scholarly journals The long non-coding RNA HOTAIRM1 promotes tumor aggressiveness and radiotherapy resistance in glioblastoma

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Ulvi Ahmadov ◽  
Daniel Picard ◽  
Jasmin Bartl ◽  
Manuela Silginer ◽  
Marija Trajkovic-Arsic ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Promoter Methylation ◽  
Methylation Status ◽  
Idh Mutation ◽  
Glioblastoma Cells ◽  
Down Regulation ◽  
Knock Down ◽  
Radiotherapy Resistance

AbstractGlioblastoma is the most common malignant primary brain tumor. To date, clinically relevant biomarkers are restricted to isocitrate dehydrogenase (IDH) gene 1 or 2 mutations and O6-methylguanine DNA methyltransferase (MGMT) promoter methylation. Long non-coding RNAs (lncRNAs) have been shown to contribute to glioblastoma pathogenesis and could potentially serve as novel biomarkers. The clinical significance of HOXA Transcript Antisense RNA, Myeloid-Specific 1 (HOTAIRM1) was determined by analyzing HOTAIRM1 in multiple glioblastoma gene expression data sets for associations with prognosis, as well as, IDH mutation and MGMT promoter methylation status. Finally, the role of HOTAIRM1 in glioblastoma biology and radiotherapy resistance was characterized in vitro and in vivo. We identified HOTAIRM1 as a candidate lncRNA whose up-regulation is significantly associated with shorter survival of glioblastoma patients, independent from IDH mutation and MGMT promoter methylation. Glioblastoma cell line models uniformly showed reduced cell viability, decreased invasive growth and diminished colony formation capacity upon HOTAIRM1 down-regulation. Integrated proteogenomic analyses revealed impaired mitochondrial function and determination of reactive oxygen species (ROS) levels confirmed increased ROS levels upon HOTAIRM1 knock-down. HOTAIRM1 knock-down decreased expression of transglutaminase 2 (TGM2), a candidate protein implicated in mitochondrial function, and knock-down of TGM2 mimicked the phenotype of HOTAIRM1 down-regulation in glioblastoma cells. Moreover, HOTAIRM1 modulates radiosensitivity of glioblastoma cells both in vitro and in vivo. Our data support a role for HOTAIRM1 as a driver of biological aggressiveness, radioresistance and poor outcome in glioblastoma. Targeting HOTAIRM1 may be a promising new therapeutic approach.

Down-regulation of ribosomal protein S15A inhibits proliferation of human glioblastoma cells in vivo and in vitro via AKT pathway

Tumor Biology ◽  
2015 ◽  
Vol 37 (4) ◽  
pp. 4979-4990 ◽  
Author(s):  
Yiqun Yao ◽  
Yongjian Liu ◽  
Xiupeng Lv ◽  
Bin Dong ◽  
Feng Wang ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Akt Pathway ◽  
Glioblastoma Cells ◽  
Down Regulation ◽  
Human Glioblastoma ◽  
Human Glioblastoma Cells

Regulation of the EGFR-E2F3a axis by the interferon regulatory factor (IRFs) and by promoter methylation of miR-34a in ovarian cancer

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16522-e16522
Author(s):  
D. Reimer ◽  
M. Hubalek ◽  
S. Riedle ◽  
S. Skvortsov ◽  
M. Erdel ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Promoter Methylation ◽  
Methylation Status ◽  
Family Members ◽  
Alternative Mechanism ◽  
Mrna Levels ◽  
Knock Down ◽  
Egfr Activation

