scholarly journals Modeling Myeloma Treatment through Epigenetic Modification: Synergistic Combination of EZH2 and Histone Deacetylase Inhibitors

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5719-5719 ◽  
Author(s):  
Taylor S Harding ◽  
Jessica Swanson ◽  
Brian Van Ness
Keyword(s):  
Histone Deacetylase ◽  
Epigenetic Modification ◽  
Expression Profiles ◽  
Migration And Invasion ◽  
Specific Gene ◽  
Aberrant Expression ◽  
New Agents ◽  
Cell Functions ◽  
Synergistic Cytotoxicity ◽  
Double Agent

Abstract Multiple Myeloma (MM) management has been dramatically improved over the last decade through the clinical application of new agents including proteasome inhibitors (PIs). Despite the initial efficacy of new agents, MM remains mostly incurable. Heterogeneity in patient drug response, tumor sub-clonal heterogeneity and the eventual emergence drug-resistant relapse in most patients all greatly support the need for novel therapeutic strategies that overcome drug resistance and improve the efficacy of existing treatments. The epigenetic regulator enhancer of zeste homolog 2 (EZH2) methylates histone H3 at lysine 27 (H3K27) to silence gene transcription and regulate multiple cell functions including differentiation and stem cell maintenance. Aberrant expression and activity of EZH2 has been observed in many cancers as a facilitator of oncogenisis, proliferation, migration and invasion. Accumulating evidence suggests that EZH2 is also aberrantly expressed in MM. We have previously demonstrated that EZH2 acts as an oncogene in human myeloma cell lines (HCMLs) and that siRNA depletion of EZH2 is sufficient to arrest HCML proliferation (Croonquist & Van Ness, Oncogene 24.41, 2005). Recently, specific EZH2 chemical inhibitors (EZH2i’s) have been developed and shown efficacy in lymphoma; however, no published studies have evaluated the efficacy of these inhibitors in MM. We tested the single agent cytotoxicity of the specific EZH2i’s GSK-126 and EPZ-6438 in several HMCLs using high-throughput Cell-Titer Glow (Promega) viability assays. We found that both GSK-126 and EPZ-6438 demethylate H3K27 in HCMLs at concentrations and rates previously described in other cancer types (demonstrated through western blot), however these concentrations and treatment schedules failed to induced cytotoxicity in HMCLs alone. While neither drug demonstrated consistent double-agent synergy with PIs (Bortezomib, Carfilzomib, Ixazomib and Oprozomib), both GSK-126 and EPZ-6438 demonstrated significant synergistic cytotoxicity with the histone deacetylase inhibitor (HDACi) panobinostat in all HCMLs tested (n=7). This double agent synergy was effective when HCMLs were pre-treated with EZH2i’s for three days prior to panobinostat treatment and in some cases induced up to an 85% increase in cytotoxicity at concentrations that do not induce a significant reduction in cell viability as single agents. We conclude that GSK-126 and EPZ-6438 pre-treatment is a potent enhancer of panobinostat cytotoxicity in HMCLs. HDACi’s have been shown to act synergistically with current MM chemotherapeutics in pre-clinical models. These data may demonstrate an additional agent to increase HDAC efficacy in MM treatment. Specific gene targets of EZH2 inhibition are being investigated by kinetic gene expression profiles in HMCLs after treatment and linked to mechanisms further promoted by HDAC inhibitors. These results will provide a comprehensive pre-clinical analysis of epigenetic modification as a therapeutic strategy in treating myeloma. Disclosures No relevant conflicts of interest to declare.

scholarly journals MicroRNA-99b predicts clinical outcome of osteosarcoma and suppresses tumor cell proliferation, migration and invasion

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Shi ◽  
Xingfa Guan
Keyword(s):  
Cell Proliferation ◽  
Cell Lines ◽  
Prognostic Value ◽  
Cox Regression ◽  
Expression Profiles ◽  
Migration And Invasion ◽  
Aberrant Expression ◽  
Cox Regression Analysis ◽  
Normal Tissues

