameworks have been developed to reveal the underlying mechanisms of drug delivery and optimise effective delivery plans. This review provides an overview of currently available models, their integration with advanced medical imaging modalities, and code packages for personalised drug delivery. The potential to incorporate new technologies (i.e., machine learning) in this field is also addressed for development.

EZH2 can be used as a therapeutic agent for inhibiting endothelial dysfunction

Enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of polycomb repressor complex 2 and plays important roles in endothelial cell homeostasis. EZH2 functionally methylates lysine 27 of histone H3 and represses gene expression through chromatin compaction. EZH2 mediates the effects of environmental stimuli by regulating endothelial functions, such as angiogenesis, endothelial barrier integrity, inflammatory signaling, and endothelial mesenchymal transition. Numerous studies have been conducted to determine the significance of EZH2 in endothelial function. The aim of this review is to provide a concise summary of the roles EZH2 plays in endothelial function and elucidate its therapeutic potential in cardiovascular diseases.

Landscape of NcRNAs involved in drug resistance of breast cancer

Breast cancer (BC) leads to the most amounts of deaths among women. Chemo-, endocrine-, and targeted therapies are the mainstay drug treatments for BC in the clinic. However, drug resistance is a major obstacle for BC patients, and it leads to poor prognosis. Accumulating evidences suggested that noncoding RNAs (ncRNAs) are intricately linked to a wide range of pathological processes, including drug resistance. Till date, the correlation between drug resistance and ncRNAs is not completely understood in BC. Herein, we comprehensively summarized a dysregulated ncRNAs landscape that promotes or inhibits drug resistance in chemo-, endocrine-, and targeted BC therapies. Our review will pave way for the effective management of drug resistance by targeting oncogenic ncRNAs, which, in turn will promote drug sensitivity of BC in the future.

Attenuation of SARS-CoV-2 replication and associated inflammation by concomitant targeting of viral and host cap 2'-O-ribose methyltransferases

The SARS‐CoV‐2 infection cycle is a multistage process that relies on functional interactions between the host and the pathogen. Here, we repurposed antiviral drugs against both viral and host enzymes to pharmaceutically block methylation of the viral RNA 2'‐O‐ribose cap needed for viral immune escape. We find that the host cap 2'‐O‐ribose methyltransferase MTr1 can compensate for loss of viral NSP16 methyltransferase in facilitating virus replication. Concomitant inhibition of MTr1 and NSP16 efficiently suppresses SARS‐CoV‐2 replication. Using in silico target‐based drug screening, we identify a bispecific MTr1/NSP16 inhibitor with anti‐SARS‐CoV‐2 activity in vitro and in vivo but with unfavorable side effects. We further show antiviral activity of inhibitors that target independent stages of the host SAM cycle providing the methyltransferase co‐substrate. In particular, the adenosylhomocysteinase (AHCY) inhibitor DZNep is antiviral in in vitro, in ex vivo, and in a mouse infection model and synergizes with existing COVID‐19 treatments. Moreover, DZNep exhibits a strong immunomodulatory effect curbing infection‐induced hyperinflammation and reduces lung fibrosis markers ex vivo. Thus, multispecific and metabolic MTase inhibitors constitute yet unexplored treatment options against COVID‐19.

Impact of Composition and Morphology of Ketoconazole-Loaded Solid Lipid Nanoparticles on Intestinal Permeation and Gastroplus-Based Prediction Studies

