scholarly journals The H3K36me2 writer-reader dependency in H3K27M-DIPG

2021 ◽  
Author(s):  
Jia-Ray Yu ◽  
Gary LeRoy ◽  
Devin Bready ◽  
Joshua D. Frenster ◽  
Ricardo Saldaña-Meyer ◽  
...  
Keyword(s):  
Cellular Proliferation ◽  
Histone H3 ◽  
Pediatric Brain Tumor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Therapeutic Interventions ◽  
Functional Pathway ◽  
Proliferation In Vitro

AbstractThe lysine-to-methionine mutation at residue 27 of histone H3 (H3K27M) is a driving mutation in Diffuse Intrinsic Pontine Glioma (DIPG), a highly aggressive form of pediatric brain tumor with no effective treatment and little chance of survival. H3K27M reshapes the epigenome through a global inhibition of PRC2 catalytic activity, the placement of methylation at lysine 27 of histone H3 (H3K27me2/3), promoting oncogenesis of DIPG. As a consequence, a histone modification H3K36me2, antagonistic to H3K27me2/3, is aberrantly elevated. Here, we investigate the role of H3K36me2 in H3K27M-DIPG by tackling its upstream catalyzing enzymes (writers) and downstream binding factors (readers). We determine that NSD1 and NSD2 are the key writers for H3K36me2. Loss of NSD1/2 in H3K27M-DIPG impedes cellular proliferation in vitro and tumorigenesis in vivo, and disrupts tumor-promoting gene expression programs. Further, we demonstrate that LEDGF and HDGF2 are the main readers that mediate the pro-tumorigenic effects downstream of NSD1/2-H3K36me2. Treatment with a chemically modified peptide mimicking endogenous H3K36me2 dislodges LEDGF/HDGF2 from chromatin and specifically inhibits the proliferation of H3K27M-DIPG. Together, our results indicate a functional pathway of NSD1/2-H3K36me2-LEDGF/HDGF2 as an acquired dependency in H3K27M-DIPG and suggest a possibility to target this pathway for therapeutic interventions.

scholarly journals HNRNPA2B1 promotes multiple myeloma progression by increasing AKT3 expression via m6A-dependent stabilization of ILF3 mRNA

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fengjie Jiang ◽  
Xiaozhu Tang ◽  
Chao Tang ◽  
Zhen Hua ◽  
Mengying Ke ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Cellular Proliferation ◽  
Aberrant Expression ◽  
The Stability ◽  
Induced Apoptosis ◽  
Proliferation In Vitro

AbstractN6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic RNAs while accumulating studies suggest that m6A aberrant expression plays an important role in cancer. HNRNPA2B1 is a m6A reader which binds to nascent RNA and thus affects a perplexing array of RNA metabolism exquisitely. Despite unveiled facets that HNRNPA2B1 is deregulated in several tumors and facilitates tumor growth, a clear role of HNRNPA2B1 in multiple myeloma (MM) remains elusive. Herein, we analyzed the function and the regulatory mechanism of HNRNPA2B1 in MM. We found that HNRNPA2B1 was elevated in MM patients and negatively correlated with favorable prognosis. The depletion of HNRNPA2B1 in MM cells inhibited cell proliferation and induced apoptosis. On the contrary, the overexpression of HNRNPA2B1 promoted cell proliferation in vitro and in vivo. Mechanistic studies revealed that HNRNPA2B1 recognized the m6A sites of ILF3 and enhanced the stability of ILF3 mRNA transcripts, while AKT3 downregulation by siRNA abrogated the cellular proliferation induced by HNRNPA2B1 overexpression. Additionally, the expression of HNRNPA2B1, ILF3 and AKT3 was positively associated with each other in MM tissues tested by immunohistochemistry. In summary, our study highlights that HNRNPA2B1 potentially acts as a therapeutic target of MM through regulating AKT3 expression mediated by ILF3-dependent pattern.

scholarly journals The H3K36me2 writer-reader dependency in H3K27M-DIPG

2021 ◽  
Vol 7 (29) ◽  
pp. eabg7444
Author(s):  
Jia-Ray Yu ◽  
Gary LeRoy ◽  
Devin Bready ◽  
Joshua D. Frenster ◽  
Ricardo Saldaña-Meyer ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cellular Proliferation ◽  
Pediatric Brain Tumor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Chemically Modified ◽  
Functional Pathway ◽  
Pediatric Brain ◽  
Global Inhibition