Abstract Background Osteosarcoma (OS) is a malignancy predominantly occurred in children and adolescents. Numerous microRNAs are involved in the pathogenesis of various cancers. This study aimed to investigate the expression profiles of miR-99b and its prognostic value in OS patients, and further analyze the biological function of miR-99b in the tumor progression by using OS cells. Methods Expression of miR-99b was measured using quantitative real-time PCR. Kaplan-Meier survival curves and Cox regression analysis were performed to evaluate the prognostic value of miR-99b. OS cell lines were used to investigate the effects of miR-99b on cell proliferation, migration and invasion. Results A significant decreased expression of miR-99b was observed in the OS tissues and cell lines respectively compared with the normal tissues and cells. Aberrant expression of miR-99b was associated with the patients’ metastasis and TNM stage, and could be used to predict the prognosis of OS. The expression of miR-99b was regulated in vitro by cell transfection, and we found that the overexpression of miR-99b led to suppressed cell proliferation, migration and invasion, whereas the knockdown of miR-99b resulted in the opposite results. Conclusions In one word, the aberrantly expressed miR-99b serves a prognostic biomarker for OS patients. OS cell proliferation, migration and invasion can be inhibited by the overexpression of miR-99b, suggesting that the methods to increase miR-99b expression may be novel therapeutic strategies in OS.

scholarly journals Loss of miR-1469 expression mediates melanoma cell migration and invasion

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256629
Author(s):  
Mallory J. DiVincenzo ◽  
Zoe Barricklow ◽  
Emily Schwarz ◽  
Maribelle Moufawad ◽  
J. Harrison Howard ◽  
...  
Keyword(s):  
Disease Progression ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Myeloid Cell ◽  
Migration And Invasion ◽  
Specific Gene ◽  
Primary Cutaneous Melanoma ◽  
Cell Functions ◽  
Invasive Capacity ◽  
A375 Melanoma Cell Line

Tumor ulceration is considered one of the most prognostically significant findings in primary cutaneous melanoma, associated with decreased disease-free and overall survival. However, the unique features associated with ulcerated melanoma that contribute to a poor prognosis in affected patients remain poorly defined. microRNAs are small, non-coding RNAs that function to inhibit expression of specific gene targets, therefore altering the functions of cells in which they are expressed. miR-1469 is a novel miR with significantly decreased expression in ulcerated melanoma tissue relative to non-ulcerated tumors. We hypothesized that loss of miR-1469 expression in melanoma contributes to altered tumor cell functions mediating disease progression. Transfection of a miR-1469 mimic resulted in a significant reduction in the migratory and invasive capacity of the CHL1 and MEL39 melanoma cell lines (>58.1% reduction, p < 0.0332), as well as the invasive capacity of the A375 melanoma cell line (>50% reduction, p < 0.0021). Expression of myeloid cell leukemia-1 (MCL1), a miR-1469 target gene, was reduced in the A375 and MEL39 cell lines by immunoblot. No significant differences in viability, resistance to apoptotic stimuli, or proliferation were observed following transfection. These findings together demonstrate how migration and invasion are specific functions through which miR-1469 expression in melanoma cells can contribute to the differences in disease progression associated with tumor ulceration.

scholarly journals Transcriptional Repression by Neuron-Restrictive Silencer Factor Is Mediated via the Sin3-Histone Deacetylase Complex

2000 ◽  
Vol 20 (6) ◽  
pp. 2147-2157 ◽  
Author(s):  
Avtar Roopra ◽  
Lisa Sharling ◽  
Ian C. Wood ◽  
Teresa Briggs ◽  
Ulla Bachfischer ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Gene Transcription ◽  
Transcriptional Repression ◽  
Neuronal Cell ◽  
Dominant Negative ◽  
Specific Gene ◽  
Aberrant Expression ◽  
Neuronal Gene ◽  
Repressor Element