Ketoconazole (KTZ) is a potential oral antifungal agent to control systemic and local infections. This study addresses the impact of composition (tween 80 and compritol as CATO) and morphology on permeation (stomach, jejunum, and ileum) profiles of KTZ-loaded solid lipid nanoparticles (SLNs) in rats followed by in vivo pharmacokinetic prediction and simulation using GastroPlus. The selected formulations were characterized for size, size distribution, zeta potential, entrapment efficiency, total drug content, morphology, in vitro drug release, ex vivo permeation and drug deposition, penetration potential, and GastroPlus-based in vivo prediction in rats. The results showed that there was considerable impact of pH, composition (CATO and tween 80), size, total drug content, and entrapment efficiency on in vitro drug release and permeation across the stomach, jejunum, and ileum. Ex vivo findings suggested pH, composition, size, and permeability coefficient-dependent permeation of SLNs across the stomach, jejunum, and ileum. Confocal laser scanning microscopy (CLSM) confirmed a relatively high degree of penetration of the optimized formulation "K-SLN4" (66.1% across the stomach, 51.5% across the jejunum, and 47.9% across the ileum) as compared to KSUS (corresponding values of 21.7%, 18.2%, and 17.4%). Finally, GastroPlus predicted in vivo dissolution/absorption as 0.012 μg/mL of K-SLN4 as compared to KSUS (the drug suspension with 0.0058 μg/mL) and a total regional absorption of 80.0% by K-SLN4 as compared to 60.1% of KSUS. There was only an impact of dose on C _max (maximum plasma concentration) and area under the curve (AUC) in rats. Thus, the present strategy could be a promising alternative to parenteral and topical delivery systems for long-term therapy against systemic and local mycoses with high patient compliance.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

Use of Modeling and Simulation to Predict the Influence of Triazole Antifungal Agents on the Pharmacokinetics of Crizotinib

Crizotinib is used for the treatment of c-ros oncogene 1-positive advanced non-small-cell lung cancer. Triazole antifungal agents are widely used for invasive fungal infections in clinical practice. To predict the potential influence of different triazoles (voriconazole, fluconazole, and itraconazole) on the pharmacokinetics of crizotinib by modeling and simulation the physiologically based pharmacokinetic models were established and validated in virtual cancer subjects through Simcyp software based on the essential physicochemical properties and pharmacokinetic data collected. The validated physiologically based pharmacokinetic models were applied to predict the drug-drug interactions between crizotinib and different triazoles (voriconazole, fluconazole, or itraconazole) in patients with cancer. Crizotinib and triazole antifungal agents were administered orally. The predicted plasma concentration vs time profiles of crizotinib, voriconazole, fluconazole, and itraconazole showed good agreement with observed, respectively. The geometric mean area under the plasma concentration-time curve (AUC) of crizotinib was increased by 84%, 58%, and 79% when coadministered with voriconazole, fluconazole, or itraconazole at multiple doses, respectively. The drug-drug interaction results showed increased pharmacokinetic exposure (maximum plasma concentration and area under the plasma concentration-time curve) of crizotinib when coadministrated with different triazoles (voriconazole > itraconazole > fluconazole). Among the 3 triazoles, voriconazole exhibited the most significant influence on the pharmacokinetic exposure of crizotinib. In clinic, adverse drug reactions and toxicity related to crizotinib should be carefully monitored, and therapeutic drug monitoring for crizotinib is recommended to guide dosing and optimize treatment when coadministered with voriconazole, fluconazole, or itraconazole.

Histone 3 Lysine 27 Trimethylation Signature in Breast Cancer

Cancer development and progression rely on complicated genetic and also epigenetic changes which regulate gene expression without altering the DNA sequence. Epigenetic mechanisms such as DNA methylation, histone modifications, and regulation by lncRNAs alter protein expression by either promoting gene transcription or repressing it. The presence of so-called chromatin modification marks at various gene promoters and gene bodies is associated with normal cell development but also with tumorigenesis and progression of different types of cancer, including the most frequently diagnosed breast cancer. This review is focused on the significance of one of the abundant post-translational modifications of histone 3- trimethylation of lysine 27 (H3K27me3), which was shown to participate in tumour suppressor genes' silencing. Unlike other reviews in the field, here the overview of existing evidence linking H3K27me3 status with breast cancer biology and the tumour outcome is presented especially in the context of diverse breast cancer subtypes. Moreover, the potential of agents that target H3K27me3 for the treatment of this complex disease as well as H3K27 methylation in cross-talk with other chromatin modifications and lncRNAs are discussed.

