Dataset Information

Contribution of microRNA-1275 to Claudin11 protein suppression via a polycomb-mediated silencing mechanism in human glioma stem-like cells.

ABSTRACT: Glioblastomas show heterogeneous histological features, and tumor cells show distinct phenotypic states that confer different functional attributes and an aggressive character. However, the molecular mechanisms underlying the heterogeneity in this disease are poorly understood. Glioma stem-like cells (GSCs) are considered able to aberrantly differentiate into diverse cell types and may contribute to the establishment of tumor heterogeneity. Using a GSC model, we investigated differentially expressed microRNAs (miRNAs) and associated epigenetic mechanisms that regulate the differentiation of GSCs. miRNA profiling using microarray technology showed that 13 and 34 miRNAs were commonly up-regulated and down-regulated in two independent GSC lines during differentiation, respectively. Among this set of miRNAs, quantitative PCR analysis showed that miRNA-1275 (miR-1275) was consistently down-regulated during GSC differentiation, along with the up-regulation of its target, CLDN11, an important protein during oligodendroglial lineage differentiation. Inhibition of miR-1275 with a specific antisense oligonucleotide (anti-miR-1275) in GSCs increased the expression of CLDN11, together with significant growth suppression. Epigenetic analysis revealed that gain of histone H3 lysine 27 trimethylation (H3K27me3) in the primary microRNA-1275 promoter was closely associated with miR-1275 expression. Treatment with 3-deazaneplanocin A, an inhibitor of H3K27 methyltransferase, attenuated CLDN11 induction by serum stimulation in parallel with sustained miR-1275 expression. Our results have illuminated the epigenetic regulatory pathways of miR-1275 that are closely associated with oligodendroglial differentiation, which may contribute to the tissue heterogeneity seen in the formation of glioblastomas. Given that inhibition of miR-1275 induces expression of oligodendroglial lineage proteins and suppresses tumor cell proliferation, this may be a potential therapeutic target for glioblastomas.

SUBMITTER: Katsushima K

PROVIDER: S-EPMC3431641 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature

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Contribution of microRNA-1275 to Claudin11 protein suppression via a polycomb-mediated silencing mechanism in human glioma stem-like cells.

Katsushima Keisuke K Shinjo Keiko K Natsume Atsushi A Ohka Fumiharu F Fujii Makiko M Osada Hirotaka H Sekido Yoshitaka Y Kondo Yutaka Y

The Journal of biological chemistry 20120626 33

Glioblastomas show heterogeneous histological features, and tumor cells show distinct phenotypic states that confer different functional attributes and an aggressive character. However, the molecular mechanisms underlying the heterogeneity in this disease are poorly understood. Glioma stem-like cells (GSCs) are considered able to aberrantly differentiate into diverse cell types and may contribute to the establishment of tumor heterogeneity. Using a GSC model, we investigated differentially expre ...[more]

PMID: 22736761

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Project description:Glioblastomas show heterogeneous histological features, in which tumor cells show distinct phenotypic states that confer different functional attributes. This functional and morphological heterogeneity characterizes aggressive glioblastoma; however, molecular mechanisms underlying the heterogeneity are poorly understood. Glioma stem-like cells (GSCs) are considered able to aberrantly differentiate into diverse cell types and may contribute the establishment of tumor heterogeneity. Using the GSC model, we investigated the differentially expressed microRNAs(miRNAs) and associated epigenetic mechanism that regulate the differentiation of GSCs. MiRNA-microarray showed that 13 and 34 miRNAs were commonly upregulated and downregulated in two independent GSC lines during differentiation, respectively. Among those miRNAs, quantitative-PCR analysis showed that miR-1275 was consistently downregulated during the GSC differentiation along with the upregulation of its target, CLDN11, a marker of oligodendroglial-lineage differentiation. Compellingly, inhibition of miR-1275 with specific antisense oligonucleotide (anti-miR-1275) in GSC increased the expression of CLDN11, together with significant growth suppression. Epigenetic analysis revealed that gain of histone H3 lysine 27 trimethylation (H3K27me3) and loss of H3K9Ac in the pri-miR-1275 promoter were closely associated with the miR-1275 expression. Treatment of 3-Dezaneplanocin-A, an inhibitor of H3K27 methyltransferase, impaired the GSC differentiation in parallel with sustained miR-1275 expression. Our results illuminated the epigenetic regulatory pathways of miR-1275 closely associated with oligodendroglial differentiation, which may contribute to the tissue heterogeneity formation of glioblastomas. Inhibition of miR-1275 induces the GSC differentiation and suppresses tumor cell proliferation, miR-1275 may be a potential therapeutic target for glioblastomas. Human miRNA Microarray V3 kits (G4470C; Agilent Technologies, Santa Clara, California) were used according to the manufacturer’s protocols. This microarray system contains probes for all 866 human and 89 human viral miRNAs reported from the Sanger database v12.0 (http://microrna.sanger.ac.uk/sequences/). Each miRNA species is printed 20 times with replicate probes on the array. Total RNA was isolated with TRIzol reagent (Invitrogen).　One hundred ng of total RNA was labeled with pCp-Cy3 (Agilent Technologies) and 15 units of T4 RNA ligase (GE Healthcare, Little Chalfont, Buckinghamshire, UK) at 16°C for 2 hours. Labeled samples were purified with MicroBio-Spin 6 columns (Bio-Rad, Richmond, CA) and hybridized to microarray at 55 °C with rotation at 20 rpm for 20 hours. Microarrays were scanned by an Agilent Scanner (Agilent Scan Control 7.0 software) and analyzed using Agilent Feature Extraction 10.7 software for miRNA microarray.