ABSTRACT A large number of neuron-specific genes characterized to date are under the control of negative transcriptional regulation. Many promoter regions of neuron-specific genes possess the repressor element repressor element 1/neuron-restrictive silencing element (RE1/NRSE). Its cognate binding protein, REST/NRSF, is an essential transcription factor; its null mutations result in embryonic lethality, and its dominant negative mutants produce aberrant expression of neuron-specific genes. REST/NRSF acts as a regulator of neuron-specific gene expression in both nonneuronal tissue and developing neurons. Here, we shown that heterologous expression of REST/NRSF inSaccharomyces cerevisiae is able to repress transcription from yeast promoters engineered to contain RE1/NRSEs. Moreover, we have taken advantage of this observation to show that this repression requires both yeast Sin3p and Rpd3p and that REST/NRSF physically interacts with the product of the yeast SIN3 gene in vivo. Furthermore, we show that REST/NRSF binds mammalian SIN3A and HDAC-2 and requires histone deacetylase activity to repress neuronal gene transcription in both nonneuronal and neuronal cell lines. We show that REST/NRSF binding to RE1/NRSE is accompanied by a decrease in the acetylation of histones around RE1/NRSE and that this decrease requires the N-terminal Sin3p binding domain of REST/NRSF. Taken together, these data suggest that REST/NRSF represses neuronal gene transcription by recruiting the SIN3/HDAC complex.

Examination of the dynamics of global DNA methylation pattern establishment during spermatogenesiss

2007 ◽  
Vol 30 (4) ◽  
pp. 90
Author(s):  
Kirsten Niles ◽  
Sophie La Salle ◽  
Christopher Oakes ◽  
Jacquetta Trasler
Keyword(s):  
Dna Methylation ◽  
Germ Cell ◽  
Germ Cells ◽  
Epigenetic Modification ◽  
Methylation Pattern ◽  
Chromosome 9 ◽  
Specific Gene ◽  
Global Methylation ◽  
Dna Methylation Pattern ◽  
Methylation Patterns

Background: DNA methylation is an epigenetic modification involved in gene expression, genome stability, and genomic imprinting. In the male, methylation patterns are initially erased in primordial germ cells (PGCs) as they enter the gonadal ridge; methylation patterns are then acquired on CpG dinucleotides during gametogenesis. Correct pattern establishment is essential for normal spermatogenesis. To date, the characterization and timing of methylation pattern acquisition in PGCs has been described using a limited number of specific gene loci. This study aimed to describe DNA methylation pattern establishment dynamics during male gametogenesis through global methylation profiling techniques in a mouse model. Methods: Using a chromosome based approach, primers were designed for 24 regions spanning chromosome 9; intergenic, non-repeat, non-CpG island sequences were chosen for study based on previous evidence that these types of sequences are targets for testis-specific methylation events. The percent methylation was determined in each region by quantitative analysis of DNA methylation using real-time PCR (qAMP). The germ cell-specific pattern was determined by comparing methylation between spermatozoa and liver. To examine methylation in developing germ cells, spermatogonia from 2 day- and 6 day-old Oct4-GFP (green fluorescent protein) mice were isolated using fluorescence activated cell sorting. Results: As compared to liver, four loci were hypomethylated and five loci were hypermethylated in spermatozoa, supporting previous results indicating a unique methylation pattern in male germ cells. Only one region was hypomethylated and no regions were hypermethylated in day 6 spermatogonia as compared to mature spermatozoa, signifying that the bulk of DNA methylation is established prior to type A spermatogonia. The methylation in day 2 spermatogonia, germ cells that are just commencing mitosis, revealed differences of 15-20% compared to day 6 spermatogonia at five regions indicating that the most crucial phase of DNA methylation acquisition occurs prenatally. Conclusion: Together, these studies provide further evidence that germ cell methylation patterns differ from those in somatic tissues and suggest that much of methylation at intergenic sites is acquired during prenatal germ cell development. (Supported by CIHR)

The Predominant microRNAs in β-cell Clusters for Insulin Regulation and Diabetic Control