Role of EZH2 in bone marrow mesenchymal stem cells and immune-cancer interactions

In recent years, methylation modification has been determined to be vital for the biological regulation of normal cells, tumor cells, and tumor microenvironment immune cells. Enhancer of zeste homology 2 (EZH2), a component of the Polycomb Repressive Complex 2 (PRC2), catalyzes the trimethylation of the downstream gene in the tri-methylates histone three lysine 27 (H3K27me3) position, which causes chromatin pyknosis, and thus, silences the expression of related genes. In this paper, we reviewed the role of EZH2 in regulating bone marrow mesenchymal stem cell differentiation and the immune cell function in tumor microenvironment, summarized all types of existing EZH2 inhibitors and the main clinical trials, and proposed relevant ideas for potential clinical applications.

Antihistamine Drug Ebastine Inhibits Cancer Growth by Targeting Polycomb Group Protein EZH2

Enhancer of zester homolog 2 (EZH2), a histone lysine methyltransferase and the catalytic component of polycomb repressive complex 2, has been extensively investigated as a chromatin regulator and a transcriptional suppressor by methylating H3 at lysine 27 (H3K27). EZH2 is upregulated or mutated in most cancers, and its expression levels are negatively associated with clinical outcomes. However, the current developed small-molecule inhibitors targeting EZH2 enzymatic activities could not inhibit the growth and progression of solid tumors. Here, we discovered an antihistamine drug, ebastine, as a novel EZH2 inhibitor by targeting EZH2 transcription and subsequently downregulating EZH2 protein level and H3K27 trimethylation in multiple cancer cell lines at concentrations below 10 μmol/L. The inhibition of EZH2 by ebastine further impaired the progression, migration, and invasiveness of these cancer cells. Overexpression of Ezh2 wild-type and its mutant, H689A (lacking methyltransferase activity), rescued the neoplastic properties of these cancer cells after ebastine treatment, suggesting that EZH2 targeted by ebastine is independent of its enzymatic function. Next-generation RNA-sequencing analysis also revealed that C4-2 cells treated with 8 μmol/L ebastine showed a gene profiling pattern similar to EZH2-knockdown C4-2 cells, which was distinctively different from cells treated with GSK126, an EZH2 enzyme inhibitor. In addition, ebastine treatment effectively reduced tumor growth and progression, and enhanced progression-free survival in triple-negative breast cancer and drug-resistant castration-resistant prostate cancer patient-derived xenograft mice. Our data demonstrated that ebastine is a novel, safe, and potent anticancer agent for patients with advanced cancer by targeting the oncoprotein EZH2.

Long Non-Coding RNA HOTAIR in Breast Cancer Therapy

Breast cancer (BC) is the most common cancer type among women, and morbidity and mortality rates are still very high. Despite new innovative therapeutic approaches for all BC molecular subtypes, the discovery of new molecular biomarkers involved in tumor progression has been fundamental for the implementation of personalized treatment strategies and improvement of patient management. Many experimental studies indicate that long non-coding RNAs (lncRNAs) are strongly involved in BC initiation, metastatic progression, and drug resistance. In particular, aberrant expression of HOX transcript antisense intergenic RNA (HOTAIR) lncRNA plays an important role in BC contributing to its progression and represents a predictor of BC metastasis. For its proven prognostic value, HOTAIR could represent a potential therapeutic target in BC. In the present review, we summarize the role of HOTAIR in cancer progression and drug resistance, in particular in BC, and we illustrate the main approaches for silencing it.

