scholarly journals macroH2A2 shapes chromatin accessibility at enhancer elements in glioblastoma to modulate a targetable self-renewal epigenetic network

2021 ◽  
Author(s):  
Ana Nikolic ◽  
Anna Bobyn ◽  
Francesca Maule ◽  
Katrina Ellestad ◽  
Xueqing Lun ◽  
...  
Keyword(s):  
Chromatin Accessibility ◽  
Epigenetic Mechanism ◽  
Epigenetic Mechanisms ◽  
Direct Role ◽  
Self Renewal ◽  
In Vivo Models ◽  
Chromatin Regulators ◽  
New Treatment

Self-renewal is a crucial property of glioblastoma cells and is enabled by the choreographed function of chromatin regulators and transcription factors. Identifying targetable epigenetic mechanisms of self-renewal could represent an important step toward developing new and effective treatments for this universally lethal cancer. Here we uncover a targetable epigenetic axis of self-renewal mediated by the histone variant macroH2A2. Using patient-derived in vitro and in vivo models, we show that macroH2A2 has a direct role in shaping chromatin accessibility at enhancer elements to antagonize transcriptional programs of self-renewal. Pharmaceutical inhibition of the chromatin remodeler Menin increased macroH2A2 levels and repressed self-renewal. Our results reveal a targetable epigenetic mechanism of self-renewal controlled by macroH2A2 and suggest new treatment approaches for glioblastoma patients.

scholarly journals STEM-29. THE HISTONE VARIANT macroH2A2 ORCHESTRATES AN ACTIONABLE CHROMATIN PROGRAM OF STEMNESS IN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii202-ii202
Author(s):  
Ana Nikolic ◽  
Anna Bobyn ◽  
Katrina Ellestad ◽  
Xueqing Lun ◽  
Michael Johnston ◽  
...  
Keyword(s):  
Chromatin Accessibility ◽  
Histone Variant ◽  
Clinical Settings ◽  
Glioblastoma Cells ◽  
Self Renewal ◽  
Viral Mimicry ◽  
Experimental Findings ◽  
Preclinical Work

Abstract Glioblastoma cells with the crucial stemness property of self-renewal constitute therapy-resistant reservoirs that seed tumor relapse. Effective targeting of these cells in clinical settings has been hampered by their relative quiescence, which invalidates the cell replication bias of most current treatments. Furthermore, although their dependence on specific chromatin and transcriptional states for the maintenance of stemness programs has been proposed as a vulnerability, these nuclear programs have been challenging to target pharmaceutically. Therefore the identification of targetable chromatin paradigms regulating self-renewal would represent a significant advancement for this incurable malignancy. Here we report a new role for the histone variant macroH2A2 in modulating a targetable epigenetic network of stemness in glioblastoma. By integrating transcriptomic, bulk and single-cell epigenomic datasets we generated from patient-derived models and surgical specimens, we show that macroH2A2 represses a transcriptional network of stemness through direct regulation of chromatin accessibility at enhancer elements. Functional assays in vitro and in vivo further showcase that macroH2A2 antagonizes self-renewal and stemness in glioblastoma preclinical models. In agreement with our experimental findings, high expression of macroH2A2 is a positive prognostic factor in clinical glioblastoma cohorts. Reasoning that increasing macroH2A2 levels could be an effective strategy to repress stemness programs and ameliorate patient outcome, we embarked on a screen to identify compounds that could elevate macroH2A2 levels. We report that an inhibitor of the chromatin remodeler Menin increases macroH2A2 levels, which in turn repress self-renewal. Additionally, we provide evidence that Menin inhibition induces viral mimicry programs and the demise of glioblastoma cells. Menin inhibition is being tested in clinical trials for blood malignancies (NCT04067336). Our preclinical work therefore reveals a novel and central role for macroH2A2 in an epigenetic network of stemness and suggests new clinical approaches for glioblastoma.

scholarly journals Concurrent stem- and lineage-affiliated chromatin programs precede hematopoietic lineage restriction

2020 ◽  
Author(s):  
Fatemeh Safi ◽  
Parashar Dhapola ◽  
Sarah Warsi ◽  
Eva Erlandsson ◽  
Ewa Sitnicka ◽  
...  
Keyword(s):  
Chromatin Accessibility ◽  
Signal Processing Algorithm ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Hematopoietic Lineage ◽  
Stem And Progenitor Cells ◽  
Transition Points ◽  
Lineage Priming