2020 ◽  
Vol 21 (7) ◽  
pp. 722-734
Author(s):  
Adele Soltani ◽  
Arefeh Jafarian ◽  
Abdolamir Allameh
Keyword(s):  
Mirna Expression ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Diabetic Control ◽  
In Vitro Proliferation ◽  
Cell Functions ◽  
Mirna Expression Profiles ◽  
Multiple Processes ◽  
The Impact

micro (mi)-RNAs are vital regulators of multiple processes including insulin signaling pathways and glucose metabolism. Pancreatic &#946;-cells function is dependent on some miRNAs and their target mRNA, which together form a complex regulative network. Several miRNAs are known to be directly involved in &#946;-cells functions such as insulin expression and secretion. These small RNAs may also play significant roles in the fate of &#946;-cells such as proliferation, differentiation, survival and apoptosis. Among the miRNAs, miR-7, miR-9, miR-375, miR-130 and miR-124 are of particular interest due to being highly expressed in these cells. Under diabetic conditions, although no specific miRNA profile has been noticed, the expression of some miRNAs and their target mRNAs are altered by posttranscriptional mechanisms, exerting diverse signs in the pathobiology of various diabetic complications. The aim of this review article is to discuss miRNAs involved in the process of stem cells differentiation into &#946;-cells, resulting in enhanced &#946;-cell functions with respect to diabetic disorders. This paper will also look into the impact of miRNA expression patterns on in vitro proliferation and differentiation of &#946;-cells. The efficacy of the computational genomics and biochemical analysis to link the changes in miRNA expression profiles of stem cell-derived &#946;-cells to therapeutically relevant outputs will be discussed as well.

Insights into therapeutic targets and biomarkers using integrated multi-‘omics’ approaches for dilated and ischemic cardiomyopathies

2021 ◽  
Author(s):  
Austė Kanapeckaitė ◽  
Neringa Burokienė
Keyword(s):  
Machine Learning ◽  
Single Cell ◽  
Learning Algorithm ◽  
Expression Profiles ◽  
Therapeutic Targets ◽  
Development Stage ◽  
Biological Data ◽  
Specific Gene ◽  
Tissue Remodelling ◽  
Pharmacological Management

Abstract At present, heart failure (HF) treatment only targets the symptoms based on the left ventricle dysfunction severity; however, the lack of systemic ‘omics’ studies and available biological data to uncover the heterogeneous underlying mechanisms signifies the need to shift the analytical paradigm towards network-centric and data mining approaches. This study, for the first time, aimed to investigate how bulk and single cell RNA-sequencing as well as the proteomics analysis of the human heart tissue can be integrated to uncover HF-specific networks and potential therapeutic targets or biomarkers. We also aimed to address the issue of dealing with a limited number of samples and to show how appropriate statistical models, enrichment with other datasets as well as machine learning-guided analysis can aid in such cases. Furthermore, we elucidated specific gene expression profiles using transcriptomic and mined data from public databases. This was achieved using the two-step machine learning algorithm to predict the likelihood of the therapeutic target or biomarker tractability based on a novel scoring system, which has also been introduced in this study. The described methodology could be very useful for the target or biomarker selection and evaluation during the pre-clinical therapeutics development stage as well as disease progression monitoring. In addition, the present study sheds new light into the complex aetiology of HF, differentiating between subtle changes in dilated cardiomyopathies (DCs) and ischemic cardiomyopathies (ICs) on the single cell, proteome and whole transcriptome level, demonstrating that HF might be dependent on the involvement of not only the cardiomyocytes but also on other cell populations. Identified tissue remodelling and inflammatory processes can be beneficial when selecting targeted pharmacological management for DCs or ICs, respectively.

scholarly journals Histone deacetylase (HDAC) 9: versatile biological functions and emerging roles in human cancer

2021 ◽  
Author(s):  
Chun Yang ◽  
Stéphane Croteau ◽  
Pierre Hardy
Keyword(s):  
Histone Deacetylase ◽  
Posttranslational Modifications ◽  
Histone Deacetylases ◽  
Muscle Development ◽  
Target Genes ◽  
Human Cancer ◽  
Expression Patterns ◽  
Aberrant Expression ◽  
Physiological Processes ◽  
Cancer Pathogenesis