DZNep-mediated apoptosis in B-cell lymphoma is independent of the lymphoma type, EZH2 mutation status and MYC, BCL2 or BCL6 translocations

Enhancer of zeste homolog 2 (EZH2) tri-methylates histone 3 at position lysine 27 (H3K27me3). Overexpression and gain-of-function mutations in EZH2 are regarded as oncogenic drivers in lymphoma and other malignancies due to the silencing of tumor suppressors and differentiation genes. EZH2 inhibition is sought to represent a good strategy for tumor therapy. In this study, we treated Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) cell lines with 3-deazaneplanocin—A (DZNep), an indirect EZH2 inhibitor which possesses anticancer properties both in-vitro and in-vivo. We aimed to address the impact of the lymphoma type, EZH2 mutation status, as well as MYC, BCL2 and BCL6 translocations on the sensitivity of the lymphoma cell lines to DZNep-mediated apoptosis. We show that DZNep inhibits proliferation and induces apoptosis of these cell lines independent of the type of lymphoma, the EZH2 mutation status and the MYC, BCL2 and BCL6 rearrangement status. Furthermore, DZNep induced a much stronger apoptosis in majority of these cell lines at a lower concentration, and within a shorter period when compared with EPZ-6438, a direct EZH2 inhibitor currently in phase II clinical trials. Apoptosis induction by DZNep was both concentration-dependent and time-dependent, and was associated with the inhibition of EZH2 and subsequent downregulation of H3K27me3 in DZNep-sensitive cell lines. Although EZH2, MYC, BCL2 and BCL6 are important prognostic biomarkers for lymphomas, our study shows that they poorly influence the sensitivity of lymphoma cell lines to DZNep-mediated apoptosis.

The Pharmacokinetic Prediction of Cyclosporin A after Coadministration with Wuzhi Capsule

We aim to describe the influence of principal ingredients of Wuzhi capsule, schisandrin A (SIA) and schisantherin A (STA), on the pharmacokinetics of cyclosporin A (CsA) and to quantify the herb-drug interactions (HDIs) between SIA, STA, and CsA. CsA is a first-line immunosuppressant for anti-rejection therapy after solid organ transplantation, while narrow therapeutic window associated with strong hepatotoxicity largely limited its use. Wuzhi capsule, a liver-protective drug, was approved for coadministration with CsA to reduce the hepatotoxicity. There are few studies exploring HDIs of CsA when coadministered with Wuzhi capsule. The essential adjusted physicochemical data and pharmacokinetic parameters of SIA, STA, and CsA were collected. Then physiologically based pharmacokinetic (PBPK) models of SIA, STA, and CsA were built and verified in healthy subjects using Simcyp respectively. The refined PBPK models were used to estimate potential HDIs between CsA and SIA, STA. The simulated plasma concentration-time curves of CsA, SIA, and STA were in good accordance with the observed profiles respectively. CsA pharmacokinetics were improved after coadministration. After a single dose and multiple doses, the area under the plasma concentration-time curve (AUC) of CsA was increased by 47% and 226% when coadministered with STA, respectively, and by 8% and 36% when coadministered with SIA, respectively. PBPK models sufficiently described the pharmacokinetics of CsA, SIA, and STA. Compared with SIA, STA inhibited CsA metabolism to a greater extent. Our result revealed the dose of CsA can be reduced to maintain similar profile when used concomitantly with Wuzhi capsule.

Predicting the Effects of Different Triazole Antifungal Agents on the Pharmacokinetics of Tamoxifen