e16522 Background: Although, EGFR targeting has reached “bedside” in various tumor entities, including ovarian cancer, the essential role of E2F3a in EGFR mediated proliferation remained uncovered. Recently, we outlined the clinical relevance of E2F3a in ovarian cancer. Now we were able to elucidate the pathway between EGFR activation and E2F3a induction. Methods: Promoter mapping of E2F family members was assessed using the JASPER software. E2F3a protein was assessed by immunoblot analyses in siRNA based IRF-1, IRF-2 knockdown HOC-7 cells. Cell growth was determined by MTT assays after siRNA based knockdown of E2F3a. Expression of E2F3a regulating miR-34a, miR-210 and miR-20a were assessed by RT-PCR in 130 ovarian cancer patients and methylation status of the E2F3a promoter and of miRNA promoters were estimated using Methyllight. 6p22 amplification status of patients was determined by FISH analyses. Results: Promoter mapping of E2F family members revealed that IRF-1 and IRF-2 are potential intermediate components of the herein described EGFR-E2F3a axis. As evidenced by knock-down of IRF-1, IRF-2 or both, the ratio between the two mutually antagonistic IRF-1 and IRF-2 was found to be substantial for EGF induced E2F3a up-regulation. E2F3a knock-down yielded a complete abolishment of EGF induced cancer cell proliferation. Although, activated EGFR status showed a highly significant correlation with E2F3a expression, a subgroup of patients presented high E2F3a mRNA levels without EGFR activation. Within this subgroup promoter methylation of miRNA-34a, that regulates E2F3a, was revealed to represent an alternative mechanism of E2F3a regulation in ovarian cancer, whereas promoter methylation of E2F3a itself was not relevant in E2F3a control. Unlike in prostate or bladder cancer 6p22 amplification was not found to be relevant for E2F3a up-regulation in ovarian cancer. Conclusions: Our present data point to the substantial role of the ratio between IRF-1 and IRF-2 in EGFR mediated E2F3a induction. Furthermore, in vivo regulation of E2F3a involves methylation and thereby silencing of miR-34a. Targeting of the herein described molecular pathway, downstream EGFR, could represent an appealing therapeutic approach in ovarian cancer. No significant financial relationships to disclose.

scholarly journals Does promoter methylation of the SLC30A5 (ZnT5) zinc transporter gene contribute to the ageing-related decline in zinc status?

2009 ◽  
Vol 68 (2) ◽  
pp. 142-147 ◽  
Author(s):  
L. J. Coneyworth ◽  
J. C. Mathers ◽  
D. Ford
Keyword(s):  
Promoter Methylation ◽  
Promoter Region ◽  
Cpg Island ◽  
Methylation Status ◽  
Degenerative Diseases ◽  
Zinc Status ◽  
Age Related ◽  
Zn Status

A decline in Zn status with ageing may contribute to the development of frailty, including impaired immune function, and increased incidence of age-related degenerative diseases. This decline may be a result of reduced dietary Zn intake and/or impaired Zn absorption in the gut. The Zn transporter ZnT5 may play a key role in the absorption of dietary Zn. The corresponding gene (SLC30A5) has a CpG island in its promoter region, so could be regulated by epigenetic mechanisms. It is hypothesised that methylation of the SLC30A5 promoter region is increased with age and that a resulting reduction in ZnT5 expression contributes to the decline in Zn status observed with ageing. This hypothesis has been addressed through (1) studies of effects of SLC30A5 promoter methylation on gene expression in vitro and (2) in vivo measurements of the DNA methylation status of this gene domain. It has been established in vitro that methylation of the human SLC30A5 promoter region results in reduced expression of an associated reporter gene. Second, this gene region shows variable levels of methylation in vivo. Correlation between the level of methylation at this locus and age would support the hypothesis that age-related hypermethylation of this region has the potential to modulate dietary Zn absorption. This premise is being investigated by analysis of additional samples from a human adult cohort to test the hypothesis that methylation of the SLC30A5 promoter region contributes to the age-related decline in Zn status.

scholarly journals In Vivo and In Vitro Assays Evaluating the Biological Activity of Taurine, Glucose and Energetic Beverages

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2198
Author(s):  
Marcos Mateo-Fernández ◽  
Fernando Valenzuela-Gómez ◽  
Rafael Font ◽  
Mercedes Del Río-Celestino ◽  
Tania Merinas-Amo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Drosophila Melanogaster ◽  
Biological Activity ◽  
Biological Effects ◽  
Methylation Status ◽  
Repetitive Sequences ◽  
Energy Drinks ◽  
Red Bull

Taurine is one of the main ingredients used in energy drinks which are highly consumed in adolescents for their sugary taste and stimulating effect. With energy drinks becoming a worldwide phenomenon, the biological effects of these beverages must be evaluated in order to fully comprehend the potential impact of these products on the health due to the fact nutrition is closely related to science since the population consumes food to prevent certain diseases. Therefore, the aim of this study was to evaluate the biological effects of taurine, glucose, classic Red Bull® and sugar-free Red Bull® in order to check the food safety and the nutraceutical potential of these compounds, characterising different endpoints: (i) Toxicology, antitoxicology, genotoxicology and life expectancy assays were performed in the Drosophila melanogaster model organism; (ii) The in vitro chemopreventive activity of testing compounds was determined by assessing their cytotoxicity, the proapoptotic DNA-damage capability to induce internucleosomal fragmentation, the strand breaks activity and the modulator role on the methylation status of genomic repetitive sequences of HL-60 promyelocytic cells. Whereas none tested compounds showed toxic or genotoxic effect, all tested compounds exerted antitoxic and antigenotoxic activity in Drosophila. Glucose, classic Red Bull® and sugar-free Red Bull® were cytotoxic in HL-60 cell line. Classic Red Bull® induced DNA internucleosomal fragmentation although none of them exhibited DNA damage on human leukaemia cells. In conclusion, the tested compounds are safe on Drosophila melanogaster and classic Red Bull® could overall possess nutraceutical potential in the in vivo and in vitro model used in this study. Besides, taurine could holistically be one of the bioactive compounds responsible for the biological activity of classic Red Bull®.