SUMMARYThe emerging notion of hematopoietic stem- and progenitor cells (HSPCs) as a low-primed cloud without sharply demarcated gene expression programs raises the question on how cellular fate options emerge, and at which stem-like stage lineage priming is initiated. Here we investigated single-cell chromatin accessibility of Lineage−, cKit+, Sca1+ (LSK) HSPCs spanning the early differentiation landscape. Application of a signal-processing algorithm to detect transition points corresponding to massive alterations in accessibility of 571 transcription factor-motifs revealed a population of LSK FMS-like tyrosine kinase 3(Flt3)intCD9high cells that concurrently display stem-like and lineage-affiliated chromatin signatures pointing to a simultaneous gain of both Lympho-Myeloid and Megakaryocyte-Erythroid programs. Molecularly and functionally, these cells position between stem cells and committed progenitors, display multi-lineage capacity in vitro and in vivo, but lack self-renewal activity. This integrative molecular analysis resolves the heterogeneity of cells along hematopoietic differentiation and permits investigation of chromatin-mediated transition between multipotency and lineage restriction.

scholarly journals Inhibition of the Lysophosphatidylinositol Transporter ABCC1 Reduces Prostate Cancer Cell Growth and Sensitizes to Chemotherapy

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2022 ◽  
Author(s):  
Aikaterini Emmanouilidi ◽  
Ilaria Casari ◽  
Begum Gokcen Akkaya ◽  
Tania Maffucci ◽  
Luc Furic ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Growth ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Prostate Cancer Cell ◽  
Cancer Cell Growth ◽  
Direct Role ◽  
In Vivo Models

Expression of ATP-binding cassette (ABC) transporters has long been implicated in cancer chemotherapy resistance. Increased expression of the ABCC subfamily transporters has been reported in prostate cancer, especially in androgen-resistant cases. ABCC transporters are known to efflux drugs but, recently, we have demonstrated that they can also have a more direct role in cancer progression. The pharmacological potential of targeting ABCC1, however, remained to be assessed. In this study, we investigated whether the blockade of ABCC1 affects prostate cancer cell proliferation using both in vitro and in vivo models. Our data demonstrate that pharmacological inhibition of ABCC1 reduced prostate cancer cell growth in vitro and potentiated the effects of Docetaxel in vitro and in mouse models of prostate cancer in vivo. Collectively, these data identify ABCC1 as a novel and promising target in prostate cancer therapy.

scholarly journals Epigenetic modulation of intestinal Na+/H+ exchanger-3 expression

2018 ◽  
Vol 314 (3) ◽  
pp. G309-G318 ◽  
Author(s):  
Anoop Kumar ◽  
Pooja Malhotra ◽  
Hayley Coffing ◽  
Shubha Priyamvada ◽  
Arivarasu N. Anbazhagan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Dna Methyltransferase ◽  
Dna Demethylation ◽  
Epigenetic Mechanism ◽  
Mrna Levels ◽  
In Vivo Models ◽  
Epigenetic Modulation

Na+/H+ exchanger-3 (NHE3) is crucial for intestinal Na+ absorption, and its reduction has been implicated in infectious and inflammatory bowel diseases (IBD)-associated diarrhea. Epigenetic mechanisms such as DNA methylation are involved in the pathophysiology of IBD. Whether changes in DNA methylation are involved in modulating intestinal NHE3 gene expression is not known. Caco-2 and HuTu 80 cells were used as models of human intestinal epithelial cells. Normal C57/BL6, wild-type, or growth arrest and DNA damage-inducible 45b (GADD45b) knockout (KO) mice were used as in vivo models. NHE3 gene DNA methylation levels were assessed by MBDCap (MethyMiner) assays. Results demonstrated that in vitro methylation of NHE3 promoter construct (p-1509/+127) cloned into a cytosine guanine dinucleotide-free lucia vector decreased the promoter activity in Caco-2 cells. DNA methyltransferase inhibitor 5-azacytidine (10 μM, 24 h) caused a significant decrease in DNA methylation of the NHE3 gene and concomitantly increased NHE3 expression in Caco-2 cells. Similarly, 5-azacytidine treatment increased NHE3 mRNA levels in HuTu 80 cells. 5-Azacytidine treatment for 3 wk (10 mg/kg body wt ip, 3 times/wk) also resulted in an increase in NHE3 expression in the mouse ileum and colon. Small-interfering RNA knockdown of GADD45b (protein involved in DNA demethylation) in Caco-2 cells decreased NHE3 mRNA expression. Furthermore, there was a significant decrease in NHE3 mRNA and protein expression in the ileum and colon of GADD45b KO mice. Our findings demonstrate that NHE3 gene expression is regulated by changes in its DNA methylation. NEW & NOTEWORTHY Our studies for the first time demonstrate that Na+/H+ exchanger-3 gene expression is regulated by an epigenetic mechanism involving DNA methylation.