Tamoxifen is an antiestrogen drug that is widely used in the adjuvant chemotherapy of estrogen receptor-α (ERα)-positive breast cancer. Chemotherapy could suppress immune function in breast cancer patients, which may cause invasive fungal infections (IFIs). Triazoles (voriconazole, fluconazole, and itraconazole) were commonly used for IFI. The physiologically based pharmacokinetic (PBPK) models were developed to investigate the influence of different triazoles on tamoxifen pharmacokinetics in this paper. To investigate the influence of different triazoles (voriconazole, fluconazole, itraconazole) on tamoxifen pharmacokinetics. Adjusted physicochemical data and pharmacokinetic parameters of voriconazole, fluconazole, itraconazole, and tamoxifen were obtained from published literatures. PBPK models were built and verified in healthy subjects using GastroPlus™. Voriconazole, itraconazole, and tamoxifen were administered orally. Fluconazole was administered intravenously. Simulated plasma concentration-time curves of the voriconazole, fluconazole, itraconazole, and tamoxifen showed good agreement with the observed profiles, respectively. The DDI simulations showed that the pharmacokinetic parameters of tamoxifen were increased by various degrees when coadministered with different triazoles. In healthy subjects, the area under the plasma concentration-time curve from 0 to t h (AUC_0-t) of tamoxifen was increased by 41%, 5%, and1% when coadministrated with voriconazole, fluconazole, and itraconazole, respectively. The PBPK models adequately characterized the pharmacokinetics of tamoxifen and triazoles. Among the three triazoles, voriconazole exhibited the greatest effect on tamoxifen pharmacokinetics. In clinical practice, an effective dosage adjustment of tamoxifen may need to be considered and TDM for tamoxifen is advisable to guide dosing and optimize therapy when coadministered with voriconazole.

Lung Cancer Therapy Targeting Histone Methylation: Opportunities and Challenges

Lung cancer is one of the most common malignancies. In spite of the progress made in past decades, further studies to improve current therapy for lung cancer are required. Dynamically controlled by methyltransferases and demethylases, methylation of lysine and arginine residues on histone proteins regulates chromatin organization and thereby gene transcription. Aberrant alterations of histone methylation have been demonstrated to be associated with the progress of multiple cancers including lung cancer. Inhibitors of methyltransferases and demethylases have exhibited anti-tumor activities in lung cancer, and multiple lead candidates are under clinical trials. Here, we summarize how histone methylation functions in lung cancer, highlighting most recent progresses in small molecular inhibitors for lung cancer treatment.

Functional and therapeutic significance of EZH2 in urological cancers

The enhancer of zeste homolog 2 (EZH2) is a core subunit of the polycomb repressor complex 2 (PRC2), which is overexpressed in numerous cancers and mutated in several others. Notably, EZH2 acts not only a critical epigenetic repressor through its role in histone methylation, it is also an activator of gene expression, acting through multiple signaling pathways in distinct cancer types. Increasing evidence suggests that EZH2 is an oncogene and is central to initiation, growth and progression of urological cancers. In this review, we highlight the critical role of EZH2 as a master regulator of tumorigenesis in the prostate, bladder and the kidney through epigenetic control of transcription as well as a modulation of various critical signaling pathways. We also discuss the promise and challenges for EZH2 inhibitors as future anticancer therapeutics, some of which are currently in clinical trials.

Evaluation of the impact of S-adenosylmethionine-dependent methyltransferase inhibitor, 3-deazaneplanocin A, on tissue injury and cognitive function in mice

Cancer patients display cognitive impairment due, at least partly, to the treatments. Additionally, chemotherapeutic treatments can lead to organ injury, limiting their use, and are likely to have negative impacts on patients’ quality of life. The aim of this study was to investigate the toxicity of 3-Deazaneplanocin A (DZNep) on several tissues and organs, as well as on cognitive functions. DZNep is an inhibitor of S-adenosylmethionine-dependent methyltransferase (in particular of the histone methyltransferase EZH2) which showed antitumoral functions in preclinical trials but whose effects on behavior and on organs (side effects) are not known.

Chronic injections of DZNep were performed intraperitoneally in male NMRI mice (2 mg/kg; i.p.; three times per week) during 8 weeks. A follow-up of body weight was assessed during all experiments. Histological analysis were performed on several organs. EZH2 expression and H3K27me3 were assayed by western-blot. Several behavioral tests were performed during treatment and 2 weeks after. A particular focus was made on spontaneous locomotor activity, cognitive functions (spontaneous alternation and recognition memory), and anxiety- and depression-related behavior. Hematological modifications were also assessed.

Chronic DZNep treatment transiently reduced animal growth. It had no effect on most organs but provoked a reversible splenomegaly, and persistent testis reduction and erythropoiesis. DZNep administration did not alter animal behavior.