scholarly journals LINGO-1 shRNA protects the brain against ischemia/reperfusion injury by inhibiting the activation of NF-κB and JAK2/STAT3

Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Mice Model ◽  
Down Regulation

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.

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 ApoE4 (Δ272–299) induces mitochondrial‐associated membrane formation and mitochondrial impairment by enhancing GRP75-modulated mitochondrial calcium overload in neuron

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Liang ◽  
Weijian Hang ◽  
Jiehui Chen ◽  
Yue Wu ◽  
Bin Wen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Calcium Transport ◽  
Calcium Overload ◽  
Mitochondrial Calcium ◽  
Mitochondrial Impairment

Abstract Background Apolipoprotein E4 (apoE4) is a major genetic risk factor of Alzheimer’s disease. Its C-terminal-truncated apoE4 (Δ272–299) has neurotoxicity by affecting mitochondrial respiratory function. However, the molecular mechanism(s) underlying the action of apoE4 (Δ272–299) in mitochondrial function remain poorly understood. Methods The impact of neuronal apoE4 (Δ272–299) expression on ER stress, mitochondrial-associated membrane (MAM) formation, GRP75, calcium transport and mitochondrial impairment was determined in vivo and in vitro. Furthermore, the importance of ER stress or GRP75 activity in the apoE4 (Δ272–299)-promoted mitochondrial dysfunction in neuron was investigated. Results Neuronal apoE4 (Δ272–299) expression induced mitochondrial impairment by inducing ER stress and mitochondrial-associated membrane (MAM) formation in vivo and in vitro. Furthermore, apoE4 (Δ272–299) expression promoted GRP75 expression, mitochondrial dysfunction and calcium transport into the mitochondria in neuron, which were significantly mitigated by treatment with PBA (an inhibitor of ER stress), MKT077 (a specific GRP75 inhibitor) or GRP75 silencing. Conclusions ApoE4 (Δ272–299) significantly impaired neuron mitochondrial function by triggering ER stress, up-regulating GRP75 expression to increase MAM formation, and mitochondrial calcium overload. Our findings may provide new insights into the neurotoxicity of apoE4 (Δ272–299) against mitochondrial function and uncover new therapeutic targets for the intervention of Alzheimer’s disease.

GDNF and neurturin are target-derived factors essential for cranial parasympathetic neuron development

Development ◽  
2001 ◽  
Vol 128 (19) ◽  
pp. 3773-3782 ◽  
Author(s):  
Eri Hashino ◽  
Marlene Shero ◽  
Dirk Junghans ◽  
Hermann Rohrer ◽  
Jeffrey Milbrandt ◽  
...  
Keyword(s):  
Striate Muscle ◽  
Ciliary Ganglion ◽  
Neuron Development ◽  
Down Regulation ◽  
Eye Muscle ◽  
Ciliary Ganglion Neurons ◽  
Ganglion Neurons ◽  
Parasympathetic Neuron

During development, parasympathetic ciliary ganglion neurons arise from the neural crest and establish synaptic contacts on smooth and striate muscle in the eye. The factors that promote the ciliary ganglion pioneer axons to grow toward their targets have yet to be determined. Here, we show that glial cell line-derived neurotrophic factor (GDNF) and neurturin (NRTN) constitute target-derived factors for developing ciliary ganglion neurons. Both GDNF and NRTN are secreted from eye muscle located in the target and trajectory pathway of ciliary ganglion pioneer axons during the period of target innervation. After this period, however, the synthesis of GDNF declines markedly, while that of NRTN is maintained throughout the cell death period. Furthermore, both in vitro and in vivo function-blocking of GDNF at early embryonic ages almost entirely suppresses ciliary axon outgrowth. These results demonstrate that target-derived GDNF is necessary for ciliary ganglion neurons to innervate ciliary muscle in the eye. Since the down-regulation of GDNF in the eye is accompanied by down-regulation of GFRα1 and Ret, but not of GFRα2, in innervating ciliary ganglion neurons, the results also suggest that target-derived GDNF regulates the expression of its high-affinity coreceptors.

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