Melatonin modifies tumor hypoxia and metabolism by inhibiting HIF-1α and energy metabolic pathway in the in vitro and in vivo models of breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Carbonic Anhydrases ◽  
In Vivo Models ◽  
Ca Ix ◽  
Gene And Protein Expression

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 

Current Challenges in the Development of Vaccines and Drugs Against Emerging Vector-borne Diseases

2019 ◽  
Vol 26 (16) ◽  
pp. 2974-2986 ◽  
Author(s):  
Kwang-sun Kim
Keyword(s):  
New Host ◽  
In Vivo Models ◽  
Vector Borne Diseases ◽  
Novel Drugs ◽  
Huge Impact ◽  
Tick Borne Disease ◽  
Vector Borne ◽  
Living Organisms

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.

Potential for Treatment of Neurodegenerative Diseases with Natural Products or Synthetic Compounds that Stabilize Microtubules

2020 ◽  
Vol 26 (35) ◽  
pp. 4362-4372
Author(s):  
John H. Miller ◽  
Viswanath Das
Keyword(s):  
Natural Products ◽  
Neurodegenerative Diseases ◽  
In Vivo Models ◽  
Synthetic Compounds ◽  
Stabilizing Agents ◽  
Animal Models Of Disease ◽  
Model Studies ◽  
Models Of Disease

No effective therapeutics to treat neurodegenerative diseases exist, despite significant attempts to find drugs that can reduce or rescue the debilitating symptoms of tauopathies such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, or Pick’s disease. A number of in vitro and in vivo models exist for studying neurodegenerative diseases, including cell models employing induced-pluripotent stem cells, cerebral organoids, and animal models of disease. Recent research has focused on microtubulestabilizing agents, either natural products or synthetic compounds that can prevent the axonal destruction caused by tau protein pathologies. Although promising results have come from animal model studies using brainpenetrant natural product microtubule-stabilizing agents, such as paclitaxel analogs that can access the brain, epothilones B and D, and other synthetic compounds such as davunetide or the triazolopyrimidines, early clinical trials in humans have been disappointing. This review aims to summarize the research that has been carried out in this area and discuss the potential for the future development of an effective microtubule stabilizing drug to treat neurodegenerative disease.

A Review on Opuntia Species and its Chemistry, Pharmacognosy, Pharmacology and Bioapplications

2020 ◽  
Vol 16 (8) ◽  
pp. 1227-1244
Author(s):  
Dharmendra Kumar ◽  
Pramod K. Sharma
Keyword(s):  
Human Consumption ◽  
In Vivo Models ◽  
Sugar Amino Acids ◽  
Opuntia Species ◽  
Therapeutic Uses ◽  
Anti Inflammatory ◽  
Online Library ◽  
Different Parts

Background:: Opuntia species, locally known as prickly pear was used for various purposes as food, medicine, beverage, source of dye and animal food. Many studies have revealed its pharmacology activity from time to time. This review is a collection of chemistry, pharmacognosy, pharmacology and bioapplications of the cactus family. Methods: Many sources were used to collect information about Opuntia species such as Pub med, Google scholar, Agris, science direct, Embase, Merk index, Wiley online library, books and other reliable sources. This review contains studies from 1812 to 2019. Results: The plants from the cactus family offer various pharmacological active compounds including phenolic compounds, carotenoids, betalains, vitamins, steroids, sugar, amino acids, minerals and fibers. These bioactive compounds serve various pharmacological activities such as anticancer, antiviral, anti-diabetic, Neuroprotective, anti-inflammatory, antioxidant, Hepatoprotective, antibacterial, antiulcer and alcohol hangover. According to various studies, Opuntia species offer many bioapplications such as fodder for animal, soil erosion, prevention, human consumption and waste water decontamination. Finally, different parts of plants are used in various formulations that offer many biotechnology applications. Conclusion: Different parts of Opuntia plant (fruits, seeds, flowers and cladodes) are used in various health problems which include wound healing, anti-inflammatory and urinary tract infection from ancient times. Nowadays, researches have extended several pharmacological and therapeutic uses of Opuntia species as discussed in this review. Many in-vitro and in-vivo models are also discussed in this review as the proofs of research findings. Various research gaps have been observed in current studies that require attention in the future.

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