Histone H3K27M is a driving mutation in diffuse intrinsic pontine glioma (DIPG), a deadly pediatric brain tumor. H3K27M reshapes the epigenome through a global inhibition of PRC2 catalytic activity and displacement of H3K27me2/3, promoting oncogenesis of DIPG. As a consequence, a histone modification H3K36me2, antagonistic to H3K27me2/3, is aberrantly elevated. Here, we investigate the role of H3K36me2 in H3K27M-DIPG by tackling its upstream catalyzing enzymes (writers) and downstream binding factors (readers). We determine that NSD1 and NSD2 are the key writers for H3K36me2. Loss of NSD1/2 in H3K27M-DIPG impedes cellular proliferation and tumorigenesis by disrupting tumor-promoting transcriptional programs. Further, we demonstrate that LEDGF and HDGF2 are the main readers mediating the protumorigenic effects downstream of NSD1/2-H3K36me2. Treatment with a chemically modified peptide mimicking endogenous H3K36me2 dislodges LEDGF/HDGF2 from chromatin and specifically inhibits the proliferation of H3K27M-DIPG. Our results indicate a functional pathway of NSD1/2-H3K36me2-LEDGF/HDGF2 as an acquired dependency in H3K27M-DIPG.

scholarly journals Diffuse intrinsic pontine glioma: current insights and future directions

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dilakshan Srikanthan ◽  
Michael S. Taccone ◽  
Randy Van Ommeren ◽  
Joji Ishida ◽  
Stacey L. Krumholtz ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Gene Mutations ◽  
Pediatric Brain Tumor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Current Standard ◽  
In Vivo Models ◽  
Landscape Models

AbstractDiffuse intrinsic pontine glioma (DIPG) is a lethal pediatric brain tumor and the leading cause of brain tumor–related death in children. As several clinical trials over the past few decades have led to no significant improvements in outcome, the current standard of care remains fractionated focal radiation. Due to the recent increase in stereotactic biopsies, tumor tissue availabilities have enabled our advancement of the genomic and molecular characterization of this lethal cancer. Several groups have identified key histone gene mutations, genetic drivers, and methylation changes in DIPG, providing us with new insights into DIPG tumorigenesis. Subsequently, there has been increased development of in vitro and in vivo models of DIPG which have the capacity to unveil novel therapies and strategies for drug delivery. This review outlines the clinical characteristics, genetic landscape, models, and current treatments and hopes to shed light on novel therapeutic avenues and challenges that remain.

932 Targeting the 19S Proteasomal Subunit, Rpt4, in Colon Cancer Cells Induces Cell Death and Reduces Cellular Proliferation In Vitro and In Vivo

2013 ◽  
Vol 144 (5) ◽  
pp. S-166-S-167
Author(s):  
Karen Boland ◽  
Caoimhin Concannon ◽  
Niamh McCawley ◽  
Elaine W. Kay ◽  
Deborah McNamara ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Cellular Proliferation ◽  
Colon Cancer Cells ◽  
Proliferation In Vitro

Abstract 115: Nuclear CaMKII is a Histone H3 Kinase that Remodels Chromatin During Cardiac Hypertrophy

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Salma Mahmoud ◽  
Muhammad Kunhi ◽  
Gillian H Little ◽  
Yan Bai ◽  
Woojin An ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Cardiac Muscle ◽  
Chromatin Remodeling ◽  
Cellular Proliferation ◽  
Recombinant Adenovirus ◽  
Phosphorylation Site ◽  
Histone H3 ◽  
Functional Link