Abstract Background HDAC9 (histone deacetylase 9) belongs to the class IIa family of histone deacetylases. This enzyme can shuttle freely between the nucleus and cytoplasm and promotes tissue-specific transcriptional regulation by interacting with histone and non-histone substrates. HDAC9 plays an essential role in diverse physiological processes including cardiac muscle development, bone formation, adipocyte differentiation and innate immunity. HDAC9 inhibition or activation is therefore a promising avenue for therapeutic intervention in several diseases. HDAC9 overexpression is also common in cancer cells, where HDAC9 alters the expression and activity of numerous relevant proteins involved in carcinogenesis. Conclusions This review summarizes the most recent discoveries regarding HDAC9 as a crucial regulator of specific physiological systems and, more importantly, highlights the diverse spectrum of HDAC9-mediated posttranslational modifications and their contributions to cancer pathogenesis. HDAC9 is a potential novel therapeutic target, and the restoration of aberrant expression patterns observed among HDAC9 target genes and their related signaling pathways may provide opportunities to the design of novel anticancer therapeutic strategies.

scholarly journals miR-29a sensitizes the response of glioma cells to temozolomide by modulating the P53/MDM2 feedback loop

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Qiudan Chen ◽  
Weifeng Wang ◽  
Shuying Chen ◽  
Xiaotong Chen ◽  
Yong Lin
Keyword(s):  
Molecular Mechanism ◽  
Feedback Loop ◽  
Glioma Cells ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Transcriptional Level ◽  
Aberrant Expression ◽  
Altered Expression ◽  
P53 Signaling

AbstractRecently, pivotal functions of miRNAs in regulating common tumorigenic processes and manipulating signaling pathways in brain tumors have been recognized; notably, miR‐29a is closely associated with p53 signaling, contributing to the development of glioma. However, the molecular mechanism of the interaction between miR-29a and p53 signaling is still to be revealed. Herein, a total of 30 glioma tissues and 10 non-cancerous tissues were used to investigate the expression of miR‐29a. CCK-8 assay and Transwell assay were applied to identify the effects of miR-29a altered expression on the malignant biological behaviors of glioma cells in vitro, including proliferation, apoptosis, migration and invasion. A dual-luciferase reporter assay was used to further validate the regulatory effect of p53 or miR-29a on miR-29a or MDM2, respectively, at the transcriptional level. The results showed that miR-29a expression negatively correlated with tumor grade of human gliomas; at the same time it inhibited cell proliferation, migration, and invasion and promoted apoptosis of glioma cells in vitro. Mechanistically, miR-29a expression was induced by p53, leading to aberrant expression of MDM2 targeted by miR-29a, and finally imbalanced the activity of the p53-miR-29a-MDM2 feedback loop. Moreover, miR-29a regulating p53/MDM2 signaling sensitized the response of glioma cells to temozolomide treatment. Altogether, the study demonstrated a potential molecular mechanism in the tumorigenesis of glioma, while offering a possible target for treating human glioma in the future.

scholarly journals Decreased level of miR-1301 promotes colorectal cancer progression via activation of STAT3 pathway

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fangfang Yang ◽  
Hua Wang ◽  
Bianbian Yan ◽  
Tong Li ◽  
Lulu Min ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Migration ◽  
Cancer Progression ◽  
Luciferase Assay ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Aberrant Expression ◽  
Cell Migration And Invasion ◽  
Lovo Cells ◽  
Colorectal Cancer Progression

Abstract The molecular pathogenesis of colorectal cancer (CRC) has been widely investigated in recent years. Accumulating evidence has indicated that microRNA (miRNA) dysregulation participates in the processes of driving CRC initiation and progression. Aberrant expression of miR-1301 has been found in various tumor types. However, its role in CRC remains to be elucidated. In the present study, we identified miR-1301 was enriched in normal colorectal tissues and significantly down-regulated in CRC. Decreased level of miR-1301 strongly correlated with aggressive pathological characteristics, including advanced stage and metastasis. Bioinformatics and dual luciferase assay demonstrated that STAT3 is a direct target of miR-1301. Gain and loss-of-function assays showed that miR-1301 had no effect on cell proliferation. Overexpression of miR-1301 suppressed cell migration and invasion capacity of pSTA3-positive LoVo cells, but not pSTAT3-negative SW480 cells, while inhibition of miR-1301 consistently promoted cell migration and invasion in both cell lines. Additionally, miR-1301 inhibition restored the suppressed migration and invasion of STAT3- knockdown LoVo cells. MiR-1301 functioned as a tumor suppressor to modulate the IL6/STAT3 signaling pathway. In summary, this study highlights the significant role of miR- 1301/STAT3 axis in CRC metastasis.

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