Project description:Glioblastomas show heterogeneous histological features, in which tumor cells show distinct phenotypic states that confer different functional attributes. This functional and morphological heterogeneity characterizes aggressive glioblastoma; however, molecular mechanisms underlying the heterogeneity are poorly understood. Glioma stem-like cells (GSCs) are considered able to aberrantly differentiate into diverse cell types and may contribute the establishment of tumor heterogeneity. Using the GSC model, we investigated the differentially expressed microRNAs(miRNAs) and associated epigenetic mechanism that regulate the differentiation of GSCs. MiRNA-microarray showed that 13 and 34 miRNAs were commonly upregulated and downregulated in two independent GSC lines during differentiation, respectively. Among those miRNAs, quantitative-PCR analysis showed that miR-1275 was consistently downregulated during the GSC differentiation along with the upregulation of its target, CLDN11, a marker of oligodendroglial-lineage differentiation. Compellingly, inhibition of miR-1275 with specific antisense oligonucleotide (anti-miR-1275) in GSC increased the expression of CLDN11, together with significant growth suppression. Epigenetic analysis revealed that gain of histone H3 lysine 27 trimethylation (H3K27me3) and loss of H3K9Ac in the pri-miR-1275 promoter were closely associated with the miR-1275 expression. Treatment of 3-Dezaneplanocin-A, an inhibitor of H3K27 methyltransferase, impaired the GSC differentiation in parallel with sustained miR-1275 expression. Our results illuminated the epigenetic regulatory pathways of miR-1275 closely associated with oligodendroglial differentiation, which may contribute to the tissue heterogeneity formation of glioblastomas. Inhibition of miR-1275 induces the GSC differentiation and suppresses tumor cell proliferation, miR-1275 may be a potential therapeutic target for glioblastomas. Human miRNA Microarray V3 kits (G4470C; Agilent Technologies, Santa Clara, California) were used according to the manufacturerM-bM-^@M-^Ys protocols. This microarray system contains probes for all 866 human and 89 human viral miRNAs reported from the Sanger database v12.0 (http://microrna.sanger.ac.uk/sequences/). Each miRNA species is printed 20 times with replicate probes on the array. Total RNA was isolated with TRIzol reagent (Invitrogen).M-cM-^@M-^@One hundred ng of total RNA was labeled with pCp-Cy3 (Agilent Technologies) and 15 units of T4 RNA ligase (GE Healthcare, Little Chalfont, Buckinghamshire, UK) at 16M-BM-0C for 2 hours. Labeled samples were purified with MicroBio-Spin 6 columns (Bio-Rad, Richmond, CA) and hybridized to microarray at 55 M-BM-0C with rotation at 20 rpm for 20 hours. Microarrays were scanned by an Agilent Scanner (Agilent Scan Control 7.0 software) and analyzed using Agilent Feature Extraction 10.7 software for miRNA microarray.

Project description:BackgroundNeuroendocrine prostate cancer (NEPC) is a highly aggressive subtype of prostate cancer (PCa) for which the median survival remains less than a year. Current treatments are only palliative in nature, and the lack of suitable pre-clinical models has hampered previous efforts to develop novel therapeutic strategies. Addressing this need, we have recently established the first in vivo model of complete neuroendocrine transdifferentiation using patient-derived xenografts. Few genetic differences were observed between parental PCa and relapsed NEPC, suggesting that NEPC likely results from alterations that are epigenetic in nature. Thus, we sought to identify targetable epigenetic regulators whose expression was elevated in NEPC using genome-wide profiling of patient-derived xenografts and clinical samples.ResultsOur data indicate that multiple members of the polycomb group (PcG) family of transcriptional repressors were selectively upregulated in NEPC. Notably, CBX2 and EZH2 were consistently the most highly overexpressed epigenetic regulators across multiple datasets from clinical and xenograft tumor tissues. Given the striking upregulation of PcG genes and other transcriptional repressors, we derived a 185-gene list termed 'neuroendocrine-associated repression signature' (NEARS) by overlapping transcripts downregulated across multiple in vivo NEPC models. In line with the striking upregulation of PcG family members, NEARS was preferentially enriched with PcG target genes, suggesting a driving role for PcG silencing in NEPC. Importantly, NEARS was significantly associated with high-grade tumors, metastatic progression, and poor outcome in multiple clinical datasets, consistent with extensive literature linking PcG genes and aggressive disease progression.ConclusionsWe have explored the epigenetic landscape of NEPC and provided evidence of increased PcG-mediated silencing associated with aberrant transcriptional regulation of key differentiation genes. Our results position CBX2 and EZH2 as potential therapeutic targets in NEPC, providing opportunities to explore novel strategies aimed at reversing epigenetic alterations driving this lethal disease.

Dataset Information

Contribution of microRNA-1275 to Claudin11 protein suppression via a polycomb-mediated silencing mechanism in human glioma stem-like cells.

Publications

Contribution of microRNA-1275 to Claudin11 protein suppression via a polycomb-mediated silencing mechanism in human glioma stem-like cells.

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