Background and Purpose: Calcium/calmodulin-dependent protein kinase II (CaMKII) is a ubiquitous serine/threonine kinase implicated in pathological events such as cardiac hypertrophy. In this study we investigated the role of a specific nuclear isoform of CaMKII in chromatin remodeling and in transcriptional regulation in cardiac muscle. Methods: Comprehensive experimental approaches performed in primary cardiomyocyte cultures were used including chromatin immunoprecipitation assays (ChIP), q-PCR, chromatin remodeling assays, in vitro phosphorylation/transcription assays, production of recombinant adenovirus, siRNA technology, fluorescence microscopy and mass spectrometry. Results: We found that CaMKIIδB targets specific components of chromatin during cardiac hypertrophy and binds to nucleosomes through its association domain in a cooperative model. CaMKIIδB also increased chromatin relaxation, and this action was dependent on its kinase activity. The observation that CaMKIIδB interacts with chromatin suggested to us that histones maybe novel substrates of the kinase in cardiac muscle. To test this hypothesis, we performed in vitro kinase assays and found that histone H3 is a bona fide CaMKIIδB substrate and Ser-10 appears to be a predominant phosphorylation site. Increased histone H3 Ser-10 phosphorylation was observed following hypertrophic stimulation and was not associated with cellular proliferation, whereas depletion of CaMKIIδB significantly reduced histone H3 Ser-10 phosphorylation in primary cardiomyocytes. Interestingly, we found that H3 S10 phosphorylation and recruitment of CaMKIIδB occur at promoters of fetal cardiac genes. To establish the functional link between H3 phosphorylation by CaMKIIδB, chromatin remodeling and transcription activation, we developed an in vitro transcription system and using it we found that CaMKIIδB increased chromatin accessibility and mediated transcription of the Mef2 transcription factor. Conclusion: Taken together, these findings highlight a new role of CaMKIIδB as relevant histone H3 kinase and link for the first time epigenetic changes by CaMKII to cardiac hypertrophy.

scholarly journals PDTM-25. STUDY OF ONC201 IN PRE-CLINICAL MODELS OF DIPG

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi192-vi192
Author(s):  
Ajay Sharma ◽  
Yanlai Lai ◽  
Bridget Kennis ◽  
Sreepradha Sridharan ◽  
Tara Dobson ◽  
...  
Keyword(s):  
Intraperitoneal Administration ◽  
Pediatric Brain Tumor ◽  
Standard Of Care ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Tumor Burden ◽  
Phosphorylated Akt ◽  
Ic50 Values ◽  
Different Response

Abstract Diffuse Intrinsic Pontine Glioma (DIPG) is an incurable pediatric brain tumor that occur in the pons and brainstem and have a peak onset of age between 6–9 years of age. Radiation is currently used as standard of care. Chemotherapy has shown no improvements in survival. Here, we report our study of ONC201, a first-in-class anticancer small molecule developed by Oncoceutics, Inc., against DIPG cells in vitro and in mouse orthotopic models. ONC201 was discovered in a screen as a p53-independent inducer of the pro-apoptotic cytokine TRAIL. It is known to directly and selectively inhibit dopamine receptor D2 (DRD2), a member of the G protein-coupled receptor (GPCR) family. MTT assays to determine the sensitivity of DIPG cells to ONC201 revealed a slight but not significantly different response to the drug based on their expression of wild type (WT) histone H3 or histone H3K27M mutant protein, with IC50 values in the range of 3-8mM. Decrease in cell growth was associated with a decrease in AKT and ERK phosphorylation and an increase in TRAIL expression. In vivo, intraperitoneal administration of ONC201 to mice bearing pontine DIPG tumors, once every week for 6 weeks, caused a significant reduction in tumor burden relative to untreated controls as measured by bioluminescence assays. However, stoppage of treatment resulted in tumor regrowth within 6 weeks, suggesting the existence of a population that were not eliminated by the current schedule of ONC210. Single cell proteomic analyses-based comparison of untreated and ONC201-treated DIPG cells showed an expected global reduction in pro-survival signals such as phosphorylated AKT and ERK. Molecules with potential to predict susceptibility of cells to ONC201 were also revealed, and are being confirmed by transcriptome analyses. Results of a chemical screen to target ONC201-refractory tumor cells will be discussed.

scholarly journals Critical Role of Gα12 and Gα13 for Human Small Cell Lung Cancer Cell Proliferation In vitro and Tumor Growth In vivo

2010 ◽  
Vol 16 (5) ◽  
pp. 1402-1415 ◽  
Author(s):  
Marius Grzelinski ◽  
Olaf Pinkenburg ◽  
Thomas Büch ◽  
Maike Gold ◽  
Stefanie Stohr ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Critical Role ◽  
Small Cell ◽  
Cancer Cell Proliferation ◽  
Lung Cancer Cell ◽  
Small Cell Lung ◽  
Proliferation In Vitro

scholarly journals Overexpression of membrane metalloendopeptidase inhibits substance P stimulation of cholangiocarcinoma growth