In conclusion, this study is encouraging for the use of DZNep for cancer treatment. Indeed, it has no effect on animal behavior, conferring an advantageous safety, and induces irreversible side effects limited on testis which are unfortunately found in most chemotherapy treatments.

Enhancer of zeste homolog 2 (EZH2) inhibitors

Dysregulation of the histone methyltransferase EZH2 plays a critical role in the development of a variety of malignancies including B-cell lymphomas. As a result, a series of small molecule inhibitors of EZH2 have been developed and studied in the pre-clinical setting. Three EZH2 inhibitors: tazemetostat (EPZ-6438), GSK2816126 and CPI-1205 have moved into phase I/phase II clinical trials in patients with non-Hodgkin lymphoma and genetically defined solid tumors. Early data from the tazemetostat trials indicate an acceptable safety profile and early signs of activity in diffuse large B-cell lymphoma and follicular lymphoma, including patients with EZH2 wild-type and mutant tumors. In this review, we present the rationale, key pre-clinical and early clinical findings of small molecule EZH2 inhibitors for use in lymphoma as well as future challenges and potential opportunities for combination therapies.

Modeling of the Nanoparticles Absorption Under a Gastrointestinal Simulated Ambient Condition

Proanthocyanidins (PAs) have several bioactivities, but they are unstable in the digestive tract and possess low bioavailability. Nanoencapsulation stabilizes these compounds for oral administration. The intestinal absorption of grape seed and skin extracts, and the poly-lactic acid (PLA) nanoparticles loaded with such extracts was modeled, taking into consideration physicochemical process parameters, evaluating the PAs concentration profile in the human small intestine. Density (ρ), solubility, viscosity (μ), diffusion coefficient (D), and the global mass transfer coefficient (K) for both substrates were estimated, simulating their passing from the intestine into the blood at 37°C. For the seed and skin extracts encapsulated in PLA the physicochemical parameters were: D = 1.81 × 10^^-5 and D = 5.72 × 10^^-5 cm²/s; K = 3.4 × 10^^-3 and K = 2.47 × 10^^-4 cm/s, respectively. Lower resistance was offered by the seed extract than by skin extracts (nanoencapsulated), which was explained by differences in structural composition, and average molecular weight of the two kinds of extracts, which should be more favorable to the mass transfer in comparison to the raw extracts. The concentration profile of grape extracts in the small intestine was modeled through a pure convection model, and the encapsulated extract on PLA nanoparticles using a mixed regime model, which described the process of dissolution and absorption of the grape extracts from the intestine to the blood stream. The absorbed fraction predicted by the model was 42.7 and 24.2% for seed and skin extracts, respectively. Those values increased to 100% for both extracts after the simulation with the nanoencapsulated extracts. Consequently, extract encapsulation should produce a significant increase in intestinal absorption.

EZH2 inhibitors: a patent review (2014-2016)

INTRODUCTION

The histone methyltransferase EZH2 is the catalytic subunit of the PRC2 complex involved in H3K27 trimethylation. Aberrant PRC2 activity has been reported in several cancers and EZH2 overexpression has been associated with poor outcome in different tumors. EZH2 somatic mutations and deletions was found in lymphomas, myelodysplastic and myeloproliferative disorders and associated with higher H3K27me3 levels. Numerous chemical entities have been studied as EZH2 inhibitors in the recent years and some of them entered the cancer clinical arena. Areas covered: This review summarizes recent efforts in the drug development of EZH2 inhibitors reported in the patent literature covering the 2014-2016 period, and their potential use as therapeutics mainly in cancerous diseases. Expert opinion: Despite the number of compounds described, only a few of them entered the clinical arena. Moreover, most of the compounds developed share a common 2-pyridone ring pharmacophore. Recently, secondary mutants have been described to be resistant to the standard EZH2 inhibitors treatment. Based on these data a lot of effort is still required to find new chemical entities that inhibit EZH2 directly, or indirectly (via PRC2 disruption). Several issues are still to be settled, such as drug resistance and the importance of selectivity over EZH1 or somatic EZH2 mutants.