2014 ◽  
Vol 306 (9) ◽  
pp. G759-G768 ◽  
Author(s):  
Fanyin Meng ◽  
Sharon DeMorrow ◽  
Julie Venter ◽  
Gabriel Frampton ◽  
Yuyan Han ◽  
...  
Keyword(s):  
Substance P ◽  
Functional Role ◽  
Xenograft Model ◽  
Subsequent Increase ◽  
Proliferation In Vitro ◽  
Proteolytic Product ◽  
Stimulation Of

Substance P (SP) promotes cholangiocyte growth during cholestasis by activating its receptor, NK1R. SP is a proteolytic product of tachykinin (Tac1) and is deactivated by membrane metalloendopeptidase (MME). This study aimed to evaluate the functional role of SP in the regulation of cholangiocarcinoma (CCA) growth. NK1R, Tac1, and MME expression and SP secretion were assessed in human CCA cells and nonmalignant cholangiocytes. The proliferative effects of SP (in the absence/presence of the NK1R inhibitor, L-733,060) and of L-733,060 were evaluated. In vivo, the effect of L-733,060 treatment or MME overexpression on tumor growth was evaluated by using a xenograft model of CCA in nu/nu nude mice. The expression of Tac1, MME, NK1R, PCNA, CK-19, and VEGF-A was analyzed in the resulting tumors. Human CCA cell lines had increased expression of Tac1 and NK1R, along with reduced levels of MME compared with nonmalignant cholangiocytes, resulting in a subsequent increase in SP secretion. SP treatment increased CCA cell proliferation in vitro, which was blocked by L-733,060. Treatment with L-733,060 alone inhibited CCA proliferation in vitro and in vivo. Xenograft tumors derived from MME-overexpressed human Mz-ChA-1 CCA cells had a slower growth rate than those derived from control cells. Expression of PCNA, CK-19, and VEGF-A decreased, whereas MME expression increased in the xenograft tumors treated with L-733,060 or MME-overexpressed xenograft tumors compared with controls. The study suggests that SP secreted by CCA promotes CCA growth via autocrine pathway. Blockade of SP secretion and NK1R signaling may be important for the management of CCA.

scholarly journals LncRNA-URHC Functions as a ceRNA to Regulate Danjb9 Expression by Competitively Binding to miR-5007-3p in Hepatocellular Carcinoma

2021 ◽  
Author(s):  
kunwei niu ◽  
Shibin Qu ◽  
Xuan Zhang ◽  
Jimin Dai ◽  
Jianlin Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Biological Effects ◽  
Luciferase Reporter ◽  
Underlying Mechanisms ◽  
Proliferation In Vitro ◽  
Hcc Cells

Abstract Background: Hepatocellular carcinoma (HCC) is often diagnosed at a late stage, when the prognosis is poor. The regulation of long non-coding RNAs (lncRNAs) plays a crucial role in HCC. However, the precise regulatory mechanisms of lncRNA signaling in HCC remain largely unknown. We study aim to investigate the underlying mechanisms of lncRNA (upregulated in hepatocellular carcinoma) URHC in HCC. Methods: RT-qPCR, fluorescence in situ hybridization (FISH) staining, EdU, colony formation, and tumor xenografts experiments were used to identify localized and biological effects of URHC on HCC cells in vitro and in vivo. The bioinformatics analysis, Dual-luciferase reporter assay, and rescue experiments revealed the potential mechanism of URHC.Results: URHC silencing may inhibit the HCC cells proliferation in vitro and in vivo. We found that URHC was mainly localized in the cytoplasm. The expression of miR-5007-3p was negatively regulated by URHC. And miR-5007-3p could reverse the effect of URHC in HCC cells. The expression of DNAJB9 was negatively regulated by miR-5007-3p but positively regulated by URHC. These suggesting of lncRNA-URHC positively regulated the level of DNAJB9 by sponging miR-5007-3p.Conclusion: Together, our study elucidated the role of URHC as a miRNA sponge in HCC, and shed new light on lncRNA-directed diagnostics and therapeutics in HCC.

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