miR-202 Diminishes TGFβ Receptors and Attenuates TGFβ1-Induced EMT in Pancreatic Cancer

Previous studies in our laboratory identified that 3-deazaneplanocin A (DZNep), a carbocyclic adenosine analog and histone methyl transferase inhibitor, suppresses TGFβ-induced epithelial-to-mesenchymal (EMT) characteristics. In addition, DZNep epigenetically reprograms miRNAs to regulate endogenous TGFβ1 levels via miR-663/4787-mediated RNA interference (Mol Cancer Res. 2016 Sep 13. pii: molcanres.0083.2016) (1). Although DZNep also attenuates exogenous TGFβ-induced EMT response, the mechanism of this inhibition was unclear. Here, DZNep induced miR-202-5p to target both TGFβ receptors, TGFBR1 and TGFBR2, for RNA interference and thereby contributes to the suppression of exogenous TGFβ-induced EMT in pancreatic cancer cells. Lentiviral overexpression of miR-202 significantly reduced the protein levels of both TGFβ receptors and suppressed TGFβ signaling and EMT phenotypic characteristics of cultured parenchymal pancreatic cancer cells. Consistently, transfection of anti-miRNAs against miR-202-5p resulted in increased TGFBR1 and TGFBR2 protein expressions and induced EMT characteristics in these cells. In stellate pancreatic cells, miR-202 overexpression slowed growth as well as reduced stromal extracellular membrane matrix protein expression. In orthotopic pancreatic cancer mouse models, both immunodeficient and immunocompetent, miR-202 reduced tumor burden and metastasis. Together, these findings demonstrate an alternative mechanism of DZNep in suppressing TGFβ signaling at the receptor level and uncover the EMT-suppressing role of miR-202 in pancreatic cancer.Implications: These findings support the possibility of combining small molecule-based (e.g., DZNep analogs) or large molecule-based (e.g., miRNAs) epigenetic modifiers with conventional nucleoside analogs (e.g., gemcitabine, capecitabine) to improve the antimetastatic potential of current pancreatic cancer therapy. Mol Cancer Res; 15(8); 1029-39. ©2017 AACR.

Inhibition of S-Adenosylmethionine-Dependent Methyltransferase Attenuates TGFβ1-Induced EMT and Metastasis in Pancreatic Cancer: Putative Roles of miR-663a and miR-4787-5p

The identification of epigenetic reversal agents for use in combination chemotherapies to treat human pancreatic ductal adenocarcinomas (PDAC) remains an unmet clinical need. Pharmacologic inhibitors of Enhancer of Zeste Homolog 2 (EZH2) are emerging as potential histone methylation reversal agents for the treatment of various solid tumors and leukemia; however, the surprisingly small set of mRNA targets identified with EZH2 knockdown suggests novel mechanisms contribute to their antitumorigenic effects. Here, 3-deazaneplanocin-A (DZNep), an inhibitor of S-adenosyl-L-homocysteine hydrolase and EZH2 histone lysine-N-methyltransferase, significantly reprograms noncoding microRNA (miRNA) expression and dampens TGFβ1-induced epithelial-to-mesenchymal (EMT) signals in pancreatic cancer. In particular, miR-663a and miR-4787-5p were identified as PDAC-downregulated miRNAs that were reactivated by DZNep to directly target TGFβ1 for RNA interference. Lentiviral overexpression of miR-663a and miR-4787-5p reduced TGFβ1 synthesis and secretion in PDAC cells and partially phenocopied DZNep's EMT-resisting effects, whereas locked nucleic acid (LNA) antagomiRNAs counteracted them. DZNep, miR-663a, and miR-4787-5p reduced tumor burden in vivo and metastases in an orthotopic mouse pancreatic tumor model. Taken together, these findings suggest the epigenetic reprogramming of miRNAs by synthetic histone methylation reversal agents as a viable approach to attenuate TGFβ1-induced EMT features in human PDAC and uncover putative miRNA targets involved in the process.

IMPLICATIONS

The findings support the potential for synthetic histone methylation reversal agents to be included in future epigenetic-chemotherapeutic combination therapies for pancreatic cancer. Mol Cancer Res; 14(11); 1124-35. ©2016 AACR.

Inhibition of histone methyltransferase EZH2 ameliorates early acute renal allograft rejection in rats

BACKGROUND

Although histone methyltransferases EZH2 has been proved to have significant regulatory effect on the immune rejection after hematopoietic stem cell transplantation, its role in solid-organ transplantation remains uncovered. In this study, we investigate whether histone methylation regulation can impact renal allograft rejection in rat models.

RESULTS

Allogeneic rat renal transplantation model (Wistar to Lewis) was established, and the recipients were administrated with EZH2 inhibitor DZNep after transplantation. Renal allografts and peripheral blood were collected on day 5 after transplantation for histological examination and mechanism investigation. We found that inhibition of EZH2 by DZNep after transplantation significantly ameliorated acute rejection (AR), with decreased histological injury and reduced inflammatory infiltration in renal allografts. Attenuation of AR was due to the prohibited activation of alloreactive T cells, the subsequent impaired production of inflammatory cytokines, and also the elevated apoptosis of alloreactive T cells in both renal allografts and periphery. However, inhibition of EZH2 did not increase the regulatory T cells during the AR.

CONCLUSIONS

Disruption of EZH2 by DZNep suppressed the immune responses of alloreactive T cells and ameliorated AR of renal allografts. This suggests a therapeutic potential of targeting histone methyltransferases EZH2 in treating allograft rejection after solid organ transplantation.

Solidified SNEDDS of loratadine: formulation using hydrophilic and hydrophobic grades of Aerosil®, pharmacokinetic evaluations and in vivo–in silico predictions using GastroPlus™

Hydrophilic and hydrophobic grades of Aerosil® were employed to develop solid-SNEDDS of loratadine and evaluated for their influence on powder, physicochemical and biopharmaceutical properties.

Enhancer of Zeste Homolog 2 Inhibition Attenuates Renal Fibrosis by Maintaining Smad7 and Phosphatase and Tensin Homolog Expression

Enhancer of zeste homolog 2 (EZH2) is a methyltransferase that induces histone H3 lysine 27 trimethylation (H3K27me3) and functions as an oncogenic factor in many cancer types. However, the role of EZH2 in renal fibrogenesis remains unexplored. In this study, we found high expression of EZH2 and H3K27me3 in cultured renal fibroblasts and fibrotic kidneys from mice with unilateral ureteral obstruction and humans with CKD. Pharmacologic inhibition of EZH2 with 3-deazaneplanocin A (3-DZNeP) or GSK126 or siRNA-mediated silencing of EZH2 inhibited serum- and TGFβ1-induced activation of renal interstitial fibroblasts in vitro, and 3-DZNeP administration abrogated deposition of extracellular matrix proteins and expression of α-smooth muscle actin in the obstructed kidney. Injury to the kidney enhanced Smad7 degradation, Smad3 phosphorylation, and TGFβ receptor 1 expression, and 3-DZNeP administration prevented these effects. 3-DZNeP also suppressed phosphorylation of the renal EGF and PDGFβ receptors and downstream signaling molecules signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2 after injury. Moreover, EZH2 inhibition increased the expression of phosphatase and tensin homolog (PTEN), a protein previously associated with dephosphorylation of tyrosine kinase receptors in the injured kidney and serum-stimulated renal interstitial fibroblasts. Finally, blocking PTEN with SF1670 largely diminished the inhibitory effect of 3-DZNeP on renal myofibroblast activation. These results uncovered the important role of EZH2 in mediating the development of renal fibrosis by downregulating expression of Smad7 and PTEN, thus activating profibrotic signaling pathways. Targeted inhibition of EZH2, therefore, could be a novel therapy for treating CKD.